Apparatus and method for producing high-purity copper alloys

Abstract

In one embodiment, a method for producing a high-purity copper alloy includes the steps of providing raw materials to a melting furnace and melting the raw materials. The method further includes the step of bubbling an inert gas into the molten copper alloy to form a high-purity copper alloy. In one embodiment, the raw materials have a composition configured to form a molten copper alloy containing at least 50% by weight of copper, and the melting furnace is configured to rotate around a central axis. The embodiment also covers apparatus for producing a high-purity copper alloy and a method for manufacturing the apparatus.

Description

[Technical Field]

[0001] (Cross-reference of related applications) This application is a continuation of U.S. application 18 / 295,752, filed on April 4, 2023, claiming priority to U.S. Provisional Patent Application 63 / 494442, filed on April 5, 2023, and to U.S. Provisional Patent Application 63 / 362509, filed on April 5, 2022, and to U.S. Provisional Patent Application 63 / 387076, filed on December 12, 2022. The contents of each of these applications are incorporated herein by reference in their entirety.

[0002] The disclosed technology relates, in general, to apparatus and methods for producing copper-based alloys, and more specifically, to apparatus for producing high-purity copper-based alloys with reduced impurities. [Background technology]

[0003] Copper can be alloyed with various elements, resulting in a range of useful properties, including high toughness, high ductility, high thermal conductivity, high electrical conductivity, and high corrosion resistance. Due to these properties, copper alloys have many applications. For example, some copper alloys are used in electrical components, fixtures, locks, and door handles. Others are used in architecture, springs, connectors, and terminals. Depending on the application, improvements in mechanical and chemical properties are required for copper alloys. [Overview of the project]

[0004] For the purpose of summarizing the advantages achieved in this disclosure and the prior art, specific purposes and advantages of this disclosure are described herein. Not all such purposes or advantages are achieved in any particular embodiment. Therefore, for example, a person skilled in the art will recognize that the present invention may be embodied or practiced in a manner that achieves or optimizes one advantage or group of advantages taught herein, without necessarily achieving other purposes or advantages that may be taught or suggested herein.

[0005] All of these embodiments are intended to be within the scope of the present invention disclosed herein. These and other embodiments will be readily apparent to those skilled in the art from the following detailed description of preferred embodiments with reference to the accompanying drawings, but the present invention is not limited to any particular preferred embodiment disclosed.

[0006] In one embodiment, an apparatus for producing a copper alloy comprises a sealed melting furnace configured to form a molten copper alloy containing at least 50% by weight of copper under a sealed inert atmosphere and to bubble an inert gas through the molten copper alloy. The apparatus further comprises a transfer ladle configured to receive the molten copper alloy from the melting furnace under a sealed inert atmosphere and to transfer the molten copper alloy to one or more molds or shot pits configured to solidify the molten copper alloy.

[0007] In another embodiment, an apparatus for producing a copper alloy includes a sealed melting furnace configured to form a molten copper alloy containing at least 50 wt% copper under a sealed inert atmosphere and to bubble an inert gas through the molten copper alloy. The apparatus further includes a transfer ladle configured to receive the molten copper alloy from the melting furnace via a rate control element and to transfer the molten copper alloy to one or more molds or shot pits configured to solidify the molten copper alloy.

[0008] In another embodiment, a method for producing a copper alloy includes the step of providing a plurality of raw material pieces having a composite composition configured to form a molten copper alloy containing at least 50% by weight of copper into a melting furnace. The method further includes the steps of flowing an inert gas through gaps between the raw material pieces before heating, and heating the raw material pieces while flowing the inert gas through them, thereby melting the raw material pieces to form a molten copper alloy. The method further includes the step of bubbling the inert gas through the molten copper alloy. The method further includes the step of transferring the molten copper alloy to a transfer ladle.

[0009] In another embodiment, a method for producing a copper alloy includes the step of providing a plurality of raw material pieces having a composite composition configured to form a molten copper alloy containing at least 50% by weight of copper into a melting furnace. The method further includes the step of heating the raw material pieces to form a molten copper alloy. The method further includes the step of bubbling an inert gas through the molten copper alloy. The method further includes the step of transferring the molten copper alloy to a transfer ladle. One or more of the steps of heating the raw material pieces, bubbling an inert gas, and transferring the molten copper alloy are performed at least in a partially sealed inert atmosphere, the sealed inert atmosphere being configured to substantially prevent outside air from mixing with the sealed inert atmosphere.

[0010] In another embodiment, a method for producing a copper alloy includes the step of providing a plurality of raw material pieces having a composite composition configured to form a molten copper alloy containing at least 50% by weight of copper into a melting furnace. The method further includes the step of heating the raw material pieces to form a molten copper alloy. The method further includes the step of bubbling the inert gas through the molten copper alloy. The method further includes the step of transferring the molten copper alloy to a transfer ladle, the transfer step including limiting the rate at which the molten copper alloy is transferred from the melting furnace to the transfer ladle to less than 100 inches / second.

[0011] In another embodiment, an apparatus for producing a copper alloy comprises a melting furnace configured to form a molten copper alloy containing at least 50% by weight of copper. The melting furnace comprises a diffusion lining containing an aluminum silicate ceramic having a porous structure adapted for bubbling an inert gas through the molten copper alloy.

[0012] In another embodiment, an apparatus for producing a copper alloy comprises a melting furnace configured to form a molten copper alloy containing at least 50% by weight of copper. The melting furnace comprises a diffusion lining having a porous structure that substantially covers the bottom inner surface thereof and is adapted to bubble an inert gas into the molten copper alloy.

[0013] In another embodiment, an apparatus for producing a copper alloy comprises a melting furnace configured to form a molten copper alloy containing at least 50% by weight of copper. The melting furnace comprises a diffusion lining having a porous structure. The diffusion lining is formed on at least two different inner surfaces of the melting furnace, and as a result, the diffusion lining is adapted to bubble an inert gas through the molten copper alloy from at least two different inner surfaces.

[0014] In another embodiment, a method for manufacturing an apparatus for producing a copper alloy includes the step of providing a melting furnace chamber configured to form a molten copper alloy containing at least 50% by weight of copper. The method further includes the step of forming a diffusion lining on the inner surface of the melting furnace chamber, wherein the diffusion lining comprises an aluminum silicate ceramic material having a porous structure adapted to bubble an inert gas through the molten copper alloy.

[0015] In another embodiment, a method for manufacturing an apparatus for producing a copper alloy includes the step of providing a melting furnace chamber configured to form a molten copper alloy containing at least 50% by weight of copper. The method further includes the step of forming a diffusion lining having a porous structure adapted to substantially cover the bottom inner surface of the melting furnace and to bubble an inert gas into the molten copper alloy.

[0016] In another embodiment, a method for manufacturing an apparatus for producing a copper alloy includes the step of providing a melting furnace chamber configured to form a molten copper alloy containing at least 50% by weight of copper. The method further includes the step of forming a diffusion lining having a porous structure on at least two different inner surfaces of the melting furnace so that the diffusion lining is adapted to bubble an inert gas through the molten copper alloy from the at least two different inner surfaces.

[0017] In another aspect, a method of manufacturing an apparatus for manufacturing an alloy includes providing a melting furnace chamber and disposing a layer of compressed powder on the inner surface of the melting furnace chamber. The compressed powder includes a mixture of silica and alumina. The method further includes sintering the compressed powder in the melting furnace to form a diffusion lining on the inner surface. The diffusion lining includes an aluminosilicate ceramic material having a porous structure adapted to diffuse gas.

[0018] In another aspect, a method of manufacturing an apparatus for manufacturing an alloy includes providing a melting furnace chamber and disposing a layer of compressed powder on the inner surface of the melting furnace chamber. The method further includes selectively sintering the surface portion of the compressed powder, thereby forming a diffusion lining including a sintered ceramic layer on the inner surface over an unsintered ceramic layer.

[0019] In another aspect, a method of manufacturing an apparatus for manufacturing an alloy includes providing a melting furnace chamber and disposing a layer of compressed powder on the inner surface of the melting furnace chamber. The method further includes using heat from a heated material disposed within the melting furnace chamber to sinter the compressed powder, thereby forming a diffusion lining on the inner surface.

[0020] In another aspect, a method of manufacturing a copper-based alloy includes providing a raw material having a composition configured to form a molten copper-based alloy containing at least 50 wt% copper to a melting furnace and heating the raw material to melt the raw material and form a molten copper-based alloy. The method further includes bubbling an inert gas through the molten copper-based alloy using a diffusion lining formed on the inner surface of the melting furnace chamber. The diffusion lining includes an aluminosilicate ceramic material having a porous structure adapted to bubble an inert gas through the molten copper-based alloy.

[0021] In another aspect, a method of manufacturing a copper-based alloy includes providing a raw material having a composition configured to form a molten copper-based alloy containing at least 50% by weight of copper to a melting furnace, and heating the raw material to melt the raw material and form the molten copper-based alloy. The method further includes bubbling an inert gas through the molten copper-based alloy using a diffusion lining formed within a melting furnace chamber. The diffusion lining substantially covers an inner surface of the bottom of the melting furnace and has a porous structure adapted to bubble an inert gas into the molten copper-based alloy.

[0022] In another aspect, a method of manufacturing a copper-based alloy includes providing a raw material having a composition configured to form a molten copper-based alloy containing at least 50% by weight of copper to a melting furnace, and heating the raw material to melt the raw material and form the molten copper-based alloy. The method further includes bubbling an inert gas through the molten copper-based alloy using a diffusion lining having a porous structure. The diffusion lining is formed on at least two different inner surfaces of the melting furnace, and as a result, the diffusion lining is adapted to bubble an inert gas through the molten copper-based alloy from at least two different inner surfaces.

[0023] In another aspect, an apparatus for manufacturing a copper-based alloy includes a melting furnace configured to form a molten copper-based alloy containing at least 50% by weight of copper, and the melting furnace is configured to rotate about a central axis. The apparatus further includes one or more diffuser blocks including a porous diffusion material adapted to bubble an inert gas through the molten copper-based alloy.

[0024] In another aspect, an apparatus for manufacturing a copper-based alloy includes a melting furnace configured to form a molten copper-based alloy containing at least 50% by weight of copper, and the melting furnace is configured to rotate about a central axis extending in the longitudinal direction of the melting furnace. The apparatus further includes one or more diffuser blocks adapted to bubble an inert gas through the molten copper-based alloy in a direction intersecting the central axis.

[0025] In another embodiment, an apparatus for producing a copper alloy comprises a melting furnace configured to form a molten copper alloy containing at least 50% by weight of copper. The apparatus further comprises a flame injector configured to direct the flow of flame along the central axis of the melting furnace and to serve as a heat source for forming the molten copper alloy. The apparatus further comprises one or more diffuser blocks containing a porous structure adapted to bubbling an inert gas through the molten copper alloy.

[0026] In another embodiment, a method for producing a copper alloy includes the step of providing a raw material having a composition configured to form a molten copper alloy containing at least 50% by weight of copper into a melting furnace, wherein the melting furnace is configured to rotate around a central axis. The method further includes the step of heating the raw material to melt it and form a molten copper alloy. The method further includes the step of bubbling an inert gas through the molten copper alloy using one or more diffuser blocks containing porous diffusion material.

[0027] In another embodiment, a method for producing a copper alloy includes the step of providing a raw material having a composition configured to form a molten copper alloy containing at least 50% by weight of copper into a melting furnace. The method further includes the step of rotating the melting furnace so that one or more diffuser blocks are positioned below the raw material. The method further includes the step of heating the raw material to melt it and form a molten copper alloy. The method further includes the step of bubbling an inert gas through the molten copper alloy.

[0028] In another embodiment, a method for producing a copper alloy includes the step of providing a raw material having a composition configured to form a molten copper alloy containing at least 50% by weight of copper into a chamber of a melting furnace. The method further includes the step of injecting a flame stream along the central axis of the melting furnace to heat and melt the raw material to form a molten copper alloy. The method further includes the step of bubbling an inert gas through the molten copper alloy. [Brief explanation of the drawing]

[0029] [Figure 1] This is a schematic diagram of an apparatus for producing copper-based alloys with low impurity content, according to several embodiments.

[0030] [Figure 1A] This is a schematic side view of a sealed configuration of a melting furnace for producing copper-based alloys, according to several embodiments.

[0031] [Figure 1B] This is a schematic side view of an open configuration of a melting furnace for producing high-purity copper alloys, according to several embodiments.

[0032] [Figure 2] This is a schematic diagram of an apparatus for producing copper-based alloys with low impurity content, according to several other embodiments.

[0033] [Figure 3A] This is a schematic diagram of an apparatus for producing copper-based alloys with low impurity content, according to several other embodiments.

[0034] [Figure 3B] Figure 3A is a detailed perspective view of a portion of the apparatus shown in Figure 3A, which includes a transfer wheel for producing a copper-based alloy with a low impurity content, according to several other embodiments.

[0035] [Figure 3C] Figure 3A is a detailed side view of a portion of the apparatus shown in Figure 3A, which includes a transfer wheel for producing a copper-based alloy with a low impurity content, according to several other embodiments.

[0036] [Figure 4A] A schematic cross-sectional view of a diffuser according to an embodiment is shown.

[0037] [Figure 4B] This is a photograph of a diffuser according to an embodiment.

[0038] [Figure 4C] This is a photograph of a diffuser installed at the bottom of a melting furnace according to an embodiment.

[0039] [Figure 5] A method for producing a copper-based alloy with a low impurity content is shown according to the embodiment.

[0040] [Figure 6A] This is a schematic side view of a melting furnace equipped with a diffusion lining for producing high-purity copper alloys, according to several embodiments.

[0041] [Figure 6B] This is a schematic side view of a melting furnace equipped with a diffusion lining for producing high-purity copper alloys, according to some other embodiments.

[0042] [Figure 6C] Figures 6A and 6B show cross-sectional views of the diffusion lining for a melting furnace.

[0043] [Figure 7A] A method for forming a diffusion lining in a melting furnace for producing high-purity copper alloys is shown according to various embodiments.

[0044] [Figure 7B] This is a schematic side view of a melting furnace in the stage of forming a diffusion lining therein for producing a high-purity copper-based alloy according to the method shown in Figure 7A.

[0045] [Figure 7C] This is a schematic side view of a melting furnace in another step, where a diffusion lining is formed within it for producing a high-purity copper alloy according to the method shown in Figure 7A.

[0046] [Figure 7D] This is a schematic side view of a melting furnace in another step, where a diffusion lining is formed within it for producing a high-purity copper alloy according to the method shown in Figure 7A.

[0047] [Figure 7E] This is a schematic side view of a melting furnace in another step, where a diffusion lining is formed within it for producing a high-purity copper alloy according to the method shown in Figure 7A.

[0048] [Figure 7F] This is a schematic side view of a melting furnace in another step, where a diffusion lining is formed within it for producing a high-purity copper alloy according to the method shown in Figure 7A.

[0049] [Figure 8] According to the embodiment, a method for producing a copper-based alloy with a low impurity content using diffusion lining is shown.

[0050] [Figure 9A] This is a schematic perspective view of a rotary furnace system for producing copper-based alloys with low impurity content, according to several embodiments.

[0051] [Figure 9B] This is a schematic side view of the rotary furnace system shown in Figure 9A, along the cylindrical axis from the first base side.

[0052] [Figure 9C] This is a schematic side view of the rotary furnace system shown in Figure 9A, along the cylindrical axis from the second base side.

[0053] [Figure 10] This is a schematic cross-sectional view of a diffuser block according to several embodiments.

[0054] [Figure 11] This is a schematic cross-sectional view of a rotary furnace loading configuration for producing copper-based alloys with low impurity content, according to several embodiments.

[0055] [Figure 12A]This is a schematic cross-sectional view of a molten configuration of a rotary furnace for producing copper-based alloys with low impurity content, according to several embodiments.

[0056] [Figure 12B] This is another schematic cross-sectional view of a molten configuration of a rotary furnace for producing copper-based alloys with low impurity content, according to some embodiments.

[0057] [Figure 13] This is a schematic cross-sectional view of an injection configuration for a rotary furnace for producing copper-based alloys with low impurity content, according to several embodiments.

[0058] [Figure 14] According to the embodiment, a method for producing a copper-based alloy with a low impurity content using diffusion lining is shown. [Modes for carrying out the invention]

[0059] This disclosure can be understood by referring to the following detailed description. For the purpose of clarifying the description, please note that some elements in the various drawings are not drawn to scale, are represented schematically or conceptually, or otherwise do not precisely correspond to the specific physical configuration of the embodiment.

[0060] Various impurities in copper alloys can degrade their desirable properties. The presence of various undesirable impurities in various parts formed from copper alloys can be caused by the presence of these impurities in raw materials such as copper turning materials, e.g., copper alloy scrap. For example, various impurities in copper turning materials or copper alloy scrap that serve as raw materials can adversely affect the mechanical and chemical properties of cast copper parts, potentially leading to higher failure rates during jig casting, shorter part lifespan, and thus higher replacement costs. High failure rates can lead to increased manufacturing costs for copper parts, such as copper jigs used in plumbing. Therefore, improvements in equipment and methods are needed to reduce the impurity content in copper raw materials and thereby limit the incorporation of impurities into the final product. Consequently, there is a need for technologies to produce copper alloys with low impurity levels, such as copper ingots or copper shots, for improved mechanical properties, while reducing costs, improving casting efficiency, and extending part lifespan.

[0061] The inventors have discovered that oxygen and oxygen-related defects can be particularly detrimental to copper alloys. Oxygen-related defects include, for example, trapped oxygen-containing voids or pockets, and oxides in copper alloys. While not bound by any theory, the formation of such oxygen-containing voids or pockets can be caused by a relatively large amount of oxygen dissolving in the molten copper alloy. For example, as the molten copper alloy cools and solidifies, the solubility of oxygen in the copper alloy decreases, leading to the nucleation of oxygen-containing voids or pockets. These voids or pockets, which are thus formed and do not escape into the atmosphere, become trapped in the solidified copper alloy, resulting in voids and pores, and consequently, a deterioration of mechanical properties such as yield strength and toughness. In particular, oxygen-containing voids or pockets can act as centers of stress concentration, serving as the initiation sites of fracture. Other oxygen-related impurities may include oxygen compounds such as copper oxide, which can precipitate in copper alloys and degrade their mechanical properties.

[0062] The inventors have found that in order to effectively reduce oxygen and oxygen-related impurities in copper alloys, the oxygen content should be reduced from the molten copper alloy, starting from the melting process. Furthermore, after forming a molten copper alloy with reduced oxygen content, it is necessary to prevent the introduction or reintroduction of oxygen and oxygen-related impurities before solidification. Therefore, in order to improve the mechanical properties of a copper alloy, for example by reducing its oxygen content, the disclosed embodiments relate to apparatus and methods for reducing the oxygen content in a molten copper alloy, starting from the melting process, and maintaining a low oxygen content throughout the solidification process, including transfer to a mold. According to various embodiments, an apparatus for producing a copper ingot or copper shot comprises a sealed melting furnace configured to form a molten copper alloy under a sealed inert atmosphere and to bubble an inert gas through the molten copper alloy. The apparatus further comprises a transfer ladle configured to receive the molten copper alloy from the melting furnace under a sealed inert atmosphere and to transfer the molten copper alloy to one or more molds, such as an ingot mold or a part mold, configured to solidify the molten copper alloy into, for example, a copper ingot or a copper part. A transfer ladle may be configured to receive molten copper alloy from the melting furnace through a speed control element. The transfer ladle may also be configured to transfer the molten copper alloy to a shot pit configured to solidify the molten copper alloy into shots. The transfer ladle may be sealed or not, depending on the tolerance for the amount of oxygen and oxygen-related impurities in the solidified copper alloy. Bubbling an inert gas through the molten alloy as described herein is sometimes called sparging. Furnaces according to this disclosure can reduce the impurity content in copper alloys and parts made therefrom, such as ingots, shots, or fixtures, which may be due to sparging of the molten copper alloy in the furnace as described herein. By reducing the oxygen and oxygen-related impurity content in copper alloys and parts made therefrom, and in particular by reducing the amount of oxygen or oxygen-related impurities through sparging, certain mechanical properties of copper, including tensile strength and ductility, can be improved.

[0063] According to various embodiments, a sparging furnace comprises a melting furnace configured to melt copper-based raw materials. The melting furnace is configured to flow an inert gas through the raw material before melting and during heating, for example, through a diffuser, to bubble the inert gas through the molten alloy in the melting furnace. The melting furnace may be in an inert gas atmosphere. Bubbling an inert gas through the molten copper-based alloy as configured allows for the entrainment of undesirable impurities, which can be removed from the molten copper-based alloy. Undesirable impurities include, but are not limited to, oxygen or oxygen-related impurities. As described herein, oxygen or oxygen-related impurities include, but are not limited to, bound and unbound oxygen such as atomic oxygen (O), molecular oxygen (O2, O3), and any compounds formed with or by oxygen, including, but not limited to, water, metal and nonmetallic hydroxides, metal and nonmetallic oxyhydrides, and metal and nonmetallic oxides. Undesirable oxygen-related impurities, such as oxides, may form a slag layer or slag island on the molten copper-based alloy after being entrained by the inert gas. The slag layer may be removed from the molten material, thereby removing oxide impurities from the molten alloy.

[0064] The inventors have found that a sparging furnace configured in this manner can effectively remove impurities, including oxygen and oxygen-related impurities, from molten copper alloys. As described herein, impurity removal may be described in the context of removing oxygen-related impurities, but embodiments are not limited in this way, and it will be understood that other impurities can be removed in the same manner. Although not bound by any theory, sparging removes impurities such as oxygen from molten alloys according to Henry's Law, which states that at equilibrium, the concentration of a gas in a liquid is proportional to the partial pressure of that gas in contact with the liquid. According to Henry's Law, since inert gas bubbles initially do not contain oxygen, as they pass through the molten alloy, the oxygen dissolved in the molten alloy is removed from the molten alloy and escapes into the ambient atmosphere as a mixture with the inert gas. Furthermore, oxide particles and other oxygen-related impurities may be removed by electrostatic force. Although not bound by any theory, as small inert gas bubbles move through the molten alloy, small oxide particles and oxygen-related impurities may adhere to the inert gas bubbles via electrostatic force. Removal of oxygen or oxygen-related impurities by inert gas bubbling may be preferable to methods that rely on chemical reactions between reactive elements, such as reducing gases, and oxygen or oxygen-related impurities in molten copper alloys. Strong reducing gases may not be suitable for some manufacturing facilities because they increase the risk to workers and require strong safety warnings. Furthermore, some elements, such as Zr, act as deoxidizers, but the amount used during processing may need to be reduced, for example, to reduce manufacturing costs. The inventors have found that removing and suppressing impurities, including oxygen and oxygen-related impurities, from molten alloys, as described herein according to embodiments, correlates with improvements in the mechanical properties of cast copper alloys, ingots, or copper shots.

[0065] The inventors have further found that when a molten alloy with a low impurity content, for example, a low oxygen content, is formed in this manner, it is necessary to prevent the reintroduction of impurities, including oxygen and oxygen-related impurities, into the molten alloy. For this purpose, in some embodiments, the melting furnace is sealed and positioned under an inert gas atmosphere. By controlling the atmosphere, the reintroduction of oxygen or oxygen-related impurities into the metal alloy can be effectively prevented or reduced. However, embodiments are not limited in this way, and the melting furnace may be opened to the ambient atmosphere if some reintroduction of oxygen or oxygen-related impurities is acceptable, or if the inert gas can be flushed through the system at a flow rate high enough to substantially suppress the mixing of outside air with the inert atmosphere inside the melting furnace.

[0066] The inventors have further found that as the molten alloy is transferred from the furnace to the transfer ladle, its speed should be carefully controlled to reduce any excess turbulence, as this excess turbulence can reintroduce impurities, such as oxygen or oxygen-related impurities, including any slag that may form on the surface of the molten alloy. Accordingly, according to some embodiments, a speed control device, such as a ramp or launder, connects the molten furnace to the transfer ladle. The speed control device is configured to transfer the copper-based alloy to the transfer ladle without excess turbulence and without the entrainment of oxygen-containing atmospheric gas or other oxygen-related impurities, including oxides, that may be present in the system.

[0067] The inventors have further found that, in order to further reduce or effectively prevent the reintroduction of impurities, including oxygen or oxygen-related impurities, into the molten alloy, the transfer conduit between the melting furnace and the transfer ladle, and optionally, the transfer conduit between the transfer ladle and the mold, may be at least partially sealed and arranged under an inert atmosphere. Thus, in some embodiments, the transfer ladle is at least partially encapsulated and configured to receive the molten copper alloy from a rate control device. In some embodiments, the transfer ladle and the rate control device may be sealed under a common inert atmosphere as the melting furnace. In some embodiments, the transfer ladle is configured, for example, to pour or pour the molten copper alloy into a mold, such as an ingot mold or a component mold. After being poured into the mold, the sparged molten copper alloy may cool and harden to become a sparged copper alloy in solid form.

[0068] System and method for producing high-purity copper alloys using inert gas Figures 1 to 3 show furnace systems configured to produce copper alloys with reduced impurity content, including oxygen or oxygen-related impurities, according to various embodiments disclosed herein. Figures 1A and 1B show two different configurations of the melting furnace of a furnace system for producing copper alloys, according to several embodiments. Figure 5 shows a method for producing copper alloys using one of the furnace systems shown in Figures 1 to 3, according to an embodiment. Each of the furnace systems 100, 200, and 300 shown in Figures 1, 2, and 3, respectively, comprises a melting furnace, which can be in a closed configuration (Figure 1A) or an open configuration (Figure 1B). Each of the melting furnaces 108A (Figure 1A) and 108B (Figure 1B) is configured to form a molten copper alloy containing at least 50 wt% copper, to flow an inert gas through the raw material before melting and during heating, and to bubble the inert gas through the molten copper alloy. Each of the furnace systems 100, 200, and 300 further comprises a transfer ladle configured to receive molten copper alloy from a melting furnace and transfer the molten copper alloy to one or more molds or shot pits configured to solidify the molten copper alloy.

[0069] Method 500 shown in Figure 5 can be carried out using any of the furnace systems 100, 200, and 300. Method 500 for producing a copper alloy includes step 504 of providing a plurality of raw material pieces having a composite composition configured to form a molten copper alloy containing at least 50% by weight of copper into a melting furnace. Method 500 further includes step 508 of flowing an inert gas through the gaps between the raw material pieces and step 512 of heating the raw material pieces while flowing the inert gas through them, thereby melting the raw material pieces to form a molten copper alloy. Method 500 further includes step 516 of bubbling the inert gas through the molten copper alloy. Method 500 further includes step 520 of transferring the molten copper alloy to a transfer ladle. The furnace systems 100, 200, and 300 shown in Figures 1, 2, and 3 will be described in detail below together with Method 500 shown in Figure 5.

[0070] Figure 1 is a schematic diagram of a sparging furnace system 100 for producing copper alloys with low impurity content, including oxygen or oxygen-related impurities, such as ingots, ingot shots, or copper components, according to one embodiment. The sparging furnace system 100 includes a melting furnace 108, which can be configured as a closed melting furnace 108A (Figure 1A) or an open melting furnace 108B (Figure 1B). As disclosed herein, unless otherwise indicated, references made to the melting furnace 108 are understood to apply to either or both of the melting furnaces 108A (Figure 1A) and 108B (Figure 1B).

[0071] The melting furnace 108 is connected to a gas supply source 102 via a gas line 104 and a diffuser 106. Referring to Figures 1A and 1B, the melting furnace 108 is enclosed by a chamber wall 134. The melting furnace 108 is provided with refractory linings 130A, 130B, which include a suitable refractory material at least on its inner surface. Refractory lining 130 lines the bottom inner surface of the melting furnace 108, and refractory lining 130B lines the side walls of the melting furnace 108. If the melting furnace 108 is a closed melting furnace 108A, the melting furnace 108A further includes a lid 130. As shown in Figure 1, the melting furnace 108 includes an opening for removing the molten copper alloy 110. For example, in Figure 1, the opening is located at the top of the melting furnace 108. The opening may be connected to a channel, for example, a speed control element 114. The diffuser 106 is configured to bubble an inert gas through the molten copper alloy 110 formed in the melting furnace 108. The diffuser 106 has a surface area that covers a portion of the cross-sectional area of ​​the molten copper alloy 110 formed in the melting furnace 108, and removes impurities from the path of bubbles passing through the cross-sectional area. The melting furnace 108 is configured to produce the molten copper alloy 110 from copper-based raw materials. As the inert gas flows through the diffuser 106, it forms bubbles 112 that pass through the molten copper alloy 110. The bubbles 112 pass through the molten copper alloy 110, entraining impurities from the molten copper alloy 110, including oxygen and oxygen-related impurities.

[0072] After impurities are removed from the melting furnace 108, the molten copper alloy 110 is transferred through an opening formed through the side wall 134 of the melting furnace 108, as shown in Figure 1 (not shown in Figures 1A and 1B for clarity). Alternatively, the molten copper alloy 110 may be transferred by tilting the melting furnace to allow it to flow out of the melting furnace 108. In the illustrated configuration, the molten copper alloy 110 is transferred at a controlled rate from the melting furnace 108 to the transfer ladle 116 via a first speed control element 114. As described herein, gravity-utilizing inclined ramps or rounders may be used to control the rate, among other structures. In some embodiments, the transfer ladle 116 comprises one or more injectors 124. After being transferred to the transfer ladle 116, the molten copper alloy 110 is transferred to one or more ingot molds 118, for example, by pouring or injecting through the injectors 124. The molten copper alloy 110 solidifies in the mold 118 to form a solidified copper alloy ingot. The mold 118 may be moved via a conveyor belt 120, where it may be further processed, for example, cooled, before being collected.

[0073] Continuing with reference to Figure 1, in some embodiments, the mold 118 may be any suitable mold, including an ingot mold and a jig mold. In some embodiments, the mold 118 may be a mold for a final part, such as a jig mold. In some embodiments, the jig mold may be any suitable plumbing fixture, such as a mold for a faucet, valve, or pipe.

[0074] Continuing with reference to Figure 1, in some embodiments, the mold 118 can be replaced by hardware suitable for producing metal shots. For example, some shot production methods involve passing a molten copper alloy through a screen, e.g., a stainless steel screen, and immersing it in a fluid, e.g., water, where the molten copper alloy is quenched and solidified into a metal shot. In some other shot production methods, air or other suitable gas is passed through the molten copper alloy, and the molten copper alloy is quenched in a fluid such as water. While two exemplary methods of preferred shot production methods are described, it should be understood that other known shot production methods are also within the scope of this disclosure.

[0075] Continuing with Figure 1, the gas supply system supplies an inert gas to the melting furnace. In some embodiments, the inert gas may include, for example, argon (Ar) or any other noble gas. In some other embodiments, the inert gas may include nitrogen (N2). In some embodiments, the inert gas may be any one or a combination of preferred inert gases. In some embodiments, the inert gas may not contain a reactive gas, substantially or essentially, including a reducing or oxidizing gas (e.g., hydrogen). In these embodiments, the inert gas does not contain a reactive gas, such as hydrogen, except for an impurity level of the reactive gas.

[0076] Continuing with Figure 1, the gas supply system is configured to purge or begin flowing an inert gas through the raw material before the raw material is substantially melted. The inventors have found that it may be important to reduce the presence of ambient oxygen and / or moisture in the melting furnace 108 not only during the melting of the raw material but also before the formation of the molten alloy 110 (e.g., before and during heating). Otherwise, undesirable oxidation of the raw material from ambient oxygen and / or moisture can be accelerated at high temperatures during heating before the formation of the molten alloy 110. Oxides thus formed on the surface of the raw material may be relatively stable at the temperature of the molten alloy 110 and may remain in oxide form or release oxygen into the molten alloy 110, thereby contributing to oxygen and oxygen-related impurities in the molten alloy 110, which may adversely affect the mechanical properties of the resulting ingot or shot. Furthermore, the inventors have found that oxides can also be formed from surface-adsorbed oxygen or moisture, which can also be effectively removed by flowing an inert gas through the raw material. Therefore, before substantially heating the raw materials and throughout the entire melting process, the inert gas is purged through the raw materials in the furnace 108. In some embodiments, the step of flowing the inert gas includes flowing it at a sufficient flow rate before and during melting so that the raw materials are substantially in a flowing inert gas atmosphere.

[0077] As described above, the melting furnace 108 can be configured as either a sealed configuration (108A, Figure 1A) or an open configuration (108B, Figure 1B). Referring to Figure 1A, in the sealed configuration of the melting furnace 108A, a lid 130 or equivalent device may be used to seal the furnace 108A. In the sealed configuration, the surfaces of the raw materials and the molten alloy 110 may be placed in a substantially inert atmosphere. As disclosed herein, a substantially inert atmosphere means an atmosphere in which the ambient air above the molten alloy 110 is substantially reduced, for example, to less than 50%, 40%, 30%, 20%, 10% of a normal atmosphere, or within the range defined by any of these values. In the sealed configuration illustrated in Figure 1A, for example, the configuration using a lid 130 is an effective way to place the surface of the molten alloy 110 in a substantially inert atmosphere, but embodiments are understood to be not limited thereto. For example, the inventors have found that even without the lid 130, a substantially inert atmosphere can still be achieved in the open configuration of the melting furnace 108B (Figure 1B) by increasing the inert gas flow rate to suppress the presence of ambient air. If the inert gas flow rate or purge flow rate is sufficiently high, the surfaces of the raw materials and molten alloy 110 can be placed in a substantially inert gas atmosphere even without a lid, or without a lid that partially encloses the internal volume of the furnace 108.

[0078] In some embodiments, purging or flowing an inert gas through the raw material before substantially melting the raw material can be done, for example, 5, 10, 30, or 60 minutes or more before substantial heating for initiating melting can begin. During purging, before initiating the melting of the raw material, the melting furnace 108 may be heated to a relatively low temperature, for example, below 200°C, which is insufficient to substantially oxidize the raw material but substantially below the melting temperature sufficient to promote moisture removal.

[0079] As described herein, a sealed system or its components refers to an arrangement in which the sealed sparging furnace system 100 or its subcomponents are substantially physically sealed or isolated from the external atmosphere, at least partially, during its operation. For example, during the filling of raw materials, which may include multiple raw material pieces, the volume occupied by the raw materials decreases as the raw material pieces melt. Therefore, during the loading process of the melting furnace 108, the chamber lid may be opened one or more times, if present, before the molten alloy 110 reaches the filling line of the melting furnace 108, which represents the liquid level of the melting furnace 108 when it is fully loaded. According to embodiments, an inert gas may be flowed into and through the melting furnace throughout the entire loading process until the molten alloy 110 reaches the filling line, which may include several cycles of adding solid raw material pieces into the pool of molten alloy 110. The chamber lid may also be opened during the addition of raw materials to fill the melting furnace 108, but it is understood that the inert gas can flow into the melting furnace 108 and through the additional raw materials, thereby reducing or substantially preventing the oxidation of the additional raw materials. However, once the melting furnace 108 is fully loaded, the system 100, including at least the gas supply source 102, the gas line 104, the melting furnace 108, the first speed control element 114, and the transfer ladle 116, may be sealed or enclosed from the external atmosphere, at least temporarily, during which time it is purged with inert gas from the gas supply source 102 to suppress the introduction of oxygen therein. Thus, in method 500 (Figure 5), one or more of the steps of circulating the inert gas 508, heating the raw material pieces 512, and bubbling the inert gas through the molten copper alloy 516 are performed at least partially under a sealed inert atmosphere, and the sealed inert atmosphere is configured to substantially prevent outside air from mixing with the sealed inert atmosphere. In the configuration illustrated in Figure 1, the transfer of the molten alloy 110 into the transfer ladle 116 through the first speed control element 114 can be performed at least partially under a sealed inert atmosphere, and the sealed inert atmosphere is configured to substantially prevent outside air from mixing with the sealed inert atmosphere.An enclosure for isolating relevant parts of the sealed sparging furnace system 100 from the outside air may be implemented, for example, using one or more valves located therein, between, for example, the melting furnace 108 and the transfer ladle 116 and / or between the transfer ladle 116 and the outside world. For example, the injector 124 may be equipped with a valve or other shut-off mechanism that functions to isolate the transfer ladle 116 and the melting furnace 108 before being opened to inject the molten alloy from there.

[0080] The raw materials can exist in various forms, including one or more alloy pieces and / or elemental metal pieces. The raw material pieces may or may not have the same composition. However, the raw material pieces have a composite composition configured to form a molten copper-based alloy having the target composition of the alloy to be formed, and contain at least 50% by weight of copper. Depending on the size of the raw material pieces, the inventors have further discovered that the amount or flow rate of inert gas effective in suppressing oxidation of the raw materials before melting, as described above, may vary. The amount or flow rate of inert gas may depend, in particular, on the relative amount of open space between the raw material pieces forming the raw materials for producing the molten alloy 110, or on the permeability of the copper-based alloy raw material material. When the raw materials include relatively large raw material pieces, there may be a relatively large amount of open space or permeability, and the amount of surface area of ​​the alloy exposed to the inert gas may be relatively small. For example, in some embodiments, the raw material material may include raw material pieces that are relatively large in size and correspondingly have a high amount of open space or permeability. For highly permeable raw materials, a relatively high inert gas flow rate, for example, about 5 liters / minute or more, may be suitable for removing various impurities, including oxygen and oxygen-related impurities, from the raw material. In some embodiments, the raw material may include raw material pieces that are relatively small in size and correspondingly have a small amount of open space or low permeability. For example, the raw material may be relatively small copper alloy turning material (e.g., copper scrap). For less permeable raw materials, a relatively low inert gas flow rate, for example, less than about 5 liters / minute, may be suitable for removing impurities, including oxygen and oxygen-related impurities, from the raw material. The inert gas flow rates before melting described herein may have any value that is the same as or different from the inert gas flow rate during bubbling of the inert gas through the molten alloy 110, as described below, and these values ​​are not repeated herein for the sake of brevity.

[0081] The inventors have found that, as described above, specific combinations of various process parameters may be effective in effectively removing impurities, including oxygen and oxygen-related impurities, from the molten alloy 110. In particular, the inventors have found that the size, density, and velocity distribution of bubbles 112 moving through the molten alloy 110 may correlate with the effectiveness of the impurity removal process. If the size, density, and velocity of the bubbles 112 are too small or too low, the bubbles may be too slow or ineffective in removing oxygen or oxygen-related impurities. On the other hand, if the size, density, and velocity of the bubbles 112 are too large or too high, the bubbles may generate substantial turbulence as they rise and burst on the surface of the molten alloy 110. The inventors have found that if such turbulence is substantial, it may not only negate the removal of oxygen or oxygen-related impurities but may even increase the content of oxygen or oxygen-related impurities. Therefore, the inventors have found that controlling the size, density, and velocity distribution of inert gas bubbles may be important. The size, density, and velocity distribution of bubbles can be optimized based on various factors, for example, the viscosity of the molten alloy 110, the flow rate of the inert gas passing through the molten alloy 110, the cross-sectional area of ​​the molten alloy 110 through which the inert gas flows, the porosity of the diffuser 106, and the volume of the molten alloy 110, which is partially defined by the dimensions of the furnace 108. It will be understood that these parameters may be interdependent. For example, the flow rate of the inert gas is determined by the flow rate of the inert gas and the cross-sectional area through which it passes through the diffuser. Furthermore, certain values ​​of flow parameters such as flow rate may be particularly relevant if they are proportional to the total volume of the molten alloy 110.

[0082] The viscosity of the molten alloy 110 depends, in particular, on its composition and temperature. For a given composition among the various compositions of the molten alloy 110 described herein, including a molten copper-based alloy composition containing at least 50 wt% copper, the viscosity can be controlled by controlling the temperature of the molten alloy 110 to a temperature higher than the melting temperature, for example, the liquidus temperature. For this and other reasons, the inventors have found that the methods described herein may be effective in removing impurities, including oxygen and oxygen-related impurities, from the molten alloy 110 when the molten alloy 110 is heated to a temperature 100 to 400°C higher than the liquidus temperature of the alloy. According to various embodiments, the molten alloy 110 is heated to a temperature higher than 50°C, 100°C, 150°C, 200°C, 250°C, 300°C, 350°C, 400°C, 450°C, or any temperature within the range defined by any of these values.

[0083] As described above, the inventors have found that the flow rate of the inert gas during bubbling should be optimized so that the size, density, and velocity distribution of the inert gas bubbles are effective in reducing various impurities, including oxygen and oxygen-related impurities, but so as not to generate excessive turbulence that could have adverse effects. Furthermore, as described above, the optimized flow rate differs depending on whether the melting furnace 108 is in a closed configuration (Figure 1A) or an open configuration (Figure 1B). According to various embodiments, when the melting furnace 108A (Figure 1A) is in a closed configuration, the inert gas is bubbling into the melting furnace 108A at any value within the range defined by these values, such as 10 liters / min, 9 liters / min, 8 liters / min, 7 liters / min, 6 liters / min, 5 liters / min, 4 liters / min, 3 liters / min, 2 liters / min, greater than 1 liter / min, or 1 to 10 liters / min, 2 to 6 liters / min, for example, at a flow rate of about 4 liters / min. According to various embodiments, when the melting furnace 108B (Figure 1B) is in an open configuration, the inert gas is bubbled into the melting furnace 108B at a higher flow rate than in the closed configuration. For example, the flow rate in the open configuration may be any value within the range defined by these values, such as 13 liters / min, 12 liters / min, 11 liters / min, 10 liters / min, 9 liters / min, 8 liters / min, 7 liters / min, 6 liters / min, 5 liters / min, greater than 4 liters / min, or 4 to 13 liters / min or 5 to 9 liters / min, for example, about 7 liters / min. If the configuration of the closed melting furnace 108A and the open melting furnace 108B are the same, the optimized flow rate of the inert gas in the open melting furnace configuration 108A is only 2 liters / min, 3 liters / min, 4 liters / min, or within the range defined by any of these values, compared to the closed melting furnace 108A.

[0084] To further control the size, density, and velocity distribution of inert gas bubbles, the inert gas is flowed into the melting furnace through a diffuser 106 having an effective diffuser area, thereby controlling the flux. According to various embodiments, the inert gas is diffused through a diffuser 106 having a diameter d (Figure 1A) within a range defined by 5 cm, 10 cm, 15 cm, 20 cm, 25 cm, 30 cm, 35 cm, 40 cm, 45 cm, greater than 50 cm, or any of these values.

[0085] The size, density, and velocity distribution of the inert gas bubbles can also be controlled by the pores of the diffuser 106. The pore size of the diffuser 106 should be controlled so that the bubbles have an appropriate size, density, and velocity distribution while preventing the molten liquid alloy from seeping in. The diffuser 106 can have an average pore diameter of 20 mm, 30 mm, 40 mm, 50 mm, 60 mm, 70 mm, 80 mm, 90 mm, greater than 100 mm, or a value defined by any of these values. Furthermore, the diffuser 106 has a porosity defined as the ratio of voids to the overall macroscopic volume, and this ratio is within the range defined by 10%, 15%, 20%, 25%, 30%, greater than 35%, or any of these values.

[0086] In the illustrated embodiment, the diffuser 106 is located on the bottom surface of the melting furnace. However, the embodiment is not limited to such an arrangement, and the diffuser 106 may be formed on other surface locations, including the sides.

[0087] Figures 4A and 4B show schematic cross-sectional views and photographs, respectively, of diffusers that meet the criteria described herein according to an embodiment. Figure 4C is a photograph of a diffuser installed at the bottom of a melting furnace 108 according to an embodiment. As shown in Figure 4A, the diffuser 400 comprises a gas inlet 404 into which an inert gas is introduced and a container 408 for holding diffuser material or medium 412. The illustrated diffuser material or medium 412 includes a porous refractory ceramic material. Figure 4B is a photograph of an example of a diffuser 400 having a diffuser material or medium formed mainly of porous alumina and silica. The diffuser material or medium 412 contains alumina in an amount of mol%, for example, 65 mol%, within the range defined by 50-80 mol%, 55-75 mol%, 60-70 mol%, or any of these values. The diffuser material or medium 412 further contains silica in an amount of mol%, for example, 24 mol%, within the range defined by 10-35 mol%, 15-30 mol%, 20-25 mol%, or any of these values. The diffuser material or medium can have various properties and structures as described below with respect to the diffusion lining shown in Figures 6A and 6B. For example, the diffuser material 412 has a porosity of 27.6% and a density of 2.45 g / cm³. 3 It has a density of . The diffuser material or lining 412 may also have a two-layer structure as described with respect to Figures 6A and 6B.

[0088] Continuing with reference to Figures 4A to 4C, according to the embodiment, the inert gas is bubbling into the melting furnace 108 at the aforementioned flow rate, for example, 1 to 10 liters / min, through a diffusion material or medium 412 (Figure 4A) having a diameter of 5 to 50 cm (d in Figure 1A), in a furnace capable of melting alloys of a value within the range defined by 1,000 pounds, 2,000 pounds, 5,000 pounds, 10,000 pounds, 20,000 pounds, 50,000 pounds, or any of these values. For example, the inert gas is bubbling into the melting furnace at a flow rate of 1 to 10 liters / min in a 4,000-pound furnace, or a furnace capable of melting an amount of alloy of about 4,000 pounds.

[0089] Referring again to Figures 1A and 1B, in addition to the capacities of the melting furnaces 108A and 108B, the furnaces may have a volume defined by an area, such as a cylindrical area, and a height. In various embodiments, the furnaces may have a cylindrical volume defined by an inner diameter D of 50 cm, 100 cm, 150 cm, 200 cm, 250 cm, 300 cm, 350 cm, 400 cm, 450 cm, greater than 500 cm, or within a range defined by any of these values. The melting furnaces 108A and 108B may further have a height H of 50 cm, 100 cm, 150 cm, 200 cm, 250 cm, 300 cm, 350 cm, 400 cm, 450 cm, greater than 500 cm, or within a range defined by any of these values, so that when the molten alloy 110 is fully loaded, the molten metal may have a filling line F at a height measured from the bottom of the furnace.

[0090] The inventors have found that, in combination with various other configurations of the melting furnace 108, the disclosed inert gas flow rates produce combinations of bubble size, density per unit volume, and velocity distribution suitable for producing the various advantageous effects described herein. The bubble density is such that excessive bubble coalescence in the molten metal is substantially avoided, and the velocity and size are such that excessive turbulence is avoided. In some embodiments, the diffuser 106 may have an average pore distribution correlated with the bubble size and density per unit volume such that the inert gas bubbles do not substantially coalesce or have excessive velocity.

[0091] When sealed, the atmosphere in contact with the molten alloy 110 in the melting furnace 108 can be determined by an inert gas introduced by a gas supply system. In some embodiments, the atmosphere in the melting furnace is argon. In some embodiments, the atmosphere in the melting furnace is nitrogen. In some embodiments, the atmosphere in the melting furnace is any suitable inert gas.

[0092] Referring to Figures 1A and 1B, the melting furnace 108 (108A, 108B) is configured to melt the raw material. As shown in Figures 1A and 1B, the melting furnace 108 may be an induction furnace, but is not limited to this. The melting furnace 108 can be configured to have a variable internal temperature to accommodate various copper alloy systems. In some embodiments, the temperature of the melting furnace 108 is 700°F to 3000°F. In some embodiments, the temperature of the melting furnace 108 is a value within the range defined by 900°F, 1000°F, 1200°F, 1400°F, 1600°F, 1800°F, 2000°F, 2200°F, 2400°F, 2500°F, or 3000°F, or any of these values.

[0093] Continuing with Figures 1A and 1B, the induction-type melting furnace 108 (108A, 108B) includes an induction coil 138 surrounding at least a portion of the melting furnaces 108A, 108B. The induction heating system includes an induction power source that converts linear power into alternating current and supplies it to the coil 138 to generate an electromagnetic field within the coil. The raw material placed within the coil is then subjected to this field, which induces an electric current within it, and subsequently generates enough heat to melt the raw material. Advantageously, the inventors have found that, in some circumstances, to obtain optimal results, the uppermost winding of the coil 138 should remain below the filling wire (F). Such a configuration allows the lower region of the molten alloy 110 to be at a higher temperature than the upper region of the molten alloy 110. The inventors have found that such a configuration enhances the effectiveness of impurity removal. While not bound by any theory, the improved effectiveness may be partly due to the fact that impurity removal can occur more effectively in the higher-temperature lower region due to the increased local solubility of the impurities. Subsequently, in the upper region, impurities are incorporated into the slag at the outermost surface of the molten alloy 110 and thus removed from the molten copper alloy 110. According to one embodiment, the uppermost winding of the induction coil 138 is positioned at or below the vertical level corresponding to the upper surface of the molten copper alloy 110 or the filling line F. The induction coil 138 may have a height measured from the inner bottom surface of the melting furnace 108, corresponding to a percentage within the range defined by 90%, 80%, 60%, 50%, 40%, 30%, or any of these values, relative to the height of the molten copper alloy 110.

[0094] The operating frequency of an induction heating system can be influenced by the range of raw material sizes for the application. While not bound by any theory, this may be due to the "skin effect," which relates to the depth below the surface of the metal raw material to which the electromagnetic field induces current. Generally, higher operating frequencies result in thicker skin depths, while lower operating frequencies result in deeper skin depths. Skin depth correlates with the penetration of the heating effect. Skin depth, or penetration depth, depends on the operating frequency, material properties, and raw material temperature. In principle, for a given material, induction heating of a raw material piece can be performed at a high operating frequency when the raw material piece is small, and at a low operating frequency when the raw material piece is large. According to various embodiments, the raw material can have minimum main dimensions, e.g., width, of 2 cm, 5 cm, 10 cm, 20 cm, 30 cm, 40 cm, 50 cm or more, or within a range defined by any of these values. The inventors have found that, in order to melt the copper alloy raw material pieces according to the embodiment, the optimal frequency of the melting furnace 108 is set to a frequency within the range defined by 10 kHz, 5 kHz, 2 kHz, 1 kHz, less than 500 kHz, or any of these values, for example, 600 kHz.

[0095] As described above, the inventors have found that in order to facilitate the removal of impurities, including oxygen and oxygen-related impurities, from the molten alloy 110, the molten alloy 110 is heated to a temperature 100 to 400°C higher than the melting temperature of the alloy, for example, the liquidus temperature. On the other hand, the inventors have found that it is advantageous to lower the temperature of the molten metal in the furnace to near the liquidus before transferring the molten alloy 110 to the mold. Therefore, according to various embodiments, the molten alloy 110 is cooled by a temperature above 50°C, 100°C, 150°C, 200°C, 250°C, 300°C, 350°C, 400°C, 450°C, or any temperature within the range defined by any of these values, immediately before being transferred from the melting furnace 108. However, the temperature inside the melting furnace 108 remains above the melting temperature of the alloy.

[0096] After forming a molten alloy 110 with a low content of impurities, including oxygen or oxygen-related impurities, the molten alloy is transferred to a transfer ladle 116. The inventors have found that the content of oxygen or oxygen-related impurities may not be constant as a function of the depth of the molten alloy 110. Generally, the inventors have found that the content of oxygen or oxygen-related impurities tends to increase toward the surface of the molten alloy 110. Therefore, advantageously, if a portion of the molten alloy 110 with a lower oxygen content than the average is desired, the molten alloy 110 in the lower part of the melting furnace can be preferentially transferred to the transfer ladle 116. This can be achieved, for example, by connecting a first speed control element 114 to the lower part of the melting furnace 108, for example, the lower part within the bottom 10%, 20%, 30%, 40%, 50%, or 60%. Alternatively, the molten alloy 110 may be preferentially pumped from its bottom using a mechanical pump and then transferred to the transfer ladle 116.

[0097] Continuing with Figure 1, as described above, after a molten alloy 110 with a low content of impurities, including oxygen or oxygen-related impurities, is formed in the melting furnace 108, the molten alloy 110 can be transferred to a transfer ladle 116 via a first speed control element 114, for example, a rounder or ramp, which may be under a sealed atmosphere and / or an inert atmosphere to reduce the reintroduction of oxygen or oxygen-related impurities. In some embodiments, bubbling of an inert gas through the molten alloy 110 can be continued throughout the entire process of transferring the molten copper-based alloy to the transfer ladle 116. If the first speed control element 114 is sealed or isolated from the ambient atmosphere as shown, the atmosphere within the first speed control element can be the same as the atmosphere of the melting furnace. Thus, the atmosphere within the first speed control element is argon, nitrogen, and / or any suitable inert gas.

[0098] The first velocity control element 114 is configured to introduce the molten alloy 110 into the transfer ladle 116 at a controlled velocity to suppress turbulence that may introduce or reintroduce impurities, including oxygen or oxygen-related impurities. The inventors have found that velocity control at this stage may also be important to prevent or suppress the introduction or reintroduction of oxygen and oxygen-related impurities into the molten alloy 110 as it cools, thereby suppressing the formation of voids in the molten alloy 110. The first velocity control element 114 may be, for example, a rounder or a sloping channel, which may be sealed and shielded from the external atmosphere, as shown in the figure. In some embodiments, the first speed control element 114 can be set to 1 inch / second, 2 inches / second, 5 inches / second, 10 inches / second, 15 inches / second, 16 inches / second, 17 inches / second, 18 inches / second, 19 inches / second, 20 inches / second, 21 inches / second, 22 inches / second, 23 inches / second, 24 inches / second, 25 inches / second, 26 inches / second, 27 inches / second, 29 inches / second, 30 inches / second, 35 inches / second, 40 inches / second, 45 inches / second The system is configured to transfer the molten alloy 110 from the melting furnace 108 to the transfer ladle 116 at a speed of 5 to 30 inches per second, 50 inches / second, 55 inches / second, 60 inches / second, 65 inches / second, 70 inches / second, 75 inches / second, 80 inches / second, 85 inches / second, 90 inches / second, 95 inches / second, 100 inches / second, 105 inches / second, 110 inches / second, 115 inches / second, or 120 inches / second, or within a range defined by any of these values. In some embodiments, the first speed control element 114 is configured to transfer the molten alloy 110 from the melting furnace 108 to the transfer ladle 116 at a speed of 5 to 30 inches / second. In some embodiments, the first speed control element 114 controls the speed of the molten copper alloy as it is transferred from the melting furnace 108 to the transfer ladle 116.

[0099] Continuing with reference to Figure 1, in some embodiments, in order to control the speed of the molten alloy 110 within the speed range disclosed above, the closed sparging furnace system 100 is configured to use a first speed control element 114 to transfer the molten alloy 110 from the melting furnace 108 to the transfer ladle 116, the first speed control element 114 being configured to control the speed of the flowing molten alloy 110 by using gravity and positioning such that, for example, the vertical drop is about 0.5 to 5 inches for a horizontal length of about 3 to 5 feet. In some embodiments, the first speed control element 114 is configured such that the drop is 0.5 to 2 inches or 1 to 2 inches for a length of 3 feet, 4 feet, 5 feet, or 3 to 5 feet. The first speed control element may have an angle of 5 to 10 degrees, 10 to 20 degrees, 20 to 30 degrees, 30 to 40 degrees, 40 to 50 degrees, 50 to 60 degrees, or a value within the range defined by any one of these values, with respect to a horizontal plane parallel to the ground.

[0100] Thus, by forming a molten alloy 110 with a low content of impurities, including oxygen or oxygen-related impurities, in the melting furnace 108, and then transferring the molten alloy 110 to the transfer ladle 116 under a sealed and / or inert atmosphere, the reintroduction of impurities can be further suppressed. Therefore, as shown in the figures, according to various embodiments, the transfer ladle 116 and the first speed control element 114 connecting the melting furnace 108 and the transfer ladle 116 may be sealed. If the transfer ladle 116 is sealed from the ambient atmosphere, the atmosphere inside the transfer ladle 116 may be common to or shared with the atmosphere inside the melting furnace 108 and / or the first speed control element 114. Therefore, the atmosphere inside the transfer ladle is argon, nitrogen, and / or any suitable inert gas.

[0101] Continuing with Figure 1, after the molten alloy 110 is transferred to the transfer ladle 116 at a controlled speed using a first speed control element 114, the molten alloy 110 is injected into the mold 118 using an injector 124. The injector 124 may be, for example, a gravity-driven injector, where the molten alloy 110 is injected solely by gravity. For example, the injector 124 may include a piston, which is typically mounted on a valve seat having an opening smaller than the diameter of the piston. In this configuration, the injector 124 is closed, and the system 100, including one or more of the transfer ladle 116, the first speed control element 114, and the melting furnace 108, is sealed in a common inert atmosphere and may be connected by the common inert atmosphere. When the piston is lifted from the valve seat, the molten alloy 110 is able to flow through the valve seat opening, thereby injecting the molten alloy 110 into the mold 118 by gravity. The inventors have found that, in order to prevent excessive turbulence that could again cause the introduction or reintroduction of oxygen or oxygen-related impurities as the molten alloy 110 solidifies, the distance between the injection tip of the injector 124 and the mold 118 should not exceed 0.5”, 1.0”, 1.5”, 2.0”, 2.5”, 3.0”, or 3.5”, or should be within the range defined by any of these values.

[0102] Figure 2 is a schematic diagram of a closed sparging furnace system 200 for producing copper alloys with low oxygen or oxygen-related impurity content, e.g., ingots, copper shots, or copper components, according to one embodiment. The closed sparging furnace system 200 shares a variety of components that are broadly configured as with the corresponding components of the closed sparging furnace system 100 described above, and some detailed descriptions of these components may be omitted herein for brevity. The closed sparging furnace system 200 includes a gas source 102 connected via a gas line 104 to a diffuser 106 configured to bubble gas through molten copper alloy 110 in a melting furnace 108. In the same manner as described above with respect to Figure 1, as the inert gas flows through the diffuser 106, the system 200 is configured to form inert gas bubbles 112 that pass through the molten copper alloy 110. The bubbles 112 pass through the molten copper alloy 110, as described above, entraining impurities from the molten copper alloy 110, including oxygen and oxygen-related impurities. After impurities are removed from the melting furnace 108, the molten copper alloy 110 is transferred at a first controlled rate via a first speed control element 114 from the melting furnace 108 to the transfer ladle 116. In some embodiments, the transfer ladle 116 includes one or more injectors 124.

[0103] The inventors have found that, in addition to advantageously controlling the speed of the molten alloy 110 delivered from the melting furnace 108 to the transfer ladle 116 using a first speed control element 114 under certain circumstances, it may be even more advantageous to further control the speed of the molten alloy 110 delivered from the transfer ladle 116 to the mold 118. To address these and other needs, in the system 200 shown in Figure 2, unlike the system 100 in Figure 1 where the molten alloy 110 is directly transferred from the transfer ladle 116 to the mold 118, the molten copper alloy 110 is transferred to the transfer ladle 116 and then to the mold 118 via a second speed control element 218. The second speed control element 218 can be, for example, a rounder or an inclined channel, and can be sealed and shielded from the external atmosphere. The molten alloy 110 solidifies in the mold 118, producing a solidified copper alloy. The mold 118 can be moved via a conveyor belt 120, where it may be further processed.

[0104] In addition to the first speed control element 114, which may be configured as described above with respect to Figure 1, the system 200 shown in Figure 2 includes a second speed control element 218. The additional speed control element provides additional speed control to further reduce the reintroduction of oxygen or oxygen-related impurities into the copper-based molten alloy 1204 when it is introduced into the ingot mold 118. The second speed control element 218 may be configured according to the various configuration parameters (including dimensions and gradients) described above with respect to the first speed control element 114, but a detailed description thereof is omitted herein for the sake of brevity.

[0105] With this configuration, in the system 200 shown in Figure 1, a molten alloy 110 with reduced oxygen or oxygen-related impurity content is formed in the melting furnace 108 and transferred at a first speed to the transfer ladle 116 using a first speed control element 114. The molten alloy 110 may then be transferred to the ingot mold 118 at a second speed, further reduced from the first speed, using a second speed control element 218. In some embodiments, the speed control element 218 is sealed from the ambient atmosphere. However, embodiments are not limited in this way, and in some other embodiments, the second speed control element 218 may be open to the ambient atmosphere. In some embodiments, the atmosphere inside the second speed control element 218 can be the same as the atmosphere inside the melting furnace 108 and / or the first speed control element 114 and / or the transfer ladle 116. Thus, the atmosphere inside the second speed control element 218 may be argon, nitrogen, and / or any suitable inert gas.

[0106] The second speed control element 218 is configured to transfer the molten copper alloy 110 from the transfer ladle at a speed having any of the above-described values ​​with respect to the speed of the molten copper alloy 110 controlled by the first speed control element 114. However, since the speed of the molten alloy 110 reaching the second speed control element 218 is already reduced by the first speed control element 114, it is understood that the speed of the molten alloy 110 reaching the mold 118 will be substantially lower than the speed of the molten alloy 110 reaching the mold 118 without the presence of the second speed control element 218, as shown in Figure 1, for example. According to various embodiments, the second speed of the molten alloy 110 at the end of the second speed control element 218 is a value within the range defined by 20%, 30%, 40%, 50%, 60%, 70%, or any of these values ​​of the first speed of the molten alloy at the end of the first speed element 112.

[0107] As discussed above with respect to Figure 1, the inventors have found that the turbulence caused by vertically dropping the molten alloy 110 can introduce or reintroduce oxygen or oxygen-related impurities into the molten alloy 110. Therefore, the vertical drop between the injection tip of the injector 124 and the second velocity control element 218, and the vertical drop between the second velocity control element 218 and the mold 118 should not exceed 0.5”, 1.0”, 1.5”, or 2.0”, or should be within the range defined by any of these values, in order to prevent excessive turbulence.

[0108] With this configuration, the second speed control element 218 is configured to transfer the molten copper alloy 110 from the transfer ladle 216 to the ingot mold 118 at a substantially reduced speed and without vertical descent.

[0109] Figure 3A is a schematic diagram of a closed sparging furnace system 300 for producing copper alloys with low oxygen or oxygen-related impurity content, such as ingots, copper shots, or copper components, according to another embodiment. In particular, system 300 shows one exemplary implementation of a conveyor system 304. The upper figure shows a top view of system 300 including the conveyor system 304, and the lower figure shows a side view of the conveyor system 304. The closed sparging furnace system 300 shares a variety of components that are broadly configured as with the corresponding components of the closed sparging furnace systems 100 and 200 described above in relation to Figures 1 and 2, respectively, and a detailed description of these components may be omitted herein for brevity. Unlike systems 100 and 200 described above in relation to Figures 1 and 2, system 300 comprises two melting furnaces 108 for higher productivity. However, the embodiments are not limited to such ones, and it will be understood that any one of systems 100, 200, and 300 may have a preferred number, e.g., one or more, of the melting furnaces 108. After oxygen-related impurities are removed from the melting furnace 108 in the same manner as described above, the molten copper alloy 110 is transferred from the melting furnace 108 to the transfer wheel 316 via a first speed control element 114 at a first controlled speed, and optionally further via a second speed control element 218 at a second controlled speed, which may be the same as or slower than the first speed. Unlike systems 100 and 200 described with respect to Figures 1 and 2, the second speed control element 218, if present, is connected directly to the first speed control element 114 without being separated by a transfer ladle. The molten alloy 110 is then injected into one or more molds 118. Furthermore, unlike systems 100 and 200 (Figures 1 and 2), in the illustrated system 300, the molten alloy 110 is injected into the mold 118 using a transfer wheel 316, also called a casting wheel, which will be explained in more detail with respect to Figures 3B and 3C. The injected molten alloy 110 is then dripped into one or more molds 118 and transported by a conveyor belt 120 of the conveyor system 304.The conveyor belt 120 may be driven by a suitable drive assembly, which may include, for example, a motor drive unit 324. The conveyor system 304 may optionally include, for example, a cooling fan 308 and a knocker 312 for loosening the ingots from the mold and collecting them into the collection bin 320.

[0110] Figures 3B and 3C show detailed perspective and side views, respectively, of parts of the system 300 shown in Figure 3A for producing copper alloys with low oxygen or oxygen-related impurity content, according to several other embodiments. The parts of the system 300 shown in Figures 3B and 3C show further details of the system 300, including the arrangement of the transfer wheel 316 and the conveyor belt 120. The side view of 3C is along the direction of movement of the conveyor belt 120. In particular, as described above with respect to Figure 3A, in the system 300, the molten alloy 110 is injected into the mold 118 via the transfer wheel 316 instead of the transfer ladle 116 described with respect to Figures 1 and 2. Unlike the transfer ladle 116 (Figures 1 and 2), where the injectors 124 are separated only by a linear distance, for example along the bottom surface of the transfer ladle 116, in the transfer wheel 316, the injectors 328 are separated by an arc defined by the separation angle between them and extend in different directions. As shown in Figures 3B and 3C, the transfer wheel 316 is configured to rotate about a central radial (z) axis. In the illustrated transfer wheel 316, but not limited to, the z axis generally extends in the direction of the flow of molten metal 110 in the second speed control element 218.

[0111] The multiple injectors 328 of the transfer wheel 316 are inclined to extend radially at an oblique angle with respect to the z-axis. The oblique extension angle of the injectors 328 allows for a further reduction in the speed at which the molten alloy 110 is delivered to the mold 118, instead of injecting the molten metal 110 vertically into the mold 118 as described above, with respect to the configurations shown in systems 100 and 200 (Figures 1 and 2).

[0112] The motor drive unit 324 is configured to synchronize the motion of the transfer wheel 316 and the conveyor belt 120. The motor drive unit 324 is configured to rotate the transfer wheel 316 around the z-axis at a predetermined angular velocity and to linearly translate the regularly spaced molds 118 such that the transfer wheel 316 adjacent to the inclined injector 328 is separated by an arc corresponding to the linear distance between adjacent molds 118. Thus, as the transfer wheel 316 rotates, adjacent molds 118 are filled with molten metal 110 by the corresponding molds in the injector 328.

[0113] Referring to Figure 3B, gate valves 332 are located at the ends of each arm of the first speed control element 114. The gate valves 332 are configured to seal the molten metal 110 and keep it in an inert atmosphere until it is ready to be transferred to the transfer wheel 316. For illustrative purposes, the second speed control element 218 is shown open at its top. However, during operation, the second speed control element 218 may also be sealed in an inert atmosphere and benefit from it as described above.

[0114] According to various embodiments, the apparatus is configured such that the molten copper alloy formed in the mold 118 according to the embodiment and ultimately solidified has a substantially lower oxide content compared to copper alloys produced using a conventional copper furnace. In some embodiments, the solidified copper alloy has an oxide content that is 5%, 10%, 15%, 20%, 25%, 30%, 50%, 75%, or up to 99%, or any value in between, compared to a solidified copper alloy produced by a conventional reference furnace using the same raw materials.

[0115] According to various embodiments, the apparatus according to the embodiments is configured to achieve one or more of the following with respect to a reference solidified copper alloy formed from a reference apparatus configured such that one or more test results obtained from a solidified copper alloy using the ASTM E8 / E8M-21 method are the same as those of the apparatus except that the melting furnace and transfer ladle are in the same sealed inert atmosphere: the ultimate tensile strength increases by at least 10 ksi, 20 ksi, 40 ksi, 50 ksi, or any of these values; the 0.5% yield strength increases by at least 1, 2, 3, 6, 8, 10 ksi, or any of these values; the elongation increases by at least 3%, 5%, 10%, 20%, 30%, 40%, 50%, or any of these values; and the reduction in cross-sectional area increases by at least 3%, 5%, 10%, or any of these values.

[0116] A system including a reinforced diffuser assembly for manufacturing high-purity copper alloys. The above describes various aspects of furnace systems configured to produce copper alloys with reduced impurity content, and methods for producing copper alloys using such systems. As mentioned above, controlling the inert gas bubble properties, in particular, can be important for generating optimized conditions to reduce the impurity content from the molten copper alloy 110. The bubble properties include bubble size, density per unit volume, and velocity distribution. These bubble properties are determined by various flow properties, including flow rate through the diffuser 106, flux, and pore size distribution.

[0117] In the illustrated melting furnaces 108A and 108B (Figures 1A and 1B), the diffuser 106 has a diameter d (Figure 1A) smaller than the diameter D of the melting furnace 108. The diffuser 106 will be further described with reference to Figures 4A to 4C. As shown in Figure 4A, the diffuser material or medium 412 is connected to an inlet 404 for the flow of inert gas. The diameter d of the diffuser 106 in contact with the molten copper alloy 110 may be optimized to allow the inert gas to flow uniformly from its outer surface. The porosity may be optimized to control the size of the inert gas bubbles. The inventors have found that because the diameter d or area of ​​the diffuser 106 is smaller than the diameter D or area of ​​the melting furnaces 108A and 108B, the inert gas bubbles 112 cannot flow substantially across the entire cross-section of the molten copper alloy 110. As a result, depending on the diffusivity of impurities, the molten copper alloy 110 outside the path of the inert gas bubbles 112 may not be effectively purified. Therefore, the inventors recognized the need to increase the cross-sectional area of ​​the molten copper alloy 110 through which the inert gas bubbles pass toward the surface.

[0118] To address these and other needs, and to further improve upon the various embodiments disclosed herein, further embodiments of the apparatus for producing copper alloys include a melting furnace configured to form a molten copper alloy containing at least 50% by weight of copper. According to the embodiment, the melting furnace 108 includes a diffuser assembly comprising one or more diffuser linings. The diffuser assembly includes a diffusion lining formed on the surface of the melting chamber wall. The diffusion lining can be used as an addition to or replacement for the diffuser 106 described above.

[0119] Figures 6A and 6B are schematic side views of a melting furnace equipped with a diffuser assembly for producing a high-purity copper alloy, according to several embodiments. The diffuser assembly includes a diffuser 400 and one or both of diffusion linings 400A, 400B. Unlike the melting furnaces 108A, 108B described with respect to Figures 1A and 1B, in which the diffuser 400 is configured to be in contact with the molten copper alloy 110, in the embodiments shown in Figures 6A and 6B, the diffuser 400 is positioned to a depth inside the diffusion linings 400A, 400B. With this configuration, the inert gas diffusing from the diffuser 400 crosses the diffusion lining 400A positioned above it, and as a result, the inert gas is further diffused by the diffusion lining 400 before being introduced into the molten copper alloy 110. According to various embodiments, the diffusion linings 400A, 400B include a porous high-temperature refractory ceramic material. The ceramic material comprises an aluminum silicate having a porous structure adapted to bubble an inert gas through a molten copper-based alloy. With respect to Figures 1A and 1B, the refractory linings 130A and 130B described above have a similar structure to the diffusion linings 400A and 400B and / or can be formed using similar methods as described herein, and it will be understood that the diffusion linings 400A and 400B play an important role in further diffusing the inert gas before it is introduced into the molten metal 110, thereby forming inert gas bubbles inside.

[0120] Figure 6A shows a melting furnace 600A including a diffusion lining 400A, which substantially covers its bottom inner surface and has a porous structure adapted to bubble an inert gas into the molten copper alloy 110. Figure 6B shows a melting furnace 600B including diffusion linings 400A, 400B formed on at least two different inner surfaces, e.g., the bottom and side walls of the melting furnace 608B.

[0121] The melting furnace 608A includes the various features described above with respect to the melting furnace 108 (Figures 108A, 108B) with respect to Figures 1, 1A, 1B, and 2. The melting furnace 608A can be configured as a closed melting furnace similar to the melting furnace 108A (Figure 1A), or as an open melting furnace 108B (Figure 1B). As disclosed herein, unless otherwise indicated, any reference made to the melting furnace 108 will be understood to apply to either or both of the melting furnaces 108A, 108B. As described above with respect to Figures 1A and 1B, the melting furnaces 608A, 608B receive an inert gas supply source 102 via a diffuser 400. The melting furnaces 608A, 608B are sealed by a chamber wall 134 containing a suitable refractory material. The chamber wall 134 may be formed of a relatively airtight refractory material so as not to contaminate the molten copper alloy 110 with respect to ambient air. The melting furnaces 608A and 608B are surrounded by coils 138 for induction heating of the raw materials, as described above.

[0122] In the molten chamber 608A shown in Figure 6A, the diffuser assembly according to the embodiment includes a diffuser 400 and a diffusion lining 400A. Advantageously, the diffusion lining 400A surrounds the diffuser 400 and covers a larger area than the diffuser 400. In this configuration, the upper surface of the diffuser 400 is positioned below the upper surface of the diffusion lining 400A. The inert gas diffusing from the diffuser 400 traverses the thickness of the diffusion lining 400A that covers the diffuser 400 and diffuses further across that thickness. As a result, the diffusion lining 400A substantially increases the cross-sectional area of ​​the molten copper alloy 110 that the inert gas bubbles 612 traverse vertically, compared to having the diffuser 400 alone, for example, as described above with respect to Figures 1A and 1B. The inventors found that, due to the limited thickness and surface area of ​​the diffuser 400, if inert gas enters the molten copper alloy 110 directly from the diffuser 400, the inert gas bubbles cannot enter uniformly across the entire cross-section of the molten copper alloy 110, but rather pass through an effective area far smaller than the effective cross-sectional area of ​​the molten copper alloy 110. On the other hand, in the illustrated two-stage diffuser assembly, the inert gas first diffuses through the diffuser 400 and then further diffuses through the diffusion lining 400A. Since the inert gas exiting the diffuser 400 has already flowed through an increased cross-sectional area relative to the cross-sectional area of ​​the gas line, further diffusion of the inert gas through the diffusion lining 400A is promoted, and the inert gas exiting the diffusion lining 400A can flow substantially uniformly across substantially the entire cross-sectional area of ​​the molten copper metal 110. As a result, as shown in Figure 6A, the inert gas bubbles 612 cover a substantially larger cross-sectional area than the cross-sectional area covered by the diffuser 400 alone. The inventors have discovered that by using a two-stage diffuser assembly, the efficiency of impurity removal for a given flow rate of inert gas can be substantially improved.

[0123] In the molten chamber 608B shown in Figure 6B, the diffuser assembly according to the embodiment includes a diffuser 400 and a diffusion lining 400A, similar to that shown in molten chamber 608A (Figure 6A). Advantageously, in addition to the diffusion lining 400A covering the bottom surface of the molten chamber 608B, the molten chamber 608B further includes a diffusion lining 400B covering the side walls of the molten chamber 608B. The diffusion linings 400A and 400B covering the bottom and side wall inner surfaces are adapted to further increase the cross-sectional area of ​​the molten copper alloy 110 through which the inert gas bubbles 612 pass. In addition to the diffusion lining 400A covering a larger area of ​​the molten copper alloy 110 through which the inert gas bubbles pass vertically, compared to having only the diffuser 400, the diffusion lining 400B further allows the inert gas bubbles 612 to enter the molten copper alloy 110 laterally or horizontally on the sides of the molten copper alloy 110. In the illustrated three-stage diffuser assembly, the inert gas first diffuses through the diffuser 400, as described above with respect to Figure 6A, and then diffuses further through the diffusion lining 400A. Furthermore, the portion of the inert gas exiting the diffusion lining 400A that does not bubble through the molten copper alloy 110 enters the diffusion lining 400B. The inert gas entering the diffusion lining 400B further diffuses into it at the lateral sidewalls before entering the molten copper alloy 110. As a result, as shown in Figure 6B, the inert gas bubbles 612 cover a substantially larger cross-sectional area compared to having the diffuser 400 alone, the diffusion lining 400A alone, or a combination of the diffuser 400 and the diffusion lining 400. The inventors have found that by using the three-stage diffuser assembly, the impurity removal efficiency for a given flow rate of inert gas can be substantially improved.

[0124] In addition to increasing the surface area of ​​the molten copper alloy 110 into which an inert gas is introduced to improve the removal of impurities already present in the raw material, it will be understood that the diffusion linings 400A and 400B allow for the removal of excess moisture or oxygen that could be absorbed by the chamber walls of the melting furnaces 608A and 608B before the raw material is melted. Since the substantial surface area of ​​the melting furnaces 608A and 608B is covered by the diffusion linings 400A and 400B and the inert gas is flowed through the diffuser 400, the diffusion linings 400A and 400B can substantially prevent oxygen and / or moisture from entering the molten copper alloy 110 from the chamber walls before the raw material is melted. Without the diffusion linings 400A and 400B, the oxygen and / or moisture absorbed on the inner surface of the melting furnaces 608A and 608B can be released and introduced into the molten copper alloy 110, thus having a detrimental effect on the resulting copper alloy (including ingots and shots) as described above.

[0125] The various parameters related to the operation of the melting furnaces 608A and 608B are substantially the same as those described above with respect to Figures 1, 1A, 1B, and 2, and for the sake of brevity, the details of the same features are not repeated herein.

[0126] Figure 6C is a cross-sectional view of diffusion linings 400A and 400B according to various embodiments. Diffusion linings 400A and 400B according to various embodiments include a refractory material containing alumina, silica, and aluminosilicate. The composition is such that the molten copper alloy 110 is not contaminated at high temperatures. In addition to a chemical composition adapted to the high-temperature melting of the copper alloy, diffusion linings 400A and 400B have a physical structure adapted to mechanical strength, in addition to an optimized porosity for controlling inert gas bubble properties, in a manner similar to that described above for the diffuser 400.

[0127] The inventors have found that by using diffusion linings 400A, 400B having at least two different layers or regions, it is possible to satisfy a variety of chemical and physical properties suitable for effective sparging as described herein. Diffusion lining 400A comprises an upper layer or region 400A-2 and a lower layer or region 400A-1, and diffusion lining 400B comprises an upper layer or region 400B-2 and a lower layer or region 400B-1. The upper layers 400A-2, 400B-2 are configured to be closer to, for example, in contact with, the molten copper alloy 110, and are configured to be interposed between the lower layers 400A-1, 400B-1 and the molten copper alloy 110.

[0128] According to the embodiment, the upper layers 400A-2, 400B-2 are formed of sintered ceramic layers, and the lower layers 400A-1, 400B-1 are formed of unsintered ceramic layers. In particular, the upper layers 400A-2, 400B-2 may be partially or locally sintered ceramic layers, where adjacent ceramic particles are partially fused together, leaving gaps between them, and retaining a porous surface for diffusing inert gas. In contrast, the lower layers 400A-1, 400B-1 may be unsintered ceramic layers, such as compressed ceramic power layers, where adjacent ceramic particles are in contact with each other without being fused by sintering, and there are gaps between them for diffusing inert gas. Such a two-layer structure provides mechanical stability to the diffusion linings 400A, 400B and, at the same time, provides a high porosity adapted for diffusing inert gas into the molten copper alloy 110.

[0129] The embodiments are not limited in this way, but in some embodiments, the upper layers 400A-2, 400B-2 and the lower layers 400A-1, 400B-1 are formed from the same initial compressed ceramic powder layer. As described later, the surface portion of the compressed ceramic powder layer may be partially sintered to form a two-layer structure. In these embodiments, the sintered upper layers 400A-2, 400B-2 and the unsintered lower layers 400A-1, 400B-1 have substantially the same chemical composition but different phases. That is, the initial compressed ceramic powder layer may contain component ceramic compounds that form new phases of the upper layers 400A, 400B-2 during sintering. The inventors have found that one particularly preferred ceramic powder composition is a mixture of alumina and silica configured to form mullite during sintering.

[0130] Mullite (3Al2O3·2SiO2) is particularly suitable as the upper layers 400A-1 and 400B-1 due to its low density, high thermal stability, high chemical stability in harsh environments, low thermal conductivity, and favorable strength and creep behavior. Mullite is the only thermodynamically stable crystalline compound in the alumina-silica (Al2O3-SiO2) phase diagram. The compound decomposes and melts at a temperature of 1828±10°C. Therefore, according to the embodiment, the initial compressed powder layer contains a mixture having a composition that can form a substantial volume fraction of mullite.

[0131] The two-layer structure is formed by locally exposing the surface of the compressed ceramic powder layer to a sintering temperature sufficient to form mullite from the powder composition, as described later. The resulting two-layer structure comprises an upper sintered layer 400A-2, 400B-2 containing mullite and a lower unsintered layer 400A-1, 400B-1 formed mainly of alumina and silica. According to some embodiments, the two-layer structure is formed using a powder composition containing alumina in an amount of mol% within the range defined by 50-80 mol%, 55-75 mol%, 60-70 mol%, or any of these values, for example, about 65 mol%. The powder composition further contains silica in an amount of mol% within the range defined by 10-35 mol%, 15-30 mol%, 20-25 mol%, or any of these values, for example, about 24 mol%. The powder composition may further contain 2-8 mol%, 4-6 mol%, or about 5 mol% of SiC, 1-3 mol%, 1.5-2.5 mol%, or about 2.2 mol% of TiO2, and 0.5-2 mol%, 1-1.5 mol%, or about 1.2 mol% of Fe2O3. It will be understood that substantial deviation from the mullite-forming composition may result in insufficient mechanical, thermal, or chemical stability. For example, the Al2O3-SiO2 system has a eutectic composition with a melting point of 1587±10°C corresponding to a composition of about 6 mol% Al2O3, which may lead to a decrease in performance with respect to the various properties mentioned above.

[0132] The inventors have determined that a suitable average particle size for the starting powder to form diffusion linings 400A and 400B is D=D0(2 -f We discovered that it can be defined using what is known in the industry as the phi (f) scale, based on the relationship (wherein D0 is a reference diameter of 1 mm). For example, the f scales 2-1, 3-2, 4-3, and 8-4 correspond to 0.25-0.5 mm, 125-250 mm, 62.5-125 mm, and 3.9-62.5 mm, respectively. The inventors determined that a suitable average particle size for mullite-forming powder is less than 125 mm, less than 100 mm, less than 75 mm, less than 50 mm, for example, less than 63 mm, which corresponds to f scale 4.

[0133] According to various embodiments, the diffusion linings 400A and 400B have a suitable thickness to allow the inert gas to diffuse from the diffusion linings 400A and 400B through their substantial area. The diffusion linings 400A and 400B according to various embodiments have a thickness of 2 inches, 3 inches, 4 inches, 5 inches, 6 inches, more than 7 inches, or within a range defined by any of these values. In Figures 6A and 6B, this thickness corresponds to the thickness of the diffusion lining 400A above the surface of the diffuser 400, and in Figure 6B, this thickness corresponds to the thickness of the diffusion lining 600B. For example, the diffusion material or medium of the diffuser 400 can be about 2 inches, and the thickness of the diffusion lining 400A above the diffuser 400 can be about 3 to 4 inches, relative to a total thickness of 5 to 6 inches. Similarly, the thickness of the diffusion lining 400B can be about 3 to 4 inches. It will be understood that if the diffusion linings 400A and 400B are too thin, insufficient diffusion of the inert gas will occur, which may lead to localized bubble formation, as opposed to bubble formation across the substantial cross-sectional area of ​​the molten copper-based metal 110.

[0134] Continuing with reference to Figure 6C, according to various embodiments, the sintered upper layers 400A-2, 400B-2 have a thickness of 1 inch, 0.8 inches, 0.6 inches, 0.4 inches, 0.2 inches, less than 0.1 inches, or within the range defined by any of these values. The remainder of the diffusion lining 400A, 400B can be the unsintered bottom layers 400A-1, 400B-1.

[0135] Furthermore, the diffusion linings 400A and 400B have a porosity defined as the ratio of voids to the overall macroscopic volume, and the porosity is within the range defined by 10%, 15%, 20%, 25%, 30%, 35%, or any of these values.

[0136] According to some embodiments, the diffusion linings 400A and 400B have the same structure and / or composition as the diffuser 400. That is, the diffuser 400 may have the same mullite-forming composition, or it may have a two-layer structure including a sintered ceramic layer and an unsintered ceramic layer. Advantageously, by matching the composition and / or structure of the refractory material between the diffuser 400 and the diffusion linings 400A and 400B, the flow of inert gas through the diffuser 400 and further through the refractory linings 400A and 400B into the molten copper-based metal 110 can be optimized. However, the embodiments are not limited in this way, and in other embodiments, the diffusion linings 400A and 400B may have a different composition and structure from that of the diffuser 400.

[0137] Referring again to Figures 6A and 6B, in the illustrated embodiments, the diffusion linings 400A and 400B substantially cover the entire bottom and side wall surfaces of the melting furnaces 608A and 608B, respectively, but the embodiments are not limited thereto. For example, the diffusion lining 400A may have a diameter greater than the diameter of the diffuser 400 but smaller than the inner diameter D (Figure 1A) of the melting furnaces 608A and 608B. For example, the diameter of the diffusion lining 400A may be less than 0.8D, 0.6D, 0.4D, or within the range defined by any of these values. Similarly, the diffusion lining 400B may have a height lower than the filling line height F (Figure 1A) of the melting furnaces 608A and 608B. For example, the height of the diffusion lining 400B may be less than 0.8F, 0.6F, 0.4F, or within the range defined by any of these values.

[0138] The following describes a method for manufacturing a melting furnace including a diffusion lining. Figure 7A shows a method for forming a diffusion lining in a melting furnace for producing a high-purity copper alloy according to various embodiments. Method 700 includes step 704 of providing a melting furnace chamber configured for forming a molten alloy. The method further includes step 708 of forming a diffusion lining on the inner surface of the melting furnace chamber, the diffusion lining comprising a ceramic material having a porous structure adapted to bubbling an inert gas through the molten copper alloy.

[0139] According to various embodiments, step 704 of providing a molten alloy includes the step of providing a copper-based alloy containing at least 50% by weight of copper. According to various embodiments, step 708 of forming a diffusion lining includes the step of providing a diffusion lining containing a ceramic material such as an aluminum silicate ceramic material having a porous structure adapted to bubbling an inert gas through the molten copper-based alloy. According to various embodiments, step 708 of forming a diffusion lining includes the step of substantially covering the bottom inner surface of a melting furnace and the step of having a porous structure adapted to bubbling an inert gas through the molten copper-based alloy. According to various embodiments, step 708 of providing a diffusion lining includes the step of forming a diffusion lining having a porous structure on at least two different inner surfaces of a melting furnace, such that the diffusion lining is adapted to bubbling an inert gas through the molten copper-based alloy from at least two different inner surfaces.

[0140] According to various embodiments, step 708 of forming a diffusion lining includes placing a compressed powder layer on the inner surface of a melting furnace chamber. The compressed ceramic powder layer comprises a mixture of silica and alumina. Step 708 of forming a diffusion lining further includes sintering the compressed ceramic powder layer in the melting furnace to form a diffusion lining on the inner surface. According to embodiments, the sintering step includes selectively sintering the surface portion of the compressed ceramic powder layer, thereby forming a diffusion lining on the inner surface having a two-layer structure including a sintered ceramic layer on an unsintered ceramic layer. According to embodiments, the step of sintering the compressed ceramic powder layer includes in-situ sintering using power from the melting furnace itself. In particular, the step of sintering the compressed ceramic powder layer includes forming a diffusion lining on the inner surface using heat from heated material placed in the melting furnace chamber. The diffusion lining thus formed comprises an aluminum silicate ceramic material having a porous structure adapted to diffuse an inert gas through it. Method 700 is further described herein with reference to Figures 7B to 7F.

[0141] Figures 7B to 7F are schematic side views of a melting furnace at various stages of forming a diffusion lining inside in order to construct a melting furnace for producing a high-purity copper-based alloy according to method 700 shown in Figure 7A.

[0142] Referring to Figure 7B, step 704, which provides the melting chamber, includes providing a melting furnace 700B similar to the melting chambers 108A and 108B described above with respect to Figures 1A and 1B. The melting furnace 700B includes a frame including a chamber wall 134 formed of a relatively airtight and suitable refractory material. A diffuser 400 is provided above the central region of the bottom inner surface of the melting furnace 700B. An inert gas is introduced into the molten copper alloy 110 through a gas inlet 404 formed through the bottom plate of the melting furnace 700B, as described above with respect to Figure 4C.

[0143] After the diffuser 400 is installed, a compressed ceramic powder layer 704 for forming the diffusion lining 400A (Figures 6A-6C) is formed on the inner surface of the bottom of the melting furnace 700B. To form the compressed ceramic powder layer 704A, ceramic powder having the composition and particle size described above in Figures 6A-6C is poured onto the bottom of the melting furnace 700B and onto the diffuser 400. The ceramic powder is beaten to remove air pockets and densify it to form a compressed ceramic powder layer 704A having the thickness described above in Figures 6A-6C.

[0144] Referring to Figures 7C and 7D, after a compressed ceramic powder layer 704A is formed on the base or bottom surface of the melting furnace 700B (Figure 7B), a further compressed ceramic powder layer 704B (Figures 6B-6C) is formed on the side wall surface of the melting furnace 700C in order to form a diffusion lining 400B. Referring to Figure 7C, a heating can 708 is placed on the compressed ceramic powder layer 704A. The heating can 708 is made of a metal that can form a molten metal liquid by induction heating in place using an induction coil 138. The heating can 708 is configured to be heated to a temperature sufficient to melt together with the raw materials placed inside it, and provides heat for partially or locally sintering the compressed ceramic powder layers 704A and 704B in contact with it. According to the embodiment, but not limited to, the heating can 708 can be made of an iron-based alloy such as mild steel. The heating vessel 708 has dimensions such that the width of the gap 712 formed between the outer surface of the heating vessel 708 and the inner side wall of the melting furnace 700C corresponds to the final thickness of the diffusion lining 400B.

[0145] Referring to Figure 7D, in order to form the compressed ceramic powder layer 704B, ceramic powder having the composition and particle size described above in Figures 6A to 6C is poured into the gap 712 between the side wall of the melting furnace 700C (Figure 7C) and the outer surface of the heating vessel 708. The ceramic powder is beaten to remove air pockets and densify it to form a compressed ceramic powder layer 704B having a thickness defined by the width of the gap 712 and a height corresponding to the filling line (F) or that portion, as described above in Figures 6A to 6C. For example, it will be understood that if only the diffusion lining 403A is to be formed as shown in Figure 6B, the formation of the ceramic powder layer 704B can be omitted.

[0146] Referring to Figures 7E and 7F, the compressed ceramic powder layers 704A and 704B thus formed on the bottom and side walls of the melting furnace 700E are ready to be partially or locally sintered, respectively, to form the two-layer structure described above with respect to Figure 6C. Partial or locally sintering of the surface areas of the ceramic powder layers 704A and 704B is performed in situ using the induction coil 138. In particular, local sintering is performed indirectly using the induction coil 138, using heat from the molten liquid formed by melting the can 708 and the heating material placed therein, as described herein. Referring to Figure 7E, the can 708 is filled with the heating material 712. Similar to the heating can 708, the heating material 712 is formed from an iron-based material that can be heated to a temperature sufficient to partially or locally sinter the compressed ceramic powder layers 704A and 704B in contact with it in situ within the melting furnace 700E using the induction coil 138, for example, to form a heated molten metal mixture. According to the embodiments, but not limited to, the heating material 712 can be formed from an iron-based material such as mild steel or cast iron. The heating material 712 and the heating can 708 can be formed from the same material or from different materials. Nevertheless, both the heating material 712 and the heating can 708 are adapted to form a molten metal mixture that can be melted and heated to a temperature sufficient to sinter at least the surface areas of the compressed ceramic powder layers 704A and 704B.

[0147] Referring to Figure 7F, after the heating vessel 708 is filled with the heating material 712, both the heating vessel 708 and the heating material 712 are induction heated using the induction coil 138 to a temperature high enough to form a heated molten metal mixture 716 containing molten mild steel and / or cast iron. The heated molten metal mixture 716 is further heated on the bottom and side walls of the melting furnace 700F to a temperature high enough to provide sufficient heat to partially or locally melt the compressed ceramic powder layers 704A and 704B, for example, in their surface areas.

[0148] It will be understood that the heating conditions for forming the heated molten metal mixture 716 depend on the sintering temperature at which the compressed ceramic powder layers 704A and 704B sinter at least their surface regions to form the two-layer structure described above, for example, in relation to Figure 6C. According to the embodiment, the sintering temperature used is 0.7T m , 0.75T m , 0.8T m and 0.85T m Ultra-high power output of 0.9T m It can be less than or within the range defined by any of these values, T m This is the melting temperature of the compressed ceramic powder layers 704A and 704B. For example, in the case of a ceramic powder having a mullite-forming composition with a melting temperature of 1828°C, the heated molten metal mixture 716 can be heated to about 1280°C to 1650°C, for example, about 1430°C (about 2600°F). After sintering, for example, the final diffusion linings 403A and 403B having the two-layer structure described above with respect to Figure 6C are formed. Then, the heated molten metal mixture 712 is poured out to obtain a melting furnace 608A (Figure 6A) or 608B (Figure 6B).

[0149] Figure 8 shows a method for producing a low-impurity copper alloy using a melting furnace with a diffusion lining, according to an embodiment. The illustrated method may incorporate various features of Method 500 for producing a low-impurity copper alloy, as described in relation to Figure 5. Various features that may be common between Method 500 (Figure 5) and Method 800 (Figure 8) are omitted herein for brevity. Similar to Method 500 in Figure 5, Method 800 includes step 804 of supplying raw materials to a melting furnace. The raw materials may have a composition configured to form a molten copper alloy containing at least 50 wt% copper, but are not limited. Method 800 further includes step 808 of heating and melting the raw materials to form a molten alloy, e.g., a copper alloy. The method further includes step 818 of bubbling an inert gas through the molten alloy, e.g., a copper alloy. However, unlike Method 500 (Figure 5), Method 800 includes step 812 of bubbling an inert gas through the alloy using a diffusion lining formed on the inner surface of the melting furnace chamber. The diffusion lining can have any configuration of the diffusion linings 400A and 400B described above with respect to Figures 6A and 6C. For example, the diffusion linings 400A and 400B include an aluminum silicate ceramic material having a porous structure adapted to bubbling an inert gas through a molten copper alloy. According to an embodiment, step 812 of bubbling an inert gas through a molten copper alloy may include using a diffusion lining that substantially covers the bottom inner surface of a melting furnace and has a porous structure adapted to bubbling an inert gas into the molten copper alloy. According to an embodiment, step 812 of bubbling an inert gas through a molten copper alloy may include using a diffusion lining formed on at least two different inner surfaces of a melting furnace, such that the diffusion lining is adapted to bubbling an inert gas through the molten copper alloy from at least two different inner surfaces. [Examples]

[0150] Examples of the experiment To prepare the test specimens used to obtain mechanical test results, copper raw materials, such as alloy C87850, were melted at 1950°F in a 4000 lb furnace, and argon gas was bubbling through the copper alloy into the molten furnace at a rate of 4 liters / minute for 90 minutes. The reference ingot was also produced using the same system, but without sparging, for example, by bubbling argon through the molten copper alloy in the molten furnace. Both the copper ingot produced using argon gas and the reference copper ingot were tested using ASTM E8 / E8M-21 (American Society for Testing Materials Standard Test Methods for Tension Testing of Metallic Materials E8 / E8M-21). The results of these tests are shown in Table 1. [Table 1]

[0151] As shown, the measured mechanical properties of the specific C87850 alloy are clearly superior. For example, the ultimate tensile strength is improved by 47%. Similar results were repeatedly obtained for various copper alloys. Similar comparisons were made for four representative copper alloys, including C87850, C89833, C99500, and C96400. The nominal compositions of the four alloys are shown in Table 2. [Table 2]

[0152] For each alloy system shown in Table 2, copper ingots were produced with and without sparging using argon gas, and tested using ASTM E8 / E8M-21 (American Society for Testing Materials Standard Test Methods for Tension Testing of Metallic Materials E8 / E8M-21). The results of these tests are shown in Table 3. [Table 3]

[0153] The measured mechanical properties of sparged ingots are clearly superior. For example, the ultimate tensile strength is improved by 46%, 189%, 6%, and 82% for alloys with C87850, C89833, C99500, and C96400 alloy compositions.

[0154] As disclosed herein, copper-based alloy compositions in various embodiments including raw material compositions include, by weight percent, amounts of Cu in the range defined by 50%, 60%, 70%, 80%, 90%, 95%, or any of these values; amounts of Sn in the range defined by 0.1%, 0.2%, 0.5%, 1%, 2%, 5%, 10%, or any of these values; amounts of Pb in the range defined by 0.01%, 0.02%, 0.05%, 0.1%, 0.2%, 0.5%, or any of these values; and 0.1% Zn in amounts greater than %, 0.2%, 0.5%, 1%, 2%, 5%, 10%, 20%, 30%, or within the range defined by any of these values; Fe in amounts greater than 0.1%, 0.2%, 0.5%, 1%, 2%, 5%, 10%, or within the range defined by any of these values; Sb in amounts greater than 0.01%, 0.02%, 0.05%, 0.1%, 0.2%, 0.5%, or within the range defined by any of these values; Zn in amounts greater than %, 0.2%, 0.5%, 1%, 2%, 5%, 10%, 20%, 30%, 40%, or within the range defined by any of these values. The amounts of Ni, greater than 0.01%, 0.02%, 0.05%, 0.1%, 0.2%, 0.5%, or the amounts of S, greater than 0.01%, 0.02%, 0.05%, 0.1%, or the amounts of P, greater than 0.01%, 0.02%, 0.05%, 0.1%, 0.2%, 0.5%, 1%, 2%, 5%, or the amounts of Al, greater than 0.01%, 0.02%, 0.05%, 0.1%, 0.2%, 0.5%, 1%, 2%, 5%, or the amounts of Al, greater than 0.01%, 0.02%, 0. A quantity of Si with values ​​greater than 0.5%, 0.1%, 0.2%, 0.5%, 1%, 2%, 5%, or within the range defined by any of these values; a quantity of Mn with values ​​greater than 0.01%, 0.02%, 0.05%, 0.1%, 0.2%, 0.5%, 1%, 2%, or within the range defined by any of these values; a quantity of Bi with values ​​greater than 0.01%, 0.02%, 0.05%, 0.1%, 0.2%, 0.5%, 1%, 2%, 5%, or within the range defined by any of these values; 0.01%, 0.02%, 0.05%, 0.1%, 0.2%, 0.The alloy may contain Nb in amounts greater than 5%, 1%, or 2%, or within the range defined by any one of these values. Furthermore, the copper-based alloy composition may contain any one or more elements disclosed in Table 2, within the range defined by any one of the corresponding amounts, including those corresponding to the C87850, C89833, C99500, and C96400 alloy compositions.

[0155] System and method for producing high-purity copper alloys using a rotary furnace The above has described various features of apparatus and methods for forming high-purity copper alloys. While such apparatus and methods have been specifically mentioned in the context of induction melting furnaces, various embodiments are not limited thereto. Unless otherwise stated in this disclosure, the various embodiments disclosed above are applicable to other types of furnaces, including rotary furnaces. A rotary furnace comprises a cylindrical or barrel-shaped chamber configured to rotate around an axis when heat-treating its contents. The chamber may be slightly tilted so that the contents can pass from one end of the chamber to the other. The sample can be moved, mixed, or stirred as the rotary furnace rotates.

[0156] As disclosed herein, the features of a rotary melting furnace can share similar features with those of an induction melting furnace. For example, both types can include barrel-shaped or cylindrical furnace bodies. Such similarities may not be repeated herein for the sake of brevity. While there are similarities between induction melting furnaces and rotary melting furnaces, there are also several notable differences. For example, as described above, an induction furnace can have an upright cylindrical furnace body, the cylindrical axis of which extends generally longitudinally in the vertical direction. In these configurations, the diffuser according to the embodiment may be located at the bottom of the furnace, corresponding to the base of the cylindrical furnace body. In addition, an induction melting furnace is stationary during the melting process. Therefore, the inert gas bubbling through the diffuser moves from the bottom of the stationary furnace through the raw materials and molten metal towards the top of the furnace.

[0157] Conversely, a rotary furnace may have a cylindrical furnace body, the cylindrical axis of which extends horizontally and generally longitudinally. In this configuration, the diffuser can be positioned at the bottom of the furnace at a specific rotational angle corresponding to a portion of the curved cylindrical side wall. Furthermore, during operation, the rotary furnace may be either stationary or rotating. A rotary melting furnace can rotate at a predetermined speed, inducing motion of the molten metal and the inert gas bubbles within it. Advantageously, such motion can extend the residence time of the inert gas bubbles in the molten metal. An extended residence time of the inert gas increases the probability that impurities in the molten metal (including oxygen or oxides) to which the inert gas can bind are exposed to the inert gas, thereby improving the efficiency of removing unwanted impurities by the inert gas. Below, a system and method for producing high-purity copper alloys using a rotary melting furnace are disclosed.

[0158] Figures 9A to 13 show embodiments of sparging rotary furnace systems configured to produce copper alloys with reduced impurity content, including oxygen or oxygen-related impurity content, according to various embodiments disclosed herein. Figure 9A shows a schematic perspective view of a sparging rotary furnace system for producing copper alloys, including the rotary furnace. Figures 9B and 9C show schematic side views of the rotary furnace from opposing ends, according to several embodiments. Figure 10 shows a cross-sectional view of a diffuser block configured to bubble inert gas through a molten copper alloy, according to several embodiments. Figures 11 to 13 show different ways in which the rotary furnace may be configured during the copper alloy production process, including loading, melting, and injection configurations, according to several embodiments. Figure 14 shows a method for producing a copper alloy using one of the sparging rotary furnace systems shown in Figures 9A to 13, according to several embodiments.

[0159] The sparging rotary furnace system 90 shown in Figure 9A comprises a rotary furnace 900 configured for sparging according to an embodiment. The rotary furnace 900 is configured to form a molten copper alloy containing at least 50 wt% copper from solid raw material pieces in one or more batches. The sparging rotary furnace includes a diffuser assembly 940 for flowing an inert gas into the rotary furnace 900. The inert gas may be introduced through the solid raw material or bubbling through the molten copper alloy formed from the raw material. The rotary furnace 900 may be configured to rotate around a central axis 902 in both clockwise and counterclockwise directions. As used herein, the central axis refers to an axis passing through the geometric center of the shape, or an axis with respect to the shape that exhibits rotational symmetry. In the case of a rotary furnace 900 having a cylindrical shape, the central axis is along the longitudinal direction of the cylinder. By rotating to various angular positions around the central axis 902, the rotary furnace 900 can be positioned in various configurations, including a loading configuration, a melting configuration, and a pouring configuration. An inert gas may be introduced into the furnace chamber in one or more of the loading, melting, and pouring configurations. The rotary furnace 900 may be heated before the raw materials are introduced, and the molten copper alloy formed from the raw materials may be cooled before being poured out of the furnace. An inert gas may be supplied to the furnace chamber before or during the introduction of raw materials, before or during the heating and / or melting of raw materials, and / or before or during the loading of the molten copper alloy. The inert gas may be introduced into the rotary furnace 900 in various configurations. For example, the inert gas may be introduced into an atmosphere sealed by the furnace above the raw materials or molten copper alloy, may be flowed through gaps between solid raw material pieces, or may be bubbling through the molten copper alloy. Although not explicitly shown in Figure 9A, the sparging rotary furnace system 90 may further include a transfer ladle configured to receive the molten copper alloy from the melting furnace and transfer the molten copper alloy to one or more molds or shot pits configured to solidify the molten copper alloy, in a manner described elsewhere in this specification.

[0160] Methods 500 shown in Figure 5 and 1400 shown in Figure 14 can be carried out using a sparging rotary furnace system 90. Various features that may be common to methods 500 and 1400 are omitted herein for brevity. Method 1400 includes step 1404 of providing a melting furnace with a raw material having a composition configured to form a molten copper-based alloy containing at least 50 wt% copper. The melting furnace is configured to rotate around a central axis. Method 1400 further includes step 1408 of heating the raw material to melt it and form a molten copper-based alloy. Method 1400 further includes step 1412 of bubbling an inert gas through the molten copper-based alloy using one or more diffuser blocks containing porous diffusion material. Although not shown in Figure 14, as described elsewhere in this application, the inert gas may begin to flow into the furnace before the raw material is introduced and / or before and during the melting of the raw material.

[0161] Method 1400 may include additional steps that can be performed on the spraying rotary furnace system 90 shown in Figure 9A. For example, Method 1400 may include the steps of configuring the melting furnace into a loading configuration before the step 1404 of providing the raw materials, configuring the melting furnace into a melting configuration before the step 1408 of heating the raw materials, and configuring the melting furnace into an injection configuration before transferring the molten copper alloy. According to an embodiment, heat may be applied to the melting furnace before the step 1404 of providing the raw materials to the melting furnace. According to an embodiment, the step of bubbling an inert gas through the molten copper alloy may include using a diffusion block located at the bottom of the melting furnace and having a porous structure adapted to bubbling an inert gas into the molten copper alloy, corresponding to the curved surface inside the barrel-shaped furnace. According to an embodiment, the diffusion block may bubble an inert gas into the molten copper alloy from at least two different positions as the furnace rotates. According to one embodiment, the step of transferring the molten copper alloy to a transfer ladle may include the step of circulating an inert gas using a diffusion block that is located on the wall of the melting furnace and has a porous structure adapted to directly circulate the inert gas into the atmosphere above the molten copper alloy.

[0162] Referring again to Figure 9A, the sparging rotary furnace system 90 for producing copper alloys with low oxygen or oxygen-related impurity content, such as ingots, copper shots, or copper components, comprises a rotary furnace 900 configured to rotate in both directions about a central axis 902. The rotary furnace 900 of the rotary furnace system may have a burner inlet 910 at one end of the furnace and an exhaust portal 914 at the other end opposite the burner inlet 910. Figure 9B shows a schematic diagram of the rotary furnace 900 as seen from the burner end. Figure 9C further shows a schematic diagram of the rotary furnace 900 as seen from the exhaust end. Although not shown in Figures 9A to 9C, the sparging rotary furnace system 90 may further include a variety of components (including components related to transferring molten copper alloys from the rotary furnace) that are broadly configured as the corresponding components of induction sparging furnace systems described elsewhere in this specification. Some detailed descriptions of these components are omitted herein for the sake of brevity.

[0163] As shown in Figure 9A, the burner inlet 910 of the sparging rotary furnace system 90 may be connected to the burner system via the burner line 960. The burner system is configured to supply a fuel flow to the furnace, which is ignited into a flame, in order to heat the raw materials to form a molten copper alloy. The ignited flame may burn in the furnace chamber 906 of the rotary furnace 900, supplying heat to the furnace wall 908, the raw materials, and the molten copper alloy. The fuel may be a gas or a liquid, or may be mixed with air or oxygen. The fuel may be a suitable gaseous hydrocarbon, such as natural gas. The burner system may compress the fuel and inject it as a flow through the burner inlet at high speed or high pressure. The fuel may be ignited when it enters the furnace chamber 906, for example, using a spark generated outside or inside the furnace chamber, and may burn completely or incompletely inside the furnace chamber 906, consuming the oxygen in the chamber. The fuel may be supplied continuously, intermittently, or at an adjustable rate during the production of the molten copper alloy, depending on the heating requirements of the production process. The operator may adjust the amount, rate, or composition of the fuel to control the thermal energy transferred to the furnace during various stages of the manufacturing process described herein, depending on the state of the alloy inside the furnace.

[0164] Continuing with reference to Figure 9A, the rotary furnace 900 further comprises an exhaust portal 914 configured to discharge exhaust from the furnace. The exhaust may include products of fuel combustion, products of supplying inert gases to the furnace, or products of melting or heating copper alloys. The exhaust portal 914 may be located at the end of the furnace opposite the burner inlet 910. In some other embodiments, the exhaust portal may be located elsewhere, for example, at the same end as the burner inlet 910, or on the side of the burner inlet. An exhaust duct 972 may be detachably positioned adjacent to the exhaust portal 914 to guide the exhaust away from the exhaust portal 914. The exhaust duct 972 can further isolate the atmosphere inside the furnace chamber 906 from the external atmosphere, keeping the atmosphere sealed and sufficiently inert, while allowing inert gases to flow into the chamber. The exhaust duct 972 may also reduce the amount of heat escaping through the exhaust portal, saving energy costs for the manufacturing process. Although not explicitly shown in Figure 9A, the exhaust portal 914 may further include an exhaust door for further isolation and / or insulation of the furnace chamber from the outside. Since exhaust is often hazardous, an exhaust duct 972 helps to guide the exhaust towards a safe location for further processing, for example, into a baghouse. The inside of the exhaust duct may be lined with a refractory material to protect from high-temperature exhaust, for example, the same material as the furnace lining 920 of the rotary furnace 900. During furnace operation, the exhaust duct 972 may be positioned adjacent to the exhaust portal 914, for example, in contact with it, thereby substantially sealing the furnace chamber 906 from the surrounding atmosphere. When the rotary furnace 900 is not in operation, the exhaust duct may be moved away from the exhaust portal, leaving a gap between the exhaust duct and the exhaust portal, which may be used for inspection or maintenance purposes. A sanitary hood 970 may be provided above the exhaust portal 914 to help collect any residual exhaust that is not guided toward the exhaust duct.

[0165] Continuing with Figure 9A, the exhaust may be hot, move at high speed, and may contain gases, liquids, or solid waste from the manufacturing process. Such exhaust could pose a fire hazard if collected directly from the exhaust duct 972. Therefore, in some embodiments, a drop-bottom cavity configured to reduce the velocity or temperature of the exhaust before collection may be provided after the exhaust portal 914. The drop-bottom cavity may be located, for example, between the exhaust duct 972 and the baghouse. The drop-bottom cavity may be in the shape of a cubic cavity having a size larger than the exhaust duct 972, for example, larger than 0.5m, 1m, 1.5m, 2m, 3m, 4m, 5m, 7m, 10m, or within a range defined by any of these values. When the exhaust enters the drop-bottom cavity from the exhaust duct, the expanded space available within the cavity helps to reduce the velocity of the exhaust, which can facilitate the easier separation and fall of hazardous solid waste from the exhaust. Collecting and treating the exhaust after it has passed through a drop-bottom cavity can be safer.

[0166] Continuing with reference to Figures 9A to 9C, the rotary furnace 900 can be configured to be heated by an ignited flame to have a suitable internal temperature for melting various raw materials and forming various copper-based alloys. In some embodiments, the internal temperature of the melting furnace 108 may be between 700°F and 3000°F. In some embodiments, the temperature of the melting furnace 108 may be within the range defined by 900°F, 1000°F, 1200°F, 1400°F, 1600°F, 1800°F, 2000°F, 2200°F, 2400°F, 2500°F, or 3000°F, or any of these values. The internal temperature of the furnace may not be uniform and may be determined by one or more thermometers taking measurements inside the furnace. The internal temperature of the furnace may be estimated by one or more thermometers taking measurements outside the furnace. The internal temperature of the furnace and the temperature of the molten alloy may also be determined from the color or spectrum of the thermal radiation of the furnace and the alloy, respectively.

[0167] Continuing with Figures 9A to 9C, the rotary furnace 900 may be elongated, with its elongation axis aligned with the central axis 902. The total length measured inside the furnace along the elongation direction may be 50 cm, 100 cm, 150 cm, 200 cm, 250 cm, 300 cm, 350 cm, 400 cm, 450 cm, 500 cm, 600 cm, 700 cm, 800 cm, 1000 cm, or within the range defined by any of these values. The cross-section of the rotary furnace 900 taken perpendicular to the elongation axis may be substantially circular and may have an inner diameter greater than 50 cm, 100 cm, 150 cm, 200 cm, 250 cm, 300 cm, 350 cm, 400 cm, 450 cm, 500 cm, or within the range defined by any of these values. The rotary furnace 900 may have the ability to melt alloys weighing more than 1,000 pounds, 2,000 pounds, 5,000 pounds, 10,000 pounds, 20,000 pounds, 50,000 pounds, or within the range defined by any of these values, when fully loaded.

[0168] In some embodiments, the rotary furnace 900 is configured to rotate or oscillate continuously over an angular range of values ​​greater than 5°, 10°, 15°, 20°, 30°, 45°, 60°, 75°, 90°, 120°, 150°, 180°, 240°, 300°, 360°, or within the range defined by any of these values. The speed at which the furnace rotates may be constant or non-uniform and may be greater than 1° / min, 5° / min, 10° / min, 15° / min, 30° / min, 45° / min, 60° / min, 90° / min, 120° / min, 180° / min, 270° / min, 360° / min, 480° / min, 720° / min, or within the range defined by any of these values. Rotation may be achieved by providing one or more gear rings along the outer circumference of the rotary furnace to receive driving motion from a motor, and the motor may be controlled by an operator so that the rotational speed and angular position of the furnace can be adjusted.

[0169] Continuing with reference to Figures 9A to 9C, in some embodiments, the furnace may be provided in a cylindrical shape, with its circumference at the center being similar to that of the ends of the furnace. In some embodiments, the furnace may also be provided in a barrel shape, with its circumference at the center being larger than that of the ends of the furnace. Furthermore, the rotary furnace may have two end walls corresponding to the cylindrical or barrel-shaped base (including a burner end wall 912 and an exhaust end wall 916 connected by a curved side wall 918), with the burner inlet 910 located on the burner end wall 912 and the exhaust portal 914 located on the exhaust end wall 916 opposite the burner end wall. The rotation axis 902 may intersect the center points of both the burner end wall and the exhaust end wall. The furnace side wall 918 connecting the exhaust end wall 916 and the burner end wall 912 may be elongated along the central axis 902. The side wall 918 may be substantially cylindrically symmetric with respect to the central axis. A substantial portion of the side wall may be cylindrical such that a substantial portion of the side wall 918 is straight and substantially parallel to the central axis. The burner end wall 912, the exhaust end wall 916, and the side wall 918 surround the furnace chamber 906.

[0170] The interior of the furnace wall 908 of the rotary furnace 900 is lined with a suitable refractory material similar to that described above for induction furnaces, in order to facilitate reaching and maintaining these temperatures. The interior of the furnace wall 908 may be made of one or more refractory materials, for example, refractory bricks or firebricks. The interior of the furnace wall 908 may be covered with a furnace lining 920 comprising silicon carbide, alumina, silica, mullite, zirconia, or other suitable refractory ceramics or clays. The thickness of the refractory lining may be 1 cm, 5 cm, 10 cm, 15 cm, 20 cm, 25 cm, 30 cm, 35 cm, 40 cm, 50 cm, 60 cm, 80 cm, 100 cm, 120 cm, or a value within the range defined by any of these values.

[0171] Continuing with reference to Figures 9A to 9C, the rotary furnace 900 may further comprise a loading portal 930. Multiple raw material pieces having a composite composition configured to form a molten copper alloy containing at least 50 wt% copper may be supplied through the loading portal 930. The loading portal may be provided on a curved side wall 918 of the rotary furnace 900. In some embodiments, the loading portal may comprise a loading portal door 932 made of refractory material. The loading portal door may be closed during the production of the molten copper alloy to isolate the atmosphere inside the furnace chamber from the external atmosphere or to provide additional insulation by preventing heat from escaping through the loading portal. The height and / or width of the loading portal 930 may be 10 cm, 15 cm, 20 cm, 25 cm, 30 cm, 45 cm, 50 cm, 60 cm, 75 cm, 100 cm, 125 cm, 150 cm, 175 cm, 200 cm, 250 cm, 300 cm, or any of these values ​​within the range defined by the above.

[0172] Continuing with reference to Figures 9A to 9C, the rotary furnace 900 may further include an injection portal 934 configured to transfer molten copper alloy from the furnace into, for example, a transfer ladle, mold, or shot pit. In some embodiments, as shown in Figures 9A to 9C, the injection portal 934 may be located on the side wall of the rotary furnace, or it may be in the shape of a circular or elliptical hole passing through the curved side wall 918 of the rotary furnace 900. Depending on the configuration of the transfer system that receives the molten alloy exiting, the injection portal 934 may be located near the center along the extension axis of the furnace, or near the end. The injection portal 934 may be located at least 5°, 10°, 15°, 20°, 30°, 45°, 60°, 75°, 90°, 120°, 150°, 180°, or within the range defined by any of these values, in the azimuthal direction around the central axis 902, away from the loading portal. The width of the injection portal 934 may be greater than 1 cm, 1.5 cm, 2 cm, 2.5 cm, 3 cm, 4 cm, 5 cm, 7.5 cm, 10 cm, 12.5 cm, 15 cm, 20 cm, or 30 cm, or within the range defined by any of these values. The injection portal 934 may further include an injection portal stopper 936 configured to prevent molten alloy from flowing out of the injection portal 934 when the injection portal is submerged under the alloy. The injection portal may also include a spout configured to control the direction and velocity of the flow of the molten copper-based alloy during transfer.

[0173] In some embodiments, the central axis 902 on which the rotary furnace 900 rotates may extend substantially parallel to the ground level such that the axis of rotation is parallel to the top surface level of the molten alloy. In other embodiments, the central axis may be inclined with respect to the ground level such that one end of the furnace holds more molten alloy than the other end. The inclination angle of the central axis may be greater than 1°, 2°, 3°, 5°, 10°, 15°, 20°, 30°, or 45°, or within the range defined by any of these values. In some embodiments, the rotary furnace 900 may be configured to rotate around a second axis different from the central axis 902. Rotation around the second axis may change the inclination of the furnace and the central axis with respect to the ground level so that the contents of the furnace can be moved from one side of the furnace to the other. For example, the second axis on which the furnace rotates may be parallel to the ground and perpendicular to the central axis.

[0174] In some other embodiments, although not shown in Figures 9A to 9C, the burner inlet 910 and exhaust portal 914 may be located on the same side of the rotary furnace 900, for example, on the same end wall of the furnace. In some other embodiments, one or both of the burner inlet 910 and exhaust portal 914 may be located on the side wall 918 of the furnace. In some other embodiments, one or both of the burner inlet 910 and exhaust portal 914 may be located on the door of the rotary furnace 900, and the door may be located on the end wall or side wall of the furnace. In some other embodiments, as shown in Figures 9A to 9C, the central axis 902 may extend through one or both of the burner inlet 910 and exhaust portal 914. In some other embodiments, although not shown in Figures 9A to 9C, one or both of the burner inlet 910 and exhaust portal 914 may be located off-axis from the central axis 902.

[0175] In some embodiments, as shown in Figures 9A–9C, the loading portal 930, the injection portal 934, and the exhaust portal 914 may be provided as separate portals and may be located on different walls of the rotary furnace 900. In some embodiments, although not shown in Figures 9A–9C, two or all of the loading portal 930, the injection portal 934, and the exhaust portal 914 may be the same portal. Providing one or more common portals for loading, injection, and exhaust can be beneficial in saving costs because it reduces heat loss, better isolates the internal atmosphere from the external atmosphere, or simplifies the construction of the furnace. In some embodiments, the burner injector may also be provided through any one of the portals discussed above.

[0176] Continuing with reference to Figures 9A to 9C, the rotary furnace 900 may further comprise a diffuser assembly 940 configured to introduce an inert gas into the rotary furnace 900 and bubble the inert gas through, for example, a molten copper alloy. A gas supply source 950 may be connected to the diffuser assembly 940 via a gas line 952. As the rotary furnace 900 rotates and moves the diffuser assembly 940 with it, the gas line 952 may be made of a flexible material or structure to adapt to this movement. The gas supply source 950 may also be configured to supply pressurized inert gas to the diffuser assembly 940, and the pressurized inert gas may not essentially contain oxygen, hydrogen, moisture, and / or any substances that may react with or adversely affect the purity of the molten copper alloy. In some embodiments, the inert gas may include a noble gas, such as argon (Ar), or a mixture of noble gases. In other embodiments, the inert gas may include nitrogen gas (N2). After passing through the gas line 952, the inert gas is diffused through the diffuser assembly 940 and flows through the raw materials into the furnace chamber 906, or is bubbling into the molten copper alloy. The gas supply source may be provided with one or more valves to control the flow rate of the inert gas entering the furnace chamber 906 through the gas line 952 and the diffuser assembly 940.

[0177] The furnace chamber 906 may be partially, substantially, or completely sealed before, during, or after melting and heating the molten copper alloy. For reasons discussed elsewhere in this application, it may be advantageous to at least partially enclose the furnace. A sealed system or component as described herein may refer to an arrangement in which the system or component is substantially physically sealed, or otherwise isolated from the external atmosphere. For example, the atmosphere inside the furnace chamber 906 may be kept substantially inert by flowing an inert gas into the sealed system or component and / or maintaining positive pressure with the inert gas, without physically sealing it. For example, by supplying a continuous or intermittent flow of inert gas, it may be sufficient to prevent air from the external atmosphere from flowing back into and accumulating in the chamber, and the substantially inert atmosphere in the furnace chamber 906 may be maintained by replacing the sealed atmosphere with the supplied inert gas. In some embodiments, the substantially inert atmosphere of the furnace chamber may have a similar composition to the supplied inert gas. In some embodiments, the substantially inert atmosphere of the furnace chamber may include argon (Ar). In some embodiments, the substantially inert atmosphere of the furnace chamber contains substantially higher levels of nitrogen gas (N2) compared to the external atmosphere. In some embodiments, the substantially inert atmosphere of the furnace chamber contains substantially lower levels of oxygen, hydrogen, moisture, or other reactive or undesirable substances that may adversely affect the purity of the molten copper alloy compared to the external atmosphere.

[0178] Continuing with reference to Figures 9A to 9C, the diffuser assembly 940 may comprise one or more diffuser blocks containing porous diffusion material adapted to bubbling an inert gas through a molten copper alloy. The porous diffusion material may be the same as that described above for rotary furnaces. The diffuser block assembly 940 may comprise one, two, three, four, five, six, or more than six diffuser blocks and may be mounted on the furnace side wall 918 opposite the loading portal 930. In the illustrated embodiment, the diffuser assembly 940 comprises four diffuser blocks 9401, 9402, 9403, and 9404. One or more valves may be provided in the inert gas path to collectively or independently control the flow rates to different diffuser blocks 9401 to 9404. One or more diffuser blocks of the diffuser assembly 940 may be arranged linearly or in an array. For example, diffuser blocks 9401-9404 are arranged on the side wall 918 of the furnace along a line parallel to the central axis 902. The spacing between adjacent diffuser blocks can be optimized so that the inert gas flux is dispersed to cover a considerable area of ​​the molten metal. For example, the spacing can be greater than 1 cm, 2 cm, 5 cm, 10 cm, 15 cm, 20 cm, 30 cm, 50 cm, 75 cm, 1 m, 1.25 m, 1.5 m, 2 m, or within the range defined by any of these values, in the direction along the central axis, in the azimuthal direction, or in the vertical direction. The position, shape, size, and porosity and particle size of the diffusion material in the diffuser blocks can be adjusted to suit the specific shape of the furnace and the amount or composition of the molten alloy, and are not limited to the embodiments disclosed herein. In some other embodiments, some of the one or more diffuser blocks 9401-9404 may be positioned substantially apart from other diffuser blocks along the azimuthal direction around the central axis or along the vertical direction of the furnace, such that at a particular angular position of the rotary furnace, a portion of the diffuser assembly remains below the surface of the copper alloy and another portion of the diffuser assembly is in contact with the atmosphere above the alloy.

[0179] As discussed herein and elsewhere in this application, in order to optimize the removal of impurities from the molten alloy, the inventors have found that increasing the contact area between the inert gas bubbles and the molten alloy is beneficial. Therefore, it may be advantageous to increase both the distance the inert gas bubbles travel in the molten alloy and the residence time of the inert gas bubbles in the molten alloy. In the illustrated embodiment, it may be advantageous to bubble the inert gas from the bottom of the molten alloy. Therefore, it may be beneficial to position at least some of the diffuser blocks so that they remain at the bottom of the molten alloy for at least a portion of the time during the manufacturing process. For example, in the molten configuration of the rotary furnace 900, as shown in Figure 12A, it may be beneficial to position at least one of the diffuser blocks 9401-9404 at the bottom of the furnace chamber 906. The remaining one or more diffuser blocks may be positioned at the same azimuthal angle around the central axis and spaced apart in the direction along the central axis. The diffuser blocks may be arranged such that, at a specific rotation angle of the rotary furnace 900, one or more diffuser blocks are simultaneously rotated to their respective lowered positions, thereby increasing the upward distance over which bubbles in the alloy diffused through each diffuser block travel.

[0180] The inventors have further found that increasing the cross-sectional area of ​​the inert gas bubbles relative to the cross-sectional area of ​​the molten copper alloy in the same horizontal plane may be beneficial in order to enhance the effectiveness of the inert gas bubbles in removing impurities. For example, the diffuser blocks may be positioned such that the cross-sectional area of ​​the inert gas bubbles diffused through the diffuser blocks can be greater than 30%, 50%, 60%, 70%, 80%, or 90% of the cross-sectional area of ​​the molten copper alloy in the same cross-section, or within the range defined by any of these values. To increase the cross-sectional area of ​​the inert gas bubbles, it may be beneficial to extend the diffuser blocks to substantially cover the length of the rotary furnace. For example, as shown in Figure 9A, the four diffuser blocks 9401-9404 are extended to cover the length of the furnace 900 along the direction of the central axis 902. It may also be beneficial to extend the diffuser blocks over a considerable area of ​​the furnace wall, for example, over the bottom area of ​​the rotary furnace 900 extending in both the longitudinal and azimuthal directions. To spread in the azimuthal direction, this may be achieved by arranging the diffuser blocks in a two-dimensional array, or by offsetting some locations of the diffuser blocks in the second direction from the single-row profile in the first direction. A similar effect may also be achieved by gently oscillating the rotary furnace 900 back and forth in the azimuthal direction around the central axis 902 during heating of the molten copper alloy, so that inert gas bubbles can pass through different vertical cross-sections of the molten alloy as the azimuthal position of the diffuser blocks changes. The inventors have further discovered that such gentle oscillating can result in gentle non-turbulent stirring or mixing of the alloy, since the motion of the furnace walls can be transmitted from the inner walls of the furnace to the molten alloy via the viscous resistance of the liquid alloy. This internal motion of the alloy, accompanied by the gentle oscillating of the furnace, can drag the inert gas bubbles inside, causing them to move horizontally or in the azimuthal direction, and subsequently, the average trajectory of the inert bubbles may deviate from a linear upward path. For example, the bubbles may be made to rise by oscillating motion and diffuse into a curved or zigzag trajectory.Therefore, oscillating motion can increase the distance traveled by inert gas bubbles in the molten alloy and increase their residence time compared to bubbles diffused in a stationary furnace. The inventors have found that the increased distance traveled and residence time of inert gas bubbles promotes bonding between the inert gas and impurities in the molten metal, including oxygen or oxides, thereby improving the effectiveness of the inert gas in capturing and removing undesirable impurities.

[0181] Oscillations can occur for short periods or over considerable periods during the heating of molten copper alloys. The speed at which the rotary furnace 900 produces gentle oscillations may be greater than 1° / min, 5° / min, 10° / min, 15° / min, 30° / min, 45° / min, 60° / min, 90° / min, 120° / min, 180° / min, 270° / min, 360° / min, 480° / min, and 720° / min, or within the range defined by any of these values. The range of the oscillating motion may be greater than 1°, 2°, 5°, 10°, 20°, 30°, 45°, 60°, 75°, 90°, 120°, 150°, and 180°, or within the range defined by any of these values.

[0182] Figure 10 is a schematic cross-sectional view of an exemplary diffuser block 1000 according to several embodiments. Diffuser block 1000 corresponds to any one of the diffuser blocks 9401 to 9404 described with respect to Figure 9A. According to some embodiments, the diffuser block of the sparging rotary furnace system 90 may also share a wide variety of components, as well as the corresponding components of the diffuser 106 described herein, some of which are omitted in detail for brevity.

[0183] As shown in Figure 10, the diffuser block 1000 comprises a gas inlet 1008 for receiving an inert gas, a diffuser 1004 for bubbling the inert gas into a molten copper alloy, a container 1012 connected to the gas inlet 1008 to hold the diffuser 1004 and prevent the inert gas from leaking out of the container 1012, and a diffuser lining 1016 surrounding the container and the diffuser material. The diffuser lining 1016 may have a coefficient of thermal expansion that matches the coefficient of thermal expansion of the furnace lining in order to reduce thermal stress when the diffuser block 1000 is incorporated into the furnace. The diffuser lining 1016 may have a composition similar to that of the furnace lining 920 (Figure 9A). The gas inlet 1008 may be connected to a gas supply source 950 via a gas line 952 (Figure 9A). The container may include a material that is impermeable to the inert gas, such as steel such as stainless steel. The diffusion material may be placed within a volume defined by the container 1012, as shown in Figure 10, or, in other embodiments, may be provided to form a projection or recess from the edge of the container. The diffuser block 1000 may be installed inside the rotary furnace 900, as shown in Figures 9A to 9C, and the upper surface of the diffuser block 1000 in Figure 10 is exposed to the furnace chamber 906 and configured to come into contact with the molten copper alloy. The diffuser block may be further secured to the furnace by providing a bracket outside the furnace.

[0184] As shown in FIG. 10, the diffusion material 1004 includes a porous refractory ceramic material, which may be formed using a compressed ceramic powder such as alumina, silica, or mullite, and is at least partially sintered to improve its mechanical integrity and reduce its permeability to the molten alloy. The diffusion material may contain alumina in an amount of more than 60 wt%, more than 70 - 99 wt%, more than 80 wt%, 85 - 95 wt%, or within a range defined by any of these values, for example, 90 wt%. The diffusion material may further contain silica in an amount of less than 50 wt%, less than 35 wt%, 10 - 25 wt%, 15 - 21 wt%, or within a range defined by any of these values, for example, 18 wt%. The diffusion material may further contain chromium(III) oxide Cr2O3 in an amount of less than 10 wt%, less than 5 wt%, less than 2 wt%, 0.5 - 1.5 wt%, or within a range defined by any of these values, for example, 1 wt%. The diffusion material can have various properties and structures described herein with respect to the diffusion lining described in FIGS. 6A and 6B. For example, the diffusion material can have a density of 2.45 g / cm 3 3.

[0185] The size, density, and velocity distribution of inert gas bubbles may be affected, in particular by the pores of the diffusion material 1004. The pore size of the diffuser 106 can be controlled so that bubbles diffusing through it into the molten alloy have an appropriate size, density, and velocity distribution, while preventing the molten liquid alloy from penetrating the diffuser block. In some embodiments, the pore distribution in the diffusion material may be optimized in combination with other factors so that the distribution of bubble size, bubble number, bubble volume density, and bubble velocity does not result in substantial bubble coalescence or substantial turbulence of the molten alloy. The average pore diameter of the diffuser 106 can be greater than 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm, or within the range defined by any of these values. The porosity of the diffusion material, defined as the ratio of voids to the overall macroscopic volume, may be greater than 10%, 15%, 20%, 25%, 30%, or 35%, or within the range defined by any of these values, for example, 27.6%. In some embodiments, the diffusion material 1004 may comprise any of the materials and properties described above with respect to a diffuser 400 as shown in Figures 4A to 4C, or to diffusion linings 400A and 400B as shown in Figures 6A to 6B.

[0186] Continuing with Figure 10, the diffuser lining 1016 surrounding the diffusion material is in direct contact with the rotary furnace lining 920, providing a seal between the diffuser block and the furnace lining to prevent leakage of the molten alloy. Since rotary furnaces can undergo extreme temperature fluctuations, their components can also undergo significant thermal expansion and contraction. Such temperature fluctuations may include uneven thermal expansion or contraction due to large thermal gradients between adjacent components. If the thermal expansion coefficients of the diffuser lining and the furnace lining do not match, undesirable stresses or gaps may form between them, which can ultimately lead to fracture or leakage. Therefore, the inventors have found it advantageous to provide the diffuser block 1000 with a diffuser lining 1016 comprising a material having a thermal expansion coefficient similar to that of the furnace lining, for example, within 50%, 30%, 20%, 10%, 5%, or 1%, or within the range defined by any of these values ​​of the thermal expansion coefficient of the furnace lining 920. The diffuser lining may be formed using mullite bricks containing 70–80 volume% alumina and 20–30 volume% silica. The diffuser lining 1016 may also contain materials substantially similar in composition and structure to the furnace lining 920 (Figures 9A–9C) or the refractory linings 130A and 130B (Figures 1A and 1B). Matching the composition of the diffuser lining 1016 to that of the furnace lining 920 allows the diffuser lining to expand and contract at the same rate, thereby maintaining a tight fit of the diffuser block over the expected lifespan of the sparging rotary furnace system.

[0187] As shown in Figure 10, the cross-sectional profile of the body 1020 of the diffuser block 1000 may be slightly or substantially trapezoidal or conical. The upper side of the body 1020 may be configured to be in contact with and exposed to the molten metal in the furnace chamber 906, and the lower side of the body may be configured to connect to the gas inlet 1008 and face the outside of the furnace. The width of the upper side of the body 1020 may be narrower than the width of the lower side of the body. The sides of the body 1020 of the diffuser block 1000 may be the sides of the diffuser lining 1016 extending upward from the bottom surface and may be inclined inward. This constricted trapezoidal or conical contour may help to provide a better seal around the diffuser block when inserted from the outside into a hole with a matching constricted shape on the side wall 918. The hole may be a through hole penetrating the wall of the furnace chamber. Brackets can also be provided on the outside of the furnace to apply an inward force to the diffuser block, further reinforcing the seal between the diffuser block and the furnace wall, or to strengthen the fit. The upper and lower sides, or both, of the diffuser block 1000 may also have a curvature that matches the curvature of the furnace wall. For example, the diffuser block 1000 shown in Figure 10 has a convex curvature on its bottom surface to match the curvature of the cylindrical side wall 918 of the rotary furnace 900 shown in Figure 9A.

[0188] Continuing with reference to Figure 10, when installed in the rotary furnace 900 (Figure 9A), according to some embodiments, the upper surface of the diffuser block may be substantially coplanar with the inner surface of the furnace lining. The upper surface of the diffuser block may also protrude from the furnace lining or form a recess from the furnace lining. The upper surface of the diffuser block 1000 may be configured to bubble in contact with the inert gas diffused into the molten copper alloy, and is not limited to having a flat profile as shown. A curved profile, such as a convex or concave profile of the diffusion material, can provide a larger surface area for the inert gas to diffuse compared to a flat profile. The effective area over which the inert gas diffuses from any individual diffuser block may be substantially equal to the contact area between the diffusible material and the molten copper alloy. When the diffusion block 1000 is installed in the rotary furnace 900 (Figure 9A), the effective diffusion area over which the inert gas diffuses may also be influenced by the local geometry of the furnace, and according to some embodiments, may be greater than or less than the apparent surface area of ​​the diffusion material. Sintering due to furnace heat and blockage by furnace contents may further alter the effective diffusion area or effective pore size of the diffuser block throughout the lifespan of the sparging rotation system. The effective area from which the inert gas diffuses from any individual diffuser block may have an effective diameter greater than 2 cm, 5 cm, 10 cm, 15 cm, 20 cm, 25 cm, 30 cm, 35 cm, 40 cm, 45 cm, 50 cm, or a value within the range defined by any one of these values. In some embodiments, the diffuser block may also comprise a wide range of components, similar to the corresponding components of the diffuser 400 in Figure 4A described herein. Some detailed descriptions of these components are omitted herein for brevity.

[0189] As described above, a sparging rotary furnace configured for producing copper alloys with low impurity content may be configured according to several embodiments, with at least one of the loading configuration, melting configuration, and injection configuration shown in Figures 11 to 13, respectively.

[0190] Figure 11 shows a cross-sectional view of the rotary furnace 900 in the loading configuration 1100. In the loading configuration 1100, the furnace is rotated to a loading angle, the loading portal 930 is oriented to allow for convenient loading of the raw materials, and the diffuser assembly 940 is oriented to allow the diffused inert gas 1108 to flow from below the raw materials, preferably to increase exposure to the inert gas 1108, so that it flows across the surface of the raw materials. The rotary furnace may be locked into the loading configuration when the raw materials are loaded into the furnace.

[0191] Figure 12A shows a cross-sectional view of the rotary furnace 900 in the melting configuration 1200, viewed from the end of the furnace along the central axis. Figure 12B shows a cross-sectional view of the melting configuration 1200, viewed from the side of the furnace. The flame stream 1212 that provides heat to the furnace and the inert gas bubbles diffused through the molten alloy are more clearly visible in Figure 12B. In the melting configuration 1200, the furnace is rotated to a melting angle, and the diffuser assembly 940 contacts the molten copper alloy and bubbles inert gas that diffuses through it. In the melting configuration 1200, the furnace may remain stationary at the melting angle, or it may gently oscillate around the melting angle during the melting and heating of the molten copper alloy. In some embodiments, the melting angle may be 0° to 180° away from the loading angle such that the loading portal 930 of the melting configuration 1200 is positioned at the same or higher height as the loading configuration 1100 (Figure 11), and the diffuser assembly 940 of the melting configuration 1200 is positioned at the same or lower height as the loading configuration 1100.

[0192] Figure 13 shows a cross-sectional view of the rotary furnace in injection configuration 1300. In injection configuration 1300, the furnace is rotated to an injection angle where the injection portal 934 is below the surface of the molten copper alloy 1204. In injection configuration 1300, the rotary furnace 900 may remain stationary or gradually tilt as the molten alloy is discharged to optimize the angle and velocity of the molten alloy flowing out.

[0193] Referring again to Figure 11, in the loading configuration 1100, the loading portal 930 may be rotated to the center or top of the rotary furnace 900, while at least one of the diffuser blocks from the diffuser assembly 940 is positioned in the lower half of the furnace chamber 906. For illustrative purposes, the diffuser block 9400 in Figures 11-13 may correspond to any one of the diffuser blocks 9401-9404 in Figure 9A. The loading portal 930 may be oriented about 0° to 90° above the horizontal with respect to the central axis, and the diffuser block 9400 may be oriented 0° to 90° below the horizontal with respect to the central axis. For example, the loading portal 930 may be located approximately midway along the side of the furnace 900. The raw materials 1104 having a composition mixed to form a molten copper-based alloy may be loaded into the furnace chamber 906 through the loading portal 930 with the loading portal door 932 in the open position.

[0194] Referring to Figures 11 and 12A-12B, in some embodiments, the effective volume occupied by the raw material may decrease as the solid raw material pieces melt. Therefore, multiple raw material pieces may be added in batches until the completely molten copper alloy reaches the height of the target filling line 922, which is defined by the section between the upper horizontal surface of the molten alloy and the inner surface of the rotary furnace 900. To load a batch of raw material 1104, the rotary furnace 900 may be rotated into a loading configuration 1100 and set to a stationary position, the loading portal door 932 may then be opened, and the raw material may be added through the loading portal 930, after which the loading portal door 932 may be closed again.

[0195] As described elsewhere in this application, in some embodiments, the inert gas may begin to diffuse into the furnace chamber 906 through the diffuser assembly 940 before the raw material 1104 is loaded, and / or flow through the surface and voids of the raw material 1104 while the raw material is being loaded and melted. Advantageously, flowing the gas before melting begins can reduce the amount of oxygen incorporated into the resulting molten metal. After melting, the inert gas is bubbling through the molten copper alloy 1204 throughout the entire loading process. The loading process may be stopped when the loaded raw material is completely melted and the surface of the molten alloy reaches the target filling line. The inert gas may continue to bubble through the molten copper alloy after reaching the target filling line 922. When measured from the inner bottom surface of the rotary furnace, the target filling line 922 may have a height greater than 10 cm, 20 cm, 50 cm, 100 cm, 150 cm, 200 cm, 250 cm, 300 cm, 350 cm, 400 cm, 450 cm, or 500 cm, or a value within the range defined by any of these values. Since the rotary furnace 900 can rotate during operation, the filling line is not a fixed line marked in a permanent position on the furnace wall. In some embodiments, the furnace may not be perfectly cylindrical symmetrical about the central axis, and the height of the filling line may change as the furnace rotates. However, the capacity of the rotary furnace 900, defined by the volume below the target filling line 922, is kept constant as the rotary furnace rotates. In some embodiments, once the rotary furnace 900 is filled to the target filling line 922, the molten copper alloy 1204 may occupy a percentage volume of less than 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, or within the range defined by any of these values, for example, less than 50%.

[0196] According to various embodiments disclosed herein, the rotary furnace may have the capability to produce molten copper alloys weighing more than 1,000 pounds, 2,000 pounds, 5,000 pounds, 10,000 pounds, 20,000 pounds, 50,000 pounds, 100,000 pounds, or within the range defined by any of these values. The inert gas has a contact area of ​​10 cm² with the molten alloy. 2 , 20cm 2 , 50cm 2 , 100cm 2 , 200cm 2 , 500cm 2 , 1000cm 2 , 2000m 2 , 0.5m 2 , 1m 2 Values ​​greater than or within the range defined by any of these values, for example, 25 cm 2 ~2500cm 2 The inert gas may be diffused through the porous diffusion material of the diffuser assembly 940. During the loading process, the inert gas may be supplied through the diffuser assembly at a flow rate greater than 0.1 liters / min, 0.5 liters / min, 1 liter / min, 2 liters / min, 5 liters / min, 10 liters / min, 15 liters / min, 20 liters / min, 50 liters / min, or within the range defined by any of these values, for example, 1 liter / min to 10 liters / min, or 2 to 6 liters / min, for example, about 4 liters / min.

[0197] Continuing with reference to Figures 11-12, in some embodiments, during the loading process of the rotary furnace 900, the furnace may oscillate or rotate back and forth one or more times between, for example, the loading configuration 1100 and the melting configuration 1200, and the loading portal door 932 may be opened or closed one or more times before the resulting molten alloy reaches the target filling line 922 of the rotary furnace. It will be understood that even though the loading portal door 932 may remain open while additional raw materials are being loaded into the furnace chamber 906, the partially sealed atmosphere 1112 within the furnace chamber 906 may remain substantially inert by supplying an inert gas through the diffuser assembly 940. The diffuser block 9400 may be located below the target filling line 922, or covered from above by the raw materials 1104, or submerged under the molten copper alloy 1204 after the raw materials have begun to melt. The inert gas diffused through the diffuser block 9400 can flow through the gaps between the solid raw material pieces 1104 or bubble through the molten copper alloy 1204, and then escape into the sealed atmosphere 1112 above. Therefore, the portion of the atmosphere in direct contact with the raw material 1104 or the molten copper alloy 1204 may be more inert than the rest of the sealed atmosphere 1112 in the chamber.

[0198] According to some embodiments, each batch of raw materials may be partially or completely melted before the next batch is added, and the loading portal door 932 may be closed between batches to substantially seal or isolate the enclosed atmosphere within the furnace chamber 906. The supply of heat or inert gas to the furnace may be started before loading the first batch of raw materials, paused between the addition of raw material batches, or continued throughout the addition of raw material batches. The rotary furnace 900 does not need to remain in the loading configuration 1100 throughout the entire loading process, and may be rotated to the melting configuration 1200, for example, to completely or partially melt the existing raw materials before the next batch is added. The composition and quantity of different batches of raw materials do not have to be the same and may be adjusted to best suit the composition required by the final low-impurity molten copper alloy product.

[0199] Referring to Figure 11, the raw material 1104 can exist in various forms, including one or more alloy pieces and / or elemental metal pieces. The raw material pieces may or may not have the same composition. However, the raw material pieces have a composite composition configured to form a molten copper-based alloy having the target composition of the alloy to be formed, and contain at least 50% by weight of copper. Various degrees of impurities, such as oxidation, may be present in the raw material before melting. Depending on the size of the raw material pieces, the inventors have further found that the amount or flow rate of inert gas effective in suppressing or reducing the oxidation of the raw material before and during melting may differ. The amount or flow rate of inert gas may depend, in particular, on the relative amount of open space between the raw material pieces, or the permeability of the copper-based alloy raw material material that forms the raw material for creating the molten copper-based alloy 1204. Relatively large amounts of open space or permeability that may exist when the raw material includes relatively large raw material pieces may result in a relatively small surface area of ​​the alloy exposed to the inert gas. For example, in some embodiments, the raw material material may include raw material pieces that are relatively large in size and, accordingly, have high open space or permeability. For highly permeable raw materials, a relatively high flow rate of inert gas through the diffuser assembly 940, for example, about 5 liters / minute or more, may be suitable for removing oxygen and oxygen-related impurities from the raw material. In some embodiments, the raw material may include raw material fragments of relatively small size and correspondingly smaller amounts of open space or permeability. For example, the raw material may be relatively small copper alloy turning material (e.g., copper scrap). For highly permeable raw materials, a relatively high flow rate of inert gas through the diffuser assembly 940, for example, about 5 liters / minute or more, may be suitable for removing oxygen and oxygen-related impurities from the raw material. The flow rates of inert gas before and during the melting of the raw material as described herein may also have any values ​​that are the same as or different from the flow rate of inert gas during bubbling of the inert gas through the molten alloy in the melting configuration 1200, as described herein, and these values ​​are not repeated herein for the sake of brevity.Other factors that can determine the optimal flow rate of the inert gas may include the impurity level of the raw materials, the amount of raw material batch being loaded or being loaded, the amount of existing raw materials or molten alloy present in the furnace, or the temperature of the furnace and the alloy inside the furnace.

[0200] Continuing with reference to Figure 11, in various embodiments, heat may be supplied to the rotary furnace 900 and the raw material 1104 by the burner system through the burner inlet 910 in the form of a flame 1212, before, during, or after loading the raw material. In order to keep the impurity levels in the final molten copper alloy sufficiently low, it may be beneficial to supply heat and inert gas to the furnace before loading, heating, or melting the raw material in a preheating or pre-purging process, the details of which are discussed below.

[0201] The inventors have discovered that undesirable ambient impurity-inducing substances such as oxygen, hydrogen, and moisture may be present in the atmosphere within the furnace chamber 906. Similar ambient impurity-inducing substances may also be present in the furnace lining or on the surface of the raw material through chemical reactions such as absorption, adsorption, or oxidation. At certain high temperatures, for example, the temperatures required to form molten copper alloys, some of these ambient impurity-inducing substances may be released from these surfaces into the atmosphere within the furnace chamber 906, or directly into the copper alloy. When these impurity-inducing substances come into contact with the raw material 1104 or the molten copper alloy 1204, they may react or be incorporated into the alloy, remaining in the resulting molten copper alloy and adversely affecting the mechanical, thermal, and electrical properties of the ingot or shot produced. For example, when the furnace is heated, oxygen or moisture may be released from the furnace wall 908 into the atmosphere of the furnace chamber 906, subsequently reacting with the raw material loaded into the chamber and potentially forming oxides on the surface of the raw material. When oxidized raw materials are melted, the surface oxides may remain stable in oxide form or release oxygen into the molten copper alloy, thereby contributing to oxygen and oxygen-related impurities in the final molten alloy. Therefore, preheating the furnace before loading the raw materials and pre-purging the raw materials in the furnace with an inert gas before heating or melting the raw materials can help reduce the amount of impurities present in the final molten copper alloy.

[0202] Continuing with reference to Figure 11, in various embodiments, in the loading configuration 1100, the rotary furnace 900 may be preheated to a temperature below the liquidus temperature of the copper alloy before the raw material is loaded. The inventors have found it advantageous to preheat the inside of the rotary furnace to a temperature high enough to promote or accelerate the release of impurities such as oxygen, hydrogen, or moisture from the furnace lining, but not high enough to cause significant oxidation of the raw material, for example, below 120°C, 150°C, 175°C, 200°C, 225°C, 250°C, 300°C, 350°C, 400°C, 500°C, or within the range defined by any of these values, for example, below 200°C. The inventors have also found it advantageous to pre-purge the sparging rotary furnace system 90 with an inert gas before the system is substantially heated, including pre-purging at least one of the diffuser assembly 940, the furnace chamber 906, or a transfer system configured to receive the molten copper alloy. One or more of these components of the sparging rotary furnace system 90 may be sealed in a substantially inert atmosphere, or substantially isolated or sealed from the ambient atmosphere outside the furnace system. To reduce or prevent backflow of ambient air from outside the furnace chamber, or to prevent outside air from mixing with the sealed atmosphere 1112, the loading portal door 932 may be closed, and an exhaust duct may be positioned to face the exhaust portal during a pre-purging process. Once loaded, the raw material 1104 may then be loaded into the furnace chamber 906, the loaded raw material having a substantially inert sealed atmosphere 1112 and significantly fewer impurity-inducing substances than the ambient atmosphere outside the furnace chamber. Furthermore, the inventors have found it advantageous to continue flowing an inert gas through the raw material, preferably through the gaps between the raw material pieces, while the raw material is being filled and heated. In this way, the raw material may continue to be heated and melted while surrounded by a sealed atmosphere 1112 that is substantially inert with low levels of potentially impurity-inducing substances (e.g., oxygen, hydrogen, moisture, or other reactive or undesirable substances that may adversely affect the purity of the molten copper-based alloy). Volatile impurity-inducing substances released from the raw material can also be carried away by the flow of inert gas and prevented from re-entering the molten copper-based alloy.To increase contact between the inert gas 1108 and the loaded raw material 1104, the diffuser assembly 940 can be positioned in the loading configuration 1100 in the lower half of the furnace chamber 906 so that the loaded raw material can cover at least a portion of the diffuser assembly and the inert gas 1108 can diffuse from the bottom of the raw material stack. In some embodiments, preheating or pre-purging of the furnace may continue for a period exceeding 5 minutes, 10 minutes, 20 minutes, 30 minutes, 1 hour, 2 hours, 3 hours, 5 hours, 6 hours, 10 hours, or a value within the range defined by any of these values, before the raw material is loaded. In some embodiments, purging or flowing of the inert gas through the raw material may continue for a period exceeding 1 minute, 2 minutes, 5 minutes, 10 minutes, 20 minutes, 30 minutes, 45 minutes, 60 minutes, 1 hour, 2 hours, 3 hours, or a value within the range defined by any of these values, before the raw material is substantially heated or substantially melted.

[0203] As shown in Figures 12A to 12B, after loading the raw material 1104 into the rotary furnace 900, the furnace may be configured into a melting configuration 1200 to heat and melt the raw material 1104 to form a molten copper alloy 1204. In the melting configuration 1200, the furnace is rotated to a melting angle, and the diffuser assembly 940 is in contact with the molten copper alloy, bubbling inert gas diffused from the bottom of the alloy. In the melting configuration 1200, the furnace may remain stationary at the melting angle or gently oscillate around the melting angle. In some embodiments, the melting angle may be 0° to 180° away from the loading angle, so that the loading portal 930 in the melting configuration 1200 is located at the same or greater height compared to the loading configuration 1100. In some embodiments, the diffuser assembly 940 in the melting configuration 1200 may be located at the same or less height compared to the loading configuration 1100. For example, the melting angles may be 0° to 135°, 0° to 90°, 15° to 75°, or 30° to 60° apart, and may be approximately 45° apart from the loading angle, and at least a portion of the diffuser assembly 940 may be located below the target filling line 922.

[0204] As shown in Figures 12A to 12B, in the melting configuration 1200, the loading portal 930 may be located at the top of the rotary furnace 900, away from the molten copper alloy, and the diffuser assembly 940 may be located at the bottom of the rotary furnace 900. For example, the loading portal 930 may be oriented about 45° to 90° above the horizontal with respect to the central axis, and at least one diffuser block 9400 may be oriented 45° to 90° below the horizontal with respect to the central axis. The diffuser assembly 940 may be located at the bottom of the rotary furnace 900 or near the furnace chamber 906. Heat can be supplied to the furnace to heat the molten copper in the melting configuration 1200 in the form of a flame flow by burning fuel injected into the furnace chamber 906. The inert gas 1208 diffused through the porous diffusion material of the diffuser block 9400 may be bubbling through the molten copper alloy, accompanied by impurities, such as oxygen and oxygen-related impurities.

[0205] Continuing with reference to Figures 12A and 12B, the rotary furnace 900 can be configured to have a variable internal temperature during the production of various molten copper alloys. In some embodiments, the internal temperature of the molten furnace 900 is between 700°F and 300°F. In some embodiments, the rotary furnace 900 may be configured to reach an internal temperature higher than 700°F, 900°F, 1000°F, 1200°F, 1400°F, 1600°F, 1800°F, 2000°F, 2200°F, 2400°F, 2500°F, or 3000°F, or within the range defined by any of these values. The inventors have found that heating the molten copper alloy 1204 to a temperature higher than its melting point and bubbling an inert gas 1208 through it may be advantageous for removing oxygen and oxygen-related impurities from the alloy. For example, the inventors have found it advantageous to heat the molten alloy to a temperature higher than 10°C, 20°C, 50°C, 100°C, 150°C, 200°C, 350°C, 300°C, 400°C, 450°C, 500°C, 600°C, or to a value within the range defined by any of these values ​​above the melting temperature while bubbling an inert gas.

[0206] Continuing with reference to Figures 12A and 12B, as previously mentioned, the fuel flow may be injected into the rotary furnace 900 through the burner inlet 910 equipped with an injector, ignited, and form a flame flow 1212. In some embodiments, the fuel flow may be a mixture of fuel and oxygen for efficient combustion. The flame flow 1212 may be the result of complete or incomplete combustion. In some embodiments, the fuel flow and the resulting flame 1212 may reach high speeds, such as speeds exceeding 50 m / s, 100 m / s, 150 m / s, 200 m / s, 250 m / s, 300 m / s, or within the range defined by any of these values. In some embodiments, the flame temperature may be greater than 500°C, 750°C, 1000°C, 1250°C, 1500°C, 1600°C, 1700°C, 1800°C, 1900°C, 2000°C, 2100°C, 2200°C, 2300°C, 2500°C, or within the range defined by any of these values. Fuel may be supplied by the burner system at a flow rate exceeding 500 liters / min, 1000 liters / min, 2000 liters / min, 4000 liters / min, 6000 liters / min, 8000 liters / min, or within the range defined by any of these values. The fuel may also be supplied by the burner system at flow rates exceeding 15 standard cubic feet / min (scf / min), 40 scf / min, 70 scf / min, 100 scf / min, 150 scf / min, 200 scf / min, 350 scf / min, or within the range defined by any of these values. The heat output generated by the fuel or received by the sparging rotary furnace system 90 and the molten copper alloy 1204 may exceed 0.5 Mwatts, 1.0 Mwatts, 2.0 Mwatts, 3 Mwatts, or within the range defined by any of these values. The fuel temperature and heating force may be controlled by the flow rate at which the fuel is supplied, the conditions under which the fuel is supplied (e.g., droplet size), the fuel composition, the amount of oxygen available to the fuel, and the pressure at which the fuel is supplied.

[0207] Continuing with reference to Figures 12A and 12B, in some embodiments, the fuel flow may be injected into the furnace chamber 906, and combustion may occur in a sealed atmosphere 1112 directly above the molten copper alloy. In some implementations, the flame flow 1212, which may contain unreacted oxygen, may be kept relatively narrow relative to the diameter of the furnace chamber 906 and localized in the sealed atmosphere 1112 above the raw material 1104 and / or molten copper alloy 1204 without substantially direct collision to suppress its oxidation. The fuel may be injected along the extension axis of the furnace chamber, and the resulting flame may extend over the substantial length of the furnace, for example, a substantial length along the central axis 902 of the rotary furnace 900. The heat output generated by the flame may be transferred to the rotary furnace lining 920 and the molten copper alloy by conduction, radiation, or convection. The amount of thermal energy received, and thereby the temperature of the furnace and molten alloy, may also depend on the distance between the furnace lining 920 and the molten copper alloy 1204 and the flame. The fuel flow supplied to the rotary furnace 900 to generate the flame may include gaseous or liquid hydrocarbons; for example, the fuel may include natural gas, methane, ethane, propane, butane, or oil. After compressing and / or mixing the fuel, the burner system may inject the fuel into the furnace chamber 906 through the burner inlet 910 at high speed or high pressure. Oxygen or ambient air may be mixed with the fuel and supplied through the burner inlet to help sustain the combustion of the fuel. The amount of oxygen or ambient air supplied to the fuel may be optimized so that the amount of oxygen is sufficient to maintain the flame for heating the furnace and molten alloy, but not so much that it is left from the combustion process and causes undesirable oxidation of the molten copper alloy. For example, the amount of oxygen supplied by the burner system may be approximately equal to the amount required for the complete combustion of the fuel it is supplied with. To reduce the exposure of molten copper alloys to oxygen, it may be beneficial to consume most or all of the oxygen supplied to the furnace through the burner along with the fuel by combustion. Any residual oxygen not consumed by combustion may be discharged from the furnace chamber 906 using an inert gas provided through the diffuser assembly 940.The inert gas bubbling through the molten copper alloy may help prevent the oxygen supplied through the burner from coming into contact with and bonding with the molten alloy 1204 by forming a substantially inert layer of air directly above the molten alloy, as bubbles burst at the surface of the molten alloy, separating the flame stream 1212 from the molten copper alloy. This substantially inert layer of air may be more inert than the rest of the sealed atmosphere 1112 within the furnace chamber.

[0208] Continuing with Figures 12A to 12B, in some embodiments, the local temperature of the furnace lining 920 may fluctuate and may differ from the local temperature of the molten copper alloy 1204. For example, the inventors have found that the local temperature of a portion of the furnace lining closer to the flame may be higher than the local temperature of a portion further away from the flame flow 1212. The inventors have also found that the local temperature of a portion of the furnace lining directly exposed to the flame may be higher than the local temperature of a portion submerged beneath the molten copper alloy. The local temperature of the molten copper alloy 1204 may also fluctuate. In some embodiments, the local temperature of a portion of the molten alloy closer to the flame may be higher than the local temperature of a portion of the molten alloy further away from the flame; for example, the temperature of a surface portion of the molten copper alloy may be higher than the temperature of the bottom portion of the alloy. Therefore, the inventors have found it beneficial to gently oscillate the furnace back and forth around the melting angle so that the hotter portion of the furnace can come into contact with the cooler portion of the molten alloy. After a high-temperature portion of the furnace lining comes into contact with the molten alloy, its heat is transferred to the alloy, and depending on the length of contact time, the temperature of that portion may decrease or reach equilibrium with the surrounding molten alloy. The portion of the furnace that has decreased in temperature and / or reached equilibrium may then be oscillating back to its original position closer to the flame above the molten copper alloy, where it is reheated by the flame and enters the next oscillating cycle. This oscillating motion of the furnace is transmitted to the molten alloy by viscous effects, resulting in a gentle stirring or mixing of the liquid alloy, thereby increasing the uniformity of both the temperature and chemical composition of the molten copper alloy. This gentle oscillating motion of the furnace may continue continuously or intermittently throughout the heating and melting of the copper alloy, providing more uniform heating and more efficient utilization of the heat output generated by the fuel. The angular velocity at which the rotary furnace 900 exhibits gentle oscillation may be greater than 1° / min, 5° / min, 10° / min, 15° / min, 30° / min, 45° / min, 60° / min, 90° / min, 120° / min, 180° / min, 270° / min, 360° / min, 480° / min, or 720° / min, or within the range defined by any of these values.The angular range of the oscillating motion can be greater than 1°, 2°, 5°, 10°, 20°, 30°, 45°, 60°, 75°, 90°, 120°, 150°, and 180°, or within the range defined by any of these values. As discussed elsewhere in this application, oscillating the rotary furnace 900 increases the probability that inert gas bubbles can come into contact with impurities, potentially improving the efficiency of removing impurities such as oxygen-related impurities.

[0209] Referring further to Figures 12A and 12B, the inventors also found it advantageous to supply an inert gas to the sparging rotary furnace system 90 while the molten copper alloy is being heated. The inventors further found it advantageous to diffuse the inert gas through the diffuser block 9400, to bubble the inert gas through the molten copper alloy 1204, and to fill the sealed atmosphere 1112 above the molten copper alloy 1204 with the inert gas. The sealed atmosphere 1112 above the molten copper base alloy may be a substantially inert atmosphere containing significantly fewer impurity-inducing substances than the ambient atmosphere outside the furnace chamber 906, and may be substantially or completely sealed by the rotary furnace 900 during operation. To further enhance isolation from the external atmosphere, various portals to the rotary furnace may be closed while the molten copper alloy is being heated. For example, as shown in Figure 12B, the furnace loading portal door 932 may remain closed, and the exhaust duct 972 may be positioned to direct the exhaust portal while heating the molten copper alloy 1204 and bubbling an inert gas through the molten copper alloy 1204.

[0210] Continuing with reference to Figures 12A and 12B, in some embodiments, the substantially inert atmosphere above the molten copper alloy contains one or more inert gases. In some embodiments, the substantially inert atmosphere of the furnace chamber contains argon (Ar). In some embodiments, the substantially inert atmosphere of the furnace chamber has a substantially higher nitrogen gas (N2) content compared to the external atmosphere. In some embodiments, the substantially inert atmosphere of the furnace chamber has a substantially lower content of oxygen, hydrogen, moisture, or other reactive or undesirable substances that could adversely affect the purity of the molten copper alloy compared to the external atmosphere.

[0211] To maintain a sufficiently inert atmosphere above the molten copper alloy, various portals to the furnace may be closed, but they do not need to be sealed (e.g., airtight or airtight) during loading, heating, melting, or injection of the molten copper alloy. In some embodiments, the atmosphere above the molten copper alloy may be kept substantially inert by flowing an inert gas into the furnace chamber at a sufficient rate without completely closing each and all single portals of the furnace. According to various embodiments, once the inert gas flows into the chamber at a sufficient rate and enters the furnace chamber 906 through the diffuser assembly 940, an outward flow of air from the inside to the outside of the chamber may occur through various portals of the furnace, for example, through the loading portal 930, the injection portal 934, or the exhaust portal 914, thereby suppressing backflow of outside air and sufficiently removing outside air. In other words, by diffusing the inert gas into the rotary furnace 900 through the diffuser assembly 940, a positive pressure of the inert gas may be maintained inside the furnace chamber 906, thereby keeping the sealed atmosphere 1112 substantially inert.

[0212] Continuing with reference to Figures 12A and 12B, as discussed herein, in order to optimize the removal of impurities from the molten alloy, the inventors have found that increasing the contact between the inert gas bubbles and the molten alloy is beneficial. Therefore, to increase the surface area of ​​the inert gas bubbles, it may also be beneficial to increase the distance the inert gas bubbles travel in the molten alloy and to increase the residence time of the inert gas bubbles in the molten alloy. This can be achieved by placing at least one diffuser block 9400 at or near the bottom of the molten copper alloy 1204 and bubbling inert gas 1208 from the lower point of the molten copper alloy 1204. For example, in the molten configuration 1200, it may be beneficial to place the diffuser block 9400 in contact with the bottom portion of the molten copper alloy, or at or near the bottom of the furnace chamber substantially furthest from the target filling line 922 vertically. A portion of the diffuser assembly 940 may remain in contact with the molten copper alloy 1204 when the rotary furnace gently oscillates back and forth in the melting configuration 1200. For example, the diffuser block 9400 may remain below the target filling line 922 while the inert gas is bubbling within the molten copper alloy in the melting configuration. In some embodiments, it may be advantageous to submerge all of the diffuser blocks of the diffuser assembly 940 below the molten copper alloy in the melting configuration to increase the contact area between the inert gas and the molten copper alloy. For example, the diffuser blocks may be positioned around the furnace chamber such that, at a particular rotation angle, all of the diffuser blocks of the diffuser assembly 940 are positioned below the target filling line 922.

[0213] Continuing with reference to Figures 12A and 12B, the inventors further discovered that various combinations of flow parameters related to the diffusion and bubbling of the inert gas 1208 through the molten copper alloy may be advantageous for the removal of oxygen and oxygen-related impurities from the molten copper alloy 1204. In various embodiments, the inventors found that the size distribution, volume density distribution, and velocity distribution of the inert gas bubbles 1208 moving through the molten alloy 1204 may affect the effectiveness of the bubbles in removing impurities. If the size, volume density, and velocity of the bubbles 1208 are too small or too low, the bubbles may be too slow or ineffective in removing oxygen or oxygen-related impurities. On the other hand, if the size, volume density, and velocity of the bubbles are too large or too high, the bubbles may generate substantial turbulence as they rise and rupture on the surface of the molten copper alloy 1204. The inventors have found that such turbulence, when substantial, can not only negate any removal of oxygen or oxygen-related impurities but can even increase the content of oxygen or oxygen-related impurities. Therefore, the inventors have found that controlling the size distribution, volume density distribution, and velocity distribution of the inert gas bubbles 1208 can be important for producing molten copper alloys with fewer impurities. The size, density, and velocity distribution of the bubbles can depend on a variety of factors, some examples of which include the composition, temperature, and viscosity of the molten copper alloy 1204, the total flow rate of the inert gas diffused through the diffuser assembly 940, the flux per unit area or local flow rate of the inert gas diffused into the molten alloy through the diffuser block, the porosity and pore size distribution of the diffusion material of the diffuser block, the depth or height of the molten alloy from which the bubbles rise, the cross-sectional area of ​​the molten alloy covered or not covered by the inert gas bubbles, and the total volume of the molten copper alloy 1204, the geometry of the furnace chamber 906, and any motion of the rotary furnace 900 and the molten copper alloy 1204. It will be understood that these flow parameters can be interdependent. For example, the flow rate and cross-sectional area of ​​the inert gas may determine the flux of the inert gas, and the viscosity of the molten alloy may depend on the composition and temperature of the molten alloy.

[0214] The inventors have discovered that viscosity can depend on the temperature of the molten alloy. Therefore, in order to achieve a desirable size distribution, volume density distribution, and velocity distribution of inert gas bubbles, the viscosity of the molten copper-based alloy may be adjusted by adjusting the heating power supplied to the alloy. The inventors have also discovered that in some embodiments, inert gas bubbles may be more effective in removing oxygen and oxygen-related impurities when the molten alloy is heated to a temperature higher than 10°C, 20°C, 50°C, 100°C, 150°C, 200°C, 250°C, 300°C, 350°C, 400°C, 450°C, 500°C, 550°C, 600°C, 700°C, or within the range defined by any of these values, above the melting temperature or liquidus temperature of the alloy, for example, 100°C to 400°C above the melting temperature of the molten copper-based alloy.

[0215] According to some embodiments, the total flow rate of inert gas diffused through all the diffuser blocks of the diffuser assembly 940 and bubbling into the molten copper alloy 1204 may be any value within the range defined by these values, such as 10 liters / min, 9 liters / min, 8 liters / min, 7 liters / min, 6 liters / min, 5 liters / min, 4 liters / min, 3 liters / min, 2 liters / min, more than 1 liter / min, or 1 to 10 liters / min or 2 to 6 liters / min, for example, about 4 liters / min. According to some embodiments, the individual flow rate of inert gas diffused through each diffuser block of the diffuser assembly and bubbling into the molten copper alloy 1204 may be the total flow rate divided by the number of diffuser blocks. For rotary furnaces of various capacities, the flow rate of inert gas bubbling into the molten copper alloy produced using the furnace may be adjusted accordingly. For example, in some embodiments, the flow rate of the inert gas bubbling through the molten copper alloy produced using a rotary furnace may be adjusted in proportion to the weight, volume, or cross-sectional area of ​​the molten copper alloy 1204, or in proportion to the capacity of the rotary furnace. For example, in the case of a furnace capable of producing molten copper alloys weighing more than 120,000 pounds, within the range defined by 1,000 pounds, 2,000 pounds, 5,000 pounds, 10,000 pounds, 20,000 pounds, 50,000 pounds, or any of these values, the inert gas flow rate may be 25-2,500 cm³. 2 The inert gas can be bubbled into the molten alloy at a flow rate within the above range, for example, 1 to 10 liters / minute, through a porous diffusion material having a total diffusion area. In some embodiments, the total flow rate of the inert gas that can be bubbled may be determined based on either the volume or flow rate value described above.

[0216] Figure 13 is a schematic cross-sectional view of a rotary furnace 900 in an injection configuration 1300, viewed along the central axis from the burner inlet end, according to several embodiments. As shown in Figure 13, after the raw material has been melted to form a molten copper alloy 1204, a portion of the molten alloy may be ready to be transferred from the rotary furnace 900 in the injection configuration 1300. In the injection configuration 1300, the furnace is rotated to an injection angle, where the injection portal 934 may be positioned to remain below the surface level of the molten copper alloy 1204, so that the alloy can be transferred out of the furnace through the portal at an appropriate speed. In some embodiments, the injection portal 934 may be located near the bottom of the rotary furnace 900 in the injection configuration 1300. In some embodiments, an inert gas 1108 may continue to be supplied to the rotary furnace 900 during the injection or transfer process of the molten alloy. In some embodiments, at least a portion of the diffuser assembly 940 may remain in contact with the molten alloy and continue to bubble the inert gas into the molten alloy in the injection configuration 1300. In some embodiments, at least a portion of the diffuser assembly 940 may be in contact with the sealed atmosphere 1112 above the molten alloy in the injection configuration, and the inert gas may be directly flowed into the sealed atmosphere 1112 above the molten copper alloy. In some embodiments, the diffuser block 9400 may be located above the target filling line 922 of the rotary furnace 900 and may directly diffuse the inert gas 1108 into the sealed atmosphere 1112 above the molten copper alloy 1204. Various portals of the sparging rotary furnace 900 may be closed in the injection configuration to completely or substantially seal the atmosphere 1112 inside the furnace chamber 906 from the external atmosphere.

[0217] Continuing with reference to Figure 13, in the injection configuration 1300, a transfer system (not shown) may be configured to receive the molten copper alloy from the injection portal 934. The transfer system may also be sealed in a substantially inert atmosphere and substantially isolated from the ambient external atmosphere. In some embodiments, the transfer system may include a transfer ladle, a speed control element, or a mold with various features similar to the corresponding components disclosed with respect to Figures 1-3, details of which are omitted here for brevity. Furthermore, according to some embodiments, when the molten copper alloy 1204 is ready to be transferred, the injection portal stopper 936 can be opened and a portion of the molten copper alloy 1204 can be poured into a transfer ladle having one or more ladle spouts. Once filled, the transfer ladle is then tilted and the molten copper alloy 1204 is poured through one or more ladle spouts into one or more ingot molds. The molten copper alloy 1204 solidifies in the molds to form solidified copper alloy ingots. One or more molds can be moved along a conveyor belt, where they may undergo further processing, such as cooling, before being collected.

[0218] Continuing with Figure 13, since the height of the surface level of the molten copper alloy may change during the pouring process, the pouring angle and flow rate of the molten alloy may be adjusted by continuously or intermittently tilting the melting furnace. In some embodiments, the pouring angle may be 0° to 180° away from the melting angle such that the pouring portal 934 in the pouring configuration 1300 is positioned at the same or lower height compared to the melting configuration 1200 (Figures 12 to 12B). In some embodiments, the diffuser block 9400 may be positioned at the same or higher height in the pouring configuration 1300 compared to the melting configuration 1200. For example, the pouring angle may be 0° to 135°, 0° to 90°, 15° to 75°, 30° to 60° away from the melting angle, for example, about 45° away.

[0219] Continuing with reference to Figure 13, the inventors have found that the concentration of oxygen or oxygen-related impurities can vary between different portions of the molten copper alloy 1204. In some embodiments, the inventors have found that the oxygen or oxygen-related impurity content can be higher toward the surface of the molten copper alloy 1204. Therefore, advantageously, if an alloy with a lower than average oxygen content is desired, the molten copper alloy 1204 at the bottom of the rotary furnace may be preferentially transferred through the injection portal 934. This can be achieved, according to some embodiments, by orienting the rotary furnace 900 such that the injection portal 934 is positioned to access, for example, less than 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, or 90% of the volume of the molten copper alloy. Alternatively, the molten copper alloy 1204 may be preferentially pumped from its bottom using a mechanical pump and then transferred to a transfer system. These features and various additional features related to transferring the molten copper alloy 1204 out of the melting furnace can be comparable to those associated with induction furnaces.

[0220] Continuing with reference to Figure 13, the inventors found that it may be advantageous to cool the molten copper alloy 1204 to a temperature close to but higher than its melting temperature or liquidus temperature in a substantially inert, sealed atmosphere 1112 before transferring the molten copper alloy 1204. Cooling may be performed in either the injection configuration 1300 or the melting configuration 1200. In some embodiments, the inventors found that when the molten copper alloy is transferred out of the furnace at a higher temperature, impurity-inducing substances can react or bond with the molten copper alloy more readily than at lower temperatures. Therefore, cooling the molten alloy before transferring it out of the furnace may help reduce the amount of impurities that the alloy may collect during the transfer process. Accordingly, according to various embodiments, the temperature of the molten copper alloy 1204 when transferred or injected from the sparging rotary furnace 900 may be lower than the temperature of the alloy during the melting process by only 10°C, 20°C, 50°C, 100°C, 150°C, 200°C, 250°C, 300°C, 350°C, 400°C, 450°C, 500°C, or 600°C, or any temperature within the range defined by any of these values, but remain higher than the liquidus temperature of the molten copper alloy. According to various embodiments, the temperature of the molten copper alloy when transferred or injected from the sparging rotary furnace 900 may be higher than the liquidus temperature of the molten copper alloy by only 500°C, 400°C, 300°C, 250°C, 200°C, 150°C, 50°C, or 10°C, or any temperature within the range defined by any of these values. While the molten copper alloy 1204 is being cooled, an inert gas 1108 may be supplied to the rotary furnace 900. In some embodiments, at least a portion of the diffuser assembly 940 may be positioned above the surface of the molten copper alloy, and the inert gas 1108 may be diffused directly into the sealed atmosphere 1112 while the alloy is being cooled. For example, the diffuser block 9400 may be positioned above the target filling line 922 of the rotary furnace 900, and while the alloy is being cooled, the inert gas 1108 may be flowed directly into the atmosphere above the molten copper alloy 1204 in the injection configuration 1300.In some other embodiments, while the molten copper alloy is cooling, at least a portion of the diffuser assembly 940 may be positioned below the surface of the molten copper alloy, and at least a portion of the inert gas diffused through the diffuser assembly 940 may be bubbling through the molten copper alloy 1204 before leaking into the sealed atmosphere 1112. For example, the diffuser block 9400 may be located below the target filling line 922 of the rotary furnace 900, and in the injection configuration 1300, the inert gas 1108 may be bubbling directly into the molten copper alloy 1204. Various portals of the rotary furnace 900 may be closed, and the sealed atmosphere 1112 above the molten copper alloy 1204 may be kept substantially inert during the pre-transfer cooling process. The flow rate of the inert gas bubbling into the alloy during the cooling process may differ from that during the melting process. In particular, the position of the diffuser block and the viscosity of the molten copper alloy during the cooling process may differ from those in the melting process, requiring adjustment of the inert gas flow rate to optimize the impurity removal efficiency.

[0221] Various additional embodiments are disclosed below. It is understood that any one of the additional embodiments may be combined with any other of the additional embodiments, insofar as it does not conflict with this disclosure. Additional Example I: (Embodiment 1) Apparatus for manufacturing copper-based alloys, A sealed melting furnace configured to form a molten copper alloy containing at least 50% by weight of copper under a sealed, inert atmosphere, and to bubble an inert gas through the molten copper alloy, A transfer ladle configured to receive the molten copper alloy from the melting furnace under the sealed, inert atmosphere and to transfer the molten copper alloy to one or more molds or shot pits configured to solidify the molten copper alloy, A device equipped with the following features. (Embodiment 2) Apparatus for manufacturing copper-based alloys, A sealed melting furnace configured to form a molten copper alloy containing at least 50% by weight of copper under a sealed, inert atmosphere, and to bubble an inert gas through the molten copper alloy, A transfer ladle configured to receive the molten copper alloy from the melting furnace via a speed control element and transfer the molten copper alloy to one or more molds or shot pits configured to solidify the molten copper alloy, A device equipped with the following features. (Embodiment 3) The apparatus according to Embodiment 1, wherein the transfer ladle is configured to receive the molten copper alloy from the melting furnace via a speed control element. (Embodiment 4) The apparatus according to Embodiment 2, wherein the transfer ladle is configured to receive the molten copper alloy from the melting furnace under a sealed, inert atmosphere. (Embodiment 5) The apparatus according to any one embodiment of Embodiments 1 to 4, wherein the transfer ladle is configured to transfer the molten copper alloy to the shot pit, which is configured to solidify the molten copper alloy into copper shot. (Embodiment 6) The apparatus according to any one embodiment of Embodiments 1 to 5, wherein the one or more molds are ingot molds configured to solidify the molten copper alloy into a copper ingot. (Embodiment 7) The apparatus according to any one embodiment of Embodiments 1 to 6, wherein the sealed melting furnace and the transfer ladle are configured to substantially prevent outside air from mixing with the sealed inert atmosphere. (Embodiment 8) The apparatus according to any one embodiment of Embodiments 1 to 7, wherein the melting furnace and the transfer ladle are integrally connected so as to be sealed from the external atmosphere while in a common sealed inert atmosphere. (Embodiment 9) The apparatus according to any one embodiment of Embodiments 1 to 8, wherein the inert gas and the same sealed inert atmosphere essentially consist of argon. (Embodiment 10) The apparatus according to any one embodiment of Embodiments 1 to 9, wherein the inert gas does not contain hydrogen. (Embodiment 11) The apparatus according to any one embodiment of Embodiments 1, 3, and 5-10, further comprising a speed control element, the speed control element being configured to transfer the molten copper alloy from the sealed melting furnace to the encapsulated transfer ladle at a controlled speed adapted to reduce speed-induced entrainment of the copper alloy compared to a reference copper alloy formed from a reference apparatus configured identically to the apparatus except for the presence of the speed control element. (Embodiment 12) The speed control element is a lamp, as described in Embodiment 11. (Embodiment 13) The apparatus according to embodiment 11 or 12, wherein the controlled speed is less than 100 inches / second. (Embodiment 14) The apparatus according to any one embodiment of Embodiments 1 to 13, further comprising a second speed control element configured to transfer the molten copper alloy from the encapsulated transfer ladle to one or more molds or shot pits at a second controlled speed adapted to reduce speed-induced entrainment of the copper alloy compared to a reference copper alloy formed from a reference apparatus configured in the same way as the apparatus, except for the presence of the aforementioned speed control element. (Embodiment 15) The apparatus according to embodiment 14, wherein the second speed control element comprises a lamp. (Embodiment 16) The apparatus according to embodiment 14 or 15, wherein the second control speed is less than 30 inches / second. (Embodiment 17) The apparatus according to any one embodiment of Embodiments 1 to 16, wherein the encapsulated transfer ladle is insulated. (Embodiment 18) The apparatus according to any one embodiment of Embodiments 1 to 17, further comprising a diffuser positioned at the bottom of the melting furnace and having a plurality of through-holes adapted to bubble the inert gas through the molten copper alloy in the form of inert gas bubbles having a size distribution adapted to reduce the oxygen content from the molten copper alloy. (Embodiment 19) The apparatus according to embodiment 18, wherein the diffuser is configured to flow the inert gas at a flow rate of 2 to 6 liters / minute. (Embodiment 20) The diffuser has a porosity of more than 20%, as described in the apparatus of embodiments 18 to 19. (Embodiment 21) The apparatus of embodiments 18-19, wherein the diffuser has a diameter greater than 5 cm and smaller than the inner diameter of the melting furnace. (Embodiment 22) The melting furnace is the apparatus of embodiments 18-19, having an inner diameter of more than 50 cm. (Embodiment 23) The apparatus according to any one embodiment of Embodiments 1 to 22, wherein the copper alloy has an oxygen content that is at least 10% lower than that of a reference copper alloy formed from a reference apparatus configured in the same way as the apparatus, except that the melting furnace and the transfer ladle are under the same sealed inert atmosphere. (Embodiment 24) The apparatus according to any one embodiment of Embodiments 1 to 23, wherein the apparatus is configured such that the copper alloy has an oxygen content reduced by at least 10% compared to a reference copper alloy formed from a reference apparatus configured in the same way as the apparatus, except that the melting furnace is configured to bubble the inert gas through the molten copper alloy. (Embodiment 25) The apparatus, when one or more test results obtained from the copper alloy using the ASTM E8 / E8M-21 method are compared with a reference copper alloy formed from a reference apparatus configured identically to the apparatus, except that the melting furnace and the transfer ladle are under the same sealed, inert atmosphere, The ultimate tensile strength increases by at least 5 ksi, The 0.5% yield strength increased by at least 3 ksi, Growth increased by at least 5%, The reduction in cross-sectional area increases by at least 5%. The apparatus according to any one embodiment of Embodiments 1 to 24, configured as described above. (Embodiment 26) The apparatus according to any one embodiment of Embodiments 1 to 25, wherein the copper alloy is configured to have an ultimate tensile strength increased by at least 20 ksi compared to a reference copper alloy formed from a reference apparatus configured in the same way as the apparatus, except that the melting furnace is configured to bubble the inert gas through the molten copper alloy. (Embodiment 27) The apparatus according to Embodiment 1, wherein the transfer ladle is configured to transfer the molten copper alloy to the shot pit, which is configured to solidify the molten copper alloy into copper shots. (Embodiment 28) The apparatus according to Embodiment 1, wherein the transfer ladle is configured to transfer the molten copper alloy to one of a plurality of ingot molds configured to solidify the molten copper alloy into the copper ingot. (Embodiment 29) The apparatus according to Embodiment 1, wherein the melting furnace is configured to transfer the molten copper alloy from the lower half of the volume of the molten copper alloy to the transfer ladle before transferring the remainder of the molten copper alloy. (Embodiment 30) The apparatus according to Embodiment 1, wherein the first velocity element is connected to the lower half of the melting furnace. (Embodiment 31) The apparatus according to any one embodiment of Embodiments 1 to 30, wherein the melting furnace further comprises a diffusion lining containing an aluminum silicate ceramic having a porous structure adapted to bubble the inert gas through the molten copper alloy. (Embodiment 32) The apparatus according to any one embodiment of Embodiments 1 to 30, wherein the melting furnace further comprises a diffusion lining having a porous structure adapted to substantially cover the bottom inner surface thereof and to bubble an inert gas into the molten copper alloy. (Embodiment 33) The apparatus according to any one embodiment of Embodiments 1 to 30, wherein the melting furnace further includes a diffusion lining having a porous structure, the diffusion lining being formed on at least two different inner surfaces of the melting furnace, and as a result the diffusion lining is adapted to bubble an inert gas through the molten copper alloy from the at least two different inner surfaces. (Embodiment 34) The apparatus according to embodiment 32 or 33, wherein the diffusion lining includes an aluminum silicate ceramic. (Embodiment 35) The apparatus according to embodiment 31 or 33, wherein the diffusion lining substantially covers the inner surface of the bottom of the melting furnace. (Embodiment 36) The apparatus according to embodiment 31 or 32, wherein the diffusion lining is formed on at least two different inner surfaces of the melting furnace, and as a result, the diffusion lining is adapted to bubble an inert gas through the molten copper alloy from the at least two different inner surfaces. (Embodiment 37) The apparatus is the apparatus according to any one embodiment of Embodiments 1 to 36, further relating to any one embodiment of the embodiment in Additional Embodiment III. Additional Example II: (Embodiment 1) A method for producing copper-based alloys, The steps include providing a melting furnace with a plurality of raw material pieces having a composite composition configured to form a molten copper-based alloy containing at least 50% by weight of copper, Before heating, the process involves passing an inert gas through the gaps between the raw material pieces, The steps include: heating the raw material piece while flowing the inert gas through it, thereby melting the raw material piece and forming the molten copper alloy; The steps include: bubbling the inert gas through the molten copper alloy; The steps include transferring the molten copper alloy to a transfer ladle, Methods that include... (Embodiment 2) A method for producing copper-based alloys, The steps include providing a melting furnace with a plurality of raw material pieces having a composite composition configured to form a molten copper-based alloy containing at least 50% by weight of copper, The steps include heating the raw material pieces to form the molten copper alloy, The steps include: bubbling the inert gas through the molten copper alloy; The steps include transferring the molten copper alloy to a transfer ladle, Includes, A method comprising the steps of heating the raw material pieces, bubbling the inert gas, and transferring the molten copper alloy, wherein at least one of these steps is performed under a sealed inert atmosphere, the sealed inert atmosphere being configured to substantially prevent outside air from mixing with the sealed inert atmosphere. (Embodiment 3) A method for producing copper-based alloys, The steps include providing a melting furnace with a plurality of raw material pieces having a composite composition configured to form a molten copper-based alloy containing at least 50% by weight of copper, The steps include heating the raw material pieces to form the molten copper alloy, The steps include: bubbling the inert gas through the molten copper alloy; The steps include transferring the molten copper alloy to a transfer ladle, Includes, A method comprising the transfer step of limiting the rate at which the molten copper alloy is transferred from the melting furnace to the transfer ladle to less than 100 inches per second. (Embodiment 4) The method according to Embodiment 2 or 3, further comprising the step of flowing an inert gas through the gaps between the raw material pieces before heating, and the heating step comprising heating the raw material pieces while flowing the inert gas. (Embodiment 5) One or more of the steps of heating the raw material piece, bubbling the inert gas, and transferring the molten copper-based alloy are carried out at least partially under a sealed inert atmosphere, and the sealed inert atmosphere is configured to substantially exclude the outside air from mixing with the sealed inert atmosphere. The method according to Embodiment 1 or 3. (Embodiment 6) The step of transferring includes restricting the speed of the molten copper-based alloy transferred from the melting furnace to the transfer ladle to less than 100 inches per second. The method according to Embodiment 1 or 2. (Embodiment 7) The raw material piece includes one or both of an alloy piece and an elemental metal piece. The method according to any one of Embodiments 1 to 6. (Embodiment 8) The step of flowing the inert gas includes flowing it before starting the heating of the raw material piece. The method according to any one of Embodiments 1 to 7. (Embodiment 9) The step of flowing the inert gas includes flowing it at a sufficient flow rate so that the raw material piece is substantially under a flowing inert gas atmosphere before and during melting. The method according to any one of Embodiments 1 to 8. (Embodiment 10) Before the step of transferring, the method further includes a step of adding an additional raw material piece while bubbling the inert gas through the molten copper-based alloy. The method according to any one of Embodiments 1 to 9. (Embodiment 11) The step of bubbling the inert gas is continued through the movement of the molten copper-based alloy. The method according to any one of Embodiments 1 to 10. (Embodiment 12) The step of bubbling the inert gas includes bubbling it at a sufficient flow rate so that the molten copper-based alloy is substantially under a flowing inert gas atmosphere during the bubbling of the inert gas. The method according to any one of Embodiments 1 to 11. (Embodiment 13) The method according to any one embodiment of Embodiments 1 to 12, wherein one or more of the steps of heating the raw material pieces, bubbling the inert gas, and transferring the molten copper alloy are performed under a common inert atmosphere. (Embodiment 14) The method according to Embodiment 13, wherein the common inert atmosphere includes a sealed common inert atmosphere shared by the melting furnace and the transfer ladle. (Embodiment 15) The method according to Embodiment 14, wherein the sealed inert common atmosphere is sealed by keeping the injector of the ladle closed until immediately before the molten copper alloy is injected from the ladle into the mold. (Embodiment 16) The method according to any one embodiment of Embodiments 1 to 15, wherein the step of flowing and bubbling the inert gas comprises flowing and bubbling the inert gas, which is essentially argon. (Embodiment 17) The method according to any one embodiment of Embodiments 1 to 16, wherein the step of flowing and bubbling the inert gas includes flowing and bubbling the inert gas which is substantially hydrogen-free. (Embodiment 18) The method according to any one embodiment of Embodiments 1 to 17, wherein the step of flowing and bubbling the inert gas includes diffusing the inert gas through a diffuser having a plurality of pores, which is positioned at the bottom of the melting furnace and is adapted to bubbling the inert gas in the molten copper alloy in the form of inert gas bubbles. (Embodiment 19) The method according to any one embodiment of Embodiments 1 to 18, wherein the step of flowing and bubbling the inert gas is performed by flowing it through a diffuser having a porosity of more than 20% at a flow rate of 2 to 6 liters / minute. (Embodiment 20) The method according to any one embodiment of Embodiments 1 to 19, wherein the step of flowing and bubbling the inert gas is performed by flowing it through a diffuser having a diameter greater than 5 cm and smaller than the inner diameter of the melting furnace at a flow rate of 2 to 6 liters / minute. (Embodiment 21) The method according to Embodiment 17, wherein the step of flowing and bubbling the inert gas is carried out by flowing it through the melting furnace having an inner diameter of more than 50 cm. (Embodiment 22) The method according to any one embodiment of Embodiments 1 to 21, wherein the heating step includes heating to a temperature 100 to 400°C higher than the temperature of the copper alloy. (Embodiment 23) The method according to Embodiment 22, further comprising the step of cooling the molten copper alloy to 100-400°C before the transfer step. (Embodiment 24) The method according to any one embodiment of Embodiments 1 to 23, wherein the transfer step includes pouring the molten copper alloy, which is located in the lower half of the melting furnace. (Embodiment 25) The method according to any one embodiment of Embodiments 1 to 24, wherein the transfer step includes using an inclined ramp to limit the rate at which the molten copper alloy is transferred from the melting furnace to the transfer ladle. (Embodiment 26) The method according to any one embodiment of Embodiments 1 to 25, wherein the molten copper alloy is transferred to the transfer ladle at a limited speed via an inclined lamp, and then one or more injection valves are opened to inject the molten copper alloy from the transfer ladle. (Embodiment 27) The inclined lamp is in an inert atmosphere, according to the method of embodiment 26. (Embodiment 28) The method according to Embodiment 24, wherein the step of transferring the molten copper alloy is performed in a sealed common inert atmosphere shared by the melting furnace, the transfer ladle, and the inclined lamp. (Embodiment 29) The method according to any one embodiment of Embodiments 1 to 28, wherein the molten copper alloy is transferred to the transfer ladle at a limited speed via an inclined ramp, and then one or more injection valves are opened to inject the molten copper alloy from the transfer ladle into one or more molds or shot pits, thereby solidifying the molten copper alloy. (Embodiment 30) The method according to any one embodiment of Embodiments 1 to 29, wherein the molten copper alloy is transferred to the transfer ladle at a limited speed via an inclined ramp, the molten copper alloy is injected from the transfer ladle onto a second inclined ramp to further limit the speed of the molten copper alloy, and the molten copper alloy is solidified before being placed in one or more molds or shot pits. (Embodiment 31) The method according to any one embodiment of Embodiments 1 to 30, wherein the step of bubbling the inert gas comprises bubbling using a diffusion lining formed on the inner surface of the melting furnace chamber, the diffusion lining comprising an aluminum silicate ceramic material having a porous structure adapted for bubbling the inert gas through the molten copper alloy. (Embodiment 32) The method according to any one embodiment of Embodiments 1 to 30, wherein the step of bubbling the inert gas comprises bubbling using a diffusion lining formed in the melting furnace chamber, the diffusion lining substantially covering the bottom inner surface of the melting furnace and having a porous structure adapted for bubbling the inert gas into the molten copper alloy. (Embodiment 33) The method according to any one embodiment of Embodiments 1 to 30, wherein the step of bubbling the inert gas comprises bubbling using a diffusion lining having a porous structure, the diffusion lining being formed on at least two different inner surfaces of the melting furnace, and as a result the diffusion lining being adapted to bubble the inert gas through the molten copper alloy from the at least two different inner surfaces. (Embodiment 34) The diffusion lining is the method according to embodiment 32 or 33, comprising an aluminum silicate ceramic. (Embodiment 35) The diffusion lining substantially covers the inner surface of the bottom of the melting furnace, according to the method of embodiment 31 or 33. (Embodiment 36) The diffusion lining is formed on at least two different inner surfaces of the melting furnace, and as a result, the diffusion lining is adapted to bubble an inert gas through the molten copper-based alloy from the at least two different inner surfaces, according to the method of Embodiment 31 or 32. (Embodiment 37) The method further conforms to any one of the embodiments in Additional Example VI, according to the method described in any one of Embodiments 1 to 36. Additional Example III: (Embodiment 1) An apparatus for producing a copper-based alloy, comprising: A melting furnace configured to form a molten copper-based alloy containing at least 50% by weight of copper; A diffusion lining formed on the inner surface of the melting furnace and including an aluminum silicate ceramic having a porous structure adapted to bubble an inert gas through the molten copper-based alloy; An apparatus comprising. (Embodiment 2) An apparatus for producing a copper-based alloy, comprising: A melting furnace configured to form a molten copper-based alloy containing at least 50% by weight of copper; A diffusion lining substantially covering the bottom inner surface of the melting furnace and having a porous structure adapted to bubble an inert gas into the molten copper-based alloy; An apparatus comprising. (Embodiment 3) An apparatus for producing a copper-based alloy, comprising: A melting furnace configured to form a molten copper-based alloy containing at least 50% by weight of copper; A diffusion lining having a porous structure in the melting furnace; Comprising, The diffusion lining is formed on at least two different inner surfaces of the melting furnace, and as a result, the diffusion lining is adapted to bubble an inert gas through the molten copper-based alloy from the at least two different inner surfaces. (Embodiment 4) The apparatus according to Embodiment 2 or 3, wherein the diffusion lining includes an aluminum silicate ceramic. (Embodiment 5) The apparatus according to Embodiment 1 or 3, wherein the diffusion lining substantially covers the inner surface of the bottom of the melting furnace. (Embodiment 6) The apparatus according to Embodiment 1 or 2, wherein the diffusion lining is formed on at least two different inner surfaces of the melting furnace, and as a result, the diffusion lining is adapted to bubble an inert gas through the molten copper alloy from the at least two different inner surfaces. (Embodiment 7) The apparatus according to any one embodiment of Embodiments 1 to 6, wherein the diffusion lining comprises alumina and silica. (Embodiment 8) The apparatus according to any one embodiment of Embodiments 1 to 7, wherein the diffusion lining includes mullite. (Embodiment 9) The apparatus according to any one embodiment of Embodiments 1 to 8, wherein the diffusion lining comprises at least two layers, including a sintered ceramic layer and an unsintered ceramic layer. (Embodiment 10) The apparatus according to Embodiment 9, wherein the sintered ceramic layer includes mullite. (Embodiment 11) The apparatus according to Embodiment 9, wherein the unsintered ceramic layer comprises alumina and silica. (Embodiment 12) The apparatus according to embodiment 10, wherein the sintered ceramic layer is configured to come into contact with the molten copper alloy. (Embodiment 13) The apparatus according to Embodiment 9, wherein the unsintered ceramic layer includes a compressed ceramic powder layer containing alumina and silica. (Embodiment 14) The apparatus according to Embodiment 9, wherein the sintered ceramic layer is formed by partially sintering the compressed ceramic powder layer such that the sintered ceramic layer and the unsintered ceramic layer have substantially the same chemical composition but different phases. (Embodiment 15) The apparatus according to Embodiment 9, wherein the unsintered ceramic layer contains 60-70% alumina and 20-25% silica. (Embodiment 16) The apparatus according to Embodiment 9, wherein the unsintered ceramic layer has an average particle size of less than 63 mm or includes a compressed ceramic powder layer corresponding to number 4 on the f scale. (Embodiment 17) The apparatus according to any one embodiment of Embodiments 1 to 16, wherein the diffusion lining has a thickness of 3 to 6 inches. (Embodiment 18) The apparatus according to any one embodiment of Embodiments 1 to 17, wherein the diffusion lining covers the entire inner surface of the bottom of the melting furnace. (Embodiment 19) The apparatus according to any one embodiment of Embodiments 1 to 18, wherein the diffusion lining on the inner surface of the bottom of the melting furnace has a thickness of 4 to 6 inches. (Embodiment 20) The apparatus according to any one embodiment of Embodiments 1 to 19, wherein the diffusion lining covers at least the inner side wall surface of the melting furnace. (Embodiment 21) The apparatus according to any one embodiment of Embodiments 1 to 20, wherein the diffusion lining covering the inner side wall of the melting furnace has a thickness of 3 to 4 inches. (Embodiment 22) The apparatus according to any one embodiment of Embodiments 1 to 21, wherein the diffusion lining is configured to come into contact with the molten copper alloy. (Embodiment 23) The apparatus according to any one embodiment of Embodiments 1 to 22, wherein the inert gas is essentially argon. (Embodiment 24) The apparatus according to any one embodiment of Embodiments 1 to 23, wherein the inert gas does not contain hydrogen. (Embodiment 25) The apparatus according to any one embodiment of Embodiments 1 to 24, further comprising a diffuser centrally located within the diffusion lining on the bottom inner surface of the melting furnace, wherein the diffuser includes a diffuser material located in a container having an upper surface located below the upper surface of the diffusion lining covering the bottom inner surface, and connected to an inert gas source. (Embodiment 26) The apparatus according to Embodiment 25, wherein the diffuser overlaps with a portion of the diffusion lining on the inner surface of the bottom of the melting furnace. (Embodiment 27) The apparatus according to Embodiment 26, wherein the diffuser is in contact with the diffusion lining and contains the same material as the diffusion lining. (Embodiment 28) The apparatus according to any one embodiment of embodiments 25 to 27, wherein one or both of the diffuser and the diffusion lining have a porosity of more than 20%. (Embodiment 29) The apparatus according to any one embodiment of embodiments 25 to 28, wherein the diffuser has a lateral dimension of less than 50% of the lateral dimension of the diffusion lining covering the inner surface of the bottom of the melting furnace. (Embodiment 30) The apparatus according to any one embodiment of embodiments 25 to 29, wherein the diffuser has a diameter greater than 5 cm and a diameter smaller than the diameter of the diffusion lining covering the inner surface of the bottom of the melting furnace. (Embodiment 31) The apparatus according to any one embodiment of Embodiments 25 to 30, wherein the diffusion lining covering the inner surface of the bottom of the melting furnace has a diameter of more than 50 cm. (Embodiment 32) The apparatus according to any one embodiment of Embodiments 25 to 31, wherein the melting furnace is configured to melt the copper alloy in a sealed chamber configuration in which the atmosphere above the molten copper alloy is isolated from the external atmosphere. (Embodiment 33) The apparatus according to any one embodiment of embodiments 25 to 31, wherein the melting furnace is configured to melt the copper alloy in an open chamber configuration in which the atmosphere above the molten copper alloy is exposed to the external atmosphere. (Embodiment 34) The apparatus according to embodiment 32, wherein the apparatus is configured to diffuse and flow the inert gas at a flow rate of 2 to 6 liters / minute under the sealed chamber configuration. (Embodiment 35) The apparatus according to embodiment 33, configured to diffusely flow the inert gas at a flow rate of 4 to 13 liters / minute under the open chamber configuration. (Embodiment 36) The apparatus according to any one embodiment of Embodiments 1 to 35, wherein the melting furnace is an induction furnace comprising an induction coil configured to surround the melting furnace and melt the copper-based alloy. (Embodiment 37) The apparatus according to embodiment 36, wherein the induction furnace is configured to operate at a frequency of less than 1000 Hz. (Embodiment 38) The apparatus according to embodiments 36 and 37, wherein the uppermost winding of the induction coil is positioned vertically below the filling line of the molten copper alloy. (Embodiment 39) The apparatus according to any one embodiment of Embodiments 1 to 38, further comprising an inert gas source connected to the diffusion lining and supplying the inert gas to the melting furnace. (Embodiment 40) The apparatus according to any one embodiment of Embodiments 1 to 39, further comprising a diffuser smaller than the diffusion lining covering the inner surface of the bottom of the melting furnace and embedded within the diffusion lining. (Embodiment 41) The apparatus according to Embodiment 40, wherein the diffuser and the diffusion lining include the same diffuser material. (Embodiment 42) The apparatus according to Embodiment 40, wherein the diffuser is connected to an inert gas source and includes a diffuser material disposed in a container having an upper surface positioned below the upper surface of the diffusion lining covering the bottom inner surface of the melting furnace. (Embodiment 43) The apparatus is the apparatus according to any one embodiment of Embodiments 1 to 42, further following any one embodiment of the embodiment in Additional Embodiment I. Additional Example IV: (Embodiment 1) A method for manufacturing a copper alloy manufacturing apparatus, The steps include providing a melting furnace chamber configured to form a molten copper-based alloy containing at least 50% by weight of copper, A step of forming a diffusion lining on the inner surface of the melting furnace chamber, wherein the diffusion lining comprises an aluminum silicate ceramic material having a porous structure adapted to bubble an inert gas through the molten copper alloy, Methods that include... (Embodiment 2) A method for manufacturing a copper alloy manufacturing apparatus, The steps include providing a melting furnace chamber configured to form a molten copper-based alloy containing at least 50% by weight of copper, The steps include forming a diffusion lining having a porous structure that substantially covers the inner surface of the bottom of the melting furnace and is adapted to bubble an inert gas into the molten copper alloy, Methods that include... (Embodiment 3) A method for manufacturing a copper alloy manufacturing apparatus, The steps include providing a melting furnace chamber configured to form a molten copper-based alloy containing at least 50% by weight of copper, A step of forming a diffusion lining having a porous structure on at least two different inner surfaces of the melting furnace, wherein the diffusion lining is adapted to bubble an inert gas through the molten copper alloy from the at least two different inner surfaces, Methods that include... (Embodiment 4) The diffusion lining is the method according to Embodiment 2 or 3, comprising an aluminum silicate ceramic. (Embodiment 5) The method according to Embodiment 1 or 3, wherein the step of forming the diffusion lining includes substantially covering the inner surface of the bottom of the melting furnace. (Embodiment 6) The method according to Embodiment 1 or 2, wherein the step of forming the diffusion lining is to form it on at least two different inner surfaces of the melting furnace, so that the diffusion lining is adapted to bubble the inert gas through the molten copper alloy from the at least two different inner surfaces. (Embodiment 7) The diffusion lining is a method according to any one embodiment of Embodiments 1 to 6, comprising alumina and silica. (Embodiment 8) The diffusion lining is a method according to any one embodiment of Embodiments 1 to 7, wherein the diffusion lining includes mullite. (Embodiment 9) The method according to any one embodiment of Embodiments 1 to 8, wherein the step of forming the diffusion lining includes forming at least a sintered ceramic layer and an unsintered ceramic layer. (Embodiment 10) The method according to Embodiment 9, wherein the step of forming the sintered ceramic layer includes sintering a portion of the compressed ceramic powder layer to form mullite. (Embodiment 11) The method according to Embodiment 9, wherein the step of forming the unsintered ceramic layer includes forming a compressed ceramic powder layer containing alumina and silica. (Embodiment 12) The method according to Embodiment 10, wherein the step of forming the sintered ceramic layer is configured to be in contact with the molten copper alloy. (Embodiment 13) The method according to Embodiment 9, wherein the step of forming the sintered layer and the unsintered layer is to form them from the same compressed ceramic powder layer containing alumina and silica. (Embodiment 14) The method according to Embodiment 9, wherein the step of forming the sintered ceramic layer includes partially sintering a compressed ceramic powder layer such that the sintered ceramic layer and the unsintered ceramic layer have substantially the same chemical composition but different phases. (Embodiment 15) The method according to Embodiment 9, wherein the unsintered ceramic layer contains 60-70% alumina and 20-25% silica. (Embodiment 16) The method according to Embodiment 9, wherein the unsintered ceramic layer includes a compressed ceramic powder layer having an average particle size of less than 63 mm or corresponding to number 4 on the f scale. (Embodiment 17) The diffusion lining is the method according to any one embodiment of Embodiments 1 to 16, having a thickness of 3 to 6 inches. (Embodiment 18) The method according to any one embodiment of Embodiments 1 to 17, wherein the step of forming the diffusion lining includes covering the entire inner surface of the bottom of the melting furnace. (Embodiment 19) The diffusion lining on the inner surface of the bottom of the melting furnace has a thickness of 4 to 6 inches, according to the method of any one embodiment of Embodiments 1 to 18. (Embodiment 20) The method according to any one embodiment of Embodiments 1 to 19, wherein the step of forming the diffusion lining includes covering at least the side walls of the melting furnace. (Embodiment 21) The diffusion lining covering the side wall of the melting furnace has a thickness of 3 to 4 inches (as described in any one embodiment of Embodiments 1 to 20). (Embodiment 22) The method according to any one embodiment of Embodiments 1 to 21, wherein the step of forming the diffusion lining is configured to be in contact with the molten copper alloy. (Embodiment 23) The method according to any one embodiment of Embodiments 1 to 22, wherein the inert gas is essentially argon. (Embodiment 24) The method according to any one embodiment of Embodiments 1 to 23, wherein the inert gas does not contain hydrogen. (Embodiment 25) The method according to any one embodiment of Embodiments 1 to 24, further comprising the step of positioning a diffuser at the bottom of the melting furnace, centered beneath the diffusion lining. (Embodiment 26) The method according to Embodiment 25, wherein the step of positioning the diffuser includes positioning it so as to overlap with a portion of the diffusion lining at the bottom of the melting furnace. (Embodiment 27) The method according to Embodiment 26, wherein the step of arranging the diffuser includes bringing the diffusion lining into contact with the diffuser, which comprises the same material as the diffusion lining. (Embodiment 28) The method according to any one embodiment of embodiments 25 to 27, wherein one or both of the diffuser and the diffusion lining have a porosity of more than 20%. (Embodiment 29) The method according to any one embodiment of embodiments 25 to 28, wherein the diffuser has a lateral dimension of less than 50% of the lateral dimension of the diffusion lining covering the inner surface of the bottom of the melting furnace. (Embodiment 30) The method according to any one embodiment of embodiments 25 to 29, wherein the diffuser has a diameter greater than 5 cm and a diameter smaller than the diameter of the diffusion lining covering the inner surface of the bottom of the melting furnace. (Embodiment 31) The diffusion lining covering the inner surface of the bottom of the melting furnace has a diameter of more than 50 cm, according to the method of any one embodiment of embodiments 25 to 30. (Embodiment 32) The method according to any one embodiment of Embodiments 25 to 31, further comprising the step of configuring the melting furnace to melt the copper alloy in a sealed chamber configuration in which the atmosphere above the molten copper alloy is isolated from the external atmosphere. (Embodiment 33) The method according to any one embodiment of embodiments 25 to 31, further comprising the step of configuring the melting furnace to melt the copper alloy in an open chamber configuration in which the atmosphere above the molten copper alloy is exposed to the external atmosphere. (Embodiment 34) The method according to Embodiment 32, further comprising the step of configuring the apparatus to diffuse and flow the inert gas at a flow rate of 2 to 6 liters / minute in a sealed chamber configuration. (Embodiment 35) The method according to Embodiment 33, further comprising the step of configuring the apparatus to diffusely flow the inert gas at a flow rate of 4 to 13 liters / minute in an open chamber configuration. (Embodiment 36) The method according to any one embodiment of Embodiments 1 to 35, wherein the melting furnace is an induction furnace equipped with a peripheral induction coil configured to melt the copper-based alloy. (Embodiment 37) The method according to embodiment 36, wherein the induction furnace is configured to operate at a frequency of less than 1000 Hz. (Embodiment 38) The method according to embodiments 36 and 37, wherein the uppermost winding of the induction coil is positioned at half the height of the molten copper alloy. (Embodiment 39) The method described above is the method according to any one embodiment of Embodiments 1 to 38, further following any one embodiment of the embodiment in Additional Embodiment V. Additional Example V: (Embodiment 1) A method for manufacturing an alloy manufacturing apparatus, The steps include providing a melting furnace chamber, A step of placing a compressed ceramic powder layer on the inner surface of the melting furnace chamber, wherein the compressed ceramic powder layer comprises a mixture of silica and alumina, A step of sintering the compressed ceramic powder layer in the melting furnace to form a diffusion lining on the inner surface, wherein the diffusion lining comprises an aluminum silicate ceramic material having a porous structure adapted to diffuse gas, Methods that include... (Embodiment 2) A method for manufacturing an alloy manufacturing apparatus, The steps include providing a melting furnace chamber, The steps include: placing a compressed ceramic powder layer on the inner surface of the melting furnace chamber; The steps include selectively sintering the surface portion of the compressed ceramic powder layer, thereby forming a diffusion lining including a sintered ceramic layer on the inner surface of the unsintered ceramic layer, Methods that include... (Embodiment 3) A method for manufacturing an alloy manufacturing apparatus, The steps include providing a melting furnace chamber, The steps include: placing a compressed ceramic powder layer on the inner surface of the melting furnace chamber; The steps include: using heat from the heated material placed in the melting furnace chamber to sinter the compressed ceramic powder layer, thereby forming a diffusion lining on the inner surface; Methods that include... (Embodiment 4) The method according to Embodiment 2 or 3, wherein the step of sintering the compressed ceramic powder layer includes sintering it in the melting furnace to form the diffusion lining, the diffusion lining comprising an aluminum silicate ceramic material having a porous structure adapted to diffuse gas. (Embodiment 5) The method according to Embodiment 1 or 3, wherein the sintering step includes selectively sintering the surface portion of the compressed ceramic powder layer, thereby forming a diffusion lining including a sintered ceramic layer on the inner surface of the unsintered ceramic layer. (Embodiment 6) The method according to Embodiment 1 or 2, wherein the sintering step includes using heat from a heated material placed in the melting furnace chamber to thereby form a diffusion lining on the inner surface. (Embodiment 7) The method according to any one embodiment of Embodiments 1 to 6, wherein the step of arranging the compressed ceramic powder layer includes covering the bottom surface of the melting furnace chamber with the bottom compressed ceramic powder layer. (Embodiment 8) The method according to any one embodiment of Embodiments 1 to 7, wherein the step of arranging the compressed ceramic powder layer includes covering the side wall of the melting furnace chamber with the side wall compressed ceramic powder layer. (Embodiment 9) The method according to any one embodiment of Embodiments 1 to 8, wherein the sintering step includes using heat from a material that is placed in the melting furnace chamber and heated using electricity applied to the melting furnace chamber. (Embodiment 10) The method according to Embodiment 9, wherein the power applied to the melting furnace chamber includes induced power delivered through coils surrounding the melting furnace chamber. (Embodiment 11) The method according to Embodiment 9, wherein the sintering step includes using heat from an iron-containing material that is inductively heated by power applied to the melting furnace chamber. (Embodiment 12) The method according to Embodiment 9, wherein the sintering step includes using heat from the iron-containing material to be molten using power applied to the melting furnace chamber. (Embodiment 13) The method according to Embodiment 9, wherein the material is heated to a temperature sufficient to form mullite from silica and alumina. (Embodiment 14) The diffusion lining is the method according to any one embodiment of Embodiments 1 to 13, comprising alumina and silica. (Embodiment 15) The diffusion lining is a method according to any one embodiment of Embodiments 1 to 14, wherein the diffusion lining includes mullite. (Embodiment 16) The method according to any one embodiment of Embodiments 1 to 15, wherein the step of forming the diffusion lining includes forming at least a sintered ceramic layer and an unsintered ceramic layer. (Embodiment 17) The method according to Embodiment 16, wherein the step of forming the sintered ceramic layer includes sintering a portion of the compressed ceramic powder layer to form mullite. (Embodiment 18) The method according to Embodiment 17, wherein the unsintered ceramic layer includes the remaining portion of the compressed ceramic powder layer that does not form mullite. (Embodiment 19) The method according to Embodiment 16, wherein the step of forming the sintered ceramic layer is configured to be in contact with the molten copper alloy. (Embodiment 20) The method according to Embodiment 16, wherein the step of forming the sintered layer and the unsintered layer is to form them from the same compressed ceramic powder layer containing alumina and silica. (Embodiment 21) The method according to Embodiment 16, wherein the step of forming the sintered ceramic layer includes partially sintering a compressed ceramic powder layer such that the sintered ceramic layer and the unsintered ceramic layer have substantially the same chemical composition but different phases. (Embodiment 22) The compressed ceramic powder layer comprises 60-70% alumina and 20-25% silica, according to the method of any one embodiment of Embodiments 1 to 21. (Embodiment 23) The method according to any one embodiment of Embodiments 1 to 22, wherein the compressed ceramic powder layer has an average particle size of less than 63 mm or contains particles corresponding to number 4 on the f scale. (Embodiment 24) The compressed ceramic powder layer has a thickness of 3 to 6 inches, according to the method of any one embodiment of Embodiments 1 to 23. (Embodiment 25) The method according to any one embodiment of Embodiments 1 to 24, wherein the step of arranging the compressed ceramic powder layer includes covering the entire inner surface of the bottom of the melting furnace. (Embodiment 26) The compressed ceramic powder layer on the inner surface of the bottom of the melting furnace has a thickness of 4 to 6 inches, according to the method of any one embodiment of Embodiments 1 to 25. (Embodiment 27) The method according to any one embodiment of Embodiments 1 to 26, wherein the step of arranging the compressed ceramic powder layer includes the step of covering at least the inner side wall surface of the melting furnace. (Embodiment 28) The compressed ceramic powder layer on the inner sidewall surface of the melting furnace has a thickness of 3 to 4 inches, according to any one embodiment of Embodiments 1 to 27. (Embodiment 29) A method according to any one embodiment of Embodiments 1 to 28, comprising the step of [doing something]. (Embodiment 30) The method according to any one embodiment of Embodiments 1 to 29, further comprising the step of positioning a diffuser at the bottom of the melting furnace, centered beneath the diffusion lining. (Embodiment 31) The method according to Embodiment 30, wherein the step of positioning the diffuser includes positioning it so as to overlap with a portion of the diffusion lining at the bottom of the melting furnace. (Embodiment 32) The method according to Embodiment 31, wherein the step of arranging the diffuser includes bringing the diffusion lining into contact with the diffuser, which comprises the same material as the diffusion lining. (Embodiment 33) The method according to any one embodiment of embodiments 30 to 32, wherein one or both of the diffuser and the diffusion lining have a porosity of more than 20%. (Embodiment 34) The method according to any one embodiment of embodiments 30 to 33, wherein the diffuser has a lateral dimension of less than 50% of the lateral dimension of the diffusion lining covering the inner surface of the bottom of the melting furnace. (Embodiment 35) The method according to any one embodiment of embodiments 30 to 34, wherein the diffuser has a diameter greater than 5 cm and a diameter smaller than the diameter of the diffusion lining covering the inner surface of the bottom of the melting furnace. (Embodiment 36) The diffusion lining covering the inner surface of the bottom of the melting furnace has a diameter of more than 50 cm, according to the method of any one embodiment of embodiments 30 to 35. (Embodiment 37) The method according to any one embodiment of embodiments 30 to 36, further comprising the step of configuring the melting furnace to melt the copper alloy in a sealed chamber configuration in which the atmosphere above the molten copper alloy is isolated from the external atmosphere. (Embodiment 38) The method according to any one embodiment of embodiments 30 to 37, further comprising the step of configuring the melting furnace to melt the copper alloy in an open chamber configuration in which the atmosphere above the molten copper alloy is exposed to the external atmosphere. (Embodiment 39) The method according to Embodiment 38, further comprising the step of configuring the apparatus to diffuse and flow the inert gas at a flow rate of 2 to 6 liters / minute in a sealed chamber configuration. (Embodiment 40) The method according to Embodiment 38, further comprising the step of configuring the apparatus to diffusely flow the inert gas at a flow rate of 4 to 13 liters / minute in an open chamber configuration. (Embodiment 41) The method according to any one embodiment of Embodiments 1 to 40, wherein the melting furnace is an induction furnace equipped with a peripheral induction coil configured to melt the copper-based alloy. (Embodiment 42) The method according to embodiment 41, wherein the induction furnace is configured to operate at a frequency of less than 1000 Hz. (Embodiment 43) The method according to embodiments 41 and 42, wherein the uppermost winding of the induction coil is positioned at half the height of the molten copper alloy. (Embodiment 44) The method according to any one embodiment of Embodiments 1 to 43, further comprising the step of connecting an inert gas supply source to the diffusion lining. (Embodiment 45) The method described above is a method according to any one embodiment of Embodiments 1 to 44, further following any one embodiment of the embodiment in Additional Embodiment IV. Additional Example VI: (Embodiment 1) A method for producing copper-based alloys, The steps include providing a raw material having a composition configured to form a molten copper-based alloy containing at least 50% by weight of copper into a melting furnace, The steps include heating the raw material to melt it and form the molten copper alloy, and A step of bubbling an inert gas through the molten copper alloy using a diffusion lining formed on the inner surface of the melting furnace chamber, wherein the diffusion lining comprises an aluminum silicate ceramic material having a porous structure adapted for bubbling the inert gas through the molten copper alloy, Methods that include... (Embodiment 2) A method for producing copper-based alloys, The steps include providing a raw material having a composition configured to form a molten copper-based alloy containing at least 50% by weight of copper into a melting furnace, The steps include heating the raw material to melt it and form the molten copper alloy, and A step of bubbling an inert gas through the molten copper alloy using a diffusion lining formed in the melting furnace chamber, wherein the diffusion lining substantially covers the bottom inner surface of the melting furnace and has a porous structure adapted to bubbling the inert gas into the molten copper alloy; Methods that include... (Embodiment 3) A method for producing copper-based alloys, The steps include providing a raw material having a composition configured to form a molten copper-based alloy containing at least 50% by weight of copper into a melting furnace, The steps include heating the raw material to melt it and form the molten copper alloy, and A step of bubbling an inert gas through the molten copper alloy using a diffusion lining having a porous structure, wherein the diffusion lining is formed on at least two different inner surfaces of the melting furnace, and as a result the diffusion lining is adapted to bubble the inert gas through the molten copper alloy from the at least two different inner surfaces, Methods that include... (Embodiment 4) The diffusion lining is the method according to Embodiment 2 or 3, comprising an aluminum silicate ceramic. (Embodiment 5) The diffusion lining substantially covers the inner surface of the bottom of the melting furnace, according to the method of Embodiment 1 or 3. (Embodiment 6) The method according to Embodiment 1 or 2, wherein the diffusion lining is formed on at least two different inner surfaces of the melting furnace, and as a result, the diffusion lining is adapted to bubble an inert gas through the molten copper alloy from the at least two different inner surfaces. (Embodiment 7) The diffusion lining is a method according to any one embodiment of Embodiments 1 to 6, comprising alumina and silica. (Embodiment 8) The diffusion lining is a method according to any one embodiment of Embodiments 1 to 7, wherein the diffusion lining includes mullite. (Embodiment 9) The diffusion lining comprises at least two layers, including a sintered ceramic layer and an unsintered ceramic layer, according to the method of any one embodiment of Embodiments 1 to 8. (Embodiment 10) The method according to Embodiment 9, wherein the unsintered ceramic layer includes mullite. (Embodiment 11) The method according to Embodiment 9, wherein the unsintered ceramic layer comprises alumina and silica. (Embodiment 12) The method according to Embodiment 10, wherein the sintered ceramic layer is in contact with the molten copper alloy. (Embodiment 13) The method according to Embodiment 9, wherein the unsintered layer includes a compressed ceramic powder layer containing alumina and silica. (Embodiment 14) The method according to Embodiment 9, wherein the sintered ceramic layer is formed by partially sintering a compressed ceramic powder layer such that the sintered ceramic layer and the unsintered ceramic layer have substantially the same chemical composition but different phases. (Embodiment 15) The method according to Embodiment 9, wherein the unsintered ceramic layer contains 60-70% alumina and 20-25% silica. (Embodiment 16) The method according to Embodiment 9, wherein the unsintered ceramic layer comprises compressed ceramic powder having an average particle size of less than 63 mm or corresponding to number 4 on the f scale. (Embodiment 17) The diffusion lining is the method according to any one embodiment of Embodiments 1 to 16, having a thickness of 3 to 6 inches. (Embodiment 18) The diffusion lining covers the entire inner surface of the bottom of the melting furnace, according to the method of any one embodiment of Embodiments 1 to 17. (Embodiment 19) The diffusion lining on the inner surface of the bottom of the melting furnace has a thickness of 4 to 6 inches, according to the method of any one embodiment of Embodiments 1 to 18. (Embodiment 20) The diffusion lining covers at least the side walls of the melting furnace, according to the method of any one embodiment of Embodiments 1 to 19. (Embodiment 21) The diffusion lining covering the side wall of the melting furnace has a thickness of 3 to 4 inches, according to the method of any one embodiment of Embodiments 1 to 20. (Embodiment 22) The method according to any one embodiment of Embodiments 1 to 21, wherein the diffusion lining is configured to come into contact with the molten copper alloy. (Embodiment 23) The method according to any one embodiment of Embodiments 1 to 22, wherein the inert gas is essentially argon. (Embodiment 24) The method according to any one embodiment of Embodiments 1 to 23, wherein the inert gas does not contain hydrogen. (Embodiment 25) The method according to any one embodiment of Embodiments 1 to 24, further comprising a diffuser positioned in the center below the diffusion lining at the bottom of the melting furnace. (Embodiment 26) The diffuser overlaps with a portion of the diffusion lining at the bottom of the melting furnace, according to the method of Embodiment 25. (Embodiment 27) The method according to Embodiment 26, wherein the diffuser is in contact with the diffusion lining and comprises the same material as the diffusion lining. (Embodiment 28) The method according to any one embodiment of embodiments 25 to 27, wherein one or both of the diffuser and the diffusion lining have a porosity of more than 20%. (Embodiment 29) The method according to any one embodiment of embodiments 25 to 28, wherein the diffuser has a lateral dimension of less than 50% of the lateral dimension of the diffusion lining covering the inner surface of the bottom of the melting furnace. (Embodiment 30) The method according to any one embodiment of embodiments 25 to 29, wherein the diffuser has a diameter greater than 5 cm and a diameter smaller than the diameter of the diffusion lining covering the inner surface of the bottom of the melting furnace. (Embodiment 31) The diffusion lining covering the inner surface of the bottom of the melting furnace has a diameter of more than 50 cm, according to the method of any one embodiment of embodiments 25 to 30. (Embodiment 32) The method according to any one embodiment of Embodiments 25 to 31, wherein the step of melting the raw material includes melting the molten copper alloy in a sealed chamber configuration in which the atmosphere above the molten copper alloy is isolated from the external atmosphere. (Embodiment 33) The method according to any one embodiment of Embodiments 25 to 31, wherein the step of melting the raw material includes melting the molten copper alloy in an open chamber configuration in which the atmosphere above the molten copper alloy is exposed to the external atmosphere. (Embodiment 34) The method according to Embodiment 32, wherein the step of bubbling the inert gas further includes diffusing and flowing the inert gas at a flow rate of 2 to 6 liters / minute in a sealed chamber configuration. (Embodiment 35) The method according to Embodiment 33, wherein the step of bubbling the inert gas includes diffusing and flowing the inert gas at a flow rate of 4 to 13 liters / minute in an open chamber configuration. (Embodiment 36) The method according to any one embodiment of Embodiments 1 to 35, wherein the melting step includes inductively heating the raw material by supplying power to induction coils surrounding the melting furnace. (Embodiment 37) The step of providing the raw materials includes providing a plurality of raw material pieces having a composite composition configured to form the molten copper alloy, and flowing the inert gas through the gaps between the raw material pieces before heating, The heating step includes heating the raw material piece while passing the inert gas through it, thereby melting the raw material piece and forming the molten copper alloy. The method according to any one embodiment of Embodiments 1 to 36, further comprising the step of bubbling the inert gas through the molten copper alloy and then transferring the molten copper alloy to a transfer ladle. (Embodiment 38) The step of providing the raw materials includes providing a plurality of raw material pieces having a composite composition configured to form the molten copper alloy, and flowing the inert gas through the gaps between the raw material pieces before heating, The method further includes the step of bubbling the inert gas through the molten copper alloy and then transferring the molten copper alloy to a transfer ladle. The method according to any one embodiment of Embodiments 1 to 36, wherein one or more of the steps of heating the raw material pieces, bubbling the inert gas, and transferring the molten copper alloy are performed at least partially under a sealed inert atmosphere, and the sealed inert atmosphere is configured to substantially prevent outside air from mixing with the sealed inert atmosphere. (Embodiment 39) The step of providing the raw materials includes providing a plurality of raw material pieces having a composite composition configured to form the molten copper alloy, The method further includes the step of bubbling the inert gas through the molten copper alloy and then transferring the molten copper alloy to a transfer ladle. The method according to any one embodiment of Embodiments 1 to 36, wherein the transfer step includes limiting the rate at which the molten copper alloy is transferred from the melting furnace to the transfer ladle to less than 100 inches per second. (Embodiment 40) The method according to Embodiment 38 or 39, further comprising the step of passing an inert gas through the gaps between the raw material pieces before heating, wherein the heating step comprises heating the raw material pieces while passing the inert gas through them. (Embodiment 41) The method according to Embodiment 37 or 39, wherein one or more of the steps of heating the raw material pieces, bubbling the inert gas, and transferring the molten copper alloy are performed at least partially under a sealed inert atmosphere, and the sealed inert atmosphere is configured to substantially prevent outside air from mixing with the sealed inert atmosphere. (Embodiment 42) The method according to embodiment 37 or 38, wherein the transfer step includes limiting the rate at which the molten copper alloy is transferred from the melting furnace to the transfer ladle to less than 100 inches per second. (Embodiment 43) The method described above is a method according to any one embodiment of Embodiments 37 to 42, further following any method according to any one embodiment of Embodiments 7 to 30 in Additional Example II. (Embodiment 44) The method according to any one embodiment of Embodiments 1 to 43, wherein the melting furnace is an induction furnace equipped with a peripheral induction coil configured to melt the copper-based alloy. (Embodiment 45) The method according to embodiment 44, wherein the induction furnace is configured to operate at a frequency of less than 1000 Hz. (Embodiment 46) The method according to embodiments 44 and 45, wherein the uppermost winding of the induction coil is positioned at half the height of the molten copper alloy. (Embodiment 47) The method described above is a method according to any one embodiment of Embodiments 1 to 46, further following any one embodiment of the embodiment in Additional Embodiment II. Additional Example VII: (Embodiment 1) Apparatus for manufacturing copper-based alloys, A melting furnace configured to form a molten copper alloy containing at least 50% by weight of copper, the melting furnace being configured to rotate around a central axis, One or more diffuser blocks comprising a porous diffusion material adapted to bubble an inert gas through the molten copper alloy, A device equipped with the following features. (Embodiment 2) Apparatus for manufacturing copper-based alloys, A melting furnace configured to form a molten copper alloy containing at least 50% by weight of copper, the melting furnace being configured to rotate about a central axis extending in the longitudinal direction of the melting furnace, One or more diffuser blocks adapted to bubble an inert gas through the molten copper alloy in a direction intersecting the central axis, A device equipped with the following features. (Embodiment 3) Apparatus for manufacturing copper-based alloys, A melting furnace configured to form a molten copper-based alloy containing at least 50% by weight of copper, A flame injector configured to direct the flow of flame along the central axis of the melting furnace and functioning as a heat source for forming the molten copper alloy, One or more diffuser blocks comprising a porous structure adapted for bubbling an inert gas through the molten copper alloy, A device equipped with the following features. (Embodiment 4) The apparatus according to Embodiment 1, wherein the one or more diffuser blocks further comprises a fire-resistant diffuser lining around the porous diffusion material. (Embodiment 5) The apparatus according to Embodiment 4, wherein the fire-resistant diffuser lining includes mullite. (Embodiment 6) The apparatus according to Embodiment 4, wherein the fire-resistant diffuser lining comprises alumina and silica. (Embodiment 7) The apparatus according to Embodiment 4, wherein the refractory diffuser lining has a thermal expansion coefficient within 10% of the thermal expansion coefficient of the lining of the melting furnace. (Embodiment 8) The apparatus according to Embodiment 4, wherein the fire-resistant diffuser lining and the lining of the melting furnace are made of the same material. (Embodiment 9) The apparatus according to Embodiment 1, wherein at least one of the one or more diffuser blocks includes a trapezoidal or conical cross-sectional profile. (Embodiment 10) The apparatus according to Embodiment 1, wherein at least one of the one or more diffuser blocks further comprises an outlet end configured to contact the molten copper alloy and an inlet end opposite to the outlet end, the outlet end being narrower than the inlet end. (Embodiment 11) The apparatus according to Embodiment 1, wherein one or more diffuser blocks are connected to the chamber of the melting furnace through through holes in the melting furnace. (Embodiment 12) The apparatus according to Embodiment 1, wherein the one or more diffuser blocks comprises two or more diffuser blocks. (Embodiment 13) The apparatus according to embodiment 12, wherein the two or more diffuser blocks are arranged in a line along the extension direction of the melting furnace. (Embodiment 14) The apparatus according to embodiment 12, wherein the two or more diffuser blocks are arranged in a line along the direction of the central axis. (Embodiment 15) The apparatus according to Embodiment 12, wherein two of the two or more diffuser blocks are spaced apart in a first direction by a first distance which is at least 30% of the length of the furnace chamber as measured in the first direction. (Embodiment 16) The apparatus according to embodiment 12, wherein the two or more diffuser blocks comprise four diffuser blocks. (Embodiment 17) The apparatus according to Embodiment 1, wherein one or more diffuser blocks are configured to contact the bottom surface of the molten copper alloy. (Embodiment 18) The apparatus according to Embodiment 1, wherein one or more diffuser blocks are configured to bubble an inert gas through the molten copper alloy while the melting furnace is rotating. (Embodiment 19) The apparatus according to Embodiment 1, wherein the position in which one or more diffuser blocks bubble an inert gas into the molten copper alloy moves as the melting furnace rotates. (Embodiment 20) The apparatus according to Embodiment 1, wherein one or more diffuser blocks are configured to bubble an inert gas into the molten copper alloy from at least two positions as the melting furnace rotates. (Embodiment 21) The apparatus according to Embodiment 2, wherein the one or more diffuser blocks include a porous diffusion material adapted to bubble an inert gas through the molten copper alloy. (Embodiment 22) The apparatus according to Embodiment 2, wherein the one or more diffuser blocks include a porous diffusion material structure for bubbling an inert gas through a molten copper alloy. (Embodiment 23) The apparatus according to embodiment 22, wherein one or more diffuser blocks are arranged on the side wall of the melting furnace. (Embodiment 24) The apparatus according to Embodiment 2, wherein the melting furnace further comprises a loading portal having a loading portal door. (Embodiment 25) The apparatus according to embodiment 24, wherein the loading portal is positioned at least 90 degrees away from one of the one or more diffuser blocks in an azimuthal direction with respect to the central axis. (Embodiment 26) The apparatus according to embodiment 24, wherein the loading portal is located on the opposite side of the melting furnace from the one or more diffuser blocks. (Embodiment 27) The apparatus according to embodiment 24, wherein the melting furnace further comprises an injection portal different from the loading portal. (Embodiment 28) The apparatus according to Embodiment 3, wherein the melting furnace further comprises an exhaust portal connected to the chamber of the melting furnace and configured to discharge exhaust gas of the ignited fuel. (Embodiment 29) The apparatus according to embodiment 28, wherein the exhaust portal is located on the central axis. (Embodiment 30) The apparatus according to Embodiment 28, wherein the exhaust duct is configured to further guide the exhaust gas discharged from the chamber and is detachably positioned relative to the exhaust portal. (Embodiment 31) The apparatus according to embodiment 28, wherein the exhaust portal is connected to a drop-bottom cavity configured to reduce the velocity of the exhaust, and the drop-bottom cavity has a width greater than the width of the exhaust outlet. (Embodiment 32) The flame injector is positioned on the central axis, as described in Embodiment 3. (Embodiment 33) The apparatus according to Embodiment 3, wherein the flame injector is configured to inject fuel at high pressure or high speed such that the flame extends over a considerable length of the melting furnace. (Embodiment 34) The apparatus according to any one embodiment of Embodiments 1 to 33, further comprising an inert gas source connected to one or more diffuser blocks and supplying the inert gas. (Embodiment 35) The apparatus according to any one embodiment of Embodiments 1 to 34, wherein the atmosphere surrounding the melting furnace is configured to be substantially inert. (Embodiment 36) The apparatus according to any one embodiment of Embodiments 1 to 35, wherein the atmosphere inside the melting furnace is substantially inert. (Embodiment 37) The apparatus according to any one embodiment of Embodiments 1 to 36, wherein the atmosphere above the molten copper alloy is configured to be substantially inert. (Embodiment 38) The apparatus according to any one embodiment of Embodiments 1 to 37, wherein the layer of atmosphere inside the melting furnace is directly above and in contact with the molten copper alloy and is configured to be substantially inert. (Embodiment 39) The apparatus according to any one embodiment of Embodiments 1 to 38, wherein the melting furnace is configured to melt the copper-based alloy while removing the external atmosphere from the atmosphere above the molten copper-based alloy. (Embodiment 40) The apparatus according to any one embodiment of Embodiments 1 to 39, wherein the melting furnace is configured to melt the copper-based alloy in a sealed chamber configuration, and in the sealed chamber configuration, the atmosphere above the molten copper-based alloy is isolated from the external atmosphere. (Embodiment 41) The apparatus according to any one embodiment of Embodiments 1 to 40, configured to diffuse and flow the inert gas at a flow rate of 2 to 6 liters / minute under the sealed chamber configuration. (Embodiment 42) The melting furnace is configured to melt the copper-based alloy in an open chamber configuration, and in the open chamber configuration, the atmosphere above the molten copper-based alloy is sealed from the external atmosphere but connected to the external atmosphere, as described in any one embodiment of Embodiments 1 to 41. (Embodiment 43) The apparatus according to any one embodiment of Embodiments 1 to 42, configured to diffuse and flow the inert gas at a flow rate of 4 to 13 liters / minute under the open chamber configuration. (Embodiment 44) The apparatus according to any one embodiment of Embodiments 1 to 43, wherein the inert gas consists essentially of a noble gas. (Embodiment 45) The apparatus according to any one embodiment of Embodiments 1 to 44, wherein the inert gas is essentially argon. (Embodiment 46) The apparatus according to any one embodiment of Embodiments 1 to 45, wherein the inert gas essentially does not contain hydrogen and / or water. (Embodiment 47) The apparatus according to any one embodiment of Embodiments 1 to 46, wherein the porous structure or the porous diffusion material includes alumina, silica, or aluminum silicate ceramic. (Embodiment 48) The apparatus according to any one embodiment of Embodiments 1 to 47, wherein the porous structure or the porous diffusion material contains more than 60% by weight of alumina. (Embodiment 49) The apparatus according to any one embodiment of Embodiments 1 to 48, wherein the porous structure or the porous diffusion material contains less than 50% by weight of silica. (Embodiment 50) The apparatus according to any one embodiment of Embodiments 1 to 49, wherein the porous structure or the porous diffusion material includes Cr2O3. (Embodiment 51) The apparatus according to any one embodiment of Embodiments 1 to 50, wherein the porous structure or the porous diffusion material contains less than 10% by weight of Cr2O3. (Embodiment 52) The apparatus according to any one embodiment of Embodiments 1 to 51, wherein the porosity of the porous structure or the porous diffusion material is 15 to 40 volume%. (Embodiment 53) The porous structure or porous diffusion material is 25 cm 2 The apparatus according to any one embodiment of Embodiments 1 to 52, configured to directly contact the molten copper alloy having an effective area exceeding [a certain value]. (Embodiment 54) The apparatus according to any one embodiment of Embodiments 1 to 53, wherein the porous structure or the porous diffusion material is placed in an airtight container connected to an inert gas source. (Embodiment 55) The apparatus according to any one embodiment of Embodiments 1 to 54, wherein one or more diffuser blocks are configured to bubble the inert gas through the bottom surface of the molten copper alloy by directly contacting the bottom surface of the molten copper alloy. (Embodiment 56) The apparatus according to any one embodiment of Embodiments 1 to 55, wherein one or more diffuser blocks are configured to direct the inert gas diffused through them directly into the atmosphere above the molten copper alloy. (Embodiment 57) The apparatus according to any one embodiment of Embodiments 1 to 56, wherein the one or more diffuser blocks further comprises the porous diffusion material or a fire-resistant diffuser lining around the porous diffusion material. (Embodiment 58) The apparatus according to any one embodiment of Embodiments 1 to 57, wherein the fire-resistant diffuser lining and the lining of the melting furnace are made of the same material. (Embodiment 59) The apparatus according to any one embodiment of Embodiments 1 to 58, wherein the one or more diffuser blocks comprises two or more diffuser blocks. (Embodiment 60) The apparatus according to any one embodiment of Embodiments 1 to 59, wherein the two or more diffuser blocks are spaced apart along the extension direction of the melting furnace. (Embodiment 61) The apparatus according to any one embodiment of Embodiments 1 to 60, wherein the two or more diffuser blocks are spaced apart along the direction of the central axis. (Embodiment 62) The apparatus according to any one embodiment of Embodiments 1 to 61, wherein the melting furnace further comprises a loading portal having a loading portal door. (Embodiment 63) The aforementioned central axis extends in the horizontal direction, as described in any one embodiment of Embodiments 1 to 62. (Embodiment 64) The apparatus according to any one embodiment of Embodiments 1 to 63, wherein the melting furnace comprises an outer wall including a first end, a second end opposite to the first end, and a side wall connecting the first end and the second end. (Embodiment 65) The apparatus according to any one embodiment of Embodiments 1 to 64, wherein the central axis intersects with the first end and the second end. (Embodiment 66) The apparatus according to any one embodiment of Embodiments 1 to 65, wherein the central axis does not intersect with the side wall. (Embodiment 67) The apparatus according to any one embodiment of Embodiments 1 to 66, wherein the melting furnace has a cylindrical or barrel shape, and its central axis extends in the longitudinal direction of the cylindrical or barrel shape. (Embodiment 68) The apparatus according to any one embodiment of Embodiments 1 to 67, wherein the central axis extends substantially parallel to the ground. (Embodiment 69) The apparatus according to any one embodiment of Embodiments 1 to 68, wherein the melting furnace is configured to rotate at least 45 degrees around the central axis. (Embodiment 70) The apparatus according to any one embodiment of Embodiments 1 to 69, wherein the melting furnace is configured to rotate at least 90 degrees around a central axis. (Embodiment 71) The apparatus according to any one embodiment of Embodiments 1 to 70, wherein the atmosphere enclosed by the melting furnace is substantially inert. (Embodiment 72) The apparatus according to any one embodiment of embodiments 1 to 71, wherein the melting furnace can be rotated to a first configuration, and at least one of the one or more diffuser blocks is located in the lower half of the melting furnace. (Embodiment 73) The apparatus according to any one embodiment of embodiments 1 to 72, wherein the melting furnace is configured to rotate in a second configuration, and at least one of the one or more diffuser blocks is located in the upper half of the melting furnace. (Embodiment 74) The apparatus according to any one embodiment of Embodiments 1 to 73, wherein the melting furnace is configured to heat the copper alloy in a sealed configuration, and the sealed configuration excludes the external atmosphere from the atmosphere inside the melting furnace above the molten copper alloy. (Embodiment 75) The apparatus according to any one embodiment of Embodiments 1 to 74, wherein the external atmosphere is removed by the outward flow of the inert gas. (Embodiment 76) The apparatus according to any one embodiment of Embodiments 1 to 75, wherein the melting furnace is configured to rotate into a loading configuration, in which the loading portal of the melting furnace is open, and at least one of the one or more diffuser blocks is located in the lower half of the melting furnace. (Embodiment 77) The apparatus according to any one embodiment of Embodiments 1 to 76, wherein the melting furnace is configured to be placed in a melting configuration, in which the loading portal of the melting furnace is closed, and at least one of the one or more diffuser blocks is located near the bottom of the melting furnace. (Embodiment 78) The apparatus according to any one embodiment of Embodiments 1 to 77, wherein the melting furnace is configured to be placed in an injection configuration, in which the injection portal of the melting furnace is open, and at least one of the one or more diffuser blocks is located in the upper half of the melting furnace. (Embodiment 79) The apparatus according to any one embodiment of Embodiments 1 to 78, wherein the melting furnace is configured to heat the copper-based alloy in a sealed chamber configuration, and in the sealed chamber configuration, the external atmosphere is excluded from the atmosphere above the molten copper-based alloy. (Embodiment 80) The apparatus according to any one embodiment of Embodiments 1 to 79, wherein the melting furnace is configured to form the molten copper alloy by providing a heat source extending through the central axis. (Embodiment 81) The apparatus according to any one embodiment of Embodiments 1 to 80, further comprising a flame injector configured to inject a flow of fuel ignited along the central axis of the melting furnace which functions as a heat source. (Embodiment 82) The apparatus according to any one embodiment of Embodiments 1 to 81, wherein the flame is configured to extend in a direction along the central axis. (Embodiment 83) The apparatus according to any one embodiment of Embodiments 1 to 82, wherein the flame is provided directly above the molten copper alloy. (Embodiment 84) The apparatus according to any one embodiment of Embodiments 1 to 83, wherein the fuel includes a hydrocarbon fuel. (Embodiment 85) The apparatus according to any one embodiment of Embodiments 1 to 84, wherein the fuel includes natural gas. (Embodiment 86) The apparatus according to any one embodiment of Embodiments 1 to 85, wherein the fuel includes oxygen. (Embodiment 87) The apparatus according to any one embodiment of Embodiments 1 to 86, further comprising an exhaust outlet connected to the chamber of the melting furnace, wherein the exhaust outlet is configured to discharge exhaust gas of the fuel ignited from the chamber. (Embodiment 88) The apparatus according to any one embodiment of Embodiments 1 to 87, wherein the flame injector is located at the first end of the melting furnace, and the exhaust portal is located at the second end of the melting furnace opposite the first end. Additional Example VIII: (Embodiment 1) A method for producing copper-based alloys, A step of providing a raw material having a composition configured to form a molten copper-based alloy containing at least 50% by weight of copper to a melting furnace, wherein the melting furnace is configured to rotate around a central axis, The steps include heating the raw material to melt it and form the molten copper alloy, The steps include: bubbling an inert gas through the molten copper alloy; Methods that include... (Embodiment 2) A method for producing copper-based alloys, A step of providing a raw material having a composition configured to form a molten copper-based alloy containing at least 50% by weight of copper to a melting furnace, wherein the melting furnace is configured to rotate around a central axis, The steps include heating the raw material to melt it and form the molten copper alloy, The steps include: bubbling an inert gas through the molten copper alloy using one or more diffuser blocks containing porous diffusion ma...

Claims

1. A method for producing copper-based alloys, A step of providing a raw material having a composition configured to form a molten copper-based alloy containing at least 50% by weight of copper to a melting furnace, wherein the melting furnace is configured to rotate around a central axis, The steps include heating the raw material to melt it and form the molten copper alloy, The steps include: bubbling an inert gas through the molten copper alloy; Methods that include...

2. The method according to claim 1, further comprising the step of bubbling an inert gas through the molten copper alloy using one or more diffuser blocks containing a porous diffusion material.

3. The method according to claim 2, wherein the porous diffusion material has a porosity of more than 20%.

4. The porous diffusion material is alumina, silica, aluminum silicate ceramic, and Cr ２ O ３ The method according to claim 2, comprising one or more of the following.

5. The method according to claim 1, further comprising the step of heating the raw material or the molten copper alloy in a substantially inert atmosphere.

6. The method according to claim 1, wherein the step of providing the raw materials includes providing a plurality of raw material pieces having a composite composition configured to form the molten copper alloy.

7. The method according to claim 6, further comprising the step of flowing the inert gas through the gaps between the plurality of raw material pieces before and during heating of the raw material pieces.

8. The method according to claim 1, further comprising the step of rotating the melting furnace so that, before heating, one or more diffuser blocks suitable for diffusing the inert gas are positioned beneath the raw material.

9. The method according to claim 1, further comprising the step of bubbling the inert gas from the bottom surface of the molten copper alloy.

10. The method according to claim 1, further comprising the step of bubbling the inert gas into the molten copper alloy, and then rotating the melting furnace so that one or more diffuser blocks suitable for diffusing the inert gas are positioned above the molten copper alloy in order to transfer the molten copper alloy from the melting furnace.

11. The method according to claim 10, further comprising the step of cooling the molten copper alloy in a substantially inert atmosphere before transferring the molten copper alloy from the melting furnace.

12. The method according to claim 1, wherein the inert gas is essentially a noble gas.

13. The method according to claim 1, wherein the inert gas is essentially hydrogen-free and water-free.

14. The method according to claim 1, further comprising the step of heating the molten copper alloy in a sealed chamber configuration in which the atmosphere above the molten copper alloy is isolated from the external atmosphere.

15. The method according to claim 1, wherein the step of heating the raw material includes injecting a flame stream into the melting furnace.

16. The method according to claim 15, wherein the injection of the flame flow includes injecting it into the melting furnace along the central axis of the melting furnace.

17. The method according to claim 16, wherein injecting the flame flow includes injecting a fuel flow and igniting it.

18. The method according to claim 17, wherein the fuel flow includes natural gas.

19. The method according to claim 1, further comprising the step of oscillating the melting furnace around the central axis while bubbling the inert gas in the molten copper alloy.

20. The method according to claim 1, wherein the central axis extends substantially parallel to the ground.

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