Method and apparatus for producing oxygen-free copper or oxygen-free copper alloy

Abstract

The present disclosure relates to a method and apparatus for producing oxygen-free copper or an oxygen-free copper alloy. Specifically, the present disclosure relates to a method and apparatus for producing oxygen-free copper or oxygen-free copper alloys which is capable of suppressing the generation of holes, cracks, and the like in ingots through a sufficient and uniform deoxidation reaction, and which is able to produce good quality oxygen-free copper or oxygen-free copper alloy with a good surface quality when rolled, and which is capable of producing oxygen-free copper or oxygen-free copper alloy at a low cost through reduction of fuel costs, and which is capable of reducing damage to furnace interior materials and fire hazards.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] The present application a National Stage of International Application No. PCT / KR2023 / 006250, filed on May 9, 2023, which claims priority to Korean Application No. 10-2022-0056976, filed on May 10, 2022, the entire contents of each hereby incorporated by reference.FIELD

[0002] The present disclosure relates to a method and apparatus for producing oxygen-free copper or an oxygen-free copper alloy. Specifically, the present disclosure relates to a method and apparatus for producing oxygen-free copper or oxygen-free copper alloys which is capable of suppressing the generation of holes, cracks, and the like in ingots through a sufficient and uniform deoxidation reaction, and which is able to produce good quality oxygen-free copper or oxygen-free copper alloy with a good surface quality when rolled, and which is capable of producing oxygen-free copper or oxygen-free copper alloy at a low cost through reduction of fuel costs, and which is capable of reducing damage to furnace interior materials and fire hazards.BACKGROUND

[0003] Since the presence of oxygen in copper (Cu) causes hydrogen embrittlement by reacting Cu2O with hydrogen to generate H2O and also reduces corrosion resistance, copper (Cu) that has had oxygen removed by deoxidizers to about 10 ppm or less is referred to as oxygen-free copper (OFC).

[0004] Recently, oxygen-free copper (OFC) wire is increasingly being used in applications such as motor windings for electric vehicles, wires for solar modules, transformer windings, and submarine cables to enhance performance and reliability. In particular, the growth of the electric vehicle and solar markets is expected to drive demand for oxygen-free copper (OFC). Additionally, with the miniaturization of electronic devices, there is a growing need for thinner oxygen-free copper (OFC) wires, highlighting the importance of improving the ductility and workability of oxygen-free copper (OFC).

[0005] Methods of producing oxygen-free copper (OFC) wire include the dip forming method, where oxygen-free copper is solidified and continuously rolled around the outer circumference of a core rod. Another method is the up-cast process, in which an oxygen-free copper mold is placed vertically, and solidified ingots are continuously drawn upwards through cooling within the mold. There is also the horizontal continuous casting method, where the mold is installed horizontally on the side wall of the casting furnace, and solidified ingots are continuously drawn out by cooling the oxygen-free copper within the mold.

[0006] However, these conventional methods for producing oxygen-free copper have a low production rate of 10 tons or less per hour. In this regard, for producing tough pitch copper wire, which contains 100 ppm or more of oxygen, the belt & wheel-type continuous casting and rolling method, commonly known as the Southwire Continuous Rod (SCR) process, is used, as it offers a production rate of 30 tons or more per hour.

[0007] The belt & wheel-type continuous casting and rolling method is a method of pouring molten copper from a shaft furnace into a rotating mold configured between a wheel and a belt. Through cooling, the copper solidifies into ingots, which are continuously drawn out and directly subjected to continuous rolling, thereby producing wires.

[0008] In particular, Japanese Patent No. 4593397 discloses a continuous casting and rolling method that uses a rotary moving mold, where the deoxidation treatment is performed using a reducing gas, and hydrogen concentration is controlled with an inert gas, from the furnace to the casting stage. Additionally, Japanese Patent No. 3552043 discloses a belt & wheel-type continuous casting and rolling method in which a solid reducing agent is disposed in the launder that conveys molten copper from the furnace and the tundish that injects the molten copper into the rotary moving mold.

[0009] However, in the method that performs deoxidation using a reducing gas, it is necessary to induce incomplete combustion to increase the concentration of carbon monoxide (CO) as the reducing gas within the furnace. This incomplete combustion requires more fuel, leading to an increase in the production cost of the oxygen-free copper wire. Additionally, the present inventors have confirmed through literature that conducting deoxidation reaction using a reducing gas, such as carbon monoxide (CO), for an extended period within the furnace can damage the interior materials of the inner wall of the furnace. The present inventors also observed that during prolonged operations, the wear of the interior material progresses rapidly.

[0010] In addition, when a solid reducing agent is disposed in the launder that conveys molten copper from the furnace and in the tundish that injects the molten copper into the rotary moving mold, the contact time between the molten copper and the solid deoxidizer is too short, making it difficult to ensure adequate deoxidation performance. This also leads to significant deviations in oxygen content. Furthermore, there is a high likelihood of foreign substances, such as solid deoxidizers, entering the produced oxygen-free copper wire. This may result in defects such as holes or cracks in the ingots, and may lead to poor surface quality of the wire during the rolling process.

[0011] Therefore, there is an acute need for a method and apparatus for producing oxygen-free copper or oxygen-free copper alloys which is capable of suppressing the generation of holes, cracks, and the like in ingots through a sufficient and uniform deoxidation reaction, and which is able to produce good quality oxygen-free copper or oxygen-free copper alloy with a good surface quality when rolled, and which is capable of producing oxygen-free copper or oxygen-free copper alloy at a low cost through reduction of fuel costs, and which is capable of reducing damage to furnace interior materials and fire hazards.SUMMARY

[0012] The present disclosure is directed to providing a method and apparatus for producing oxygen-free copper or oxygen-free copper alloys that, through a sufficient and uniform deoxidation reaction, is capable of suppressing the formation of holes, cracks, and other defects in ingots, while ensuring excellent surface quality during rolling, thereby producing high-quality oxygen-free copper or oxygen-free copper alloys.

[0013] In addition, the present disclosure is directed to providing a method and apparatus for producing oxygen-free copper or oxygen-free copper alloys that is capable of producing oxygen-free copper or oxygen-free copper alloys at a lower cost by reducing fuel consumption, and reducing damage to interior materials within the furnace and the risk of fire.

[0014] To achieve the objects, the present disclosure is directed to providing

[0015] a method of producing oxygen-free copper or oxygen-free copper alloys, the method comprising: introducing copper or a copper alloy material and a solid deoxidizer into a furnace to melt and deoxidize the copper or copper alloy material; conveying the deoxidized copper or copper alloy molten metal through a conveying pipe; discharging the copper or copper alloy molten metal conveyed through a pour pot into a caster; and producing the copper or copper alloy molten metal into an ingot in the caster.

[0016] Here, the solid deoxidizer may include at least one selected from the group consisting of graphite, charcoal, activated carbon, and cokes.

[0017] In addition, an introduced amount of the solid deoxidizer may be 1 kg / ton or more and 6 kg / ton or less with respect to an introduced amount of the copper or copper alloy material.

[0018] Further, the solid deoxidizer may have a size of 0.5 mm or more and 30 mm or less.

[0019] Further, a dust collector may be further provided at an upper portion of the furnace.

[0020] Further, a concentration of carbon monoxide (CO) in the furnace may be controlled to be 3.5 vol % or less.

[0021] In addition, a residence time of the solid deoxidizer inside the furnace may be 5 minutes to 2 hours.

[0022] Further, a discharge port of the pour pot may be provided with a spout torch configured to apply a flame to externally seal the copper or copper alloy molten metal being discharged into the caster and a spout burner configured to apply a flame to remelt and remove copper or copper alloy molten metal adhering to an exterior surface of the discharge port.

[0023] Here, the conveying pipe may include: an upper slag vessel configured to remove impurities generated upon melting of the copper or copper alloy material or slag from the solid deoxidizer; a holding furnace configured to perform a buffer function to compensate for a difference between an ingot production rate and a melting rate while maintaining a temperature of the copper or copper alloy molten metal; and a lower slag vessel configured to remove impurities suspended above the copper or copper alloy molten metal.

[0024] Here, the upper slag vessel may have a discharge port connected to the holding furnace, the discharge port having a shape such that a width of the discharge port is longer than a height thereof, or in which a partition wall may be provided at an upper portion of the discharge port.

[0025] In addition, a concentration of carbon monoxide may be controlled to be greater than 2.5 vol % and equal to or less than 4.0 vol % at one or more positions selected from the group consisting of the holding furnace, the lower slag vessel, and the pour pot.

[0026] Further, the lower slag vessel may be provided with a bubbler configured to inject an inert gas into the copper or copper alloy molten metal.

[0027] Here, the inert gas may include argon gas or nitrogen gas.

[0028] Further, the caster may include a moving mold caster including a casting wheel that rotates and a belt provided spaced apart from a surface of the casting wheel at a predetermined interval, and the method may further include rolling an ingot produced by the caster continuously through a rolling mill.

[0029] Meanwhile, the present disclosure is directed to providing an oxygen-free copper or oxygen-free copper alloy produced by the method of producing oxygen-free copper or oxygen-free copper alloys.

[0030] Here, the alloy may be in the form of a bar, a rod, or an ingot.

[0031] Meanwhile, the present disclosure is directed to providing an apparatus for producing oxygen-free copper or oxygen-free copper alloys, the apparatus including: a furnace configured to melt copper or copper alloy material; a conveying pipe through which the copper or copper alloy molten metal melted in the furnace is conveyed; a pour pot configured to discharge the copper or copper alloy molten metal conveyed through the conveying pipe; and a caster configured to cool the copper or copper alloy molten metal discharged from the pour pot to produce an ingot, wherein a solid deoxidizer is introduced into the furnace with the copper or copper alloy material.

[0032] Here, the solid deoxidizer may include at least one selected from the group consisting of graphite, charcoal, activated carbon, and cokes.

[0033] In addition, an introduced amount of the solid deoxidizer may be 1 kg / ton or more and 6 kg / ton or less with respect to an introduced amount of the copper or copper alloy material.

[0034] Further, the solid deoxidizer may have a size of 1 mm or more and 30 mm or less.

[0035] Further, a dust collector may be further provided at an upper portion of the furnace.

[0036] In addition, a concentration of carbon monoxide (CO) in the furnace may be controlled to be 3.5 vol % or less.

[0037] Further, a residence time of the solid deoxidizer inside the furnace may be 5 minutes to 2 hours.

[0038] Meanwhile, a discharge port of the pour pot may be provided with a spout torch configured to apply a flame to externally seal the copper or copper alloy molten metal being discharged into the caster and a spout burner configured to apply a flame to remelt and remove copper or copper alloy molten metal adhering to an exterior surface of the discharge port.

[0039] Here, the conveying pipe may include: an upper slag vessel configured to remove impurities generated upon melting of the copper or copper alloy material or slag from the solid deoxidizer; a holding furnace configured to perform a buffer function to compensate for a difference between an ingot production rate and a melting rate while maintaining a temperature of the copper or copper alloy molten metal; and a lower slag vessel configured to remove impurities suspended above the copper or copper alloy molten metal.

[0040] Here, the upper slag vessel may have a discharge port connected to the holding furnace, the discharge port having a shape such that a width of the discharge port is longer than a height thereof, or in which a partition wall may be provided at an upper portion of the discharge port.

[0041] In addition, a concentration of carbon monoxide may be controlled to be greater than 2.5 vol % and equal to or less than 4.0 vol % at one or more positions selected from the group consisting of the holding furnace, the lower slag vessel, and the pour pot.

[0042] Further, the lower slag vessel may be provided with a bubbler configured to inject an inert gas into the copper or copper alloy molten metal.

[0043] Here, the inert gas may include argon gas or nitrogen gas.

[0044] Meanwhile, the caster may include a moving mold caster including a casting wheel that rotates and a belt provided spaced apart from a surface of the casting wheel at a predetermined interval, and the apparatus may further include a rolling mill configured to continuously roll an ingot produced by the caster.

[0045] The method and apparatus for producing oxygen-free copper or oxygen-free copper alloys according to the present disclosure apply a solid deoxidizer directly within the furnace, rather than in the launder or tundish. This ensures sufficient and uniform deoxidation, effectively suppressing the generation of holes, cracks, and other defects in the ingots, thereby exhibiting excellent effects of producing high-quality oxygen-free copper or oxygen-free copper alloys with excellent surface quality during rolling.

[0046] In addition, the method and apparatus for producing oxygen-free copper or oxygen-free copper alloys according to the present disclosure minimize deoxidation reactions involving reducing gases within the furnace. As a result, it exhibits excellent effects of preventing the increase in fuel costs and production expenses associated with incomplete combustion needed to generate reducing gases and at the same time effectively suppressing damage to the interior materials in the furnace caused by reducing gases.BRIEF DESCRIPTION OF THE DRAWINGS

[0047] FIG. 1 is a view schematically illustrating an apparatus for producing oxygen-free copper or oxygen-free copper alloys according to the present disclosure.

[0048] FIG. 2 is an enlarged view of a furnace in FIG. 1.

[0049] FIG. 3 is an enlarged view of an upper slag vessel in FIG. 1.

[0050] FIG. 4 is an enlarged view of a lower slag vessel in FIG. 1.

[0051] FIG. 5 is an enlarged view of a pour pot in FIG. 1.DETAILED DESCRIPTION

[0052] Hereinafter, exemplary embodiments of the present disclosure will be described in detail. However, the present disclosure is not limited to the exemplary embodiments to be described below and may be specified as other aspects. On the contrary, the embodiments introduced herein are provided to make the disclosed content thorough and complete, and sufficiently transfer the spirit of the present disclosure to those skilled in the art. Like reference numerals indicate like constituent elements throughout the specification.

[0053] FIG. 1 is a view schematically illustrating an apparatus for producing oxygen-free copper or oxygen-free copper alloys according to the present disclosure.

[0054] There is provided a method of producing oxygen-free copper or oxygen-free copper alloys, according to the present disclosure, using the apparatus as illustrated in FIG. 1. The method may include the steps of introducing copper or a copper alloy material and a solid deoxidizer into a furnace 100 to melt and deoxidize the copper or copper alloy material, conveying the deoxidized copper or copper alloy molten metal through a conveying pipe 200, discharging the copper or copper alloy molten metal conveyed through a pour pot 300 into a caster 400, producing the copper or copper alloy molten metal into an ingot in the caster 400, and rolling an ingot produced by the caster continuously through a rolling mill 500.

[0055] FIG. 2 is an enlarged view of the furnace 100 in FIG. 1.

[0056] Specifically, in the step of melting and deoxidizing the copper or copper alloy material, copper or copper alloy material, preferably an electric copper plate, and a solid deoxidizer are introduced through an inlet port 120 in an upper portion of a shaft furnace 110 as illustrated in FIG. 2. In a state in which the electric copper plate and the solid deoxidizer are alternately stacked, the copper or copper alloy material may be melted and deoxidized using the heat of combustion of combustion gases through a burner 130 provided in one or more layers in a lower portion of the shaft furnace, while maintaining a temperature of about 1090 to 1150° C.

[0057] In addition, the upper portion of the furnace 110 may be further provided with a dust collector 140 for sucking in dust generated by the melting inside the furnace 110 and the like, and a scattering prevention device for preventing scattering of the solid deoxidizer, which is relatively small in size among the solid deoxidizer.

[0058] Conventionally, when a solid deoxidizer is introduced into a shaft furnace, the solid deoxidizer floats on top of the copper molten metal due to a difference in specific gravity. In addition, since unmelted or only partially melted copper or copper alloy material is introduced and stacked on top of the copper molten metal, it is difficult for a sufficient deoxidation reaction to occur by sufficient contact of the copper molten metal with the solid deoxidizer. The solid deoxidizer has been applied to a conveying pipe through which copper or copper alloy molten metal discharged from the furnace is conveyed or to a pour pot from which the copper or copper alloy molten metal is discharged to a caster. However, the present inventors have completed their work by experimentally confirming that, contrary to expectations, applying a solid deoxidizer directly within the furnace can, in fact, induce sufficient and uniform deoxidation reactions.

[0059] The solid deoxidizer may be introduced into the furnace 100 together with the copper or copper alloy material, or may be repeatedly introduced alternately with the copper alloy material. An introduced amount of the solid deoxidizer may be controlled to be 1 kg / ton or more and 6 kg / ton or less with respect to an introduced amount of the copper or copper alloy material. The introduced solid deoxidizer may reside in the furnace 100 for about 5 minutes to 2 hours.

[0060] Here, when the introduced amount of the solid deoxidizer is less than 1 kg / ton, the deoxidation reaction by the solid deoxidizer may be insufficient, resulting in excessive oxygen content in the ingot produced, which may cause holes, cracks, and other defects, and reduce the surface quality when rolling.

[0061] In contrast, when the introduced amount of the solid deoxidizer exceeds 6 kg / ton, the excess solid deoxidizer that is not consumed in the furnace 100 and is conveyed along with the copper molten metal to the conveying pipe 200, which may cause an overflow of the copper molten metal from the conveying pipe 200. In addition, excess solid deoxidizer in the furnace 100 may be consumed by combustion in the furnace 100, which may cause excessive smoke generation and a fire as the burned fine sparks are sucked into a dust collector that may be further provided on the upper portion of the furnace 100.

[0062] The solid deoxidizer may have a size of 30 mm or less, for example, 0.5 to 30 mm, preferably 1 to 30 mm, and may include at least one selected from the group consisting of graphite, charcoal, activated carbon, and cokes, more preferably graphite. For reference, a size of the solid deoxidizer refers to a diameter of a sphere that has been scaled to have the same volume.

[0063] Here, when the size of the solid deoxidizer is less than 1 mm, the gas pressure rising upward from the furnace 100 may cause the solid deoxidizer to be sucked into the dust collector provided at the upper portion of the furnace 100, causing a fire or dust collector failure. In contrast, when the size of the solid deoxidizer is greater than 30 mm, the solid deoxidizer may not be combusted in the furnace 100 but conveyed along with the copper molten metal, partially blocking the conveying passage and causing overflow of the copper molten metal.

[0064] When the fuel is burned through a burner provided in one or more layers in the lower portion of the furnace 100, combustion gases are generated. A concentration of carbon monoxide (CO) generated by incomplete combustion may be controlled to be 1.5 vol % or less of a total volume of the combustion gases, thereby preventing or minimizing damage to interior materials of the inner wall of the furnace (100) caused by the carbon monoxide (CO).

[0065] Meanwhile, in the step of conveying the deoxidized copper or copper alloy molten metal through the conveying pipe 200, the copper or copper alloy molten metal discharged from the furnace 100 is conveyed to the pour pot 300 while maintaining the molten state of the copper or copper alloy molten metal by maintaining a temperature of 1100 to 1200° C. using the heat of combustion generated by burning the fuel in the conveying pipe 200.

[0066] For example, the conveying pipe 200 may include an upper slag vessel 210 that removes impurities generated upon melting of the copper or copper alloy material or slag from the solid deoxidizer, a holding furnace 220 that performs a buffer function to compensate for a difference between an ingot production rate and a melting rate while maintaining a temperature of the copper or copper alloy molten metal, and a lower slag vessel 230 that removes impurities suspended above the copper or copper alloy molten metal.

[0067] FIG. 3 is an enlarged view of the upper slag vessel.

[0068] In particular, a portion of the upper slag vessel 210 that is connected to the holding furnace 220 is provided with an open discharge port 211 so that the copper or copper alloy molten metal may be conveyed to the holding furnace 220. To prevent the solid deoxidizer floating on top of the copper or copper alloy molten metal from falling into the holding furnace 220, an upper portion of the discharge port 211 may be provided with a partition wall 212 to block the solid deoxidizer from falling into the holding furnace 220. Meanwhile, instead of the partition wall 212 being provided, it is also possible to form a shape of the discharge port 211 that has a width of the discharge port 211 that is longer than a height thereof. As described above, it is important to ensure that the solid deoxidizer is not allowed to flow into the holding furnace 220. This is because, when the solid deoxidizer is conveyed beyond the holding furnace 220, overflow may be induced in the conveying passage of the copper or copper alloy molten metal. Here, an upper surface of the discharge port 211 may be in line with or lower than a lower surface of an opening 213 described below.

[0069] Here, the reason for providing the opening 213 at the front of the upper slag vessel 210 is to allow for the release of gases generated during the production of copper or copper alloy molten metal through the opening 213. Additionally, this opening permits the discharge of some of the solid deoxidizer. This helps to suppress the overflow of copper or copper alloy molten metal within the upper slag vessel 210.

[0070] In particular, the solid deoxidizer floating on top of the copper or copper alloy molten metal may be stacked at the opening 213 to act in combination with a positive pressure from the gases inside the upper slag vessel 210, preventing air from entering the upper slag vessel 210 from the outside.

[0071] In addition, a concentration of carbon monoxide (CO) may be controlled to be greater than 1.5 vol % and less than or equal to 4.0 vol % through incomplete combustion of the fuel at one or more positions selected from the group consisting of the upper slag vessel 210, the holding furnace 220, and the lower slag vessel 230 to cause an additional deoxidation reaction by carbon monoxide (CO), which is a reducing gas, to further limit the oxygen concentration in the ingot.

[0072] Further, a bubbler 231 may be further provided in one or more selected from the group consisting of the upper slag vessel 210, the holding furnace 220 and the lower slag vessel 230, preferably the lower slag vessel 230, for injecting an inert gas into the copper or copper alloy molten metal as illustrated in FIG. 4. The bubbler 231 may be provided on an upper surface of the lower slag vessel 230 in a direction perpendicular to the ground, thereby improving the structural stability and workability of the lower slag vessel 230.

[0073] An inert gas such as argon (Ar) and nitrogen (N2) may be injected into the copper or copper alloy molten metal through the bubbler 230. Accordingly, hydrogen (H2) residual in the copper or copper alloy molten metal may be discharged. When the concentration of residual hydrogen (H2) is high, there is a problem that the ingot may have holes, cracks, and other defects, or the surface defects may be caused when rolling. Therefore, since the concentration of oxygen (O2) and the concentration of hydrogen (H2) in the copper or copper alloy molten metal are inversely proportional, it is desirable to reduce the concentration of residual hydrogen (H2) by injecting an inert gas in the lower slag vessel 230 where the concentration of oxygen (O2) is kept lowest and the concentration of hydrogen (H2) is kept highest through the deoxidation reaction.

[0074] Meanwhile, the step of discharging the copper or copper alloy molten metal conveyed through the pour pot 300 into the caster 400 involves injecting the copper or copper alloy molten metal conveyed through the conveying pipe 200 into the caster 400. The pour pot 300, like the conveying pipe 200, uses the heat of combustion generated from burning fuel to maintain the molten state of the copper or copper alloy molten metal while injecting the copper or copper alloy molten metal into the caster 400.

[0075] Here, after being discharged from the discharge port of the pour pot 300 and before being injected into the caster 400, the copper or copper alloy molten metal may be exposed to external air, which may lead to the introduction of oxygen or other impurities. In this regard, as illustrated in FIG. 5, a spout torch 320 may be further provided around the discharge port of the pour pot 300. The spout torch 320 applies a flame around the copper or copper alloy molten metal to seal the copper or copper alloy molten metal from external air.

[0076] In addition, the discharge port of the pour pot 300 may be further provided with a spout burner 330 to prevent copper or copper alloy molten metal from splashing onto and solidifying on the exterior surface of the discharge port. The spout burner 330 applies a flame to the surface of the discharge port to remelt and remove any adhered copper or copper alloy molten metal. A direction of the flame applied from the spout burner 330 is perpendicular to a direction of the flame applied from the spout torch 320, so that the spout burner may be provided to ensure that the two flames do not directly interfere with each other.

[0077] In the step of producing the ingot from the copper or copper alloy molten metal in the caster 400, the caster 400 may include a moving mold caster including a rotary casting wheel 410 and a belt 420 that is spaced apart at a predetermined interval from the surface of the casting wheel. The copper or copper alloy molten metal discharged from the pour pot 300 is injected into a space provided between the casting wheel 410 and the belt 420, where it is cooled and solidified to form an ingot. The formed ingot are then conveyed to the rolling mill 500 while maintained at a temperature of 900° C. or higher, where the formed ingot is continuously rolled and produced into the form of wires.

[0078] Meanwhile, in an embodiment of the present disclosure, a casting method using a belt & wheel-type moving mold caster, as illustrated in FIG. 1, is described. However, the present disclosure is not limited to this casting method. Various other casting methods may be used, such as a casting method using a so-called double belt-type moving mold caster, which is configured with two belts (refer to Japanese Patent No. 5137642), and a casting method using a continuous caster (refer to U.S. Pat. No. 5,037,471).

[0079] Accordingly, the method and apparatus for producing oxygen-free copper or oxygen-free copper alloys according to the present disclosure apply a solid deoxidizer directly within the furnace 100 rather than in the conveying pipe 200 or the pour pot 300. This ensures sufficient and uniform deoxidation, effectively suppressing the generation of holes, cracks, and other defects in the ingots, thereby exhibiting excellent effects of producing high-quality oxygen-free copper or oxygen-free copper alloys with excellent surface quality during rolling.

[0080] In addition, the method and apparatus for producing oxygen-free copper or oxygen-free copper alloys according to the present disclosure does not perform deoxidation reactions involving reducing gases within the furnace 100. As a result, it exhibits excellent effects of preventing the increase in fuel costs and production expenses associated with incomplete combustion and at the same time effectively suppressing damage to the interior materials in the furnace caused by reducing gases.Examples1. Evaluation of Overflow and Oxygen Concentration According to Introduced Amount of Solid Deoxidizer

[0081] As shown in Table 1 below, the amount of solid deoxidizer introduced into the furnace was varied, and the occurrence of overflow in the conveying pipe and the oxygen concentration in the produced oxygen-free copper were evaluated.TABLE 1Solid deoxidizer introduced amount (kg / ton)00.512345678Oxygen300559.66.65.64.84.44.13.93.8concentration(ppm)Overflowxxxxxxxx∘∘

[0082] As shown in Table 1, when the introduced amount of solid deoxidizer is less than 1 kg / ton, the oxygen concentration in the ingot increases, making it impossible to produce oxygen-free copper. In contrast, when the introduced amount of solid deoxidizer exceeds 6 kg / ton, it was confirmed that the excessive solid deoxidizer is conveyed along with the copper molten metal into the conveying pipe, at least partially blocking the passage and causing an overflow of the copper molten metal.

[0083] Meanwhile, in Examples 1 to 6, where the introduced amount of solid deoxidizer was 1 kg / ton or more and 6 kg / ton or less, the oxygen concentration was maintained at 10 ppm or less, satisfying the conditions for oxygen-free copper wire. By appropriately adjusting the introduced amount, no overflow of the copper molten metal occurred, allowing for the stable production of high-quality oxygen-free copper wire.2. Evaluating Overflow and Dust Collector Filter Failure According to Particle Diameter in Solid Deoxidizer

[0084] As shown in Table 2 below, the average particle diameter of the solid deoxidizer introduced into the furnace was varied, and the occurrence of copper molten metal overflow, particularly in the upper slag vessel, as well as any malfunctions of the dust collector filter provided at the upper portion of the furnace, were evaluated.TABLE 2GreaterGreaterGreaterGreaterGreaterGraphitethanthanthanthanthanaverage1 mm3 mm5 mm10 mm and30 mm andGreaterparticle1 mm or3 mm or5 mm or10 mm or30 mm or50 mm orthandiameterlesslesslesslesslessless50 mmDamage∘Δxxxxxto dustcollectorfilterUpperxxxxx∘∘slagvesseloverflow

[0085] As shown in Table 2, when the average particle diameter of the graphite used as a solid deoxidizer exceeded 30 mm, overflow was observed in the upper slag vessel. Further, when the particle diameter was 1 mm or less, the solid deoxidizer was drawn into the dust collector, potentially causing a malfunction of the dust collector filter.

[0086] While the present disclosure has been described above with reference to the exemplary embodiments, it may be understood by those skilled in the art that the present disclosure may be variously modified and changed without departing from the spirit and scope of the present disclosure disclosed in the claims. Therefore, it should be understood that any modified embodiment that essentially includes the constituent elements of the claims of the present disclosure is included in the technical scope of the present disclosure.

Claims

1. A method of producing oxygen-free copper or oxygen-free copper alloys, the method comprising:introducing copper or a copper alloy material and a solid deoxidizer into a furnace to melt and deoxidize the copper or copper alloy material;conveying the deoxidized copper or copper alloy molten metal through a conveying pipe;discharging the copper or copper alloy molten metal conveyed through a pour pot into a caster; andproducing the copper or copper alloy molten metal into an ingot in the caster.

2. The method of claim 1, wherein the solid deoxidizer includes at least one selected from the group consisting of graphite, charcoal, activated carbon, and cokes.

3. The method of claim 2, wherein an introduced amount of the solid deoxidizer is 1 kg / ton or more and 6 kg / ton or less with respect to an introduced amount of the copper or copper alloy material.

4. The method of claim 2, wherein the solid deoxidizer has a size of 0.5 mm or more and 30 mm or less.

5. The method of claim 1, wherein a dust collector is further provided at an upper portion of the furnace.

6. The method of claim 1, wherein a concentration of carbon monoxide (CO) in the furnace is controlled to be 3.5 vol % or less.

7. The method of claim 1, wherein a residence time of the solid deoxidizer inside the furnace is 5 minutes to 2 hours.

8. The method of claim 1, wherein a discharge port of the pour pot is provided with a spout torch configured to apply a flame to externally seal the copper or copper alloy molten metal being discharged into the caster and a spout burner configured to apply a flame to remelt and remove copper or copper alloy molten metal adhering to an exterior surface of the discharge port.

9. The method of claim 1, wherein the conveying pipe includes:an upper slag vessel configured to remove impurities generated upon melting of the copper or copper alloy material or slag from the solid deoxidizer;a holding furnace configured to perform a buffer function to compensate for a difference between an ingot production rate and a melting rate while maintaining a temperature of the copper or copper alloy molten metal; anda lower slag vessel configured to remove impurities suspended above the copper or copper alloy molten metal.

10. The method of claim 9, wherein the upper slag vessel has a discharge port connected to the holding furnace, the discharge port having a shape such that a width of the discharge port is longer than a height thereof, or in which a partition wall is provided at an upper portion of the discharge port.

11. The method of claim 9, wherein a concentration of carbon monoxide is controlled to be greater than 2.5 vol % and equal to or less than 4.0 vol % at one or more positions selected from the group consisting of the holding furnace, the lower slag vessel, and the pour pot.

12. The method of claim 9, wherein the lower slag vessel is provided with a bubbler configured to inject an inert gas into the copper or copper alloy molten metal.

13. The method of claim 12, wherein the inert gas includes argon gas or nitrogen gas.

14. The method of claim 1, wherein the caster includes a moving mold caster including a casting wheel that rotates and a belt provided spaced apart from a surface of the casting wheel at a predetermined interval, andfurther comprising:rolling an ingot produced by the caster continuously through a rolling mill.

15. An oxygen-free copper or oxygen-free copper alloy produced by the method of producing oxygen-free copper or oxygen-free copper alloys according to claim 1.

16. The oxygen-free copper or oxygen-free copper alloy of claim 15, wherein the alloy is in the form of a bar, a rod, or an ingot.

17. An apparatus for producing oxygen-free copper or oxygen-free copper alloys, the apparatus comprising:a furnace configured to melt copper or copper alloy material;a conveying pipe through which the copper or copper alloy molten metal melted in the furnace is conveyed;a pour pot configured to discharge the copper or copper alloy molten metal conveyed through the conveying pipe; anda caster configured to cool the copper or copper alloy molten metal discharged from the pour pot to produce an ingot,wherein a solid deoxidizer is introduced into the furnace with the copper or copper alloy material.

18. The apparatus of claim 17, wherein the solid deoxidizer includes at least one selected from the group consisting of graphite, charcoal, activated carbon, and cokes.

19. The apparatus of claim 18, wherein an introduced amount of the solid deoxidizer is 1 kg / ton or more and 6 kg / ton or less with respect to an introduced amount of the copper or copper alloy material.

20. The apparatus of claim 18, wherein the solid deoxidizer has a size of 1 mm or more and 30 mm or less.

21. The apparatus of claim 17, wherein a dust collector is further provided at an upper portion of the furnace.

22. The apparatus of claim 17, wherein a concentration of carbon monoxide (CO) in the furnace is controlled to be 3.5 vol % or less.

23. The apparatus of claim 17, wherein a residence time of the solid deoxidizer inside the furnace is 5 minutes to 2 hours.

24. The apparatus of claim 17, wherein a discharge port of the pour pot is provided with a spout torch configured to apply a flame to externally seal the copper or copper alloy molten metal being discharged into the caster and a spout burner configured to apply a flame to remelt and remove copper or copper alloy molten metal adhering to an exterior surface of the discharge port.

25. The apparatus of claim 17, wherein the conveying pipe includes:an upper slag vessel configured to remove impurities generated upon melting of the copper or copper alloy material or slag from the solid deoxidizer;a holding furnace configured to perform a buffer function to compensate for a difference between an ingot production rate and a melting rate while maintaining a temperature of the copper or copper alloy molten metal; anda lower slag vessel configured to remove impurities suspended above the copper or copper alloy molten metal.

26. The apparatus of claim 25, wherein the upper slag vessel has a discharge port connected to the holding furnace, the discharge port having a shape such that a width of the discharge port is longer than a height thereof, or in which a partition wall is provided at an upper portion of the discharge port.

27. The apparatus of claim 25, wherein a concentration of carbon monoxide is controlled to be greater than 2.5 vol % and equal to or less than 4.0 vol % at one or more positions selected from the group consisting of the holding furnace, the lower slag vessel, and the pour pot.

28. The apparatus of claim 25, wherein the lower slag vessel is provided with a bubbler configured to inject an inert gas into the copper or copper alloy molten metal.

29. The apparatus of claim 25, wherein the inert gas includes argon gas or nitrogen gas.

30. The apparatus of claim 17, wherein the caster includes a moving mold caster including a casting wheel that rotates and a belt provided spaced apart from a surface of the casting wheel at a predetermined interval, andfurther comprising:a rolling mill configured to continuously roll an ingot produced by the caster.

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