Apparatus and method for producing high purity copper-based alloys

Abstract

In one aspect, a method of producing a high purity copper-based alloy includes providing a feedstock having a composition configured to form a molten copper-based alloy having at least 50% by weight copper to a melting furnace, heating the feedstock to melt the feedstock and form the molten copper-based alloy, and bubbling an inert gas through the molten copper-based alloy with a diffusion lining formed on an interior surface of the melting furnace, the diffusion lining comprising an aluminum silicate ceramic material having a porous structure adapted to bubbling the inert gas through the molten copper-based alloy. Aspects are also directed to an apparatus for producing a high purity copper-based alloy and a method of manufacturing the apparatus.

Description

[Technical field]

[0001] (CROSS REFERENCE TO RELATED APPLICATIONS) This application claims the benefit of priority to U.S. Provisional Patent Application No. 63 / 362,509, filed April 5, 2022, and U.S. Provisional Patent Application No. 63 / 387,076, filed December 12, 2022, the contents of each of which are incorporated herein by reference in their entirety.

[0002] The disclosed technology relates generally to an apparatus and method for producing copper-based alloys, and more specifically to an apparatus for producing high purity copper-based alloys having reduced impurities. [Background technology]

[0003] Copper can be alloyed with various elements to provide a variety of useful properties, including high toughness, high ductility, high thermal conductivity, high electrical conductivity, and high corrosion resistance. Because of these properties, copper-based alloys have many applications. For example, some copper-based alloys are used in electrical components, fixtures, locks, door handles, etc. Other copper-based alloys are used in architecture, springs, connectors, terminals, etc. Some applications of copper-based alloys require improved mechanical and chemical properties. Summary of the Invention

[0004] For purposes of summarizing the disclosure and the advantages achieved over the prior art, certain objects and advantages of the disclosure are described herein. Not all such objects or advantages are achieved in any particular embodiment. Thus, for example, one skilled in the art will recognize that the invention can be embodied or carried out in a manner that achieves or optimizes one or a group of advantages taught herein without necessarily achieving other objects or advantages that may be taught or suggested herein.

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

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

[0007] In another aspect, an apparatus for producing a copper-based alloy comprises a sealed melting furnace configured to form a molten copper-based alloy comprising at least 50% by weight copper under a sealed inert atmosphere and bubble an inert gas through the molten copper-based alloy, The apparatus further comprises a transfer ladle configured to receive the molten copper-based alloy from the melting furnace under the sealed inert atmosphere and transfer the molten copper-based alloy to one or more molds or shot pits configured to solidify the molten copper-based alloy.

[0008] In another aspect, a method of producing a copper-based alloy includes providing a plurality of feedstock pieces in a melting furnace having a composite composition configured to form a molten copper-based alloy having at least 50% by weight copper. The method includes flowing an inert gas through gaps between the feedstock pieces prior to heating, and heating the feedstock pieces while flowing the inert gas, thereby melting the feedstock pieces and forming a molten copper-based alloy. The method further includes bubbling the inert gas through the molten copper-based alloy. The method further includes transferring the molten copper-based alloy to a transfer ladle.

[0009] In another aspect, a method of producing a copper-based alloy includes providing a plurality of feedstock pieces in a melting furnace having a composite composition configured to form a molten copper-based alloy comprising at least 50% copper by weight. The method further includes heating the feedstock pieces to form the molten copper-based alloy. The method further includes heating the feedstock pieces to form the molten copper-based alloy. The method further includes transferring the molten copper-based alloy to a transfer ladle. One or more of the steps of heating the feedstock pieces, bubbling an inert gas, and transferring the molten copper-based alloy are performed at least in part under a sealed inert atmosphere, the sealed inert atmosphere configured to substantially exclude outside air from mixing with the sealed inert atmosphere.

[0010] In another aspect, a method of producing a copper-based alloy includes providing a plurality of feedstock pieces in a melting furnace having a composite composition configured to form a molten copper-based alloy comprising at least 50% copper by weight. The method further includes heating the feedstock pieces to form the molten copper-based alloy. The method further includes bubbling an inert gas through the molten copper-based alloy. The method further includes transferring the molten copper-based alloy to a transfer ladle, the transferring step including limiting a velocity of the molten copper-based alloy transferred from the melting furnace to the transfer ladle to less than 100 inches per second.

[0011] In another aspect, an apparatus for producing a copper-based alloy includes a melting furnace configured to form a molten copper-based alloy comprising at least 50% by weight copper, the melting furnace including a diffusion lining including an aluminum silicate ceramic having a porous structure adapted for bubbling an inert gas through the molten copper-based alloy.

[0012] In another aspect, an apparatus for producing a copper-based alloy includes a melting furnace configured to form a molten copper-based alloy comprising at least 50% by weight copper, the melting furnace including a diffusion lining substantially covering an inner bottom surface thereof and having a porous structure adapted for bubbling an inert gas through the molten copper-based alloy.

[0013] In another aspect, an apparatus for producing a copper-based alloy includes a melting furnace configured to form a molten copper-based alloy including at least 50% by weight copper. The melting furnace includes a diffusion lining having a porous structure. The diffusion lining is formed on at least two distinct inner surfaces of the melting furnace such that the diffusion lining is adapted to bubble an inert gas through the molten copper-based alloy from the at least two distinct inner surfaces.

[0014] In another aspect, a method of manufacturing an apparatus for producing a copper-based alloy includes providing a melting furnace chamber configured to form a molten copper-based alloy comprising at least 50% by weight copper, the method further includes forming a diffusion lining on an interior surface of the melting furnace chamber, the diffusion lining comprising an aluminum silicate ceramic material having a porous structure adapted for bubbling an inert gas through the molten copper-based alloy.

[0015] In another aspect, a method of manufacturing an apparatus for producing a copper-based alloy includes providing a melting furnace chamber configured to form a molten copper-based alloy comprising at least 50% by weight copper, the method further including forming a diffusion lining having a porous structure substantially covering a bottom interior surface of the melting furnace and adapted to bubbling an inert gas into the molten copper-based alloy.

[0016] In another aspect, a method of manufacturing an apparatus for producing a copper-based alloy includes providing a melting furnace chamber configured to form a molten copper-based alloy comprising at least 50% by weight copper, the method further includes forming a diffusion lining having a porous structure on at least two distinct inner surfaces of the melting furnace, such that the diffusion lining is adapted to bubbling an inert gas through the molten copper-based alloy from the at least two distinct inner surfaces.

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

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

[0019] In another aspect, a method of manufacturing an apparatus for producing an alloy includes providing a furnace chamber and disposing a compacted powder layer on an interior surface of the furnace chamber, the method further including sintering the compacted powder using heat from a heated material disposed within the furnace chamber, thereby forming a diffusion lining on the interior surface.

[0020] In another aspect, a method of producing a copper-based alloy includes providing a feedstock having a composition configured to form a molten copper-based alloy including at least 50% by weight copper to a melting furnace, and heating the feedstock to melt the feedstock and form the molten copper-based alloy. The method further includes bubbling an inert gas through the molten copper-based alloy with a diffusion lining formed on an inner surface of the melting furnace. The diffusion lining includes an aluminum silicate ceramic material having a porous structure adapted to bubbling an inert gas through the molten copper-based alloy.

[0021] In another aspect, a method of producing a copper-based alloy includes providing a feedstock having a composition configured to form a molten copper-based alloy including at least 50% by weight copper to a melting furnace, and heating the feedstock to melt the feedstock 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 in the melting furnace chamber. The diffusion lining substantially covers a bottom inner surface of the melting furnace and has a porous structure adapted to bubbling an inert gas through the molten copper-based alloy.

[0022] In another aspect, a method of producing a copper-based alloy includes providing a feedstock having a composition configured to form a molten copper-based alloy including at least 50% by weight copper to a melting furnace, and heating the feedstock to melt the feedstock 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 such that the diffusion lining is adapted to bubbling an inert gas through the molten copper-based alloy from the at least two different inner surfaces. [Brief description of the drawings]

[0023] [Figure 1] FIG. 1 is a schematic diagram of an apparatus for producing a copper-based alloy with low impurity content, in accordance with some embodiments. [Figure 1A] FIG. 1 is a schematic side view of a closed configuration of a melting furnace for producing copper-based alloys, according to some embodiments. [Figure 1B] FIG. 1 is a schematic side view of an open configuration of a melting furnace for producing high purity copper-based alloys, according to some embodiments. [Diagram 2] FIG. 2 is a schematic diagram of an apparatus for producing a copper-based alloy with low impurity content, in accordance with some other embodiments. [Figure 3A] FIG. 2 is a schematic diagram of an apparatus for producing a copper-based alloy with low impurity content, in accordance with some other embodiments. [Figure 3B]FIG. 3B is a detailed perspective view of a portion of the apparatus shown in FIG. 3A including a transfer wheel for producing copper-based alloys with low impurity content, according to some other embodiments. [Figure 3C] FIG. 3B is a detailed side view of a portion of the apparatus shown in FIG. 3A including a transfer wheel for producing copper-based alloys with low impurity content, according to some other embodiments. [Figure 4A] 1 shows a schematic cross-sectional view of a diffuser according to an embodiment. [Figure 4B] 1 is a photograph of a diffuser according to an embodiment. [Figure 4C] 1 is a photograph of a diffuser installed at the bottom of a melting furnace according to an embodiment. [Diagram 5] According to an embodiment, a method for producing a copper-based alloy having low impurity content is provided. [Figure 6A] FIG. 1 is a schematic side view of a melting furnace with a diffusion lining for producing high purity copper-based alloys, according to some embodiments. [Figure 6B] FIG. 1 is a schematic side view of a melting furnace with a diffusion lining for producing high purity copper-based alloys in accordance with some other embodiments. [Figure 6C] FIG. 6C is a cross-sectional view of the diffusion lining for the melting furnace shown in FIGS. 6A and 6B. [Figure 7A] According to various embodiments, a method for forming a diffusion lining in a melting furnace for producing high purity copper-based alloys is presented. [Figure 7B] FIG. 7B is a schematic side view of a melting furnace at the stage of forming a diffusion lining therein for producing a high purity copper-based alloy according to the method shown in FIG. 7A. [Figure 7C] 7B is a schematic side view of a melting furnace at another stage of forming a diffusion lining therein for producing a high purity copper-based alloy according to the method shown in FIG. 7A. [Figure 7D] 7B is a schematic side view of a melting furnace at another stage of forming a diffusion lining therein for producing a high purity copper-based alloy according to the method shown in FIG. 7A. [Figure 7E]7B is a schematic side view of a melting furnace at another stage of forming a diffusion lining therein for producing a high purity copper-based alloy according to the method shown in FIG. 7A. [Figure 7F] 7B is a schematic side view of a melting furnace at another stage of forming a diffusion lining therein for producing a high purity copper-based alloy according to the method shown in FIG. 7A. [Figure 8] According to an embodiment, a method for producing a copper-based alloy with low impurity content using diffusion lining is presented. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] The present disclosure may be understood by reference to the following detailed description: It should be noted that for purposes of clarity of illustration, some elements in the various drawings may not be drawn to scale, may be represented diagrammatically or conceptually, or may otherwise not precisely correspond to particular physical configurations of embodiments.

[0025] Various impurities in copper-based alloys can reduce their advantageous properties. The presence of various undesirable impurities in various components formed from copper-based alloys can be caused by the presence of these impurities in the raw material, such as copper-based turnings, e.g., copper-based alloy scrap. For example, various impurities in the copper-based turnings or copper-based alloy scrap serving as the raw material can adversely affect the mechanical and chemical properties of the cast copper-based parts, leading to higher failure rates during tool casting and shorter part life, which in turn leads to higher replacement costs. Higher failure rates can lead to increased manufacturing costs for copper-based parts, e.g., copper-based tools, such as plumbing fixtures. Therefore, improved apparatus and methods are needed to reduce the impurity content in the copper raw material, thereby limiting the incorporation of impurities into the final product. Therefore, there is a need for techniques to produce copper-based alloys, e.g., copper-based ingots or copper-based shot, with lower impurity levels for improved mechanical properties, while reducing costs, improving casting efficiency, and simultaneously extending part life.

[0026] The inventors have discovered that oxygen and oxygen-related defects can be particularly detrimental to copper-based alloys. Oxygen-related defects include, for example, trapped oxygen-containing voids or pockets, and oxides in copper-based alloys. Without being bound by any theory, such oxygen-containing void or pocket formation can be caused by a relatively large amount of oxygen dissolving in the molten copper-based alloy. For example, as the molten copper-based alloy cools and solidifies, the solubility of oxygen in the copper-based alloy decreases, leading to the nucleation of oxygen-containing voids or pockets therein. The voids or pockets thus formed and not escaping to the atmosphere can become trapped in the solidified copper-based alloy, resulting in voids and porosity, which in turn can result in the degradation of mechanical properties such as yield strength and toughness. In particular, oxygen-containing voids or pockets can act as stress concentration centers that act as fracture initiation sites. Other oxygen-related impurities can include oxygen compounds such as copper oxides that can precipitate in the copper-based alloy and degrade its mechanical properties.

[0027] The inventors have discovered that in order to effectively reduce oxygen and oxygen-related impurities in a copper-based alloy, the oxygen content should be reduced from the copper-based alloy in the molten state starting from the melting process. Also, after forming a molten copper-based alloy with reduced oxygen content, it is necessary to prevent the introduction or reintroduction of oxygen and oxygen-related impurities before solidification. Thus, the disclosed embodiments relate to an apparatus and method for reducing the oxygen content in a molten copper-based alloy starting from the melting process and maintaining a low oxygen content throughout the solidification process, including transfer to a mold, to improve the mechanical properties of the copper-based alloy, for example, by reducing its oxygen content. According to various embodiments, an apparatus for producing copper-based ingots or copper-based shots comprises a sealed melting furnace configured to form a molten copper-based alloy under a sealed inert atmosphere and bubble an inert gas through the molten copper-based alloy. The apparatus further comprises a transfer ladle configured to receive the molten copper-based alloy from the melting furnace under a sealed inert atmosphere and transfer the molten copper-based alloy to one or more molds, for example, an ingot mold or a component mold, configured to solidify the molten copper-based alloy into, for example, a copper-based ingot or a copper-based component. The transfer ladle may be configured to receive the molten copper-based alloy from the melting furnace through a rate control element. The transfer ladle may also be configured to transfer the molten copper-based alloy to a shot pit configured to solidify the molten copper-based alloy into shot. The transfer ladle may be sealed or unsealed depending on the tolerance to the amount of oxygen and oxygen-related impurities in the solidified copper alloy. As described herein, bubbling an inert gas through the molten alloy may be referred to as sparging. The furnace according to the present disclosure may reduce the impurity content in the copper-based alloy and components made therefrom, such as components such as ingots, shots, or fixtures, which may result from sparging the molten copper-based alloy in the furnace as described herein. By reducing the oxygen and oxygen-related impurity content in the copper-based alloy and components made therefrom, particularly by reducing the amount of oxygen or oxygen-related impurities by sparging, certain mechanical properties of copper may be improved, including tensile strength and ductility.

[0028] According to various embodiments, the sparging furnace comprises a melting furnace configured to melt the copper-based raw material. The melting furnace is configured to flow an inert gas through the material prior to melting and during heating, for example, bubbling the inert gas through the molten alloy in the melting furnace through a diffuser. The melting furnace may be under an inert gas atmosphere. As configured, bubbling the inert gas through the molten copper-based alloy can entrain undesirable impurities and remove them from the molten copper-based alloy. Undesirable impurities include, for example, but are not limited to, oxygen or oxygen-related impurities. As described herein, oxygen or oxygen-related impurities include combined and uncombined 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 non-metal hydroxides, metal and non-metal oxyhydrides, and metal and non-metal oxides. Undesirable oxygen-related impurities, for example oxides, may form a slag layer or slag islands on the molten copper-based alloy after being entrained by the inert gas. The slag layer may be removed from the melt, thereby removing oxide impurities from the molten alloy.

[0029] The inventors have found that a sparging furnace configured in this manner can effectively remove impurities, including oxygen and oxygen-related impurities, from a molten copper-based alloy. As described herein, impurity removal may be described in the context of removing oxygen-related impurities, but it will be understood that the embodiments are not so limited and other impurities may be removed as well. Without being bound by any theory, sparging removes impurities such as oxygen from the molten alloy according to Henry's law, which states that under 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 the inert gas bubbles are initially oxygen-free, as they pass through the molten alloy, oxygen dissolved in the molten alloy is removed from the molten alloy and escapes to the surrounding atmosphere as a mixed gas with the inert gas. Additionally, oxide particles and other oxygen-related impurities may be removed by electrostatic forces. Without being bound by any theory, as the small inert gas bubbles move through the molten alloy, the small oxide particles and oxygen-related impurities may adhere to the inert gas bubbles via electrostatic forces. Removal of oxygen or oxygen-related impurities by inert gas bubbling may be preferred over methods that rely on chemical reactions between reactive elements, such as reducing gases, and oxygen or oxygen-related impurities in molten copper-based alloys. Strong reducing gases may not be suitable for some manufacturing facilities because of increased risk to workers and the need for strong safety precautions. Furthermore, some elements, such as Zr, act as deoxidizers, but may need to be used in reduced amounts during processing, for example, to reduce manufacturing costs. The inventors have found that removing and suppressing impurities, including oxygen and oxygen-related impurities, from molten alloys described herein according to embodiments correlates with improved mechanical performance of cast copper-based alloys, ingots, or copper-based shots.

[0030] The inventors have further found that when a molten alloy having a low impurity content, e.g., a low oxygen content, is thus formed, impurities, including oxygen and oxygen-related impurities, should be prevented from being reintroduced into the molten alloy. To this end, in some embodiments, the melting furnace is enclosed and placed under an atmosphere of inert gas. Controlling the atmosphere can effectively prevent or reduce the reintroduction of oxygen or oxygen-related impurities into the metal alloy. However, the embodiments are not so limited, and the melting furnace can be open to the ambient atmosphere if some reintroduction of oxygen or oxygen-related impurities can be tolerated, or if the inert gas can be flushed through the system at a flow rate high enough to substantially inhibit mixing of outside air with the inert atmosphere in the melting furnace.

[0031] The inventors have further found that as the molten alloy is transferred from the furnace to the transfer ladle, its velocity should be carefully controlled to reduce any excessive turbulence, which may reintroduce impurities such as oxygen or oxygen-related impurities, including any slag that may form at the surface of the molten alloy, into the molten alloy. Thus, according to some embodiments, a velocity control device, for example a ramp or launder, connects the melting furnace to the transfer ladle. The velocity control device is configured to transfer the copper-based alloy to the transfer ladle without excessive turbulence and without entrainment of atmospheric gases containing oxygen or other oxygen-related impurities, including oxides, that may be present in the system.

[0032] The inventors have further found that to further reduce or effectively prevent 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 enclosed and disposed under an inert atmosphere. Thus, in some embodiments, the transfer ladle is at least partially encapsulated and configured to receive the molten copper-based alloy from the rate control device. In some embodiments, the transfer ladle and the rate control device may be enclosed under a common inert atmosphere as the melting furnace. In some embodiments, the transfer ladle is configured to transfer, e.g., pour or inject, the molten copper-based alloy into a mold, e.g., an ingot mold or a component mold. After being poured into the mold, the sparged molten copper-based alloy may cool and harden into a solid form of the sparged copper alloy.

[0033] Systems and methods for producing high purity copper-based alloys using inert gases 1-3 show furnace systems configured to produce copper-based alloys with reduced content of impurities, including oxygen or oxygen-related impurities, according to various embodiments disclosed herein. FIGS. 1A and 1B show two different configurations of a melting furnace of a furnace system for producing copper-based alloys, according to some embodiments. FIG. 5 shows a method of producing a copper-based alloy using one of the furnace systems shown in FIGS. 1-3, according to an embodiment. Each of the furnace systems 100, 200, and 300 shown in FIGS. 1, 2, and 3, respectively, includes a melting furnace, which can be in a closed configuration (FIG. 1A) or an open configuration (FIG. 1B). Each of the melting furnaces 108A (FIG. 1A), 108B (FIG. 1B) is configured to form a molten copper-based alloy containing at least 50% copper by weight, and to flow an inert gas through the feedstock prior to melting and during heating, and to bubble the inert gas through the molten copper-based alloy. Each of the furnace systems 100, 200 and 300 further comprises a transfer ladle configured to receive the molten copper-based alloy from the melting furnace and transfer the molten copper-based alloy to one or more molds or shot pits configured to solidify the molten copper-based alloy.

[0034] Any of the furnace systems 100, 200, and 300 may be used to perform the method 500 shown in FIG. 5. The method 500 for producing a copper-based alloy includes providing 504 a plurality of feedstock pieces in a melting furnace having a composite composition configured to form a molten copper-based alloy having at least 50% by weight copper. The method 500 further includes flowing 508 an inert gas through gaps between the feedstock pieces and heating 512 the feedstock pieces while flowing the inert gas through the feedstock pieces, thereby melting the feedstock pieces to form a molten copper-based alloy. The method 500 further includes bubbling 516 an inert gas through the molten copper-based alloy. The method 500 further includes transferring 520 the molten copper-based alloy to a transfer ladle. Details of the furnace systems 100, 200, and 300 shown in FIGS. 1, 2, and 3 are described below in conjunction with the method 500 shown in FIG. 5.

[0035] 1 is a schematic diagram of a sparging furnace system 100 for producing copper-based alloys, such as ingots, ingot shots, or copper-based components, having low impurity content, including oxygen or oxygen-related impurities, according to one embodiment. The sparging furnace system 100 includes a melting furnace 108, which may be configured as a closed melting furnace 108A (FIG. 1A) or an open melting furnace 108B (FIG. 1B). As disclosed herein, unless indicated to the contrary, any reference made to the melting furnace 108 is understood to apply to either or both of the melting furnaces 108A (FIG. 1A), 108B (FIG. 1B).

[0036] The melting furnace 108 is connected to the gas supply 102 via the gas line 104 and the diffuser 106. Referring to FIG. 1A and FIG. 1B, the melting furnace 108 is surrounded by a chamber wall 134. The melting furnace 108 includes refractory linings 130A, 130B including a suitable refractory material on at least its inner surface. The refractory lining 130 lines the bottom inner surface of the melting furnace 108, and the refractory lining 130B lines the sidewall surface of the melting furnace 108. When the melting furnace 108 is a closed melting furnace 108A, the melting furnace 108A further includes a lid 130. As shown in FIG. 1, the melting furnace 108 includes an opening for conveying the molten copper-based alloy 110 out. For example, in FIG. 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 a molten copper-based alloy 110 formed in a melting furnace 108. The diffuser 106 has a surface area that covers a portion of a cross-sectional area of ​​the molten copper-based alloy 110 formed in the melting furnace 108 and removes impurities in the path of gas bubbles passing through the cross-sectional area. The melting furnace 108 is configured to produce the molten copper-based alloy 110 from a copper-based source material. As the inert gas flows through the diffuser 106, it forms gas bubbles 112 that pass through the molten copper-based alloy 110. The gas bubbles 112 pass through the molten copper-based alloy 110 and entrain impurities, including oxygen and oxygen-related impurities, from the molten copper-based alloy 110.

[0037] After impurities are removed from the melting furnace 108, the molten copper-based alloy 110 is transferred through an opening formed through a sidewall 134 of the melting furnace 108, as shown in FIG. 1 (not shown in FIGS. 1A and 1B for clarity). For example, the molten copper-based alloy 110 may be transferred by tilting the melting furnace to allow the copper-based alloy 110 to flow out of the melting furnace 108. In the illustrated configuration, the molten copper-based alloy 110 is transferred at a controlled rate from the melting furnace 108 to the transfer ladle 116 via a first rate control element 114. As described herein, a sloping ramp or launder utilizing gravity, among other structures, may be used to control the rate. In some embodiments, the transfer ladle 116 includes one or more injectors 124. After being transferred to the transfer ladle 116, the molten copper-based alloy 110 is transferred to one or more ingot molds 118, for example, poured or injected through the injectors 124. The molten copper-based alloy 110 solidifies within the molds 118 to form solidified copper-based alloy ingots. The molds 118 may be moved via a conveyor belt 120 where they may be further processed, for example cooled, before being collected.

[0038] 1 , in some embodiments, the mold 118 may be any suitable mold, including ingot molds and fixed molds. In some embodiments, the mold 118 may be a mold for a final component, such as a fixed mold. In some embodiments, the fixed mold may be a mold for any suitable water fixture, such as a faucet, valve, or pipe.

[0039] 1, in some embodiments, the mold 118 can be replaced by hardware suitable for producing metal shot. For example, some shot manufacturing methods include passing the molten copper-based alloy through a screen, such as a stainless steel screen, and into a fluid, such as water, in which the molten copper-based alloy is quenched and solidified into metal shot. In some other shot production methods, air or other suitable gas is passed through the molten copper-based alloy, and the molten copper-based alloy is quenched in a fluid, such as water. Although two exemplary methods of suitable shot production methods are described, it should be understood that other known shot production methods are within the scope of this disclosure.

[0040] With continued reference to FIG. 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 includes nitrogen (N2). In some embodiments, the inert gas is any one or combination of suitable inert gases. In some embodiments, the inert gas may be substantially or essentially free of reactive gases, including reducing or oxidizing gases (e.g., hydrogen). In these embodiments, the inert gas does not include reactive gases (e.g., hydrogen), except for the amount of impurity levels of such gases, such as hydrogen.

[0041] With continued reference to FIG. 1, the gas supply system is configured to purge or begin flowing an inert gas through the feedstock material prior to substantially melting the feedstock. The inventors have discovered that it may be important to reduce the presence of ambient oxygen and / or moisture in the melting furnace 108 not only during melting of the feedstock but also prior to forming the molten alloy 110 (e.g., prior to and during heating). Otherwise, undesirable oxidation of the feedstock from ambient oxygen and / or moisture may be accelerated at high temperatures during heating prior to forming the molten alloy 110. The oxides thus formed on the surface of the feedstock may be relatively stable at the temperature of the molten alloy 110 and may remain in the form of oxides or may release oxygen in 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 discovered that oxides may also form from surface-adsorbed oxygen or moisture, which may also be effectively removed by flowing an inert gas through the feedstock. Thus, prior to substantially heating the feedstock material, and throughout the melting process, the inert gas is purged through the feedstock material in the furnace 108. In some embodiments, flowing the inert gas includes flowing at a sufficient rate such that the feedstock material is substantially under a flowing inert gas atmosphere prior to and during melting.

[0042] As mentioned above, the melting furnace 108 can be in a closed configuration (108A, FIG. 1A) or an open configuration (108B, FIG. 1B). Referring to FIG. 1A, in a closed configuration of the melting furnace 108A, a lid 130 or equivalent device may be used to seal the furnace 108A. In a closed configuration, the surface of the raw material and the molten alloy 110 may be placed under a substantially inert atmosphere. As disclosed herein, a substantially inert atmosphere refers to an atmosphere in which the ambient air above the molten alloy 110 is substantially reduced, e.g., less than 50%, 40%, 30%, 20%, 10%, or within a range defined by any of these values, relative to a normal atmosphere. It is understood that the closed configuration illustrated in FIG. 1A, e.g., using a lid 130, is an effective way to place the surface of the molten alloy 110 under a substantially inert atmosphere, but the embodiment is not so limited. For example, the inventors have discovered that even without the lid 130, a substantially inert atmosphere can still be achieved in the open configuration of the melting furnace 108B (FIG. 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 high enough, the surfaces of the feedstock and molten alloy 110 may be placed under a substantially inert gas atmosphere even without a lid or without a lid partially enclosing the interior volume of the furnace 108.

[0043] In some embodiments, purging or flowing the inert gas through the source material prior to substantially melting the feedstock may be, for example, 5, 10, 30, 60 minutes or more before substantial heating to initiate melting may begin. During purging, prior to initiating melting of the source material, the melting furnace 108 may be heated to a relatively low temperature, for example, less than 200° C., substantially below the melting temperature, insufficient to substantially oxidize the feedstock but sufficient to facilitate removal of moisture.

[0044] As described herein, a closed system or a component thereof refers to an arrangement in which the closed sparging furnace system 100 or a subcomponent thereof is substantially physically sealed or isolated from the external atmosphere at least partially during its operation. For example, during the charging of a feedstock, which may include multiple feedstock pieces, the volume occupied by the feedstock decreases as the feedstock pieces melt. Thus, during the charging process of the melting furnace 108, the chamber lid, if present, may be opened one or more times before the molten alloy 110 reaches the fill line of the melting furnace 108, which represents the liquid level of a fully loaded melting furnace 108. According to an embodiment, an inert gas may be flowed into the melting furnace and through the molten alloy 110 throughout the charging process until the molten alloy 110 reaches the fill line, which may include several cycles of adding solid feedstock pieces into the pool of molten alloy 110. Although the chamber lid may be opened during the addition of feedstock to charge the melting furnace 108, it is understood that the inert gas may flow into the melting furnace 108 and through the additional feedstock, thereby reducing or substantially preventing oxidation of the additional feedstock. However, once the melting furnace 108 is fully loaded, the system 100, including at least the gas source 102, the gas line 104, the melting furnace 108, the first rate control element 114, and the transfer ladle 116, may be at least temporarily sealed or sealed from the outside atmosphere while being purged with an inert gas from the gas source 102 to inhibit the introduction of oxygen therein. Thus, in the method 500 (FIG. 5), one or more of the steps of flowing the inert gas 508, heating the feed pieces 512, and bubbling the inert gas through the molten copper-based alloy 516 are performed at least partially under a sealed inert atmosphere, the sealed inert atmosphere configured to substantially preclude mixing of outside air with the sealed inert atmosphere. In the configuration illustrated in FIG. 1, the transfer of the molten alloy 110 through the first rate control element 114 and into the transfer ladle 116 may also be performed at least partially under a sealed inert atmosphere, the sealed inert atmosphere configured to substantially preclude mixing of outside air with the sealed inert atmosphere.Enclosure to isolate relevant portions of the closed sparging furnace system 100 from the outside atmosphere may be accomplished using, for example, one or more valves disposed therein, for example, between 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 include a valve or other shutoff mechanism that serves to isolate the transfer ladle 116 and the melting furnace 108 before being opened to drain the molten alloy therefrom.

[0045] The feedstock can be present in various forms, including one or more alloy pieces and / or elemental metal pieces. The feedstock pieces may or may not have the same composition. However, the feedstock pieces have a composite composition configured to form a molten copper-based alloy having a target composition of the alloy to be formed, and include at least 50% copper by weight. Depending on the size of the feedstock pieces, the inventors have further discovered that the amount or flow rate of the inert gas that is effective to inhibit oxidation of the feedstock before melting as described above may vary. The amount or flow rate of the inert gas may depend, among other things, on the relative amount of open space between the feedstock pieces or the permeability of the copper-based alloy feedstock material that forms the feedstock to produce the molten alloy 110. When the feedstock includes relatively large feedstock pieces, a relatively large amount of open space or permeability may be present, resulting in a relatively small amount of surface area of ​​the alloy exposed to the inert gas. For example, in some embodiments, the feedstock material may include feedstock pieces that are relatively large in size and have a correspondingly large amount of open space or permeability. For feedstocks with high permeability, a relatively high inert gas flow rate, e.g., about 5 liters / minute or more, may be suitable for removing various impurities, including oxygen and oxygen-related impurities, from the feedstock. In some embodiments, the feedstock material may include feedstock pieces that are relatively small in size and have a correspondingly low amount of open space or permeability. For example, the feedstock may be relatively small copper-based alloy turnings (e.g., copper-based scrap). For feedstocks with low permeability, a relatively low inert gas flow rate, e.g., less than about 5 liters / minute, may be suitable for removing impurities, including oxygen and oxygen-related impurities, from the feedstock. The inert gas flow rate before melting described herein may have any value that is the same or different from the inert gas flow rate during the bubbling of the inert gas through the molten alloy 110, as described below, and these values ​​will not be repeated herein for brevity.

[0046] The inventors have discovered that certain combinations of various process parameters can be effective to effectively remove impurities, including oxygen and oxygen-related impurities, from the molten alloy 110 as described above. In particular, the inventors have discovered that the size, density, and velocity distribution of the gas bubbles 112 moving through the molten alloy 110 can correlate with the effectiveness of the impurity removal process. If the size, density per unit volume, and velocity of the gas bubbles 112 are too small or too low, the gas bubbles may be too slow or ineffective at removing oxygen or oxygen-related impurities. On the other hand, if the size, density, and velocity of the gas bubbles 112 are too large or too high, the gas bubbles may create substantial turbulence as the gas bubbles rise and break at the surface of the molten alloy 110. The inventors have discovered that such turbulence, if substantial, may not only ineffectively remove oxygen or oxygen-related impurities, but may even increase the content of oxygen or oxygen-related impurities. Thus, the inventors have discovered that it may be important to control the size, density, and velocity distribution of the inert gas bubbles. The bubble size, density, and velocity distribution can be optimized based on a variety of factors, such as the viscosity of the molten alloy 110, the flow rate of the inert gas 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 defined in part by the dimensions of the furnace 108. It will be appreciated that these parameters may be interdependent. For example, the flow rate of the inert gas and the cross-sectional area through the diffuser determine the flow rate of the inert gas. Furthermore, a particular value of a flow parameter, such as a flow rate, may be particularly relevant if it is proportionally related to the total volume of the molten alloy 110.

[0047] The viscosity of the molten alloy 110 depends, among other things, on its composition and temperature. For a given composition of the various compositions of molten alloy 110 described herein, including those molten copper-based alloy compositions containing at least 50% by weight copper, the viscosity can be controlled by controlling the temperature of the molten alloy 110 above the melting temperature, e.g., the liquidus temperature. For this and other reasons, the inventors have discovered that the methods described herein can 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 between 100 and 400°C above the liquidus temperature of the alloy. According to various embodiments, the molten alloy 110 is heated to a temperature greater than 50°C, 100°C, 150°C, 200°C, 250°C, 300°C, 350°C, 400°C, 450°C, or any temperature within a range defined by any of these values.

[0048] As mentioned above, the inventors have discovered 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 do not generate excessive turbulence that may have adverse effects. Furthermore, as mentioned above, the optimized flow rate differs depending on whether the melting furnace 108 is in a closed configuration (FIG. 1A) or an open configuration (FIG. 1B). According to various embodiments, when the melting furnace 108A (FIG. 1A) is in a closed configuration, the inert gas is bubbled into the melting furnace 108A at a flow rate of 10 liters / minute, 9 liters / minute, 8 liters / minute, 7 liters / minute, 6 liters / minute, 5 liters / minute, 4 liters / minute, 3 liters / minute, 2 liters / minute, more than 1 liter / minute, or any value within the range defined by these values, such as 1 to 10 liters / minute, 2 to 6 liters / minute, for example, about 4 liters / minute. According to various embodiments, when the melting furnace 108B (FIG. 1B) is in an open configuration, the inert gas is bubbled into the melting furnace 108B at a flow rate higher than the flow rate under the closed configuration. For example, the flow rate under the open configuration may be greater than 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, 4 liters / min, or any value within a range defined by these values, such as 4-13 liters / min or 5-9 liters / min, for example, about 7 liters / min. If the closed melting furnace 108A and the open melting furnace 108B have the same configuration, the optimized flow rate of the inert gas in the open melting furnace configuration 108A is higher than the closed melting furnace 108A by 2 liters / min, 3 liters / min, 4 liters / min, or a value within a range defined by any of these values.

[0049] To further control the size, density and velocity distribution of the 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 (FIG. 1A) of 5 cm, 10 cm, 15 cm, 20 cm, 25 cm, 30 cm, 35 cm, 40 cm, 45 cm, greater than 50 cm, or a value within a range defined by any of these values.

[0050] 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 the appropriate size, density and velocity distribution while preventing the molten liquid alloy from infiltrating. The diffuser 106 can have an average pore size of more than 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm, or a value defined by any of these values. Additionally, the diffuser 106 has a porosity, defined as the ratio of voids to the overall macroscopic volume, that is more than 10%, 15%, 20%, 25%, 30%, 35%, or a value within a range defined by any of these values.

[0051] In the illustrated embodiment, the diffuser 106 is located on the bottom surface of the melting furnace, however, the embodiment is not so limited and the diffuser 106 may be formed at other surface locations, including on the sides.

[0052] 4A and 4B respectively show a schematic cross-sectional view and a photograph of a diffuser that meets the criteria described herein, according to an embodiment. FIG. 4C is a photograph of a diffuser installed at the bottom of a melting furnace 108, according to an embodiment. As shown in FIG. 4A, the diffuser 400 includes a gas inlet 404 through which an inert gas is introduced and a container 408 for holding a diffuser material or medium 412. The illustrated diffuser material or medium 412 includes a porous refractory ceramic material. FIG. 4B is a photograph of an example of a diffuser 400 having a diffuser material or medium formed primarily of porous alumina and silica. The diffuser material or medium 412 includes alumina in an amount of 50-80 mol%, 55-75 mol%, 60-70 mol%, or a mol% within a range defined by any of these values, for example, 65 mol%. The diffuser material or media 412 further comprises silica in an amount of 10-35 mol%, 15-30 mol%, 20-25 mol%, or a mol% within a range defined by any of these values, for example, 24 mol%. The diffuser material or media can have a variety of properties and structures as described below with respect to the diffusion lining depicted in Figures 6A and 6B. For example, the diffuser material 412 has a porosity of 27.6% and a pore size of 2.45 g / cm. 3 The diffuser material or lining 412 can also have a two-layer structure as described with respect to Figures 6A and 6B.

[0053] Continuing with reference to Figures 4A-4C, according to an embodiment, the inert gas is bubbled into the melting furnace 108 at a flow rate as previously described, e.g., 1-10 liters / min, through a diffuser material or medium 412 (Figure 4A) having a diameter (d in Figure 1A) of 5-50 cm in a furnace capable of melting 1000 pounds, 2000 pounds, 5000 pounds, 10,000 pounds, 20,000 pounds, 50,000 pounds, 100,000 pounds, or within a range defined by any of these values. For example, the inert gas is bubbled into the melting furnace at a flow rate of 1-10 liters / min in a 4000 pound furnace, or a furnace capable of melting an amount of alloy of about 4000 pounds.

[0054] 1A and 1B, in addition to the capacity of the melting furnace 108A, 108B, the furnace may have a volume defined by an area, e.g., a cylindrical area, and a height. In various embodiments, the furnace 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, 500 cm, or a value within a range defined by any of these values. The melting furnace 108A, 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, 500 cm, or a value within a range defined by any of these values, such that when the molten alloy 110 is fully loaded, the molten metal may have a fill line F at a height measured from the bottom of the furnace.

[0055] The inventors have discovered that the disclosed inert gas flow rates, in conjunction with various other configurations of the melting furnace 108, produce a combination of bubble size, density per unit volume, and velocity distribution suitable to provide various advantageous effects described herein. The bubble density is such that excessive coalescence of the bubbles 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 can have an average pore distribution that correlates with the bubble size and density per unit volume such that the inert gas bubbles do not substantially coalesce or have excessive velocities.

[0056] If sealed, the atmosphere in contact with the molten alloy 110 in the melting furnace 108 can be determined by the inert gas introduced by the 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.

[0057] 1A and 1B, the melting furnace 108 (108A, 108B) is configured to melt the source material. As shown in FIG. 1A and 1B, the melting furnace 108 may be, but is not limited to, an induction type furnace. The melting furnace 108 may be configured to have a variable internal temperature to accommodate various copper-based alloy systems. In some embodiments, the temperature of the melting furnace 108 is between 700°F and 3000°F. In some embodiments, the temperature of the melting furnace 108 is 900°F, 1000°F, 1200°F, 1400°F, 1600°F, 1800°F, 2000°F, 2200°F, 2400°F, 2500°F, or 300°F, or a value within a range defined by any of these values.

[0058] 1A and 1B, the melting furnace 108 (108A, 108B) configured as an induction type includes an induction coil 138 surrounding at least a portion of the melting furnace 108A, 108B. The induction heating system includes an induction power supply that converts line power to alternating current and supplies it to the coil 138 to generate an electromagnetic field within the coil. A material placed within the coil causes the field to induce a current therein, which in turn generates sufficient heat to melt the material. Advantageously, the inventors have recognized that in some circumstances, for optimal results, the top winding of the coil 138 should remain below the fill line (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 provides increased effectiveness in removing impurities. Without being bound by any theory, the increased effectiveness may be due in part to the fact that impurity removal may occur more effectively in the hotter lower region due to increased local solubility of the impurities. Thereafter, in the upper region, impurities are removed from the molten copper-based alloy 110 as they are entrapped in the slag at the top surface of the molten alloy 110. According to an embodiment, the top winding of the induction coil 138 is positioned at or below a vertical level corresponding to the top surface of the molten copper-based alloy 110 or the fill line F. The induction coil 138 may have a height corresponding to 90%, 80%, 60%, 50%, 40%, 30%, or a percentage within a range defined by any of these values, relative to the height of the molten copper-based alloy 110, as measured from the bottom inner surface of the melting furnace 108.

[0059] The operating frequency of the induction heating system may be influenced by the range of feedstock sizes for the application. Without being bound by any theory, this may be due to the "skin effect" which is related to the depth below the surface of the metal feedstock where the current is induced by the electromagnetic field. Generally, the higher the operating frequency, the thicker the skin depth and the lower the operating frequency, the deeper the skin depth. The skin depth correlates to the penetration of the heating effect. The skin depth or penetration depth depends on the operating frequency, the material properties and the temperature of the feedstock. In principle, for a given material, heating of the feedstock pieces by induction can be performed at a high operating frequency when the feedstock pieces are small and at a low operating frequency when the feedstock pieces are large. According to various embodiments, the feedstock can have a minimum major dimension, e.g., width, of more than 2 cm, 5 cm, 10 cm, 20 cm, 30 cm, 40 cm, 50 cm, or within a range defined by any of these values. The inventors have found that for melting copper-based alloy feedstock pieces according to the embodiments, the optimal frequency of the melting furnace 108 is set to less than 10 kHz, 5 kHz, 2 kHz, 1 kHz, 500 kHz, or a frequency within a range defined by any of these values, for example, 600 kHz.

[0060] As discussed above, the inventors have found that to facilitate removal of impurities, including oxygen and oxygen-related impurities, from the molten alloy 110, the molten alloy 110 is heated to a temperature between 100 and 400° C. above the melting temperature of the alloy, e.g., the liquidus temperature. On the other hand, the inventors have found that it is advantageous to reduce the temperature of the molten metal in the furnace to near the liquidus temperature before transferring the molten alloy 110 to a mold. Thus, according to various embodiments, the molten alloy 110 is cooled by more than 50° C., 100° C., 150° C., 200° C., 250° C., 300° C., 350° C., 400° C., 450° C., or any temperature within a range defined by any of these values, relative to the temperature at which the inert gas was bubbled just prior to being transferred from the melting furnace 108. However, the temperature in the melting furnace 108 remains above the melting temperature of the alloy.

[0061] After forming the molten alloy 110 with a low content of impurities, including oxygen or oxygen-related impurities, the molten alloy is transferred to the transfer ladle 116. The inventors have found that the content of oxygen or oxygen-related impurities may not be constant as a function of depth of the molten alloy 110. In general, the inventors have found that the content of oxygen or oxygen-related impurities tends to be higher toward the surface of the molten alloy 110. Thus, advantageously, if a portion of the molten alloy 110 with a lower than average content of oxygen is desired, the molten alloy 110 in the lower portion of the melting furnace may be preferentially transferred to the transfer ladle 116. This may be accomplished, for example, by connecting the first rate control element 114 to a lower portion of the melting furnace 108, for example, within the bottom 10%, 20%, 30%, 40%, 50%, or 60% of the lower portion. Alternatively, a mechanical pump may be used to preferentially pump the molten alloy 110 from its bottom portion and then transfer it to the transfer ladle 116.

[0062] Continuing with reference to FIG. 1, after the molten alloy 110 having a low content of impurities, including oxygen or oxygen-related impurities, is formed in the melting furnace 108 as described above, the molten alloy 110 can be transferred to a transfer ladle 116 via a first rate control element 114, e.g., a rounder or ramp, which may be under an enclosed and / or inert atmosphere to reduce reintroduction of oxygen or oxygen-related impurities. In some embodiments, the bubbling of an inert gas through the molten alloy 110 can continue throughout the process of transferring the molten copper-based alloy to the transfer ladle 116. If the first rate control element 114 is enclosed or isolated from the ambient atmosphere as shown, the atmosphere within the first rate control element can be the same as the atmosphere of the melting furnace. Thus, the atmosphere within the first rate control element can be argon, nitrogen, and / or any suitable inert gas.

[0063] The first rate control element 114 is configured to introduce the molten alloy 110 into the transfer ladle 116 at a controlled rate to reduce turbulence that may introduce or reintroduce impurities, including oxygen or oxygen-related impurities. The inventors have discovered that controlling the rate at this stage can also be important to prevent or reduce the introduction or reintroduction of oxygen and oxygen-related impurities into the molten alloy 110 as it cools, and to reduce the formation of voids in the molten alloy 110. The first rate control element 114 can be, for example, a launder or angled channel, which can be sealed and shielded from the outside atmosphere, as shown. In some embodiments, the first speed control element 114 can be set to any of the following speed control parameters: 1 inch / sec, 2 inches / sec, 5 inches / sec, 10 inches / sec, 15 inches / sec, 16 inches / sec, 17 inches / sec, 18 inches / sec, 19 inches / sec, 20 inches / sec, 21 inches / sec, 22 inches / sec, 23 inches / sec, 24 inches / sec, 25 inches / sec, 26 inches / sec, 27 inches / sec, 29 inches / sec, 30 inches / sec, 35 inches / sec, 40 inches / sec, 45 inches / sec, 46 inches / sec, 47 inches / sec, 48 inches / sec, 49 inches / sec, 50 inches / sec, 51 inches / sec, 52 inches / sec, 53 inches / sec, 54 inches / sec, 55 inches / sec, 56 inches / sec, 57 inches / sec, 58 inches / sec, 59 inches / sec, 60 inches / sec, 61 inches / sec, 62 inches / sec, 63 inches / sec, 64 inches / sec, 65 inches / sec, 66 inches / sec, 67 inches / sec, 68 inches / sec, 69 inches / sec, 70 inches / sec, 71 inches / sec, 72 inches / sec, 73 inches / sec, 74 inches / sec, 75 inches / sec, 76 inches / sec, 77 inches / sec, 78 inches / sec, 79 inches / sec, 80 inches / sec, 81 inches / sec, 82 inches / sec, 83 inches / sec, 84 inches / sec, 85 inches / sec, 85 inches / sec, 86 inches / sec, 87 inches / sec, 88 inches / sec, 89 inches / sec, 90 inches / sec, 91 inches / sec, 92 inches / sec, 50 in / sec, 55 in / sec, 60 in / sec, 65 in / sec, 70 in / sec, 75 in / sec, 80 in / sec, 85 in / sec, 90 in / sec, 95 in / sec, 100 in / sec, 105 in / sec, 110 in / sec, 115 in / sec, or 120 in / sec, or a value within a range defined by any of these values. In some embodiments, the first rate control element 114 is configured to transfer the molten alloy 110 from the melting furnace 108 to the transfer ladle 116 at a rate of 5 to 30 in / sec. In some embodiments, the first rate control element 114 controls the velocity of the molten copper-based alloy as it is transferred from the melting furnace 108 to the transfer ladle 116.

[0064] 1, in some embodiments, to control the velocity of the molten alloy 110 within the velocity ranges disclosed above, the closed sparging furnace system 100 is configured to transfer the molten alloy 110 from the melting furnace 108 to the transfer ladle 116 using a first rate control element 114, which is configured to control the velocity of the flowing molten alloy 110 using gravity, for example, positioned to have a vertical drop of about 0.5 to 5 inches over a horizontal length of about 3 to 5 feet. In some embodiments, the first rate control element 114 is configured to have a drop of 0.5 to 2 inches or 1 to 2 inches over a length of 3 feet, 4 feet, 5 feet, or 3 feet to 5 feet. The first rate control element can 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 a range defined by any of these values, relative to a horizontal plane parallel to the ground.

[0065] In this manner, reintroduction of impurities may be further reduced by forming a molten alloy 110 in the melting furnace 108 that is low in impurities, including oxygen or oxygen-related impurities, and then transferring the molten alloy 110 to the transfer ladle 116 under a sealed and / or inert atmosphere. Thus, as shown, according to various embodiments, the transfer ladle 116 and the first rate 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 within the transfer ladle 116 may be common or shared with the atmosphere of the melting furnace 108 and / or the first rate control element 114. Thus, the atmosphere within the transfer ladle may be argon, nitrogen, and / or any suitable inert gas.

[0066] Continuing with reference to FIG. 1 , after the molten alloy 110 is transferred to the transfer ladle 116 at a controlled rate using the first rate control element 114, the molten alloy 110 is poured into the mold 118 using the injector 124. The injector 124 may be, for example, a gravity-driven injector, where the molten alloy 110 is poured by gravity alone. For example, the injector 124 may comprise a piston that typically rests on a valve seat with 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 rate control element 114, and the melting furnace 108, may be enclosed in and connected by a common inert atmosphere. When the piston is lifted off the valve seat, the molten alloy 110 is allowed to flow through the valve seat opening, whereby the molten alloy 110 is discharged into the mold 118 by gravity. The inventors have again discovered that to prevent excessive turbulence which may again result in 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", 3.5", or have a value within a range defined by any of these values.

[0067] 2 is a schematic diagram of a closed sparging furnace system 200 for producing copper-based alloys, such as ingots, copper-based shots, or copper-based components, with low oxygen or oxygen-related impurities, according to one embodiment. The closed sparging furnace system 200 shares various components that are broadly configured similar to the corresponding components of the closed sparging furnace system 100 described above, and detailed descriptions of some 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 a molten copper-based alloy 110 in a melting furnace 108. In a similar manner as described above with respect to FIG. 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-based alloy 110. The bubbles 112 pass through the molten copper-based alloy 110, entraining impurities, including oxygen and oxygen-related impurities, from the molten copper-based alloy 110, as described above. After impurities are removed from the melting furnace 108, the molten copper-based alloy 110 is transferred at a first controlled rate from the melting furnace 108 via a first rate control element 114 to a transfer ladle 116. In some embodiments, the transfer ladle 116 includes one or more injectors 124.

[0068] The inventors have discovered that under some circumstances, in addition to advantageously controlling the rate at which the molten alloy 110 is delivered from the melting furnace 108 to the transfer ladle 116 using the first speed control element 114, it may be further advantageous to further control the rate at which the molten alloy 110 is delivered from the transfer ladle 116 to the mold 118. To address these and other needs, in the system 200 shown in FIG. 2, unlike the system 100 of FIG. 1 where the molten alloy 110 is transferred directly from the transfer ladle 116 to the mold 118, the molten copper-based 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 may be, for example, a launder or an inclined channel, and may be enclosed and shielded from the outside atmosphere. The molten alloy 110 solidifies within the mold 118 to produce a solidified copper-based alloy. The mold 118 may be moved via a conveyor belt 120 where it may be further processed.

[0069] In addition to the first rate 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 rate control element 218. The additional rate control element provides additional rate control to further reduce the reintroduction of oxygen or oxygen-related impurities into the molten alloy 210 as it is introduced into the ingot mold 118. The second rate control element 218 may be configured according to the various configuration parameters (including dimensions and gradients) described above with respect to the first rate control element 114, a detailed description of which is omitted herein for the sake of brevity.

[0070] So configured, in the system 200 shown in FIG. 1, a molten alloy 110 having a reduced content of oxygen or oxygen-related impurities may be formed in the melting furnace 108 and transferred to the transfer ladle 116 at a first velocity using the first rate control element 114, and then the molten alloy 110 may be transferred to the ingot mold 118 at a second velocity that is further reduced relative to the first velocity using the second rate control element 218. In some embodiments, the rate control element 218 is sealed from the ambient atmosphere. However, the embodiments are not so limited, and in some other embodiments, the second rate control element 218 may be open to the ambient atmosphere. In some embodiments, the atmosphere within the second rate control element 218 may be the same as the atmosphere within the melting furnace 108 and / or the first rate control element 114 and / or the transfer ladle 116. Thus, the atmosphere within the second rate control element 218 may be argon, nitrogen, and / or any suitable inert gas.

[0071] The second rate control element 218 is configured to transfer the molten alloy 110 from the transfer ladle at a rate having any value as described above with respect to the rate of the molten copper-based alloy 110 controlled by the first rate control element 114. However, it is understood that because the rate of the molten alloy 110 reaching the second rate control element 218 has already been reduced by the first rate control element 114, the rate of the molten alloy 110 reaching the mold 118 will be substantially lower than the rate of the molten alloy 110 reaching the mold 118 without the presence of the second rate control element 218, for example, as shown in FIG. 1. According to various embodiments, the second rate of the molten alloy 110 at the end of the second rate control element 218 is 20%, 30%, 40%, 50%, 60%, 70% of the first rate of the molten alloy at the end of the first rate element 112, or a value within a range defined by any of these values.

[0072] 1, the inventors have discovered that turbulence caused by vertically dropping the molten alloy 110 can introduce or reintroduce oxygen or oxygen-related impurities into the molten alloy 110. Thus, the vertical drop between the injection tip of the injector 124 and the second rate control element 218, and the vertical drop between the second rate control element 218 and the mold 118 should not exceed 0.5", 1.0", 1.5", 2.0", or have a value within a range defined by any of these values ​​to prevent excessive turbulence.

[0073] So configured, the second rate controlling element 218 is configured to transfer the molten copper-based alloy 110 from the transfer ladle 216 to the ingot mold 118 at a substantially reduced velocity and without a vertical drop.

[0074] FIG. 3A is a schematic diagram of a closed sparging furnace system 300 for producing copper-based alloys, such as ingots, copper-based shots, or copper-based components, with low oxygen or oxygen-related impurities according to another embodiment. In particular, the system 300 illustrates one exemplary implementation of a conveyor system 304. The upper diagram illustrates a top view of the system 300 including the conveyor system 304, and the lower diagram illustrates a side view of the conveyor system 304. The closed sparging furnace system 300 shares various components that are broadly configured similarly to the corresponding components of the closed sparging furnace systems 100 and 200 described above in relation to FIG. 1 and FIG. 2, respectively, and detailed descriptions of these components may be omitted herein for brevity. Unlike the systems 100 and 200 described above in relation to FIG. 1 and FIG. 2, the system 300 includes two melting furnaces 108 for higher productivity. However, it will be understood that embodiments are not so limited and any one of the systems 100, 200, and 300 may have any suitable number of melting furnaces 108, for example, one or more. After oxygen-related impurities have been removed from the melting furnace 108 in a manner similar to that described above, the molten copper-based alloy 110 is transferred from the melting furnace 108 to a transfer wheel 316 via a first speed control element 114 at a first controlled rate, and optionally further via a second speed control element 218 at a second controlled rate, which may be the same as the first rate or slower. Unlike the systems 100 and 200 described above with respect to Figures 1 and 2, the second speed control element 218, if present, is directly connected 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. Additionally, unlike systems 100 and 200 (FIGS. 1 and 2), in the illustrated system 300, the molten alloy 110 is injected into the molds 118 using a transfer wheel 316, also referred to as a casting wheel, which will be described in more detail with respect to FIGS. 3B and 3C. The molten alloy 110 thus ejected is dripped onto 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 324.The conveyor system 304 may optionally include, for example, a cooling fan 308 and a knocker 312 to loosen the ingots from the molds and collect them in a collection bin 320 .

[0075] 3B and 3C show detailed perspective and side views, respectively, of a portion of the system 300 shown in FIG. 3A for producing copper-based alloys with low content of oxygen or oxygen-related impurities, according to some other embodiments. The portion of the system 300 shown in FIG. 3B and FIG. 3C shows further details of the system 300, including the arrangement of the transfer wheel 316 and the conveyor belt 120. The side view of FIG. 3C is along the direction of movement of the conveyor belt 120. Notably, as described above with respect to FIG. 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 FIG. 1 and FIG. 2. Unlike the transfer ladle 116 (FIGS. 1 and 2) where the injectors 124 are separated by a linear distance, e.g., along the bottom surface of the transfer ladle 116, in the transfer wheel 316 the injectors 328 extend in different directions, separated by an arc defined by an angle of separation between them. 3B and 3C, the transfer wheel 316 is configured to rotate about a central radial (z) axis. Without limitation, in the illustrated transfer wheel 316, the z axis extends generally in the direction of flow of the molten metal 110 within the second speed control element 218.

[0076] The multiple injectors 328 of the transfer wheel 316 are tilted to extend radially at an oblique angle relative to the z-axis. The angle of extension of the injectors 328 is such that, 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 (FIGS. 1 and 2), the tilt of the injectors 328 allows for a further reduction in the velocity at which the molten alloy 110 is delivered to the mold 118.

[0077] The motor drive 324 is configured to synchronize the motion of the transfer wheel 316 and the conveyor belt 120. The motor drive 324 is configured to rotate the transfer wheel 316 about the z-axis at a predetermined angular velocity and linearly translate the regularly spaced molds 118 such that adjacent ones of the angled injectors 328 of the transfer wheel 316 are separated by an arc corresponding to the linear distance between adjacent ones of the molds 118. Thus, as the transfer wheel 316 rotates, adjacent ones of the molds 118 are filled with molten metal 110 by corresponding ones of the injectors 328.

[0078] 3B, a gate valve 332 is disposed at the end of each arm of the first speed control element 114. The gate valves 332 are configured to seal and keep the molten metal 110 under 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 as open at its top. However, during operation, the second speed control element 218 may also be sealed under an inert atmosphere and benefit therefrom as described above.

[0079] According to various embodiments, the apparatus is configured such that the molten copper-based alloy formed within the embodiment mold 118 and ultimately solidifies has a substantially lower oxide content as compared to a copper-based alloy produced using a conventional copper furnace. In some embodiments, the solidified copper-based alloy has 5%, 10%, 15%, 20%, 25%, 30%, 50%, 75%, or up to 99% lower oxide content, or any value therebetween, than a solidified copper-based alloy produced by a conventional reference furnace using the same feedstock materials.

[0080] According to various embodiments, an apparatus according to embodiments is configured to provide one or more test results obtained from a solidified copper-based alloy using the ASTM E8 / E8M-21 method, relative to a baseline solidified copper-based alloy formed from a baseline apparatus configured to be identical to the apparatus except that the melting furnace and transfer ladle are under the same sealed inert atmosphere, such that one or more of the ultimate tensile strength increases by at least 10 ksi, 20 ksi, 40 ksi, 50 ksi, or a value within a range defined by any of these values; the 0.5% yield strength increases by at least 1, 2, 3, 6, 8, 10 ksi, or a value within a range defined by any of these values; the elongation increases by at least 3%, 5%, 10%, 20%, 30%, 40%, 50%, or a value within a range defined by any of these values; and the reduction in cross-sectional area increases by at least 3, 5, 10%, or a value within a range defined by any of these values.

[0081] (A system including an enhanced diffuser assembly for producing high purity copper-based alloys) Described above are various aspects of furnace systems configured to produce copper-based alloys with reduced impurity content, and methods of producing copper-based alloys using such systems. As discussed above, controlling inert gas bubble characteristics, among others, can be important to generate optimized conditions for reducing impurity content from the molten copper-based alloy 110. Bubble characteristics include bubble size, density per unit volume, and velocity distribution. These bubble characteristics are determined by various flow characteristics including flow rate, flux, and pore size distribution through the diffuser 106.

[0082] In the illustrated melting furnaces 108A, 108B (FIGS. 1A and 1B), the diffuser 106 has a diameter d (FIG. 1A) that is smaller than the diameter D of the melting furnace 108. The diffuser 106 is further described with respect to FIGS. 4A-4C. As shown in FIG. 4A, the diffuser material or medium 412 is connected to an inlet 404 for flowing an inert gas. The diameter d of the diffuser 106 in contact with the molten copper-based 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 discovered that because the diameter d or area of ​​the diffuser 106 is smaller than the diameter D or area of ​​the melting furnaces 108A, 108B, the inert gas bubbles 112 cannot flow substantially across the entire cross section of the molten copper-based alloy 110. As a result, depending on the diffusivity of the impurities, the molten copper-based alloy 110 outside the path of the inert gas bubbles 112 may not be effectively cleaned. Therefore, the inventors have recognized a need to increase the cross-sectional area of ​​the molten copper-based alloy 110 through which the inert gas bubbles pass toward the surface.

[0083] To address these and other needs, and to further refine the various embodiments disclosed herein, a further embodiment of an apparatus for producing a copper-based alloy includes a melting furnace configured to form a molten copper-based alloy comprising at least 50% by weight copper. According to an embodiment, the melting furnace 108 includes a diffuser assembly including one or more diffusion linings. The diffuser assembly includes a diffusion lining formed on a surface of the melting chamber wall. The diffusion lining may be used in addition to or as an alternative to the diffuser 106 described above.

[0084] 6A and 6B are schematic side views of a melting furnace with a diffuser assembly for producing high purity copper-based alloys, according to some embodiments. The diffuser assembly includes a diffuser 400 and one or both of a diffusion lining 400A, 400B. Unlike the melting furnaces 108A, 108B described above with respect to FIGS. 1A and 1B, in which the diffuser 400 is configured to contact the molten copper-based alloy 110, in the illustrated embodiment of FIGS. 6A and 6B, the diffuser 400 is disposed at a depth inside the diffusion lining 400A, 400B. When configured, the inert gas diffusing from the diffuser 400 traverses the diffusion lining 400A disposed thereon, such that the inert gas is further diffused by the diffusion lining 400 before being introduced into the molten copper-based alloy 110. According to various embodiments, the diffusion lining 400A, 400B includes a porous high temperature refractory ceramic material. The ceramic material includes aluminum silicate having a porous structure adapted for bubbling an inert gas through the molten copper-based alloy. It will be appreciated that the refractory linings 130A, 130B described above with respect to Figures 1A, 1B may have a similar structure and / or be formed using similar methods as described herein as the diffusion linings 400A, 400B, which serve the important function of further diffusing the inert gas to form inert gas bubbles therein before being introduced into the molten metal 110.

[0085] Figure 6A shows a melting furnace 600A including a diffusion lining 400A that substantially covers its bottom inner surface and has a porous structure adapted for bubbling an inert gas into the molten copper-based alloy 110. Figure 6B shows a melting furnace 600B including at least two different inner surfaces, e.g., diffusion linings 400A, 400B formed on the bottom and sidewall surfaces of the melting furnace 608B.

[0086] The melting furnace 608A includes various features described above with respect to the melting furnace 108 (FIGS. 108A, 108B) described above with respect to FIGS. 1, 1A, 1B, and 2. The melting furnace 608A can be configured as a closed melting furnace similar to the melting furnace 108A (FIG. 1A) or as an open melting furnace 108B (FIG. 1B). As disclosed herein, unless indicated to the contrary, references made to the melting furnace 108 will be understood to apply to one or both of the melting furnaces 108A, 108B. As described above with respect to FIGS. 1A and 1B, the melting furnaces 608A, 608B receive the inert gas source 102 via the diffuser 400. The melting furnaces 608A, 608B are enclosed by chamber walls 134 comprising a suitable refractory material. The chamber walls 134 may be formed of a relatively airtight refractory material to prevent ambient air from contaminating the molten copper-based alloy 110. The melting furnaces 608A, 608B are surrounded by coils 138 for inductive heating of the feedstock, as described above.

[0087] In the melting chamber 608A shown in FIG. 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 relative to the diffuser 400. When configured, the upper surface of the diffuser 400 is located below the upper surface of the diffusion lining 400A. The inert gas diffusing from the diffuser 400 traverses and diffuses through the thickness of the diffusion lining 400A formed over the diffuser 400. As a result, the diffusion lining 400A substantially increases the cross-sectional area of ​​the molten copper-based alloy 110 that is vertically traversed by the inert gas bubbles 612 compared to having the diffuser 400 alone, for example, as described above with respect to FIG. 1A and FIG. 1B. The inventors have found that, due to the limited thickness and surface area of ​​the diffuser 400, when the inert gas directly enters the molten copper-based alloy 110 from the diffuser 400, the inert gas bubbles cannot enter uniformly across the entire cross-section of the molten copper-based alloy 110, but rather through an effective area that is much smaller than the effective area of ​​the cross-sectional area of ​​the molten copper-based alloy 110. On the other hand, in the illustrated two-stage diffuser assembly, the inert gas first diffuses through the diffuser 400 and then 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 through substantially the entire cross-sectional area of ​​the molten copper-based metal 110. As a result, as shown in FIG. 6A, the inert gas bubbles 612 cover a substantially larger cross-sectional area relative to the cross-sectional area covered by the diffuser 400 alone. The present inventors have discovered that by using a two-stage diffuser assembly, the impurity removal efficiency for a given flow rate of inert gas can be substantially improved.

[0088] In the melting chamber 608B shown in FIG. 6B, the diffuser assembly according to the embodiment includes a diffuser 400 and a diffusion lining 400A, similar to that shown in the melting chamber 608A (FIG. 6A). Advantageously, in addition to the diffusion lining 400A covering the bottom surface of the melting chamber 608B, the melting chamber 608B further includes a diffusion lining 400B covering the sidewalls of the melting chamber 608B. The diffusion linings 400A, 400B covering the bottom inner surface and the sidewall inner surface are adapted to further increase the cross-sectional area of ​​the molten copper-based alloy 110 through which the inert gas bubbles 612 pass, compared to having only the diffuser 400. In addition to covering a larger area of ​​the molten copper-based alloy 110 through which the inert gas bubbles 612 pass vertically, the diffusion lining 400A also allows the inert gas bubbles 612 to enter the molten copper-based alloy 110 laterally or horizontally at the side of the molten copper-based alloy 110. In the illustrated three-stage diffuser assembly, the inert gas first diffuses through the diffuser 400 and then further diffuses through the diffusion lining 400A, as described above with respect to FIG. 6A. Furthermore, the portion of the inert gas that exits the diffusion lining 400A that does not bubble through the molten copper-based alloy 110 enters the diffusion lining 400B. The inert gas that enters the diffusion lining 400B further diffuses therein before entering the molten copper-based alloy 110 at the lateral sidewalls. As a result, as shown in FIG. 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 the combination of the diffuser 400 and the diffusion lining 400A. The inventors have discovered that by using a three-stage diffuser assembly, the impurity removal efficiency for a given flow rate of inert gas can be substantially improved.

[0089] In addition to increasing the surface area of ​​the molten copper-based alloy 110 through which the inert gas is introduced to improve the removal of impurities already present in the feedstock, it will be appreciated that the diffusion lining 400A, 400B allows for the removal of excess moisture or oxygen that may be absorbed by the chamber walls of the melting furnace 608A, 608B prior to melting the feedstock. Because a substantial surface area of ​​the melting furnace 608A, 608B is covered by the diffusion lining 400A, 400B and flows the inert gas through the diffuser 400, the diffusion lining 400A, 400B can substantially prevent oxygen and / or moisture from the chamber walls from entering the molten copper-based alloy 110 prior to melting the feedstock material. Without the diffusion lining 400A, 400B, oxygen and / or moisture absorbed by the interior surfaces of the melting furnace 608A, 608B can be released and introduced into the molten copper-based alloy 110, detrimentally affecting the resulting copper-based alloy (including ingots and shots) as described above.

[0090] The various parameters associated with the operation of the melting furnaces 608A, 608B are substantially similar to those described above with respect to Figures 1, 1A, 1B, and 2, and details of similar features will not be repeated here for the sake of brevity.

[0091] 6C is a cross-sectional view of the diffusion lining 400A, 400B according to various embodiments. The diffusion lining 400A, 400B according to various embodiments includes refractory materials including alumina, silica, and aluminosilicates. The composition is such that the molten copper-based alloy 110 is not contaminated at high temperatures. In addition to a chemical composition adapted for high temperature melting of the copper-based alloy, the diffusion lining 400A, 400B has a physical structure adapted for mechanical strength as well as an optimized porosity for controlling inert gas bubble characteristics in a manner similar to that described above for the diffuser 400.

[0092] The inventors have discovered that a diffusion lining 400A, 400B having at least two different layers or regions can be used to meet various chemical and physical properties adapted for effective sparging as described herein above. The diffusion lining 400A includes an upper layer or region 400A-2 and a lower layer or region 400A-1, and the diffusion lining 400B includes an upper layer or region 400B-2 and a lower layer or region 400B-1. The upper layer 400A-2, 400B-2 is configured to be closer to, e.g., in contact with, the molten copper-based alloy 110 and is configured to be interposed between the lower layer 400A-1, 400B-1 and the molten copper-based alloy 110.

[0093] According to an 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, in which adjacent ceramic particles are partially fused while leaving gaps between them, and retain a porous surface for diffusing the inert gas therethrough. In contrast, the lower layers 400A-1, 400B-1 may be unsintered ceramic layers, for example, compressed ceramic power layers, in which adjacent ceramic particles contact each other without being fused by sintering, and also have gaps between them for diffusing the inert gas. Such a two-layer structure provides mechanical stability to the diffusion linings 400A, 400B, while at the same time providing a high porosity adapted to diffuse the inert gas into the molten copper-based alloy 110.

[0094] In some embodiments, the top layer 400A-2, 400B-2 and the bottom layer 400A-1, 400B-1 are formed from the same initial compacted ceramic powder layer, although the embodiments are not so limited. As described below, a surface portion of the compacted ceramic powder layer may be partially sintered to form a bi-layer structure. In these embodiments, the sintered top layer 400A-2, 400B-2 and the unsintered bottom layer 400A-1, 400B-1 have substantially the same chemical composition but different phases. That is, the initial compacted ceramic powder layer may include constituent ceramic compounds that upon sintering form new phases in the top layer 400A, 400B-2. The inventors have found that one particularly suitable ceramic powder composition is a mixture of alumina and silica configured to form mullite upon sintering.

[0095] Mullite (3Al2O3·2SiO2) is particularly suitable as the top layer 400A-1, 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 crystallizing compound in the phase diagram of the alumina-silica (Al2O3-SiO2) system. The compound decomposes and melts at a temperature of 1828±10° C. Thus, according to an embodiment, the initial compacted powder layer includes a mixture having a composition capable of forming a substantial volume fraction of mullite.

[0096] The bilayer structure is formed by locally exposing the surface of the compacted ceramic powder layer to a sintering temperature sufficient to form mullite from the powder composition, as described below. The resulting bilayer structure includes an upper sintered layer 400A-2, 400B-2 comprising mullite and a lower unsintered layer 400A-1, 400B-1 formed primarily of alumina and silica. According to some embodiments, the bilayer structure is formed using a powder composition comprising alumina in an amount of 50-80 mol%, 55-75 mol%, 60-70 mol%, or a mol% within a range defined by any of these values, for example about 65 mol%. The powder composition further comprises silica in an amount of 10-35 mol%, 15-30 mol%, 20-25 mol%, or a mol% within a range defined by any of these values, for example about 24 mol%. The powder composition may further comprise SiC in an amount of 2-8 mol%, 4-6 mol%, or about 5 mol%, TiO2 in an amount of 1-3 mol%, 1.5-2.5 mol%, or about 2.2 mol%, and Fe2O3 in an amount of 0.5-2 mol%, 1-1.5 mol%, or about 1.2 mol%. It will be appreciated that substantial deviations 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 result in reduced performance with respect to the various properties mentioned above.

[0097] The present inventors have determined that the preferred average particle size of the starting powder for forming the diffusion linings 400A and 400B is D=D0(2 -φ ) where D0 is a reference diameter of 1 mm. For example, φ scales of 2-1, 3-2, 4-3 and 8-4 correspond to 0.25-0.5 mm, 125-250 μm, 62.5-125 μm and 3.9-62.5 μm, respectively. The inventors have determined that suitable average particle sizes for the mullite-forming powder are less than 125 μm, less than 100 μm, less than 75 μm, less than 50 μm, e.g., less than 63 μm, which corresponds to a φ scale of 4.

[0098] According to various embodiments, the diffusion lining 400A, 400B has a suitable thickness such that the inert gas diffuses from the diffusion lining 400A, 400B through a substantial area thereof. The diffusion lining 400A, 400B according to various embodiments has a thickness of more than 2 inches, 3 inches, 4 inches, 5 inches, 6 inches, 7 inches, or within a range defined by any of these values. In FIG. 6A and FIG. 6B, this thickness corresponds to the thickness of the diffusion lining 400A above the surface of the diffuser 400, and in FIG. 6B, this thickness corresponds to the thickness of the diffusion lining 600B. For example, the diffusive 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 3-4 inches for a total thickness of 5-6 inches. Similarly, the thickness of the diffusion lining 400B can be about 3-4 inches. It will be appreciated that if the thickness of the diffusion linings 400A, 400B is too thin, there may be insufficient diffusion of the inert gas, which may lead to localized bubble formation as opposed to bubble formation across a substantial cross-sectional area of ​​the molten copper-based metal 110.

[0099] 6C, according to various embodiments, the sintered top layers 400A-2, 400B-2 have a thickness of less than 1 inch, 0.8 inch, 0.6 inch, 0.4 inch, 0.2 inch, 0.1 inch, or a value within a range defined by any of these values. The remainder of the diffusion linings 400A, 400B can be unsintered bottom layers 400A-1, 400B-1.

[0100] Additionally, the diffusion linings 400A, 400B have a porosity, defined as the ratio of voids to the overall macroscopic volume, that is greater than 10%, 15%, 20%, 25%, 30%, 35%, or a value within a range defined by any of these values.

[0101] According to some embodiments, the diffusion linings 400A, 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 may have a bi-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, 400B, the flow of inert gas through the diffuser 400 and through the refractory linings 400A, 400B into the molten copper-based metal 110 can be optimized. However, the embodiments are not so limited and in other embodiments, the diffusion linings 400A, 400B can have a composition and structure that differs from the composition and structure of the diffuser 400.

[0102] 6A and 6B, in the illustrated embodiment, the diffusion linings 400A and 400B cover substantially the entire bottom and sidewall surfaces of the melting furnaces 6008A, 608B, respectively, although the embodiment is not so limited. For example, the diffusion lining 400A can have a diameter larger than the diameter of the diffuser 400, but smaller than the diameter of the inner diameter D (FIG. 1A) of the melting furnaces 608A, 608B. For example, the diameter of the diffusion lining 400A can be less than 0.8D, 0.6D, 0.4D, or a value within a range defined by any of these values. Similarly, the diffusion lining 400B can have a height that is less than the height of the fill line height F (FIG. 1A) of the melting furnaces 608A, 608B. For example, the height of the diffusion lining 400B can be less than 0.8F, 0.6F, 0.4F, or a value within a range defined by any of these values.

[0103] In the following, a method for manufacturing a melting furnace including a diffusion lining is described. Figure 7A illustrates a method for forming a diffusion lining in a melting furnace for producing a high purity copper-based alloy, according to various embodiments. The method 700 includes a step 704 of providing a melting furnace chamber configured to form a molten alloy. The method further includes a step 708 of forming a diffusion lining on an inner surface of the melting furnace chamber, the diffusion lining including a ceramic material having a porous structure adapted for bubbling an inert gas through the molten copper-based alloy.

[0104] According to various embodiments, providing molten alloy 704 includes providing a copper-based alloy including at least 50% copper by weight. According to various embodiments, forming diffusion lining 708 includes providing a diffusion lining including a ceramic material, such as an aluminum silicate ceramic material, having a porous structure adapted for bubbling an inert gas through the molten copper-based alloy. According to various embodiments, forming diffusion lining 708 includes substantially covering a bottom inner surface of the melting furnace and having a porous structure adapted for bubbling an inert gas through the molten copper-based alloy. According to various embodiments, providing diffusion lining 708 includes forming a diffusion lining having a porous structure on at least two different inner surfaces of the melting furnace, such that the diffusion lining is adapted for bubbling an inert gas through the molten copper-based alloy from at least two different inner surfaces.

[0105] According to various embodiments, the step 708 of forming the diffusion lining includes disposing a compressed powder layer on the inner surface of the melting furnace chamber. The compressed ceramic powder layer includes a mixture of silica and alumina. The step 708 of forming the 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 includes selectively sintering a surface portion of the compressed ceramic powder layer, thereby forming a diffusion lining on the inner surface comprising a bi-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 electrical 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 a heated material disposed in the melting furnace chamber. The diffusion lining thus formed includes an aluminum silicate ceramic material having a porous structure adapted to diffuse an inert gas therethrough. The method 700 is further described herein with respect to Figures 7B-7F.

[0106] 7B-7F are schematic side views of a melting furnace at various stages of forming a diffusion lining therein to construct a melting furnace for producing high purity copper-based alloys according to the method 700 shown in FIG. 7A.

[0107] Referring to Figure 7B, providing a melting chamber step 704 includes providing a melting furnace 700B similar to the melting chambers 108A, 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 suitable refractory material that is relatively gas-tight. A diffuser 400 is provided in a central region of the bottom inner surface of the melting furnace 700B. An inert gas is introduced into the molten copper-based alloy 110 via a gas inlet 404 formed through the bottom plate of the melting furnace 700B, as described above with respect to Figure 4C.

[0108] After the diffuser 400 is installed, a compressed ceramic powder layer 704 to form the diffusion lining 400A (FIGS. 6A-6C) is formed on the bottom inner surface of the melting furnace 700B. To form the compressed ceramic powder layer 704A, a ceramic powder having the composition and particle size described above with respect to FIGS. 6A-6C is poured onto the bottom surface of the melting furnace 700B and the diffuser 400. The ceramic powder is tapped to remove air pockets and densified into the compressed ceramic powder layer 704A having the thickness described above with respect to FIGS. 6A-6C.

[0109] Referring to FIG. 7C and FIG. 7D, after forming the compressed ceramic powder layer 704A on the base or bottom surface of the melting furnace 700B (FIG. 7B), a further compressed ceramic powder layer 704B (FIGS. 6B-6C) is formed on the sidewall surface of the melting furnace 700C to form the diffusion lining 400B. Referring to FIG. 7C, a heating can 708 is placed on the compressed ceramic powder layer 704A. The heating can 708 is formed of a metal that can be inductively heated in situ using the induction coil 138 to form a molten metal liquid. The heating can 708 is configured to be heated to a temperature sufficient to melt with the raw material placed therein, providing heat to partially or locally sinter the contacting compressed ceramic powder layers 704A, 704B. According to an embodiment, but not limited to, the heating can 708 can be formed of an iron-based alloy, such as mild steel. Heater can 708 is sized such that the width of a gap 712 formed between the exterior surface of heater can 708 and the inner sidewall of melting furnace 700C corresponds to the final thickness of diffusion lining 400B.

[0110] 7D, to form a compressed ceramic powder layer 704B, a ceramic powder having the composition and particle size described above with respect to FIGS. 6A-6C is poured into the gap 712 between the sidewall of the melting furnace 700C (FIG. 7C) and the exterior surface of the heated can 708. The ceramic powder is allowed to remove air pockets and densify into a compressed ceramic powder layer 704B having a thickness defined by the width of the gap 712 and a height corresponding to the fill line (F) or a portion thereof, as described above with respect to FIGS. 6A-6C. It will be appreciated that the formation of the ceramic powder layer 704B may be omitted, for example, when only the diffusion lining 403A is formed as shown in FIG. 6B.

[0111] With reference to Figures 7E and 7F, the compressed ceramic powder layers 704A and 704B thus formed on the bottom and sidewall surfaces of the melting furnace 700E, respectively, are ready to be partially or locally sintered to form the bi-layer structure described above with respect to Figure 6C. The partial or local sintering of the surface regions of the ceramic powder layers 704A, 704B is performed in situ using the induction coil 138. In particular, the local sintering is performed indirectly using the induction coil 138, using heat from a molten liquid formed by melting the can 708 and the heated feedstock disposed therein, as described herein. With reference to Figure 7E, the can 708 is filled with the heated feedstock 712. Similar to the heated can 708, the heated feedstock 712 is formed from a metal, for example, an iron-based feedstock that can be heated to a temperature sufficient to form a heated molten metal mixture and to partially or locally sinter the compressed ceramic powder layers 704A, 704B in contact therewith, in situ in the melting furnace 700E, using the induction coil 138. According to an embodiment, but not limited to, the heating feedstock 712 can be formed from an iron-based material, such as mild steel or cast iron. The heating feedstock 712 and the heating can 708 can be formed from the same material or different materials. Nevertheless, both the heating feedstock 712 and the heating can 708 are adapted to melt and form a heated molten metal mixture that can be heated to a temperature sufficient to sinter at least a surface region of the compressed ceramic powder layers 704A, 704B.

[0112] 7F, after filling the heating can 708 with the heating feedstock 712, both the heating can 708 and the heating feedstock 712 are inductively heated using the induction coil 138 to a temperature high enough to form a heated molten metal mixture 716 including molten mild steel and / or cast iron. The heated molten metal mixture 716 is further heated to a temperature sufficient to provide sufficient heat to partially or locally melt the compacted ceramic powder layers 704A, 704B on the bottom and sidewall surfaces of the melting furnace 700F, for example, at the surface regions thereof.

[0113] It will be appreciated that the heating conditions for forming the molten metal mixture 716 depend on the sintering temperature at which the compressed ceramic powder layers 704A, 704B are sintered at least at their surface regions to form, for example, the bi-layer structure described above with respect to FIG. 6C. According to an embodiment, the sintering temperature used is 0.7T m , 0.75T m , 0.8T m and 0.85T m Ultra and 0.9T m or a value within a range defined by any of these values, T m is the melting temperature of the compacted ceramic powder layers 704A, 704B. For example, for 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, the final diffusion lining 403A, 403B is formed, for example, having a two-layer structure as described above with respect to FIG. 6C. The heated molten metal mixture 712 is then poured out to obtain the molten furnace 608A (FIG. 6A) or 608B (FIG. 6B).

[0114] FIG. 8 illustrates a method of producing a copper-based alloy with low impurity content using a melting furnace with a diffusion lining, according to an embodiment. The illustrated method may include various features of the method 500 of producing a copper-based alloy with low impurity content described above with respect to FIG. 5. Various features that may be in common between the method 500 (FIG. 5) and the method 800 (FIG. 8) are omitted herein for the sake of brevity. Similar to the method 500 of FIG. 5, the method 800 includes a step 804 of providing a feedstock in a melting furnace. The feedstock may have a composition configured to form a molten copper-based alloy including, but not limited to, at least 50% by weight copper. The method 800 further includes a step 808 of heating the feedstock and melting the feedstock to form a molten alloy, e.g., a copper-based alloy. The method further includes a step 818 of bubbling an inert gas through the molten alloy, e.g., a copper-based alloy. However, unlike the method 500 (FIG. 5), the method 800 includes a 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 of the configurations of the diffusion linings 400A, 400B described above with respect to Figures 6A-6C. For example, the diffusion linings 400A, 400B include an aluminum silicate ceramic material having a porous structure adapted to bubbling an inert gas through the molten copper-based alloy. According to an embodiment, the step 812 of bubbling the inert gas through the molten copper-based alloy can include using a diffusion lining that substantially covers a bottom inner surface of the melting furnace and has a porous structure adapted to bubbling the inert gas through the molten copper-based alloy. According to an embodiment, the step 812 of bubbling the inert gas through the molten copper-based alloy can include using a diffusion lining formed on at least two different inner surfaces of the melting furnace, such that the diffusion lining is adapted to bubbling the inert gas through the molten copper-based alloy from at least two different inner surfaces. EXAMPLES

[0115] To prepare the test specimens used to obtain the mechanical test results, copper feedstock, e.g., alloy C87850 feedstock, was melted at 1950°F in a 4000 lb furnace and argon gas was bubbled through the copper-based alloy in the melting furnace at a flow rate of 4 liters / min for 90 minutes. A reference ingot was also produced using the same system but without sparging, e.g., by bubbling argon through the molten copper-based alloy in the melting furnace. Both the copper ingot produced with 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]

[0116] As shown, the measured mechanical properties are clearly superior for the particular C87850 alloy. For example, the ultimate tensile strength is improved by 47%. Similar results were repeatedly obtained for various copper-base alloys. Similar comparisons were made for four representative copper-base alloys, including C87850, C89833, C99500, and C96400. The nominal compositions of the four alloys are shown in Table 2. [Table 2]

[0117] For each alloy system shown in Table 2, copper ingots were produced with and without argon gas sparging 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]

[0118] The measured mechanical properties of the sparged ingots are clearly superior, for example, the ultimate tensile strength is improved by 46%, 189%, 6% and 82% for alloys having the C87850, C89833, C99500 and C96400 alloy compositions.

[0119] As disclosed herein, the copper-based alloy compositions according to various embodiments, including the raw material compositions, may contain, in weight percent, Cu in an amount of greater than 50%, 60%, 70%, 80%, 90%, 95%, or a value within a range defined by any of these values; Sn in an amount of greater than 0.1%, 0.2%, 0.5%, 1%, 2%, 5%, 10%, or a value within a range defined by any of these values; Pb in an amount of greater than 0.01%, 0.02%, 0.05%, 0.1%, 0.2%, 0.5%, or a value within a range defined by any of these values; Zn in an amount of more than 0.1%, 0.2%, 0.5%, 1%, 2%, 5%, 10%, 20%, 30%, or a value within a range defined by any of these values; Fe in an amount of more than 0.1%, 0.2%, 0.5%, 1%, 2%, 5%, 10%, or a value within a range defined by any of these values; Sb in an amount of more than 0.01%, 0.02%, 0.05%, 0.1%, 0.2%, 0.5%, or a value within a range defined by any of these values; Ni in an amount of more than 0.01%, 0.02%, 0.05%, 0.1%, 0.2%, 0.5%, or a value within a range defined by any of these values; S in an amount of more than 0.01%, 0.02%, 0.05%, 0.1%, or a value within a range defined by any of these values; P in an amount of more than 0.01%, 0.02%, 0.05%, 0.1%, 0.2%, 0.5%, 1%, 2%, 5%, or a value within a range defined by any of these values; Al in an amount of more than 0.01%, 0.02%, 0.05%, 0.1%, 0.2%, 0.5%, 1%, 2%, 5%, or a value within a range defined by any of these values. The composition may comprise an amount of Si in an amount within a range defined by any one of the values; Mn in an amount of more than 0.01%, 0.02%, 0.05%, 0.1%, 0.2%, 0.5%, 1%, 2%, or a value within a range defined by any of these values; Bi in an amount of more than 0.01%, 0.02%, 0.05%, 0.1%, 0.2%, 0.5%, 1%, 2%, 5%, or a value within a range defined by any of these values; and Nb in an amount of more than 0.01%, 0.02%, 0.05%, 0.1%, 0.2%, 0.5%, 1%, 2%, or a value within a range defined by any of these values.Additionally, the copper-based alloy compositions may include any one or more of the elements disclosed in Table 2 within ranges defined by any of the corresponding amounts, including those corresponding to the C87850, C89833, C99500, and C96400 alloy compositions.

[0120] Below, various additional embodiments are disclosed, it being understood that any one of the additional embodiments can be combined with any other one of the additional embodiments, except where to the contrary in the present disclosure. <Additional Example I> (Embodiment 1) 1. An apparatus for producing a copper-based alloy, comprising: a sealed melting furnace configured to form a molten copper-based alloy containing at least 50% by weight copper under a sealed inert atmosphere and to bubble an inert gas through the molten copper-based alloy; a transfer ladle configured to receive the molten copper-based alloy from the melting furnace under the enclosed inert atmosphere and transfer the molten copper-based alloy to one or more molds or shot pits configured to solidify the molten copper-based alloy; An apparatus comprising: (Embodiment 2) 1. An apparatus for producing a copper-based alloy, comprising: a sealed melting furnace configured to form a molten copper-based alloy containing at least 50% by weight copper under a sealed inert atmosphere and to bubble an inert gas through the molten copper-based alloy; a transfer ladle configured to receive the molten copper-based alloy from the melting furnace via a rate control element and transfer the molten copper-based alloy to one or more molds or shot pits configured to solidify the molten copper-based alloy; An apparatus comprising: (Embodiment 3) 2. The apparatus of embodiment 1, wherein the transfer ladle is configured to receive the molten copper-based alloy from the melting furnace via a rate controlling element. (Embodiment 4) 3. An apparatus as recited in embodiment 2, wherein the transfer ladle is configured to receive the molten copper-based alloy from the melting furnace under the enclosed inert atmosphere. (Embodiment 5) 5. The apparatus of any one of embodiments 1-4, wherein the transfer ladle is configured to transfer the molten copper-based alloy to the shot pit configured to solidify the molten copper-based alloy into copper-based shot. (Embodiment 6) 6. The apparatus of any one of the preceding embodiments, wherein the one or more molds are ingot molds configured to solidify the molten copper-based alloy into a copper-based ingot. (Embodiment 7) 7. The apparatus of any one of the preceding embodiments, wherein the closed melting furnace and the transfer ladle are configured to substantially exclude mixing of outside air with the closed inert atmosphere. (Embodiment 8) 8. The apparatus of any one of the preceding embodiments, wherein the melting furnace and the transfer ladle are integrally connected such that they are sealed from an external atmosphere while under a common sealed inert atmosphere. (Embodiment 9) 9. The apparatus of any one of the preceding embodiments, wherein the inert gas and the same enclosed inert atmosphere consist essentially of argon. (Embodiment 10) The apparatus of any one of the preceding embodiments, wherein the inert gas does not include hydrogen. (Embodiment 11) 11. The apparatus of any one of embodiments 1, 3, and 5-10, further comprising a rate control element configured to transfer the molten copper-based alloy from the closed melting furnace to the encapsulated transfer ladle at a controlled rate adapted to reduce rate induced entrainment of the copper-based alloy to a reference copper-based alloy formed from a reference apparatus configured identically to the apparatus except for the presence of the rate control element. (Embodiment 12) 12. The apparatus of embodiment 11, wherein the rate control element comprises a ramp. (Embodiment 13) 13. The apparatus of embodiment 11 or 12, wherein the controlled speed is less than 100 inches / second. (Embodiment 14) 14. The apparatus of any one of the preceding embodiments, further comprising a second rate control element configured to transfer the molten copper-based alloy from the encapsulated transfer ladle to the one or more molds or the shot pit at a second controlled rate adapted to reduce rate induced entrainment of the copper-based alloy compared to a reference copper-based alloy formed from a reference apparatus configured identically to the apparatus except for the presence of the rate control element. (Embodiment 15) 15. The apparatus of embodiment 14, wherein the second rate control element comprises a ramp. (Embodiment 16) 16. The apparatus of embodiment 14 or 15, wherein the second control speed is less than 30 inches / second. (Embodiment 17) 17. The apparatus of any one of the preceding embodiments, wherein the encapsulated transfer ladle is insulated. (Embodiment 18) 18. The apparatus of any one of the preceding embodiments, further comprising a diffuser having a plurality of through holes disposed at a bottom of the melting furnace and adapted to bubbling the inert gas through the molten copper-based alloy in the form of inert gas bubbles having a size distribution adapted to reduce oxygen content from the molten copper-based alloy. (Embodiment 19) 19. The apparatus of embodiment 18, wherein the diffuser is configured to flow the inert gas at a rate of 2 to 6 liters per minute. (Embodiment 20) 20. The apparatus of claim 18, wherein the diffuser has a porosity of greater than 20%. (Embodiment 21) 20. The apparatus of embodiment 18-19, wherein the diffuser has a diameter greater than 5 cm and less than the inner diameter of the melting furnace. (Embodiment 22) 20. The apparatus of embodiment 18-19, wherein the melting furnace has an inner diameter of more than 50 cm. (Embodiment 23) 23. The apparatus of any one of the preceding embodiments, wherein the apparatus is configured such that the copper-based alloy has an oxygen content that is reduced by at least 10% compared to a reference copper-based 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. (Embodiment 24) 24. The apparatus of any one of the preceding claims, wherein the apparatus is configured such that the copper-based alloy has an oxygen content that is at least 10% reduced compared to a reference copper-based alloy formed from a reference apparatus configured identically to the apparatus, except that the melting furnace is configured to bubble the inert gas through the molten copper-based alloy. (Embodiment 25) The apparatus further comprises: comparing one or more test results obtained from the copper-based alloy using ASTM E8 / E8M-21 method to a reference copper-based 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; Ultimate tensile strength increased by at least 5 ksi 0.5% yield strength increased by at least 3 ksi; Elongation increases by at least 5% The device of any one of embodiments 1 to 24, configured to increase the reduction in cross-sectional area by at least 5%. (Embodiment 26) 26. The apparatus of any one of the preceding embodiments, wherein the apparatus is configured such that the copper-based alloy has an ultimate tensile strength increased by at least 20 ksi compared to a reference copper-based alloy formed from a reference apparatus configured identically to the apparatus, except that the melting furnace is configured to bubble the inert gas through the molten copper-based alloy. (Embodiment 27) 2. The apparatus of embodiment 1, wherein the transfer ladle is configured to transfer the molten copper-based alloy to the shot pit configured to solidify the molten copper-based alloy into the copper-based shot. (Embodiment 28) 2. The apparatus of embodiment 1, wherein the transfer ladle is configured to transfer the molten copper-based alloy to one of a plurality of ingot molds configured to solidify the molten copper-based alloy into the copper-based ingot. (Embodiment 29) 2. The apparatus of embodiment 1, wherein the melting furnace is configured to transfer the molten copper-based alloy from a bottom half of the volume of the molten copper-based alloy to the transfer ladle before transferring the remainder of the molten copper-based alloy. (Embodiment 30) 2. The apparatus of embodiment 1, wherein a first speed element is connected to a lower half of the melting furnace. (Embodiment 31) 31. The apparatus of any one of the preceding claims, wherein the melting furnace further comprises a diffusion lining comprising an aluminum silicate ceramic having a porous structure adapted for bubbling the inert gas through the molten copper-based alloy. (Embodiment 32) 31. The apparatus of any one of the preceding embodiments, wherein the melting furnace further comprises a diffusion lining having a porous structure substantially covering a bottom inner surface thereof and adapted for bubbling an inert gas into the molten copper-based alloy. (Embodiment 33) 31. The apparatus of any one of the preceding embodiments, wherein the melting furnace further comprises a diffusion lining having a porous structure, the diffusion lining being formed on at least two distinct inner surfaces of the melting furnace, such that the diffusion lining is adapted to bubble an inert gas through the molten copper-based alloy from the at least two distinct inner surfaces. (Embodiment 34) 34. The apparatus of embodiment 32 or 33, wherein the diffusion lining comprises an aluminum silicate ceramic. (Embodiment 35) 34. The apparatus of embodiment 31 or 33, wherein the diffusion lining substantially covers a bottom inner surface of the melting furnace. (Embodiment 36) 33. The apparatus of embodiment 31 or 32, wherein the diffusion lining is formed on at least two different inner surfaces of the melting furnace, such that 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 37) The device according to any one of the preceding embodiments, further according to any one of the embodiments in Additional Example III. Additional Example II (Embodiment 1) 1. A method for producing a copper-based alloy, comprising the steps of: providing a plurality of feedstock pieces in a melting furnace having a composite composition adapted to form a molten copper-based alloy having at least 50% by weight copper; flowing an inert gas through gaps between the pieces of material prior to heating; heating the feedstock pieces while flowing the inert gas, thereby melting the feedstock pieces and forming the molten copper-based alloy; bubbling the inert gas through the molten copper-based alloy; transferring the molten copper-based alloy to a transfer ladle; A method comprising: (Embodiment 2) 1. A method for producing a copper-based alloy, comprising the steps of: providing a plurality of feedstock pieces in a melting furnace having a composite composition adapted to form a molten copper-based alloy having at least 50% by weight copper; heating the feedstock pieces to form the molten copper-based alloy; bubbling the inert gas through the molten copper-based alloy; transferring the molten copper-based alloy to a transfer ladle; Including, 20. The method of claim 19, wherein one or more of the steps of heating the feedstock pieces, bubbling the inert gas, and transferring the molten copper-based alloy are performed at least partially under a sealed inert atmosphere, the sealed inert atmosphere configured to substantially exclude mixing of outside air with the sealed inert atmosphere. (Embodiment 3) 1. A method for producing a copper-based alloy, comprising the steps of: providing a plurality of feedstock pieces in a melting furnace having a composite composition adapted to form a molten copper-based alloy having at least 50% by weight copper; heating the feedstock pieces to form the molten copper-based alloy; bubbling the inert gas through the molten copper-based alloy; transferring the molten copper-based alloy to a transfer ladle; Including, The method, wherein the transferring step includes limiting a velocity of the molten copper-based alloy being transferred from the melting furnace to the transfer ladle to less than 100 inches per second. (Embodiment 4) 4. The method of claim 2 or 3, further comprising flowing an inert gas through gaps between the feedstock pieces prior to heating, and wherein the heating step comprises heating the feedstock pieces while flowing the inert gas. (Embodiment 5) 4. The method of claim 1 or 3, wherein one or more of the steps of heating the feedstock pieces, bubbling the inert gas, and transferring the molten copper-based alloy are performed at least partially under a sealed inert atmosphere, the sealed inert atmosphere configured to substantially exclude mixing of outside air with the sealed inert atmosphere. (Embodiment 6) 3. The method of claim 1 or 2, wherein the transferring step includes limiting a velocity of the molten copper-based alloy transferred from the melting furnace to the transfer ladle to less than 100 in / sec. (Embodiment 7) 7. The method of any one of the preceding claims, wherein the feedstock pieces comprise alloy pieces and / or elemental metal pieces. (Embodiment 8) 8. The method of any one of the preceding claims, wherein the flowing of the inert gas comprises flowing the inert gas before initiating the heating of the feedstock pieces. (Embodiment 9) The method according to any one of the preceding claims, wherein the step of flowing the inert gas includes flowing the inert gas at a sufficient rate such that the pieces of material are substantially under a flowing inert gas atmosphere before and during melting. (Embodiment 10) 10. The method of any one of the preceding claims, further comprising the step of adding additional feedstock pieces while bubbling the inert gas through the molten copper-based alloy prior to the transferring step. (Embodiment 11) 11. The method of any one of the preceding claims, wherein the step of bubbling the inert gas continues throughout the movement of the molten copper-based alloy. (Embodiment 12) 12. The method of any one of the preceding claims, wherein the step of bubbling the inert gas comprises bubbling the inert gas at a sufficient flow rate such that during the bubbling of the inert gas, the molten copper-based alloy is substantially under a flowing inert gas atmosphere. (Embodiment 13) 13. The method according to any one of the preceding claims, wherein one or more of the steps of heating the feedstock pieces, bubbling the inert gas, and transferring the molten copper-based alloy are carried out under a common inert atmosphere. (Embodiment 14) 14. The method of embodiment 13, wherein the common inert atmosphere comprises an enclosed common inert atmosphere shared by the melting furnace and the transfer ladle. (Embodiment 15) 15. The method of embodiment 14, wherein the sealed inert common atmosphere is sealed by keeping the transfer ladle injector closed until immediately prior to injection of the molten copper-based alloy from the transfer ladle into a mold. (Embodiment 16) 16. The method of any one of the preceding claims, wherein the step of flowing and bubbling an inert gas comprises flowing and bubbling the inert gas consisting essentially of argon. (Embodiment 17) 17. The method according to any one of the preceding embodiments, wherein the step of flowing and bubbling an inert gas comprises flowing and bubbling the inert gas that is substantially free of hydrogen. (Embodiment 18) 18. The method of any one of the preceding claims, wherein the step of flowing and bubbling the inert gas comprises diffusing through a diffuser having a plurality of holes disposed at a bottom of the melting furnace and adapted to bubble the inert gas into the molten copper-based alloy in the form of inert gas bubbles. (Embodiment 19) 19. The method of any one of the preceding claims, wherein the step of flowing and bubbling the inert gas comprises flowing through a diffuser having a porosity of greater than 20% at a rate of 2-6 liters / minute. (Embodiment 20) 20. The method of any one of the preceding claims, wherein the flowing and bubbling of the inert gas comprises flowing the inert gas at a rate of 2-6 liters / minute through a diffuser having a diameter greater than 5 cm and less than an inner diameter of the melting furnace. (Embodiment 21) 18. The method of embodiment 17, wherein the step of flowing and bubbling the inert gas comprises flowing through the melting furnace having an inner diameter of greater than 50 cm. (Embodiment 22) 22. The method of any one of the preceding claims, wherein the heating step comprises heating to a temperature 100-400°C higher than the temperature of the copper-based alloy. (Embodiment 23) 23. The method of embodiment 22, further comprising cooling the molten copper-based alloy by 100-400° C. prior to the transferring step. (Embodiment 24) 24. The method of any one of the preceding claims, wherein the transferring step comprises pouring the molten copper-based alloy located in a lower half of the melting furnace. (Embodiment 25) 25. The method of any one of the preceding claims, wherein the transferring step includes using an inclined ramp to limit the velocity of the molten copper-based alloy being transferred from the melting furnace to the transfer ladle. (Embodiment 26) 26. The method of any one of the preceding claims, wherein the molten copper-based alloy is transferred to the transfer ladle at a limited rate via an inclined ramp and then one or more pour valves are opened to drain the molten copper-based alloy from the transfer ladle. (Embodiment 27) 27. The method of embodiment 26, wherein the tilted lamp is under an inert atmosphere. (Embodiment 28) 25. The method of embodiment 24, wherein the step of transferring the molten copper-based alloy is performed under an enclosed common inert atmosphere shared by the melting furnace, the transfer ladle, and the tilted ramp. (Embodiment 29) 29. The method according to any one of the preceding claims, wherein the molten copper-based alloy is transferred to the transfer ladle at a limited rate via an inclined ramp and then one or more pour valves are opened to discharge the molten copper-based alloy from the transfer ladle into one or more molds or shot pits, and the molten copper-based alloy is allowed to solidify. (Embodiment 30) 30. The method of any one of the preceding claims, wherein the molten copper-based alloy is transferred at a limited rate via an inclined ramp to the transfer ladle, and then the molten copper-based alloy is discharged from the transfer ladle onto a second inclined ramp to further limit the rate of the molten copper-based alloy, and then the molten copper-based alloy is allowed to solidify before placing the molten copper-based alloy into one or more molds or shot pits. (Embodiment 31) 31. The method of any one of the preceding claims, wherein the step of bubbling the inert gas comprises bubbling using a diffusion lining formed on an 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-based alloy. (Embodiment 32) 31. The method of any one of the preceding claims, 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 a bottom inner surface of the melting furnace and having a porous structure adapted to bubbling the inert gas into the molten copper-based alloy. (Embodiment 33) 31. The method according to any one of the preceding claims, 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, such that the diffusion lining is adapted to bubble the inert gas through the molten copper-based alloy from the at least two different inner surfaces. (Embodiment 34) 34. The method of claim 32 or 33, wherein the diffusion lining comprises an aluminum silicate ceramic. (Embodiment 35) 34. The method of claim 31 or 33, wherein the diffusion lining substantially covers a bottom inner surface of the melting furnace. (Embodiment 36) 33. The method of claim 31 or 32, wherein the diffusion lining is formed on at least two different inner surfaces of the melting furnace, such that 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 37) The method of any one of the preceding embodiments, wherein the method further follows any one of the embodiments in Additional Example VI. Additional Example III (Embodiment 1) 1. An apparatus for producing a copper-based alloy, comprising: a melting furnace configured to form a molten copper-based alloy comprising at least 50% by weight copper; a diffusion lining formed on an inner surface of the melting furnace, the diffusion lining comprising an aluminum silicate ceramic having a porous structure adapted for bubbling an inert gas through the molten copper-based alloy; An apparatus comprising: (Embodiment 2) 1. An apparatus for producing a copper-based alloy, comprising: a melting furnace configured to form a molten copper-based alloy comprising at least 50% by weight copper; a diffusion lining substantially covering a bottom inner surface of the melting furnace and having a porous structure adapted for bubbling an inert gas into the molten copper-based alloy; An apparatus comprising: (Embodiment 3) 1. An apparatus for producing a copper-based alloy, comprising: a melting furnace configured to form a molten copper-based alloy comprising at least 50% by weight copper; a diffusion lining having a porous structure in the melting furnace; Equipped with the diffusion lining is formed on at least two distinct inner surfaces of the melting furnace, such that the diffusion lining is adapted to bubble an inert gas through the molten copper-based alloy from the at least two distinct inner surfaces. (Embodiment 4) 4. The apparatus of claim 2 or 3, wherein the diffusion lining comprises an aluminum silicate ceramic. (Embodiment 5) 4. The apparatus of claim 1 or 3, wherein the diffusion lining substantially covers a bottom inner surface of the melting furnace. (Embodiment 6) 3. The apparatus of claim 1 or 2, wherein the diffusion lining is formed on at least two distinct inner surfaces of the melting furnace, such that the diffusion lining is adapted to bubble an inert gas through the molten copper-based alloy from the at least two distinct inner surfaces. (Embodiment 7) 7. The apparatus of any one of the preceding embodiments, wherein the diffusion lining comprises alumina and silica. (Embodiment 8) 8. The apparatus of any one of the preceding embodiments, wherein the diffusion lining comprises mullite. (Embodiment 9) 9. The apparatus of any one of the preceding embodiments, wherein the diffusion lining comprises at least two layers including a sintered ceramic layer and an unsintered ceramic layer. (Embodiment 10) 10. The apparatus of embodiment 9, wherein the sintered ceramic layer comprises mullite. (Embodiment 11) 10. The apparatus of embodiment 9, wherein the green ceramic layer comprises alumina and silica. (Embodiment 12) 11. An apparatus as recited in embodiment 10, wherein the sintered ceramic layer is configured to contact the molten copper-based alloy. (Embodiment 13) 10. The apparatus of embodiment 9, wherein the green ceramic layer comprises a layer of compressed ceramic powder comprising alumina and silica. (Embodiment 14) 10. The apparatus of 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 green ceramic layer have substantially the same chemical composition but different phases. (Embodiment 15) 10. The apparatus of embodiment 9, wherein the green ceramic layer comprises 60-70% alumina and 20-25% silica. (Embodiment 16) 10. The apparatus of embodiment 9, wherein the green ceramic layer comprises a layer of compressed ceramic powder having an average grain size of less than 63 μm, or corresponding to number 4 on the φ scale. (Embodiment 17) 17. The apparatus of any one of the preceding embodiments, wherein the diffusion lining has a thickness of 3 to 6 inches. (Embodiment 18) 18. The apparatus according to any one of the preceding embodiments, wherein the diffusion lining covers the entire bottom inner surface of the melting furnace. (Embodiment 19) 19. The apparatus of any one of the preceding embodiments, wherein the diffusion lining on the bottom inner surface of the melting furnace has a thickness of 4 to 6 inches. (Embodiment 20) 20. The apparatus of any one of the preceding embodiments, wherein the diffusion lining covers at least an inner sidewall surface of the melting furnace. (Embodiment 21) 21. The apparatus of any one of the preceding claims, wherein the diffusion lining covering the inner sidewall of the melting furnace has a thickness of 3-4 inches. (Embodiment 22) 22. The apparatus of any one of the preceding embodiments, wherein the diffusion lining is configured to contact the molten copper-based alloy. (Embodiment 23) 23. The apparatus of any one of the preceding embodiments, wherein the inert gas consists essentially of argon. (Embodiment 24) 24. The apparatus of any one of the preceding embodiments, wherein the inert gas does not include hydrogen. (Embodiment 25) 25. The apparatus of any one of the preceding claims, further comprising a diffuser centrally disposed within the diffusion lining on a bottom inner surface of the melting furnace, the diffuser being connected to an inert gas source and comprising a diffuser material disposed within a vessel having an upper surface disposed below an upper surface of the diffusion lining covering the bottom inner surface. (Embodiment 26) 26. The apparatus of embodiment 25, wherein the diffuser overlaps a portion of the diffusion lining on the bottom inner surface of the melting furnace. (Embodiment 27) 27. The apparatus of embodiment 26, wherein the diffuser contacts the diffusion lining and comprises the same material as the diffusion lining. (Embodiment 28) 28. The apparatus of any one of embodiments 25-27, wherein one or both of the diffuser and the diffusion lining have a porosity greater than 20%. (Embodiment 29) 29. The apparatus of any one of embodiments 25-28, wherein the diffuser has a lateral dimension that is less than 50% of a lateral dimension of the diffusion lining that covers the bottom inner surface of the melting furnace. (Embodiment 30) 30. The apparatus of any one of embodiments 25 to 29, wherein the diffuser has a diameter greater than 5 cm and smaller than the diameter of the diffusion lining that covers the bottom inner surface of the melting furnace. (Embodiment 31) 31. The apparatus of any one of embodiments 25 to 30, wherein the diffusion lining covering the bottom inner surface of the melting furnace has a diameter of more than 50 cm. (Embodiment 32) 32. The apparatus of any one of embodiments 25 to 31, wherein the melting furnace is configured to melt the copper-based alloy in a closed chamber configuration in which an atmosphere above the molten copper-based alloy is isolated from an outside atmosphere. (Embodiment 33) 32. The apparatus of any one of embodiments 25 to 31, wherein the melting furnace is configured to melt the copper-based alloy in an open chamber configuration in which an atmosphere above the molten copper-based alloy is exposed to an external atmosphere. (Embodiment 34) 33. The apparatus of embodiment 32, wherein the apparatus is configured to diffuse the inert gas at a flow rate of 2 to 6 liters per minute under the sealed chamber configuration. (Embodiment 35) 34. The apparatus of embodiment 33, wherein the apparatus is configured to diffuse the inert gas at a flow rate of 4 to 13 liters per minute in the open chamber configuration. (Embodiment 36) 36. The apparatus of any one of the preceding embodiments, wherein the melting furnace is an induction furnace comprising an induction coil surrounding the melting furnace and configured to melt the copper-based alloy. (Embodiment 37) 37. The apparatus of embodiment 36, wherein the induction furnace is configured to operate at a frequency less than 1000 Hz. (Embodiment 38) 38. The apparatus of embodiment 36 and 37, wherein a top winding of the induction coil is positioned in a vertical position below a fill line of the molten copper-based alloy. (Embodiment 39) 39. The apparatus of any one of the preceding embodiments, further comprising an inert gas source connected to the diffusion lining and supplying the inert gas to the melting furnace. (Embodiment 40) 40. The apparatus of any one of the preceding claims, further comprising a diffuser embedded within the diffusion lining and smaller than the diffusion lining covering the bottom inner surface of the melting furnace. (Embodiment 41) 41. The apparatus of embodiment 40, wherein the diffuser and the diffusion lining comprise the same diffuser material. (Embodiment 42) 41. The apparatus of embodiment 40, wherein the diffuser is connected to an inert gas source and includes a diffuser material disposed within a vessel having an upper surface disposed below an upper surface of the diffusion lining that covers a bottom inner surface of the melting furnace. (Embodiment 43) The device according to any one of the preceding embodiments, further according to any one of the embodiments in Additional Example I. Additional Example IV (Embodiment 1) A method for manufacturing a copper-based alloy production apparatus, comprising the steps of: providing a melting furnace chamber configured to form a molten copper-based alloy comprising at least 50% by weight copper; forming a diffusion lining on an inner surface of the melting furnace chamber, the diffusion lining comprising an aluminum silicate ceramic material having a porous structure adapted for bubbling an inert gas through the molten copper-based alloy; A method comprising: (Embodiment 2) A method for manufacturing a copper-based alloy production apparatus, comprising the steps of: providing a melting furnace chamber configured to form a molten copper-based alloy comprising at least 50% by weight copper; forming a diffusion lining substantially covering a bottom inner surface of the melting furnace and having a porous structure adapted for bubbling an inert gas into the molten copper-based alloy; A method comprising: (Embodiment 3) A method for manufacturing a copper-based alloy production apparatus, comprising the steps of: providing a melting furnace chamber configured to form a molten copper-based alloy comprising at least 50% by weight copper; forming a diffusion lining having a porous structure on at least two different inner surfaces of the melting furnace, such that the diffusion lining is adapted to bubble an inert gas through the molten copper-based alloy from the at least two different inner surfaces; A method comprising: (Embodiment 4) 4. The method of claim 2 or 3, wherein the diffusion lining comprises an aluminum silicate ceramic. (Embodiment 5) 4. The method of claim 1 or 3, wherein forming the diffusion lining comprises substantially covering a bottom inner surface of the melting furnace. (Embodiment 6) 3. The method of claim 1 or 2, wherein the step of forming the diffusion lining comprises forming on at least two different inner surfaces of the melting furnace, such that the diffusion lining is adapted to bubble the inert gas through the molten copper-based alloy from the at least two different inner surfaces. (Embodiment 7) 7. The method of any one of the preceding claims, wherein the diffusion lining comprises alumina and silica. (Embodiment 8) 8. The method of any one of the preceding claims, wherein the diffusion lining comprises mullite. (Embodiment 9) 9. The method according to any one of the preceding claims, wherein the step of forming the diffusion lining comprises forming at least a sintered ceramic layer and an unsintered ceramic layer. (Embodiment 10) 10. The method of embodiment 9, wherein the step of forming the sintered ceramic layer comprises sintering a portion of a layer of compressed ceramic powder to form mullite. (Embodiment 11) 10. The method of embodiment 9, wherein the step of forming the green ceramic layer comprises forming a layer of compressed ceramic powder comprising alumina and silica. (Embodiment 12) 11. The method of embodiment 10, wherein the step of forming the sintered ceramic layer includes configuring it to contact the molten copper-based alloy. (Embodiment 13) 10. The method of claim 9, wherein the steps of forming the sintered layer and the green layer include forming them from the same compressed ceramic powder layer comprising alumina and silica. (Embodiment 14) 10. The method of claim 9, wherein forming the sintered ceramic layer comprises partially sintering a compressed ceramic powder layer such that the sintered ceramic layer and the green ceramic layer have substantially the same chemical composition but different phases. (Embodiment 15) 10. The method of embodiment 9, wherein the green ceramic layer comprises 60-70% alumina and 20-25% silica. (Embodiment 16) 10. The method of embodiment 9, wherein the green ceramic layer comprises a layer of compressed ceramic powder having an average grain size of less than 63 μm, or corresponding to number 4 on the φ scale. (Embodiment 17) 17. The method of any one of the preceding claims, wherein the diffusion lining has a thickness of 3 to 6 inches. (Embodiment 18) 18. The method according to any one of the preceding claims, wherein the forming of the diffusion lining comprises covering the entire bottom inner surface of the melting furnace. (Embodiment 19) 19. The method of any one of the preceding claims, wherein the diffusion lining on the bottom inner surface of the melting furnace has a thickness of 4 to 6 inches. (Embodiment 20) 20. The method of any one of the preceding claims, wherein the forming of the diffusion lining comprises covering at least a side wall of the melting furnace. (Embodiment 21) 21. The method of any one of the preceding claims, wherein the diffusion lining covering the sidewall of the melting furnace has a thickness of 3 to 4 inches. (Embodiment 22) 22. The method of any one of the preceding claims, wherein forming the diffusion lining comprises configuring the diffusion lining to contact the molten copper-based alloy. (Embodiment 23) 23. The method of any one of the preceding claims, wherein the inert gas consists essentially of argon. (Embodiment 24) 24. The method of any one of the preceding embodiments, wherein the inert gas does not comprise hydrogen. (Embodiment 25) 25. The method of any one of the preceding claims, further comprising centrally disposing a diffuser at the bottom of the melting furnace beneath the diffusion lining. (Embodiment 26) 26. The method of claim 25, wherein the step of positioning the diffuser includes positioning the diffuser to overlap a portion of the diffusion lining at the bottom of the melting furnace. (Embodiment 27) 27. The method of embodiment 26, wherein the step of disposing the diffuser includes contacting the diffusion lining with the diffuser comprising the same material as the diffusion lining. (Embodiment 28) 28. The method of any one of claims 25 to 27, wherein one or both of the diffuser and the diffusion lining have a porosity greater than 20%. (Embodiment 29) 29. The method of any one of claims 25 to 28, wherein the diffuser has a lateral dimension that is less than 50% of a lateral dimension of the diffusion lining that covers the bottom inner surface of the melting furnace. (Embodiment 30) 30. The method according to any one of claims 25 to 29, wherein the diffuser has a diameter greater than 5 cm and smaller than the diameter of the diffusion lining lining the bottom inner surface of the melting furnace. (Embodiment 31) 31. The method of any one of claims 25 to 30, wherein the diffusion lining covering the bottom inner surface of the melting furnace has a diameter of more than 50 cm. (Embodiment 32) 32. The method of any one of claims 25 to 31, further comprising configuring the melting furnace to melt the copper-based alloy in a closed chamber configuration in which an atmosphere above the molten copper-based alloy is isolated from an outside atmosphere. (Embodiment 33) 32. The method of any one of claims 25-31, further comprising configuring the melting furnace to melt the copper-based alloy in an open chamber configuration in which an atmosphere above the molten copper-based alloy is exposed to an external atmosphere. (Embodiment 34) 33. The method of embodiment 32, further comprising configuring the apparatus to diffuse the inert gas at a flow rate of 2 to 6 liters per minute in a closed chamber configuration. (Embodiment 35) 34. The method of embodiment 33, further comprising configuring the apparatus to diffuse the inert gas at a flow rate of 4 to 13 liters per minute in an open chamber configuration. (Embodiment 36) 36. The method of any one of the preceding claims, wherein the melting furnace is an induction furnace comprising a surrounding induction coil configured to melt the copper-based alloy. (Embodiment 37) 37. The method of embodiment 36, wherein the induction furnace is configured to operate at a frequency less than 1000 Hz. (Embodiment 38) 38. The method of claim 36 or 37, wherein the top winding of the induction coil is positioned at half the height of the molten copper-based alloy. (Embodiment 39) The method according to any one of the preceding embodiments, wherein the method further follows any one of the embodiments in Additional Example V. <Additional Example V> (Embodiment 1) 1. A method of manufacturing an alloy production apparatus, comprising: providing a melting furnace chamber; disposing a layer of compressed ceramic powder on an interior surface of the melting furnace chamber, the layer of compressed ceramic powder comprising a mixture of silica and alumina; sintering the compacted ceramic powder layer in the melting furnace to form a diffusion lining on the inner surface, the diffusion lining comprising an aluminum silicate ceramic material having a porous structure adapted to diffuse a gas; A method comprising: (Embodiment 2) 1. A method of manufacturing an alloy production apparatus, comprising: providing a melting furnace chamber; disposing a layer of compressed ceramic powder on an interior surface of the melting furnace chamber; selectively sintering a surface portion of the compressed ceramic powder layer, thereby forming a diffusion lining on the inner surface including a sintered ceramic layer on an unsintered ceramic layer; A method comprising: (Embodiment 3) 1. A method of manufacturing an alloy production apparatus, comprising: providing a melting furnace chamber; disposing a layer of compressed ceramic powder on an interior surface of the melting furnace chamber; sintering the layer of compressed ceramic powder using heat from a heated material disposed within the furnace chamber, thereby forming a diffusion lining on the interior surface. A method comprising: (Embodiment 4) 4. The method of claim 2 or 3, wherein sintering the compressed ceramic powder layer comprises sintering 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 a gas. (Embodiment 5) 4. The method of claim 1 or 3, wherein the sintering step comprises selectively sintering a surface portion of the compressed ceramic powder layer, thereby forming a diffusion lining on the inner surface comprising a sintered ceramic layer on an unsintered ceramic layer. (Embodiment 6) 3. The method of claim 1 or 2, wherein sintering includes using heat from a heated material disposed within the furnace chamber, thereby forming a diffusion lining on the inner surface. (Embodiment 7) 7. The method of any one of the preceding claims, wherein the step of disposing the compressed ceramic powder layer comprises covering a bottom surface of the melting furnace chamber with a bottom compressed ceramic powder layer. (Embodiment 8) 8. The method of any one of the preceding claims, wherein the step of disposing the compressed ceramic powder layer comprises covering a sidewall of the melting furnace chamber with a sidewall compressed ceramic powder layer. (Embodiment 9) 9. The method of any one of the preceding claims, wherein the sintering step comprises using heat from a material disposed in the furnace chamber and heated using electrical power applied to the furnace chamber. (Embodiment 10) 10. The method of embodiment 9, wherein the power applied to the melter chamber comprises inductive power delivered through a coil surrounding the melter chamber. (Embodiment 11) 10. The method of claim 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) 10. The method of claim 9, wherein the sintering step includes using heat from an iron-containing material that is melted using electrical power applied to the melting furnace chamber. (Embodiment 13) 10. The method of embodiment 9, wherein the material is heated to a temperature sufficient to form mullite from silica and alumina. (Embodiment 14) 14. The method of any one of the preceding claims, wherein the diffusion lining comprises alumina and silica. (Embodiment 15) 15. The method of any one of the preceding claims, wherein the diffusion lining comprises mullite. (Embodiment 16) 16. The method according to any one of the preceding claims, wherein the step of forming the diffusion lining comprises forming at least a sintered ceramic layer and an unsintered ceramic layer. (Embodiment 17) 17. The method of embodiment 16, wherein forming the sintered ceramic layer comprises sintering a portion of the layer of compressed ceramic powder to form mullite. (Embodiment 18) 18. The method of claim 17, wherein the green ceramic layer comprises a remaining portion of the pressed ceramic powder layer that does not form mullite. (Embodiment 19) 17. The method of embodiment 16, wherein the step of forming the sintered ceramic layer includes configuring it to contact the molten copper-based alloy. (Embodiment 20) 17. The method of embodiment 16, wherein the steps of forming the sintered layer and the green layer include forming them from the same compressed ceramic powder layer comprising alumina and silica. (Embodiment 21) 17. The method of claim 16, wherein forming the sintered ceramic layer comprises partially sintering a compressed ceramic powder layer such that the sintered ceramic layer and the green ceramic layer have substantially the same chemical composition but different phases. (Embodiment 22) 22. The method of any one of the preceding claims, wherein the compressed ceramic powder layer comprises 60-70% alumina and 20-25% silica. (Embodiment 23) 23. The method according to any one of the preceding claims, wherein the compressed ceramic powder layer comprises particles having an average grain size of less than 63 μm or corresponding to the number 4 on the φ scale. (Embodiment 24) 24. The method of any one of the preceding claims, wherein the compressed ceramic powder layer has a thickness of 3 to 6 inches. (Embodiment 25) 25. The method of any one of the preceding claims, wherein the step of disposing the layer of compressed ceramic powder comprises covering an entire bottom inner surface of the melting furnace. (Embodiment 26) 26. The method of any one of the preceding claims, wherein the layer of compressed ceramic powder on the bottom inner surface of the melting furnace has a thickness of 4 to 6 inches. (Embodiment 27) 27. The method of any one of the preceding claims, wherein the step of disposing a layer of compressed ceramic powder comprises covering at least an inner sidewall surface of the melting furnace. (Embodiment 28) 28. The method of any one of the preceding claims, wherein the layer of compressed ceramic powder on the inner sidewall surface of the melting furnace has a thickness of 3 to 4 inches. (Embodiment 29) 29. The method of any one of the preceding claims, wherein forming the diffusion lining comprises configuring the diffusion lining to contact the molten copper-based alloy. (Embodiment 30) 30. The method of any one of the preceding claims, further comprising centrally disposing a diffuser at the bottom of the melting furnace beneath the diffusion lining. (Embodiment 31) 31. The method of embodiment 30, wherein the step of positioning the diffuser includes positioning the diffuser to overlap a portion of the diffusion lining at the bottom of the melting furnace. (Embodiment 32) 32. The method of embodiment 31, wherein the step of disposing the diffuser includes contacting the diffusion lining with the diffuser comprising the same material as the diffusion lining. (Embodiment 33) 33. The method of any one of embodiments 30-32, wherein one or both of the diffuser and the diffusion lining have a porosity greater than 20%. (Embodiment 34) 34. The method of any one of claims 30 to 33, wherein the diffuser has a lateral dimension that is less than 50% of a lateral dimension of the diffusion lining that covers the bottom inner surface of the melting furnace. (Embodiment 35) 35. The method according to any one of claims 30 to 34, wherein the diffuser has a diameter greater than 5 cm and smaller than the diameter of the diffusion lining that covers the bottom inner surface of the melting furnace. (Embodiment 36) 36. The method of any one of claims 30 to 35, wherein the diffusion lining covering the bottom inner surface of the melting furnace has a diameter of more than 50 cm. (Embodiment 37) 37. The method of any one of claims 30 to 36, further comprising configuring the melting furnace to melt the copper-based alloy in a closed chamber configuration in which an atmosphere above the molten copper-based alloy is isolated from an outside atmosphere. (Embodiment 38) 38. The method of any one of claims 30-37, further comprising configuring the melting furnace to melt the copper-based alloy in an open chamber configuration in which an atmosphere above the molten copper-based alloy is exposed to an external atmosphere. (Embodiment 39) 39. The method of embodiment 38, further comprising configuring the apparatus to diffuse the inert gas at a flow rate of 2 to 6 liters per minute in a closed chamber configuration. (Embodiment 40) 39. The method of embodiment 38, further comprising configuring the apparatus to diffuse the inert gas at a flow rate of 4 to 13 liters per minute in an open chamber configuration. (Embodiment 41) 41. The method of any one of the preceding claims, wherein the melting furnace is an induction furnace comprising a surrounding induction coil configured to melt the copper-based alloy. (Embodiment 42) 42. The method of embodiment 41, wherein the induction furnace is configured to operate at a frequency less than 1000 Hz. (Embodiment 43) 43. The method of claim 41 or 42, wherein a top winding of the induction coil is positioned at half the height of the molten copper-based alloy. (Embodiment 44) 44. The method of any one of the preceding claims, further comprising connecting an inert gas supply to the diffusion lining. (Embodiment 45) The method of any one of the preceding embodiments, wherein the method further follows any one of the embodiments in Additional Example IV. <Additional Example VI> (Embodiment 1) 1. A method for producing a copper-based alloy, comprising the steps of: providing a feedstock to a melting furnace having a composition configured to form a molten copper-based alloy having at least 50% by weight copper; heating the feedstock to melt the feedstock and form the molten copper-based alloy; bubbling an inert gas through the molten copper-based alloy using a diffusion lining formed on an inner surface of the melting furnace, the diffusion lining comprising an aluminum silicate ceramic material having a porous structure adapted for bubbling the inert gas through the molten copper-based alloy; A method comprising: (Embodiment 2) 1. A method for producing a copper-based alloy, comprising the steps of: providing a feedstock to a melting furnace having a composition configured to form a molten copper-based alloy having at least 50% by weight copper; heating the feedstock to melt the feedstock and form the molten copper-based alloy; bubbling an inert gas through the molten copper-based alloy using a diffusion lining formed within the melting furnace chamber, the diffusion lining substantially covering a bottom interior surface of the melting furnace and having a porous structure adapted to bubbling the inert gas through the molten copper-based alloy; A method comprising: (Embodiment 3) 1. A method for producing a copper-based alloy, comprising the steps of: providing a feedstock to a melting furnace having a composition configured to form a molten copper-based alloy having at least 50% by weight copper; heating the feedstock to melt the feedstock and form the molten copper-based alloy; bubbling an inert gas through the molten copper-based alloy using a diffusion lining having a porous structure, the diffusion lining being formed on at least two different inner surfaces of the melting furnace such that the diffusion lining is adapted to bubble the inert gas through the molten copper-based alloy from the at least two different inner surfaces; A method comprising: (Embodiment 4) 4. The method of claim 2 or 3, wherein the diffusion lining comprises an aluminum silicate ceramic. (Embodiment 5) 4. The method of claim 1 or 3, wherein the diffusion lining substantially covers a bottom inner surface of the melting furnace. (Embodiment 6) 3. The method of claim 1 or 2, wherein the diffusion lining is formed on at least two different inner surfaces of the melting furnace, such that 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 7) 7. The method of any one of the preceding claims, wherein the diffusion lining comprises alumina and silica. (Embodiment 8) 8. The method of any one of the preceding claims, wherein the diffusion lining comprises mullite. (Embodiment 9) 9. The method of any one of the preceding claims, wherein the diffusion lining comprises at least two layers including a sintered ceramic layer and an unsintered ceramic layer. (Embodiment 10) 10. The method of claim 9, wherein the green ceramic layer comprises mullite. (Embodiment 11) 10. The method of claim 9, wherein the green ceramic layer comprises alumina and silica. (Embodiment 12) 11. The method of claim 10, wherein the sintered ceramic layer is in contact with the molten copper-based alloy. (Embodiment 13) 10. The method of claim 9, wherein the green layer comprises a layer of compressed ceramic powder comprising alumina and silica. (Embodiment 14) 10. The method of claim 9, wherein the sintered ceramic layer is formed by partially sintering a compressed ceramic powder layer such that the sintered ceramic layer and the green ceramic layer have substantially the same chemical composition but different phases. (Embodiment 15) 10. The method of embodiment 9, wherein the green ceramic layer comprises 60-70% alumina and 20-25% silica. (Embodiment 16) 10. The method of embodiment 9, wherein the green ceramic layer comprises a compressed ceramic powder having an average grain size of less than 63 μm, or corresponding to number 4 on the φ scale. (Embodiment 17) 17. The method of any one of the preceding claims, wherein the diffusion lining has a thickness of 3 to 6 inches. (Embodiment 18) 18. The method according to any one of the preceding claims, wherein the diffusion lining covers the entire bottom inner surface of the melting furnace. (Embodiment 19) 19. The method of any one of the preceding claims, wherein the diffusion lining on the bottom inner surface of the melting furnace has a thickness of 4 to 6 inches. (Embodiment 20) 20. The method according to any one of the preceding claims, wherein the diffusion lining covers at least a side wall of the melting furnace. (Embodiment 21) 21. The method of any one of the preceding claims, wherein the diffusion lining covering the sidewall of the melting furnace has a thickness of 3 to 4 inches. (Embodiment 22) 22. The method of any one of the preceding claims, wherein the diffusion lining is configured to contact the molten copper-based alloy. (Embodiment 23) 23. The method of any one of the preceding claims, wherein the inert gas consists essentially of argon. (Embodiment 24) 24. The method of any one of the preceding embodiments, wherein the inert gas does not comprise hydrogen. (Embodiment 25) 25. The method of any one of the preceding claims, further comprising a diffuser centrally disposed below the diffusion lining at the bottom of the melting furnace. (Embodiment 26) 26. The method of claim 25, wherein the diffuser overlaps a portion of the diffusion lining at the bottom of the melting furnace. (Embodiment 27) 27. The method of embodiment 26, wherein the diffuser contacts the diffusion lining and comprises the same material as the diffusion lining. (Embodiment 28) 28. The method of any one of claims 25 to 27, wherein one or both of the diffuser and the diffusion lining have a porosity greater than 20%. (Embodiment 29) 29. The method of any one of claims 25 to 28, wherein the diffuser has a lateral dimension that is less than 50% of a lateral dimension of the diffusion lining that covers the bottom inner surface of the melting furnace. (Embodiment 30) 30. The method according to any one of claims 25 to 29, wherein the diffuser has a diameter greater than 5 cm and smaller than the diameter of the diffusion lining that covers the bottom inner surface of the melting furnace. (Embodiment 31) 31. The method of any one of claims 25 to 30, wherein the diffusion lining covering the bottom inner surface of the melting furnace has a diameter of more than 50 cm. (Embodiment 32) 32. The method of any one of claims 25 to 31, wherein the step of melting the feedstock comprises melting in a closed chamber configuration in which an atmosphere above the molten copper-based alloy is isolated from an external atmosphere. (Embodiment 33) 32. The method of any one of claims 25 to 31, wherein the step of melting the feedstock comprises melting in an open chamber configuration in which an atmosphere above the molten copper-based alloy is exposed to an external atmosphere. (Embodiment 34) 33. The method of embodiment 32, wherein the step of bubbling the inert gas further comprises diffusing the inert gas at a flow rate of 2 to 6 liters per minute in a closed chamber configuration. (Embodiment 35) 34. The method of embodiment 33, wherein the step of bubbling the inert gas comprises diffusively flowing the inert gas at a flow rate of 4 to 13 liters per minute in an open chamber configuration. (Embodiment 36) 36. The method of any one of the preceding claims, wherein the melting step comprises inductively heating the feedstock by supplying power to an induction coil surrounding the melting furnace. (Embodiment 37) the step of providing the feedstock material includes providing a plurality of feedstock pieces having a composite composition configured to form the molten copper-based alloy; and flowing the inert gas through gaps between the feedstock pieces prior to heating; the heating step includes heating the feedstock pieces while flowing the inert gas, thereby melting the feedstock pieces to form the molten copper-based alloy; 37. The method of any one of the preceding claims, wherein the method further comprises transferring the molten copper-based alloy to a transfer ladle after bubbling the inert gas through the molten copper-based alloy. (Embodiment 38) the step of providing the feedstock material includes providing a plurality of feedstock pieces having a composite composition configured to form the molten copper-based alloy; and flowing the inert gas through gaps between the feedstock pieces prior to heating; The method further comprises transferring the molten copper-based alloy to a transfer ladle after bubbling the inert gas through the molten copper-based alloy; 37. The method of any one of the preceding claims, wherein one or more of the steps of heating the feedstock pieces, bubbling the inert gas, and transferring the molten copper-based alloy are performed at least partially under a sealed inert atmosphere, the sealed inert atmosphere being configured to substantially exclude mixing of outside air with the sealed inert atmosphere. (Embodiment 39) the step of providing a feedstock material includes providing a plurality of feedstock pieces having a composite composition configured to form the molten copper-based alloy; The method further comprises transferring the molten copper-based alloy to a transfer ladle after bubbling the inert gas through the molten copper-based alloy; 37. The method of any one of the preceding claims, wherein the transferring step comprises limiting a velocity of the molten copper-based alloy transferred from the melting furnace to the transfer ladle to less than 100 in / sec. (Embodiment 40) 40. The method of claim 38 or 39, further comprising flowing an inert gas through gaps between the feedstock pieces prior to heating, and wherein the heating step comprises heating the feedstock pieces while flowing the inert gas. (Embodiment 41) 40. The method of claim 37 or 39, wherein one or more of the steps of heating the feedstock pieces, bubbling the inert gas, and transferring the molten copper-based alloy are performed at least partially under a sealed inert atmosphere, the sealed inert atmosphere configured to substantially exclude mixing of outside air with the sealed inert atmosphere. (Embodiment 42) 39. The method of claim 37 or 38, wherein the transferring step includes limiting a velocity of the molten copper-based alloy transferred from the melting furnace to the transfer ladle to less than 100 in / sec. (Embodiment 43) The method according to any one of the embodiments 37 to 42, further comprising any one of the methods according to any one of the embodiments 7 to 30 in Additional Example II. (Embodiment 44) 44. The method of any one of the preceding claims, wherein the melting furnace is an induction furnace comprising a surrounding induction coil configured to melt the copper-based alloy. (Embodiment 45) 45. The method of embodiment 44, wherein the induction furnace is configured to operate at a frequency less than 1000 Hz. (Embodiment 46) 46. ​​The method of claim 44 or 45, wherein a top winding of the induction coil is positioned at half the height of the molten copper-based alloy. (Embodiment 47) The method according to any one of the preceding embodiments, wherein the method further follows any one of the embodiments in Additional Example II.

[0121] Unless the context clearly requires otherwise, throughout the specification and claims, words such as "comprises," "comprising," "including," "including," and the like, are to be interpreted in an inclusive sense, i.e., "including, but not limited to," as opposed to an exclusive or exhaustive sense. The term "coupled," as generally used herein, refers to two or more elements that may be directly connected or connected through one or more intermediate elements. Similarly, the term "connected," as generally used herein, refers to two or more elements that may be directly connected or connected through one or more intermediate elements. Furthermore, as used in this application, the terms "herein," "above," "below," and terms of similar import shall refer to this application as a whole and not to any particular portion of this application. Where the context permits, terms in the above detailed description using the singular or plural may also include the plural and the singular, respectively. The term "or" in a list of two or more items covers all of the following interpretations of that term, namely, any of the items in the list, all of the items in the list, and any combination of the items in the list.

[0122] Furthermore, conditional language used herein, such as, among others, "can," "could," "might," "may," "for example," and the like, unless specifically stated otherwise or understood otherwise within the context in which it is used, is generally intended to suggest that certain embodiments include certain features, elements and / or conditions, while other embodiments do not. Thus, such conditional language is generally not intended to imply that features, elements and / or conditions are in any way required for one or more embodiments, or that these features, elements and / or conditions may or may not be included in any particular embodiment.

[0123] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the present disclosure. Indeed, the novel apparatus, methods, and systems described herein may be embodied in various other forms. Furthermore, various omissions, substitutions, and changes in the form of the methods and systems described herein may be made without departing from the spirit of the present disclosure. For example, although blocks are presented in a given configuration, alternative embodiments may perform similar functions using different components and / or circuit topologies, and some blocks may be deleted, moved, added, sub-divided, combined, and / or modified. Each of these blocks may be implemented in a variety of different ways. Any suitable combination of the elements and acts of the various embodiments described above may be combined to provide further embodiments. The various features and processes described above may be implemented independently of each other or combined in various ways. All possible combinations and sub-combinations of the features of the present disclosure are intended to be within the scope of the present disclosure.

[0124] Furthermore, unless otherwise specified, none of the steps of the methods of the present disclosure are limited to any particular order of execution. Modifications of the disclosed examples that incorporate the spirit and essence of the present disclosure may occur to those of ordinary skill in the art, and such modifications are within the scope of the present disclosure. Additionally, all references cited herein are incorporated by reference in their entirety.

[0125] While the methods and devices described herein are susceptible to various modifications and alternative forms, specific examples thereof have been shown in the drawings and described in detail herein. However, it should be understood that the present invention should not be limited to the particular forms or methods disclosed, but rather, the present invention covers all modifications, equivalents, and alternatives falling within the spirit and scope of the various described embodiments and the appended claims. Furthermore, any particular feature, aspect, method, property, characteristic, quality, attribute, element, etc. disclosed herein in connection with an embodiment can be used in all other examples described herein. Any method disclosed herein need not be performed in the order recited. Depending on the example, one or more acts, events, or functions of any of the algorithms, methods, or processes described herein may be performed in a different sequence, or may be added, merged, or entirely excluded (e.g., not all of the described acts or events are necessary to the implementation of the method). In some examples, acts or events may be performed simultaneously. Furthermore, no element, feature, block, or step, or group of elements, features, blocks, or steps, is necessary or essential to each example. Moreover, all possible combinations, subcombinations, and rearrangements of systems, methods, features, elements, modules, blocks, and the like are within the scope of this disclosure. The use of sequence language such as "then," "next," "later," "followed by," or chronological language, unless otherwise stated or understood within the context in which it is used, is generally intended to facilitate the flow of text and is not intended to limit the sequence of operations performed. Thus, while some examples may be performed using the sequence of operations described herein, other examples may be performed after a different sequence of operations.

[0126] Ranges disclosed herein also encompass any and all overlaps, subranges, and combinations thereof. Language such as "up to," "at least," "greater than," "less than," "between," and the like includes the recited numbers. Numbers preceded by terms such as "about" or "approximately" are inclusive of the recited numbers and should be interpreted based on the context (e.g., as precisely as reasonably possible under the circumstances, e.g., ±5%, ±10%, ±15%, etc.). For example, "about 1V" includes "1V". Numbers not preceded by terms such as "about" or "approximately" can be understood based on the context as precisely as reasonably possible under the circumstances, e.g., ±5%, ±10%, ±15%, etc. For example, "1V" includes "0.9 to 1.1V". Phrases preceded by terms such as "substantially" are inclusive of the recited numbers and should be interpreted based on the context (e.g., as precisely as reasonably possible under the circumstances). For example, "substantially vertical" includes "vertical". Unless otherwise specified, all measurements are made at standard conditions, including temperature and pressure. The phrase "at least one of" is intended to require at least one item from a subsequent list, rather than one type of each item from each item in the subsequent list. For example, "at least one of A, B, and C" can include A, B, C, A and B, A and C, B and C, or A, B, and C.

Claims

1. 1. A method for producing a copper-based alloy, comprising the steps of: providing a feedstock to a melting furnace having a composition configured to form a molten copper-based alloy having at least 50% by weight copper; heating the feedstock to melt the feedstock and form the molten copper-based alloy; bubbling an inert gas through the molten copper-based alloy using a diffusion lining formed on an inner surface of the melting furnace, the diffusion lining comprising an aluminum silicate ceramic material having a porous structure adapted for bubbling the inert gas through the molten copper-based alloy; A method comprising:

2. The method of claim 1 , wherein the inert gas consists essentially of argon.

3. The method of claim 2 , wherein the inert gas does not include hydrogen.

4. The method of claim 1 , wherein the diffusion lining substantially covers at least a bottom interior surface of the melting furnace.

5. The method of claim 1 , wherein the diffusion lining comprises at least two layers comprising a sintered ceramic layer and an unsintered ceramic layer.

6. The method of claim 5 , wherein the sintered ceramic layer comprises mullite.

7. The method of claim 5 , wherein the green ceramic layer comprises alumina and silica.

8. The method of claim 5 , wherein the sintered layer and the green ceramic layer have substantially the same chemical composition but different phases.

9. 10. The method of claim 1, wherein the step of providing a feedstock material comprises providing a plurality of feedstock pieces having a composite composition configured to form the molten copper-based alloy, the method further comprising flowing the inert gas through gaps between the feedstock pieces prior to heating.

10. 10. The method of claim 9, wherein the heating step comprises heating the feedstock pieces while flowing the inert gas, thereby melting the feedstock pieces and forming the molten copper-based alloy.

11. 1. A method for producing a copper-based alloy, comprising the steps of: providing a feedstock to a melting furnace having a composition configured to form a molten copper-based alloy having at least 50% by weight copper; heating the feedstock to melt the feedstock and form the molten copper-based alloy; bubbling an inert gas through the molten copper-based alloy using a diffusion lining formed in the melting furnace, the diffusion lining substantially covering at least a bottom inner surface of the melting furnace and having a porous structure adapted to bubbling the inert gas through the molten copper-based alloy; A method comprising:

12. The method of claim 11 , wherein the inert gas consists essentially of argon.

13. 12. The method of claim 11 , wherein the step of providing a feedstock material comprises providing a plurality of feedstock pieces having a composite composition configured to form the molten copper-based alloy, the method further comprising flowing the inert gas through gaps between the feedstock pieces prior to heating.

14. 14. The method of claim 13, wherein the heating step comprises heating the feedstock pieces while flowing the inert gas, thereby melting the feedstock pieces and forming the molten copper-based alloy.

15. 14. The method of claim 13, wherein the step of bubbling the inert gas through the molten copper-based alloy comprises flowing the inert gas through a diffuser embedded in the diffusion lining covering the bottom interior surface of the melting furnace prior to flowing the inert gas through the diffusion lining.

16. 16. The method of claim 15, wherein the diffuser and the diffusion lining comprise the same diffuser material, and the diffuser comprises a diffuser material disposed within a vessel connected to a source of inert gas.

17. The method of claim 15 , wherein the diffusion lining further covers an inner sidewall of the melting furnace.

18. The method of claim 11 , wherein the diffusion lining comprises at least two layers including a sintered ceramic layer and an unsintered ceramic layer.

19. The method of claim 18 , wherein the green ceramic layer comprises alumina and silica.

20. The method of claim 18 , wherein the sintered ceramic layer comprises mullite.

21. 1. A method for producing a copper-based alloy, comprising the steps of: providing a feedstock to a melting furnace having a composition configured to form a molten copper-based alloy having at least 50% by weight copper; heating the feedstock to melt the feedstock and form the molten copper-based alloy; bubbling an inert gas through the molten copper-based alloy using a diffusion lining having a porous structure, the diffusion lining being formed on at least two different inner surfaces of the melting furnace such that the diffusion lining is adapted to bubble the inert gas through the molten copper-based alloy from the at least two different inner surfaces; A method comprising:

22. 22. The method of claim 21 , wherein the step of providing a feedstock material comprises providing a plurality of feedstock pieces having a composite composition configured to form the molten copper-based alloy, the method further comprising flowing the inert gas through gaps between the feedstock pieces prior to heating.

23. 23. The method of claim 22, wherein the heating step comprises heating the feedstock pieces while flowing the inert gas, thereby melting the feedstock pieces and forming the molten copper-based alloy.

24. The method of claim 21 , wherein the at least two different interior surfaces include a bottom interior surface and a sidewall interior surface.

25. 25. The method of claim 24, wherein the step of bubbling the inert gas further comprises diffusing the inert material through a diffuser centrally disposed within the diffusion lining at the bottom inner surface, the diffuser being disposed within a vessel connected to an inert gas source and comprising a diffuser material having an upper surface disposed below an upper surface of the diffusion lining covering the bottom inner surface.

26. 26. The method of claim 25, wherein the step of bubbling the inert gas includes diffusing the inert gas through the diffuser, followed by the diffusion lining disposed on the bottom interior surface, followed by the diffusion lining on the sidewall interior surface.

27. 27. The method of claim 26, wherein one or both of the diffuser and the diffusion lining have a porosity greater than 20%.

28. 22. The method of claim 21, wherein the melting furnace is configured to melt the copper-based alloy in an open chamber configuration in which an atmosphere above the molten copper-based alloy is exposed to an external atmosphere.

29. 22. The method of claim 21, wherein the melting furnace is an induction furnace comprising an induction coil surrounding the melting furnace and configured to melt the feedstock.

30. 30. The method of claim 29, wherein the induction furnace is configured to operate at a frequency less than 1000 Hz.

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