Method for preparing oxygen-free copper by using rare earth combined deoxidation, product and device thereof

Abstract

The application provides a method for preparing oxygen-free copper by adopting rare earth combined deoxidization, a product and a device, and comprises the following steps: a) after the purple scrap copper raw material is melted, the oxygen refining is carried out; b) the copper liquid obtained in the step a) is subjected to reduction refining; c) the combined deoxidization is carried out by adding a composite deoxidizer containing rare earth into the copper liquid obtained in the step b); d) the copper liquid obtained in the step c) is subjected to continuous casting and rolling under a protective atmosphere, and the oxygen-free copper product is obtained. Through the system integration of the deep deoxidization of the rare earth and the continuous casting and rolling process, and in combination with the anti-oxidation design of the equipment, the oxygen-free copper product with the oxygen content of less than or equal to 20 ppm can be efficiently produced by taking the purple scrap copper as the raw material, the cost is reduced by 20-30% and the efficiency is improved by more than 50% compared with the traditional continuous casting process, and the method has good industrial practical value.

Description

Technical Field

[0001] This invention relates to the field of non-ferrous metal processing technology, and in particular to a method, product and apparatus for preparing oxygen-free copper by continuous casting and rolling using rare earth combined deoxidation. Background Technology

[0002] Oxygen-free copper (oxygen content ≤20ppm) is widely used in electronics, electrical engineering, and communications due to its excellent electrical and thermal conductivity and processing properties. Traditionally, oxygen-free copper is mainly produced using the upward continuous casting process, with high-purity cathode copper as raw material. This method produces stable product quality, but suffers from high production costs, low production efficiency, and difficulty in large-scale continuous production.

[0003] On the other hand, continuous casting and rolling technology has become the mainstream technology for copper rod production due to its high efficiency and energy saving. However, because the molten copper comes into contact with air during the smelting, holding, and casting processes, it is prone to absorbing oxygen. Therefore, the traditional continuous casting and rolling process can usually only produce low-oxygen copper rods with an oxygen content of 200-400 ppm, which is difficult to meet the oxygen-free copper standard.

[0004] There have been attempts to produce oxygen-free copper rods using the purple copper refining method in the existing technology, but there are the following shortcomings: (1) The deoxidation process relies on wood insertion reduction, which is complicated and inefficient; (2) There is a lack of systematic equipment anti-oxidation design, resulting in poor product quality stability; (3) The deep integration of rare earth deoxidation and continuous casting and rolling processes has not been achieved.

[0005] Therefore, developing a method for efficiently producing high-quality oxygen-free copper using continuous casting and rolling processes, especially a low-cost technical solution using scrap copper as raw material, has significant industrial value. Summary of the Invention

[0006] This invention aims to overcome the shortcomings of the prior art and provide a method, product and apparatus for preparing oxygen-free copper by continuous casting and rolling using rare earth combined deoxidation. By organically integrating rare earth deep deoxidation technology with continuous casting and rolling process, and combining systematic equipment anti-oxidation improvement, it can achieve efficient production of oxygen-free copper products with oxygen content ≤20ppm using mixed copper as raw material.

[0007] The technical solution adopted by this invention to solve its technical problem is: In a first aspect, the present invention provides a method for preparing oxygen-free copper by continuous casting and rolling using rare earth combined deoxidation, comprising the following steps: a) The raw copper scraps are melted and then refined by oxidation; b) The copper liquid obtained in step a) is subjected to reduction refining; c) Add a rare earth-containing composite deoxidizer to the copper liquid obtained in step b) for combined deoxidation; d) The copper liquid obtained in step c) is continuously cast and rolled under a protective atmosphere to obtain oxygen-free copper products.

[0008] Furthermore, the oxidative refining described in step a) is a multi-stage oxidative refining process, which sequentially includes coke refining, quartz refining, and lime refining.

[0009] Furthermore, the composite deoxidizer in step c) comprises, by weight percentage: 60%~80% rare earth elements, 5%~15% lithium oxide, 5%~15% apatite, and 5%~10% fluorite; wherein the rare earth elements are at least one of lanthanum and cerium.

[0010] Furthermore, the amount of composite deoxidizer added in step c) is 0.01% to 0.10% of the weight of copper liquid.

[0011] Furthermore, the amount of the composite deoxidizer added is 0.03% to 0.06% of the weight of the copper liquid.

[0012] Furthermore, the temperature for combined deoxygenation in step c) is 1150℃~1170℃, and the holding time is 10~20 minutes.

[0013] In a second aspect, the present invention provides a continuous casting and rolling production apparatus for the method described in any of the above, comprising a melting furnace, a runner, a horizontal continuous casting machine and a planetary rolling mill connected in sequence. The smelting furnace is equipped with a sealed cover and a protective atmosphere inlet; The connection between the smelting furnace and the flow channel is equipped with an airlock-type rare earth feeding device. The flow channel is a closed structure and is equipped with a rotating degassing device inside; The planetary mill is equipped with a sealing cover at its entrance.

[0014] Furthermore, the airlock rare earth feeding device includes a feeding bin, an upper gate valve, a lower gate valve, and a feeding pipe, the end of which extends below the surface of the copper liquid.

[0015] Furthermore, the lining material of the closed flow channel is magnesium aluminum spinel refractory or zirconium refractory; the cooling water channel of the crystallizer of the horizontal continuous casting machine is spirally distributed, and the effective length of the crystallizer is 500~800mm.

[0016] Thirdly, the present invention provides an oxygen-free copper product prepared by any of the methods described above, wherein the oxygen content of the oxygen-free copper product is ≤20ppm and the conductivity is ≥100% IACS.

[0017] In summary, the beneficial effects of the present invention are as follows: This invention relates to a method, product, and apparatus for preparing oxygen-free copper using rare-earth combined deoxidation through continuous casting and rolling. By organically integrating rare-earth deep deoxidation technology with continuous casting and rolling processes, and combining systematic improvements to equipment oxidation prevention, it achieves efficient production of oxygen-free copper products with an oxygen content ≤20ppm from scrap copper as raw material. Specifically, it includes: (1) For the first time, the rare earth deep deoxidation technology was integrated with the continuous casting and rolling process system, breaking the technical prejudice that "continuous casting and rolling can only produce low oxygen copper rods" and realizing the efficient short-process production of oxygen-free copper; (2) Rare earth combined deoxidation can reduce the oxygen content of copper liquid to 15-20ppm, which meets or even exceeds the national standard TU2 grade oxygen-free copper requirements (≤20ppm); at the same time, the residual trace rare earth can refine the grains and improve the ductility and tensile strength of the material. (3) This invention can directly use mixed copper as raw material, without relying on high-purity cathode copper, and the raw material cost is reduced by 20-30% compared with the traditional continuous casting process; (4) The continuous production method of continuous casting and rolling increases production efficiency by more than 50% and reduces equipment investment compared with the traditional route of upward continuous casting + subsequent processing. (5) The systematic equipment anti-oxidation design ensures oxygen content control throughout the entire process from smelting to rolling, resulting in stable and reliable product quality. Attached Figure Description

[0018] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0019] Figure 1 This is a schematic diagram of the apparatus for preparing oxygen-free copper by continuous casting and rolling using rare earth combined deoxidation according to the present invention. Figure 2 This is a schematic diagram of the smelting furnace of the present invention; Figure 3 This is a schematic diagram of the structure of the airlock rare earth feeding device of the present invention; Figure 4 This is a schematic diagram of the flow channel structure of the present invention; Figure 5 This is a schematic diagram of the horizontal continuous casting machine of the present invention; Figure 6 This is a schematic diagram of the planetary rolling mill of the present invention. Figure Labels

[0020] 1—Furnace shell; 3—Vacuum pump interface; 4—Heating coil; 5—Graphite crucible; 6—Stirring paddle; 7—Casting nozzle; 8—Storage hopper; 9—Screw feeder; 10—Rotary airlock valve; 11—Nitrogen / argon inlet; 12—Nitrogen / argon outlet; 13—Feeding port; 14—Heating and insulation layer; 15—Insulation cover plate; 16—Horizontal continuous casting machine; 152—Clad cover plate; 17—Molder; 18—Cooling water jacket; 19—Cooling water inlet; 20—Cooling water outlet; 21—Traction roller; 22—Working roll; 23—Roller frame; 24—Transmission gearbox; 25—Drive motor; 26—Adjusting frame; 27—Finished product outlet; 28—Smelting furnace; 29—Airlock rare earth feeding device; 30—Stream; 31—Horizontal continuous casting machine; 32—Planetary mill. Detailed Implementation

[0021] The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, illustrating only the basic structure of the invention, and therefore only show the components relevant to the invention.

[0022] Please see Figures 1-6 In a first aspect, the present invention provides a method for preparing oxygen-free copper by continuous casting and rolling using rare earth combined deoxidation, comprising the following steps: a) The raw copper scraps are melted and then refined by oxidation; b) The copper liquid obtained in step a) is subjected to reduction refining; c) Add a rare earth-containing composite deoxidizer to the copper liquid obtained in step b) for combined deoxidation; d) The copper liquid obtained in step c) is continuously cast and rolled under a protective atmosphere to obtain oxygen-free copper products.

[0023] Furthermore, the oxidative refining described in step a) is a multi-stage oxidative refining process, which sequentially includes coke refining, quartz refining, and lime refining.

[0024] Furthermore, the composite deoxidizer in step c) comprises, by weight percentage: 60%~80% rare earth elements, 5%~15% lithium oxide, 5%~15% apatite, and 5%~10% fluorite; wherein the rare earth elements are at least one of lanthanum and cerium.

[0025] Furthermore, the amount of composite deoxidizer added in step c) is 0.01% to 0.10% of the weight of copper liquid.

[0026] Furthermore, the amount of the composite deoxidizer added is 0.03% to 0.06% of the weight of the copper liquid.

[0027] Furthermore, the temperature for combined deoxygenation in step c) is 1150℃~1170℃, and the holding time is 10~20 minutes.

[0028] Understandably, in one embodiment, the method for preparing oxygen-free copper by continuous casting and rolling using rare earth combined deoxidation according to the present invention includes the following steps: a) Sorting and packaging the mixed copper to remove surface contaminants and inclusions; b) The copper scraps obtained in step a) are put into a smelting furnace and heated to above 1300℃ to melt. The furnace temperature is controlled at 1100-1250℃. Coke, quartz and lime are added in sequence for multi-stage oxidation refining to remove impurities such as zinc, lead, tin, arsenic and antimony. c) The copper liquid obtained in step b) is reduced using a reducing agent to control the oxygen content of the copper liquid to below 200 ppm; d) Add a composite deoxidizer to the copper liquid obtained in step c). The composite deoxidizer contains rare earth elements and auxiliary deoxidizing components. The amount of rare earth added is 0.01%-0.10% of the weight of the copper liquid. The deoxidation temperature is 1150-1170℃, and the temperature is maintained for 10-20 minutes. The composition of the composite deoxidizer by weight percentage is: 60-80% rare earth elements (one or two of lanthanum and cerium), 5-15% lithium oxide, 5-15% apatite, and 5-10% fluorite. e) The copper liquid obtained in step d) is horizontally continuously cast under a protective atmosphere, and the billet is directly fed into a three-roll planetary mill for continuous rolling to obtain oxygen-free copper products.

[0029] Specifically, step b) involves multi-stage oxidative refining as follows: First-stage refining: Coke is added at a rate of 0.2% of the copper weight, and oxidation is carried out by forced air to mainly remove zinc. Secondary refining: Quartz is added at a rate of 0.15% of the copper weight, primarily to remove lead and tin; Third-stage refining: Lime is added at a rate of 0.10% of the copper weight to remove arsenic, antimony, and nickel.

[0030] Furthermore, the reducing agent in step c) is wood or natural gas, and the reduction method is either wood insertion reduction or natural gas injection reduction.

[0031] Furthermore, the amount of rare earth element added in step d) is preferably 0.03%-0.06%, and the oxygen content of the copper liquid is reduced to 15-20 ppm after rare earth deoxidation.

[0032] In a second aspect, the present invention provides a continuous casting and rolling production apparatus for the method described in any of the above, comprising a melting furnace, a runner, a horizontal continuous casting machine and a planetary rolling mill connected in sequence. The smelting furnace is equipped with a sealed cover and a protective atmosphere inlet, and a slightly positive pressure inert gas protective atmosphere is maintained inside the furnace. The connection between the smelting furnace and the flow channel is provided with an airlock rare earth feeding device, which is used to add rare earth to the copper liquid under air-isolated conditions. The flow channel is a closed structure, with the inner wall of the flow channel covered with a rare earth corrosion resistant lining material, and a rotating degassing device is installed inside, and a protective gas is introduced. The crystallizer of the horizontal continuous casting machine is a high-efficiency cooling crystallizer with a spiral distribution of cooling water channels and an effective length of 500-800 mm. The planetary mill is equipped with a sealing cover at its entrance, which is filled with a protective atmosphere to control the oxygen content to below 5%.

[0033] Furthermore, the airlock rare earth feeding device includes a feeding bin, an upper gate valve, a lower gate valve, and a feeding pipe. The end of the feeding pipe extends below the surface of the copper liquid, and the end of the feeding pipe extends 300-500mm below the surface of the copper liquid.

[0034] Furthermore, the lining material of the closed flow channel is magnesium aluminum spinel refractory or zirconium refractory; the cooling water channel of the crystallizer of the horizontal continuous casting machine is spirally distributed, and the effective length of the crystallizer is 500~800mm.

[0035] Furthermore, the planetary mill sealing cover is equipped with an oxygen content sensor, which is interlocked with the protective gas flow control system.

[0036] Thirdly, the present invention provides an oxygen-free copper product prepared by any of the methods described above, wherein the oxygen content of the oxygen-free copper product is ≤20ppm and the conductivity is ≥100% IACS.

[0037] The present invention will now be described in further detail with reference to specific embodiments: Example 1:

[0038] (1) Select 1 ton of waste copper, sort it to remove impurities such as plastic and rubber, and pack it for later use.

[0039] (2) The pretreated copper scraps are put into the smelting furnace and heated to above 1300℃ to melt. The furnace temperature is controlled at 1150-1200℃, and three-stage oxidation refining is carried out in sequence: 2kg of coke is added and oxidized by blowing air for 45 minutes, and the slag is removed; 1.5kg of quartz is added and oxidized by blowing air, and the slag is removed; 1kg of lime is added and oxidized by blowing air, and the slag is removed.

[0040] (3) The copper liquid after oxidation and refining was reduced by inserting wood. 50 kg of wood was used and inserted in 3 times to obtain pure copper.

[0041] (4) Add 1 kg of composite deoxidizer (0.1% of the weight of copper liquid) to the reduced copper liquid, including 0.7 kg of rare earth (lanthanum-cerium mixed rare earth), 0.1 kg of lithium oxide, 0.1 kg of apatite and 0.1 kg of fluorite. The deoxidation temperature is 1160℃ and the temperature is maintained for 15 minutes.

[0042] (5) The deoxidized copper liquid enters the horizontal continuous casting machine through the trough under nitrogen protection. The cross section of the billet is trapezoidal (top bottom 80mm, bottom bottom 100mm, height 80mm), and the casting speed is 400mm / min. The billet directly enters the three-roll planetary rolling mill and is rolled into Φ8mm copper rods at a rolling temperature of 800℃ and a rolling speed of 20m / min.

[0043] Testing revealed that the copper rod prepared in this embodiment has an oxygen content of 15 ppm, a conductivity of 101% IACS, a tensile strength of 260 MPa, and an elongation of 38%, meeting the requirements of the national standard TU2 oxygen-free copper rod. Example 2:

[0044] (1) Select 1 ton of waste copper, sort it to remove impurities such as plastic and rubber, and pack it for later use.

[0045] (2) The pretreated copper scraps are put into the smelting furnace and heated to above 1300℃ to melt. The furnace temperature is controlled at 1150-1200℃, and three-stage oxidation refining is carried out in sequence: 2kg of coke is added and oxidized by blowing air for 45 minutes, and the slag is removed; 1.5kg of quartz is added and oxidized by blowing air, and the slag is removed; 1kg of lime is added and oxidized by blowing air, and the slag is removed.

[0046] (3) The copper liquid after oxidation and refining was reduced by inserting wood. 50 kg of wood was used and inserted in 3 times to obtain pure copper.

[0047] (4) Add 0.5 kg of composite deoxidizer (0.05% of the weight of copper liquid) to the reduced copper liquid, including 0.7 kg of rare earth (lanthanum-cerium mixed rare earth), 0.1 kg of lithium oxide, 0.1 kg of apatite and 0.1 kg of fluorite. The deoxidation temperature is 1160℃ and the temperature is maintained for 15 minutes.

[0048] (5) The deoxidized copper liquid enters the horizontal continuous casting machine through the trough under nitrogen protection. The cross section of the billet is trapezoidal (top bottom 80mm, bottom bottom 100mm, height 80mm), and the casting speed is 400mm / min. The billet directly enters the three-roll planetary rolling mill and is rolled into Φ8mm copper rods at a rolling temperature of 800℃ and a rolling speed of 20m / min.

[0049] Testing revealed that the copper rod prepared in this embodiment has an oxygen content of 18 ppm, a conductivity of 100.5% IACS, a tensile strength of 245 MPa, and an elongation of 36%, meeting the requirements of the national standard TU2 oxygen-free copper rod.

[0050] Comparative Example 1: No rare earth composite deoxidizer was added in this comparative example; only wood insertion reduction was used.

[0051] (1) Select 1 ton of waste copper, sort it to remove impurities such as plastic and rubber, and pack it for later use.

[0052] (2) The pretreated copper scraps are put into the smelting furnace and heated to above 1300℃ to melt. The furnace temperature is controlled at 1150-1200℃, and three-stage oxidation refining is carried out in sequence: 2kg of coke is added and oxidized by blowing air for 45 minutes, and the slag is removed; 1.5kg of quartz is added and oxidized by blowing air, and the slag is removed; 1kg of lime is added and oxidized by blowing air, and the slag is removed.

[0053] (3) The copper liquid after oxidation and refining was reduced by inserting wood. 50 kg of wood was used and inserted in 3 times to obtain pure copper.

[0054] (4) Add 0.5 kg of composite deoxidizer (0.05% of the weight of copper liquid) to the reduced copper liquid, including 0.1 kg of lithium oxide, 0.1 kg of apatite and 0.1 kg of fluorite. The deoxidation temperature is 1160℃ and the temperature is maintained for 15 minutes.

[0055] (5) The deoxidized copper liquid enters the horizontal continuous casting machine through the trough under nitrogen protection. The cross section of the billet is trapezoidal (top bottom 80mm, bottom bottom 100mm, height 80mm), and the casting speed is 400mm / min. The billet directly enters the three-roll planetary rolling mill and is rolled into Φ8mm copper rods at a rolling temperature of 800℃ and a rolling speed of 20m / min.

[0056] Testing revealed that the copper rod prepared in this embodiment contained 210 ppm of oxygen, which did not meet the standard for oxygen-free copper.

[0057] Comparative Example 2: This comparative example uses the traditional upward continuous casting process to produce oxygen-free copper rods from cathode copper. (1) Put the cathode copper into the smelting furnace and heat it to above 1300℃ to melt it. The furnace temperature is controlled at 1150-1200℃, and three-stage oxidation refining is carried out in sequence: add 2kg of coke and oxidize by blowing air for 45 minutes, and remove the slag; add 1.5kg of quartz and oxidize by blowing air, and remove the slag; add 1kg of lime and oxidize by blowing air, and remove the slag.

[0058] (2) The copper liquid after oxidation and refining was reduced by inserting wood. 50 kg of wood was used and inserted in 3 times to obtain pure copper.

[0059] (3) Add 0.5 kg of composite deoxidizer (0.05% of the weight of copper liquid) to the reduced copper liquid, including 0.1 kg of lithium oxide, 0.1 kg of apatite and 0.1 kg of fluorite. The deoxidation temperature is 1160℃ and the temperature is maintained for 15 minutes.

[0060] (4) The deoxidized copper liquid flows into the upward continuous casting process under nitrogen protection. The cross section of the billet is trapezoidal (upper bottom 80mm, lower bottom 100mm, height 80mm), and the casting speed is 400mm / min. The billet directly enters the three-roll planetary rolling mill and is rolled into Φ8mm copper rods at a rolling temperature of 800℃ and a rolling speed of 20m / min.

[0061] Testing revealed that the copper rod prepared in this embodiment had an oxygen content of 12 ppm, meeting the national standard TU2 oxygen-free copper rod requirements. However, the production efficiency was only 40% of that in Example 1, and the raw material cost was 25% higher.

[0062] The following is in conjunction with the appendix Figure 1-6 The continuous casting and rolling production apparatus used in this invention will be described in detail as follows: like Figure 1 As shown, the overall structure of the continuous casting and rolling equipment for producing oxygen-free copper is as follows: the outlet of the smelting furnace 28 is connected to the air-lock rare earth feeding device 29 via the casting nozzle 7; the outlet of the air-lock rare earth feeding device 29 is connected to the inlet of the flow channel 30; the outlet of the flow channel 30 is connected to the inlet of the horizontal continuous casting machine 31; and the outlet of the horizontal continuous casting machine 31 is connected to the inlet of the planetary rolling mill 32, forming a fully continuous production line from smelting to rolling. Each connection is equipped with a sealing structure to ensure that the entire production process is carried out under an inert atmosphere.

[0063] like Figure 2 As shown, the smelting furnace 28 includes a furnace shell 1. A sealing cover (not shown) is provided on the top of the furnace shell 1 to seal the furnace and effectively prevent outside air from entering the furnace chamber. A vacuum pump interface 3 is provided on the furnace shell 1 for connecting a vacuum pump to evacuate the furnace chamber or control the atmosphere inside the furnace. A heating coil 4 is located inside the furnace shell 1, surrounding a graphite crucible 5, for heating and melting the copper material inside the graphite crucible 5. The graphite crucible 5 is located in the center of the furnace shell 1 and is used to hold the copper material and molten copper. A stirring paddle 6 is located above the graphite crucible 5, with its blades extending into the molten copper inside the graphite crucible 5 to stir the molten copper during refining and deoxidation processes, promoting uniform reaction. A casting nozzle 7 is located at the bottom of the furnace shell 1, connected to the outlet of the graphite crucible 5, through which the molten copper flows into subsequent processes. The furnace shell 1 is also provided with a protective atmosphere inlet (not shown in the figure) for introducing inert protective gas (such as nitrogen or argon) into the furnace to maintain a slightly positive pressure inert gas protective atmosphere in the furnace.

[0064] like Figure 3As shown, the air-lock type rare earth feeding device 29 is located at the connection between the smelting furnace 28 and the flow channel 30. The air-lock type rare earth feeding device 29 includes a storage hopper 8, a screw feeder 9, a rotary air-lock valve 10, and a feeding port 13. The storage hopper 8 is located at the top of the device and is used to store rare earth composite deoxidizer. The lower end of the storage hopper 8 is connected to the screw feeder 9, which is horizontally positioned to quantitatively and continuously convey the deoxidizer from the storage hopper 8 downwards. The discharge end of the screw feeder 9 is connected to the rotary air-lock valve 10, which is located between the screw feeder 9 and the feeding port 13. The intermittent rotation of the valve core achieves quantitative addition of the deoxidizer, while the sealing fit between the valve core and the valve body effectively isolates external air during the feeding process, preventing air from entering the smelting furnace and flow channel system. The feed port 13 is located at the bottom of the device, with its end extending 300-500 mm below the surface of the copper liquid in the flow channel 30, ensuring that the rare earth deoxidizer is directly injected into the copper liquid and avoids contact with air. The device is also equipped with a nitrogen / argon inlet 11 and a nitrogen / argon outlet 12 for introducing and discharging protective gases into the device to maintain an inert atmosphere inside the device.

[0065] like Figure 4 As shown, the casting trough 30 is connected between the casting nozzle 7 of the melting furnace 28 and the horizontal continuous casting machine 31. The casting trough 30 is a closed structure, covered with a heating and insulation layer 14. The heating and insulation layer 14 is arranged along the length of the casting trough to keep the copper liquid in the casting trough warm and compensate for temperature, preventing the copper liquid from cooling down during transportation. The top of the casting trough 30 is equipped with an insulation cover plate 15, which can be opened for easy cleaning and maintenance of the inside of the casting trough. One end of the casting trough 30 is connected to the casting nozzle 7 of the melting furnace 28, and the other end is connected to the horizontal continuous casting machine 16. The inner wall of the casting trough 30 is covered with a rare earth corrosion resistant lining material. The lining material is a magnesium aluminum spinel or zirconium refractory material, which can resist the corrosion of refractory materials by rare earth elements and extend the service life of the casting trough. The casting trough 30 is equipped with a rotary degassing device (not shown in the figure) for rotary degassing treatment of the copper liquid, further reducing the gas content in the copper liquid. The flow channel 30 is also provided with a protective gas inlet for introducing protective gas into the flow channel to maintain an inert atmosphere inside the flow channel. Understandably, in one embodiment, the outer surface of the flow channel 30 is provided with a fabrication cover plate 152, in which case the heat insulation cover plate 15 is located on top of the fabrication cover plate 152.

[0066] like Figure 5As shown, the horizontal continuous casting machine 31 is connected to the outlet end of the flow channel 30. The horizontal continuous casting machine 31 includes a crystallizer 17, a cooling water jacket 18, a cooling water inlet 19, a cooling water outlet 20, and a traction roller 21. The crystallizer 17 is a high-efficiency cooling crystallizer, located at the inlet end of the horizontal continuous casting machine 31. The molten copper flows into the crystallizer 17 from the flow channel 30 for cooling and solidification. The cooling water jacket 18 is fitted around the outer wall of the crystallizer 17. The cooling water jacket 18 has a cooling water inlet 19 and a cooling water outlet 20. Cooling water enters the cooling water jacket 18 through the cooling water inlet 19, flows through the outer wall of the crystallizer 17, and exits through the cooling water outlet 20, thus forcibly cooling the molten copper inside the crystallizer 17. The cooling water channels of the crystallizer 17 are spirally distributed, and the cooling water flows in the spiral direction, improving cooling efficiency and uniformity. The effective length of the crystallizer 17 is 500-800 mm. The traction roller 21 is located at the discharge end of the crystallizer 17 and is used to continuously pull the solidified billet out of the crystallizer 17.

[0067] like Figure 6 As shown, the planetary mill 32 is located at the discharge end of the horizontal continuous casting machine 31. The planetary mill 32 is a three-roll planetary mill, including work rolls 22, a roll stand 23, a transmission gearbox 24, a drive motor 25, an adjusting frame 26, and a finished product outlet 27. The roll stand 23 is the main support structure of the planetary mill 32. The work rolls 22 are installed inside the roll stand 23. There are three work rolls 22, arranged in a planetary pattern, evenly distributed around the circumference of the cast billet, performing multi-directional synchronous rolling on the billet. The drive motor 25 is located on one side of the roll stand 23 and is connected to the work rolls 22 via the transmission gearbox 24, providing rolling power to the work rolls 22. The transmission gearbox 24 is located between the drive motor 25 and the roll stand 23. The adjusting frame 26 is located at the discharge end of the roll stand 23 and is used to adjust the process parameters during the rolling process. Finished product outlet 27 is located at the discharge end of adjusting frame 26, and the rolled oxygen-free copper product is output from finished product outlet 27. A sealing hood (not shown in the figure) is installed at the inlet of planetary mill 32. The sealing hood is filled with a protective atmosphere to control the oxygen content below 5%. An oxygen content sensor is installed inside the sealing hood, interlocked with the protective gas flow control system. When the oxygen content exceeds the limit, the protective gas flow rate is automatically increased.

[0068] This invention relates to a method, product, and apparatus for preparing oxygen-free copper using rare-earth combined deoxidation through continuous casting and rolling. By organically integrating rare-earth deep deoxidation technology with continuous casting and rolling processes, and combining systematic improvements to equipment oxidation prevention, it achieves efficient production of oxygen-free copper products with an oxygen content ≤20ppm from scrap copper as raw material. Specifically, it includes: (1) For the first time, the rare earth deep deoxidation technology was integrated with the continuous casting and rolling process system, breaking the technical prejudice that "continuous casting and rolling can only produce low oxygen copper rods" and realizing the efficient short-process production of oxygen-free copper; (2) Rare earth combined deoxidation can reduce the oxygen content of copper liquid to 15-20ppm, which meets or even exceeds the national standard TU2 grade oxygen-free copper requirements (≤20ppm); at the same time, the residual trace rare earth can refine the grains and improve the ductility and tensile strength of the material. (3) This invention can directly use mixed copper as raw material, without relying on high-purity cathode copper, and the raw material cost is reduced by 20-30% compared with the traditional continuous casting process; (4) The continuous production method of continuous casting and rolling increases production efficiency by more than 50% and reduces equipment investment compared with the traditional route of upward continuous casting + subsequent processing. (5) The systematic equipment anti-oxidation design ensures oxygen content control throughout the entire process from smelting to rolling, resulting in stable and reliable product quality.

[0069] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention in any other way. Any person skilled in the art may make changes or equivalent variations to the disclosed technical content and apply them to other fields. However, any simple modifications, equivalent variations, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the protection scope of the present invention. For those skilled in the art, the specific meaning of the above terms in the present invention can be understood through specific circumstances.

Claims

1. A method for preparing oxygen-free copper by continuous casting and rolling using rare earth combined deoxidation, characterized in that, Includes the following steps: a) The raw copper scraps are melted and then refined by oxidation; b) The copper liquid obtained in step a) is subjected to reduction refining; c) Add a rare earth-containing composite deoxidizer to the copper liquid obtained in step b) for combined deoxidation; d) The copper liquid obtained in step c) is continuously cast and rolled under a protective atmosphere to obtain oxygen-free copper products.

2. The method according to claim 1, characterized in that: The oxidative refining described in step a) is a multi-stage oxidative refining process, which includes coke refining, quartz refining, and lime refining in sequence.

3. The method according to claim 1, characterized in that: Step c) The composite deoxidizer comprises, by weight percentage: 60%~80% rare earth elements, 5%~15% lithium oxide, 5%~15% apatite, and 5%~10% fluorite; the rare earth elements are at least one of lanthanum and cerium.

4. The method according to claim 1, characterized in that: The amount of composite deoxidizer added in step c) is 0.01% to 0.10% of the weight of copper liquid.

5. The method according to claim 4, characterized in that: The amount of the composite deoxidizer added is 0.03% to 0.06% of the weight of the copper liquid.

6. The method according to claim 1, characterized in that: The temperature for combined deoxygenation in step c) is 1150℃~1170℃, and the holding time is 10~20 minutes.

7. A continuous casting and rolling production apparatus for the method described in any one of claims 1 to 6, characterized in that, This includes a smelting furnace, a runner, a horizontal continuous casting machine, and a planetary rolling mill connected in sequence; The smelting furnace is equipped with a sealed cover and a protective atmosphere inlet; The connection between the smelting furnace and the flow channel is equipped with an airlock-type rare earth feeding device. The flow channel is a closed structure and is equipped with a rotating degassing device inside; The planetary mill is equipped with a sealing cover at its entrance.

8. The apparatus according to claim 7, characterized in that: The airlock rare earth feeding device includes a feeding bin, an upper gate valve, a lower gate valve, and a feeding pipe, the end of which extends below the surface of the copper liquid.

9. The apparatus according to claim 7, characterized in that: The lining material of the closed flow channel is magnesium aluminum spinel refractory or zirconium refractory; the cooling water channel of the crystallizer of the horizontal continuous casting machine is spirally distributed, and the effective length of the crystallizer is 500~800mm.

10. An oxygen-free copper product prepared by the method according to any one of claims 1 to 6, characterized in that: The oxygen-free copper product has an oxygen content of ≤20ppm and a conductivity of ≥100% IACS.

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