Method for removing high melting point oxygen-containing inclusions in high-conductivity pure copper

Abstract

The application provides a method for removing high-melting-point oxygen-containing inclusions in high-conductivity pure copper, and relates to the technical field of deep impurity removal of pure copper materials. The removal method comprises the following steps: placing a crucible containing high-conductivity pure copper raw materials into a heating furnace of an ultra-high gravity centrifugal device, heating to a complete melting temperature under an inert gas or a reducing protective atmosphere, and heat preservation and homogenization to obtain molten high-conductivity pure copper raw materials; starting a high-speed centrifugal device of the ultra-high gravity centrifugal device, and performing constant-temperature centrifugal treatment in an ultra-high gravity field for a short time to obtain treated high-conductivity pure copper raw material melt; stopping rotation, and cooling and solidifying the high-conductivity pure copper raw material melt at a controllable rate to obtain a copper ingot with uniform composition and extremely low inclusion content. The application does not require a complex vacuum system or long-time high-temperature heat preservation, is simple and easy to operate, has low cost, low energy consumption, high efficiency, and is conducive to the industrial large-scale production and promotion of ultra-high-purity and high-conductivity copper materials.

Description

Technical Field

[0001] This invention relates to the technical field of deep impurity removal from pure copper materials, and in particular to a method for removing high-melting-point oxygen-containing inclusions in highly conductive pure copper. This method is used to rapidly remove micron-sized high-melting-point oxygen-containing inclusions (mainly Cu2O) to prepare ultra-high purity, highly conductive oxygen-free copper materials. Background Technology

[0002] Pure copper is widely used in electrical, electronic, and rail transportation fields due to its excellent electrical conductivity. The conductivity of a material is closely related to its purity. Even in high-purity copper, trace amounts of inclusions such as cuprous oxide (Cu2O) can significantly increase electron scattering and reduce conductivity. More seriously, during subsequent heat treatment or service, these oxygen-containing inclusions can trigger "hydrogen embrittlement," leading to material brittleness and loss of vacuum sealing.

[0003] Currently, high-purity oxygen-free copper is mainly produced using vacuum melting or induction melting processes. While vacuum melting can achieve extremely low oxygen content (<5ppm), it involves complex equipment, high costs, and low production efficiency. Induction melting, on the other hand, requires prolonged preheating and drying of the raw materials, making the process cumbersome and limiting its capacity. Both methods rely on the natural floating of inclusions under normal gravity, resulting in low separation efficiency and requiring several hours of static holding, which not only consumes a lot of energy but also increases the risk of secondary oxidation of the melt.

[0004] Chinese patent CN110616338A discloses a method for removing impurities from copper melt and a method for preparing high-purity, high-conductivity copper. It employs a two-stage oxidation-reduction method to remove impurity elements from high-purity copper melt. In the oxidation stage, reducing impurities in the copper melt are removed by generating slag through oxidation. In the reduction stage, oxygen elements in the copper melt are removed using a reducing agent. This effectively reduces the content of impurity elements in high-purity, high-conductivity copper. However, this method clearly cannot deeply remove high-melting-point oxygen-containing inclusions from copper melt, as evidenced by the fact that the oxygen content of the impurity elements in the embodiments is not less than 5 ppm.

[0005] Chinese patent CN111961878A discloses a method for reducing high-melting-point impurity elements in scrap copper. The main processing technology includes scrap copper raw material dismantling-crushing-melting-impurity removal-casting treatment. The impurity removal process includes not only the dismantling-crushing steps, but also the addition of a mixture of slag remover and refining agent during the subsequent melting process. However, it cannot deeply remove high-melting-point oxygen-containing inclusions in the copper melt.

[0006] Chinese patent CN117587251A discloses a method for preparing high-purity oxygen-free copper, which requires adding two covering agents to cover the molten copper during the smelting process and bottom blowing inert gas to deoxidize and remove impurities. The operation is complicated, difficult, costly, and inefficient, and may introduce new impurities. The final product has an oxygen content of 3-5 ppm, which is obviously still relatively high, and the efficiency of deep removal is low.

[0007] Hypergravity technology is a process enhancement method that uses the centrifugal force field generated by rotation to simulate hypergravity, which can greatly enhance mass transfer and relative motion between multiphase systems. In recent years, this technology has shown significant advantages in materials preparation, chemical separation and other fields. However, its application in the purification of molten metals, especially for the rapid removal of micron-sized high-melting-point inclusions in highly conductive copper materials, has not yet been systematically studied or developed into a mature process.

[0008] Therefore, developing a high-efficiency, rapid, and deep purification process for copper melt is of great significance for breaking through the purity bottleneck of high-conductivity copper materials and improving their comprehensive performance. Summary of the Invention

[0009] The main objective of this invention is to address the technical problems of high energy consumption, unstable quality, and environmental unfriendliness in existing copper refining technologies, which involve complex production processes. Removing oxygen-containing inclusions through the addition of refining agents and slagging agents is costly and inefficient. Furthermore, the selection and addition of refining agents can lead to uneven impurity removal, potential side reactions, difficulty in control, and challenges in achieving deep removal, while also increasing the risk of secondary oxidation of the melt. Therefore, this invention proposes a method for removing high-melting-point oxygen-containing inclusions from highly conductive pure copper, which can solve the aforementioned problems.

[0010] The technical solution is as follows:

[0011] A method for removing high-melting-point oxygen-containing inclusions from highly conductive pure copper, comprising the following steps:

[0012] S1. Heating and melting: Place the high-conductivity pure copper raw material in a crucible, then place the crucible containing the high-conductivity pure copper raw material into the heating furnace of the centrifugal device, and heat it to the temperature of complete melting under an inert gas or reducing protective atmosphere and keep it at the temperature to obtain molten high-conductivity pure copper raw material.

[0013] S2, Hypergravity field isothermal treatment: Start the high-speed centrifuge device of the hypergravity centrifuge equipment to make the molten high-conductivity pure copper raw material in S1 undergo short-term isothermal centrifugation treatment in the hypergravity field formed by the high-speed centrifuge device to obtain the treated high-conductivity pure copper raw material melt.

[0014] S3. Cooling and solidification control: After the isothermal treatment in the hypergravity field is completed, the rotation is stopped, and the highly conductive pure copper raw material melt treated in S2 is cooled and solidified at a controllable rate to obtain a copper ingot with uniform composition and extremely low inclusion content.

[0015] Optionally, the highly conductive pure copper raw material in S1 is oxygen-free copper, and its oxygen-containing inclusions include Cu2O, Cu2S, and CuS; the crucible is a high-purity graphite crucible.

[0016] Optionally, the O content of the copper raw material in S1 is 5-35 ppm.

[0017] Optionally, the heating rate in S1 is 7℃ / min, the temperature at which complete melting occurs is 1100-1150℃, and the holding time is 20-60min.

[0018] Optionally, the gravity coefficient of the hypergravity field formed by the high-speed centrifuge device in S2 is 500-1000, and the centrifugation time is 30-60s.

[0019] Optionally, the top 3-8 mm thickness of the high-conductivity pure copper raw material melt after treatment in S2 is enriched with inclusions that account for more than 80% of the mass of the high-conductivity pure copper raw material.

[0020] Optionally, the controllable rate of cooling and solidification in S3 is 5-15℃ / min.

[0021] Optionally, S4, detection of removal method: samples are taken from different positions along the axis of copper ingots with uniform composition and extremely low inclusion content for oxygen content analysis. The oxygen content is uniformly reduced to 2.5±0.2ppm. The average oxygen removal rate of the highly conductive pure copper raw material is calculated, and the conductivity is tested.

[0022] Optionally, the average oxygen removal rate of the high-conductivity pure copper raw material in S4 is over 80%, and the conductivity is increased to 106.92% IACS.

[0023] Technical principle of the invention:

[0024] The implementation of the method described in this invention relies on a dedicated centrifugal melting device with high gravity. This device integrates a sealed melting chamber, an induction heating system, a high-speed centrifuge with precise speed control, a high-precision temperature control system, and a vacuum / inert gas protection system. In practice, highly conductive pure copper raw material is first placed in a high-purity crucible, and after loading into the device, the chamber is filled with a high-purity inert gas (such as argon). Then, under a protective atmosphere, the copper material is heated to complete melting (typically above 1085°C) and kept at that temperature for homogenization. After the melt temperature stabilizes, the centrifuge is started to quickly reach the predetermined speed, applying a high-gravity field of 500 to 1000 times the acceleration due to gravity (G) to the melt. The melt is centrifuged at a constant temperature for 30 to 60 seconds, utilizing the strong volume force driven by high gravity to rapidly migrate and enrich inclusions such as cuprous oxide (Cu₂O) with lower density towards the axis of rotation. After centrifugation, rotation is immediately stopped, and the melt is cooled and solidified at a controllable rate (e.g., 5-15°C / min), ultimately obtaining a purified copper ingot. By precisely controlling the two core process parameters, gravity coefficient (G value) and centrifugation time, the degree of purification of copper melt and the final material properties can be effectively controlled.

[0025] The above technical solution has at least the following advantages compared with the existing technology:

[0026] The above-mentioned solution, proposed by this invention, is a method for removing high-melting-point oxygen-containing inclusions in highly conductive pure copper. It can solve the technical problems of high energy consumption, unstable quality, and environmental unfriendliness in the complex production process of existing copper refining technology. The removal of oxygen-containing inclusions by adding refining agents and slagging agents has technical problems of high cost and low efficiency. In addition, the selection and addition of refining agents can cause uneven removal of impurities, possible side reactions, difficulty in control, and difficulty in deep removal. Moreover, it increases the risk of secondary oxidation of the melt.

[0027] The method of this invention, through heating and melting and holding at a constant temperature, enables the metallic copper in pure copper materials to melt while the oxide impurities remain in the solid phase.

[0028] This invention utilizes a hypergravity field constant temperature treatment, which greatly enhances the Stokes motion speed of inclusions, shortening the separation process that takes several hours in traditional processes to tens of seconds. The oxygen removal rate can reach up to 92.1%, resulting in a revolutionary improvement in production efficiency. It can achieve deep purification, reducing the oxygen content in oxygen-free copper from 31.37 ppm to below 2.70 ppm, reaching an ultra-high purity level. It also deeply removes oxide inclusions that act as electron scattering centers, increasing the material's conductivity to over 106.92% IACS, significantly optimizing its conductivity.

[0029] This invention precisely controls the degree of purification and the oxygen content distribution of the final product by adjusting two core parameters: gravity coefficient and centrifugation time, thereby achieving flexible control and balance between high conductivity and necessary mechanical strength.

[0030] The method of the present invention, through cooling and solidification control, can increase grain size and reduce grain boundaries, thereby improving conductivity.

[0031] The entire process of this invention does not require a complex vacuum system or long-term high-temperature insulation, and has outstanding advantages such as short process, high efficiency, low energy consumption and controllable cost, providing an innovative solution for the large-scale production of ultra-high purity and high conductivity copper materials.

[0032] In summary, compared with traditional methods, the method of this invention removes high-melting-point oxygen-containing inclusions from highly conductive pure copper at low cost and high efficiency by heating and melting, heat preservation and homogenization, constant temperature treatment in a hypergravity field, and cooling and solidification control. This method does not require a complex vacuum system or long-term high-temperature heat preservation, is simple to operate, low in cost, low in energy consumption, and high in efficiency, which is conducive to the large-scale industrial production and promotion of ultra-high purity and highly conductive copper materials. Attached Figure Description

[0033] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0034] Figure 1 This is a schematic diagram of a method for removing high-melting-point oxygen-containing inclusions from highly conductive pure copper according to the present invention;

[0035] Figure 2 These are scanning electron microscope (SEM) images of cuprous oxide inclusions in highly conductive pure copper raw materials, as described in Embodiment 1 of the present invention, in a method for removing high-melting-point oxygen-containing inclusions in highly conductive pure copper. Figure (a) is an SEM image of pear-shaped cuprous oxide inclusions; Figure (b) is an EDS surface scan of copper in pear-shaped cuprous oxide inclusions; Figure (c) is an EDS surface scan of oxygen in pear-shaped cuprous oxide inclusions; Figure (d) is an SEM image of elliptical cuprous oxide inclusions; Figure (e) is an EDS surface scan of copper in elliptical cuprous oxide inclusions; and Figure (f) is an EDS surface scan of oxygen in elliptical cuprous oxide inclusions.

[0036] Figure 3This is a line graph showing the changes in oxygen content and oxygen removal rate in oxygen-free copper under different gravity coefficients (G) in a method for removing high-melting-point oxygen-containing inclusions in highly conductive pure copper according to Embodiment 2 of the present invention. The red inverted triangles mark the oxygen content, and the blue equilateral triangles mark the oxygen removal rate.

[0037] Figure 4 Figure 2 is a line graph showing the effect of different gravity coefficients (G) on the conductivity and ultimate tensile strength of oxygen-free copper in a method for removing high-melting-point oxygen-containing inclusions in highly conductive pure copper according to Embodiment 2 of the present invention. Figure (a) is a line graph of conductivity (red inverted triangle) and ultimate tensile strength (blue equilateral triangle), and Figure (b) is a stress-strain curve.

[0038] Figure 5 This is a graph showing the purification results of oxygen-free copper under different centrifugation times at a fixed gravity coefficient (G=1000) in a method for removing high-melting-point oxygen-containing inclusions from highly conductive pure copper according to Embodiment 3 of the present invention. Detailed Implementation

[0039] The technical solution of the present invention will now be described with reference to the accompanying drawings.

[0040] In embodiments of the present invention, words such as "exemplarily," "for example," etc., are used to indicate that something is an example, illustration, or description. Any embodiment or design described as "exemplary" in the present invention should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of the word "exemplary" is intended to present the concept in a concrete manner. Furthermore, in embodiments of the present invention, the meaning expressed by "and / or" can be both, or either one.

[0041] In the embodiments of the present invention, the terms "image" and "picture" may sometimes be used interchangeably. It should be noted that when the distinction is not emphasized, their intended meanings are consistent.

[0042] In this embodiment of the invention, sometimes a subscript such as W1 may be written in a non-subscript form such as W1. When the difference is not emphasized, the meaning they express is the same.

[0043] To make the technical problems, technical solutions and advantages of the present invention clearer, a detailed description will be given below in conjunction with the accompanying drawings and specific embodiments.

[0044] A method for removing high-melting-point oxygen-containing inclusions from highly conductive pure copper, wherein the method for removing high-melting-point oxygen-containing inclusions from highly conductive pure copper is combined with Figure 1 Includes the following steps:

[0045] S1. Heating and melting: Place the high-conductivity pure copper raw material in a crucible; then place the crucible containing the high-conductivity pure copper raw material into the heating furnace of the centrifugal device; heat to the temperature of complete melting under an inert gas or reducing protective atmosphere and keep it at the temperature to obtain molten high-conductivity pure copper raw material;

[0046] S2, Hypergravity field isothermal treatment: Start the high-speed centrifuge device of the hypergravity centrifuge equipment to make the molten high-conductivity pure copper raw material in S1 undergo short-term isothermal centrifugation treatment in the hypergravity field formed by the high-speed centrifuge device to obtain the treated high-conductivity pure copper raw material melt.

[0047] S3. Cooling and solidification control: After the isothermal treatment in the hypergravity field is completed, the rotation is stopped, and the highly conductive pure copper raw material melt treated in S2 is cooled and solidified at a controllable rate to obtain a copper ingot with uniform composition and extremely low inclusion content.

[0048] Specifically, the high-conductivity pure copper raw material in S1 is oxygen-free copper, and its oxygen-containing inclusions include Cu2O, Cu2S, and CuS; the crucible is a high-purity graphite crucible.

[0049] Optionally, the O content of the copper raw material in S1 is 5-35 ppm.

[0050] Optionally, the highly conductive pure copper raw material in S1 is oxygen-free copper, and its oxygen-containing inclusions include Cu2O, Cu2S, and CuS; the crucible is a high-purity graphite crucible.

[0051] Optionally, the heating rate in S1 is 7℃ / min, the temperature at which complete melting occurs is 1100-1150℃, and the holding time is 20-60min.

[0052] Optionally, the gravity coefficient of the hypergravity field formed by the high-speed centrifuge device in S2 is 500-1000, and the centrifugation time is 30-60s.

[0053] Optionally, the top 3-8 mm thickness of the high-conductivity pure copper raw material melt after treatment in S2 is enriched with inclusions that account for more than 80% of the mass of the high-conductivity pure copper raw material.

[0054] Optionally, the controllable rate of cooling and solidification in S3 is 5-15℃ / min.

[0055] Optionally, S4, detection of removal method: samples are taken from different positions along the axis of copper ingots with uniform composition and extremely low inclusion content for oxygen content analysis. The oxygen content is uniformly reduced to 2.5±0.2ppm. The average oxygen removal rate of the highly conductive pure copper raw material is calculated, and the conductivity is tested.

[0056] Optionally, the average oxygen removal rate of the high-conductivity pure copper raw material in S4 is over 80%, and the conductivity is increased to 106.92% IACS.

[0057] Example 1

[0058] This embodiment describes a method for removing high-melting-point oxygen-containing inclusions from highly conductive pure copper. The high-conductivity pure copper raw material is 500g of national standard TU2 oxygen-free copper rod. The method for removing high-melting-point oxygen-containing inclusions from highly conductive pure copper includes the following steps:

[0059] S1. Heating and Melting: Place the highly conductive pure copper raw material in a high-purity graphite crucible; then place the high-purity graphite crucible containing the highly conductive pure copper raw material into the heating furnace of a centrifuge with ultragravity, and evacuate to 10°C. -2 After Pa, high-purity argon gas is introduced; the furnace temperature is heated to 1150℃ and held for 30 minutes, with a heating rate of 7℃ / min, to ensure that the copper material is completely melted and the temperature is uniform, thus obtaining molten, highly conductive pure copper raw material;

[0060] like Figure 2 As shown, from Figure 2 The SEM and EDS surface scans show that the copper oxide inclusions in the molten copper are copper oxides, which have obvious sharp edges, indicating that they have not been melted.

[0061] S2. Hypergravity field isothermal treatment: Under constant temperature of 1150℃ and argon protection, the high-speed centrifuge device of the hypergravity centrifuge is started, so that the molten high-conductivity pure copper raw material in S1 undergoes short-term isothermal centrifugation treatment in the hypergravity field formed by the high-speed centrifuge device; the centrifugation time of the isothermal centrifugation treatment is 60s, the gravity coefficient is 1000, and the treated high-conductivity pure copper raw material melt is obtained.

[0062] The top 3mm thickness of the processed high-conductivity pure copper raw material melt contains inclusions that account for 92.34% of the mass of the high-conductivity pure copper raw material.

[0063] S3. Cooling and solidification control: After the isothermal treatment in the hypergravity field is completed, the rotation is stopped, and the highly conductive pure copper raw material melt treated in S2 is cooled and solidified at a controllable rate of 10℃ / min to obtain a copper ingot with uniform composition and extremely low inclusion content.

[0064] S4. Detection of removal method: Samples were taken from different axial positions (5mm, 15mm, 25mm from the bottom) of copper ingots with uniform composition and extremely low inclusion content for oxygen content analysis. The oxygen content was uniformly reduced to 2.47-2.50ppm. The average oxygen removal rate of the highly conductive pure copper raw material was calculated, and the conductivity was tested.

[0065] In this embodiment, the average oxygen removal rate of the highly conductive pure copper raw material is 92.1%, and the conductivity is 106.92% IACS.

[0066] Example 2

[0067] This embodiment describes a method for removing high-melting-point oxygen-containing inclusions from highly conductive pure copper. The high-conductivity pure copper raw material is 500g of national standard TU2 oxygen-free copper rod. The method for removing high-melting-point oxygen-containing inclusions from highly conductive pure copper includes the following steps:

[0068] S1. Heating and Melting: Place the highly conductive pure copper raw material in a high-purity graphite crucible; then place the high-purity graphite crucible containing the highly conductive pure copper raw material into the heating furnace of a centrifuge with ultragravity, and evacuate to 10°C. -2 After Pa, high-purity argon gas is introduced; the furnace temperature is heated to 1150℃ and held for 30 minutes, with a heating rate of 7℃ / min, to ensure that the copper material is completely melted and the temperature is uniform, thus obtaining molten, highly conductive pure copper raw material;

[0069] S2. Hypergravity field isothermal treatment: Under constant temperature of 1150℃ and argon protection, the high-speed centrifuge device of the hypergravity centrifuge is started, so that the molten high-conductivity pure copper raw material in S1 undergoes short-term isothermal centrifugation treatment in the hypergravity field formed by the high-speed centrifuge device. The centrifugation time of the isothermal centrifugation treatment is 60s, and the gravity coefficient is 100, 300, 500, 800, 1000, to obtain the treated high-conductivity pure copper raw material melt.

[0070] S3. Cooling and solidification control: After the isothermal treatment in the hypergravity field is completed, the rotation is stopped, and the highly conductive pure copper raw material melt treated in S2 is cooled and solidified at a controllable rate of 10℃ / min to obtain a copper ingot with uniform composition and extremely low inclusion content.

[0071] The inclusion content of the copper ingots prepared in this embodiment, which have uniform composition and extremely low inclusion content, is 12.38ppm, 9.63ppm, 5.15ppm, 5.04ppm, and 2.47ppm respectively when the gravity coefficient is 100, 300, 500, 800, and 1000.

[0072] S4. Detection of removal method: Samples were taken from different positions (5mm from the bottom) along the axis of copper ingots with uniform composition and extremely low inclusion content for oxygen content analysis. The average oxygen removal rate of the highly conductive pure copper raw material was calculated, and the conductivity was tested.

[0073] like Figure 3 As shown, with a gravity coefficient of 1, a centrifugation time of 0s, and other conditions remaining unchanged, the O content of the high conductivity pure copper raw material in this embodiment is 31.37ppm, the oxygen removal rate is 0%, the conductivity is 103.23%IACS, and the ultimate tensile strength is 123.8MPa.

[0074] like Figure 3 and Figure 4As shown, when the gravity coefficient is 100, 300, 500, 800, and 1000, the oxygen removal rates of the high-conductivity pure copper raw material in this embodiment are 57.7%, 69.3%, 83.6%, 87.1%, and 92.1%, respectively, with corresponding conductivity of 105.12% IACS, 105.95% IACS, 106.18% IACS, 106.50% IACS, and 106.92% IACS, and corresponding ultimate tensile strengths of 118.9 MPa, 116.5 MPa, 114.1 MPa, 113.9 MPa, and 112.2 MPa.

[0075] This embodiment demonstrates that increasing the gravity coefficient is the most effective way to improve purification efficiency and depth, and a gravity coefficient exceeding 500 can effectively remove high-melting-point oxygen-containing inclusions. Simultaneously, as the oxygen content decreases, the material's conductivity monotonically increases, while the ultimate tensile strength slightly decreases due to weakened dispersion strengthening, achieving controllable performance adjustment.

[0076] Example 3

[0077] This embodiment describes a method for removing high-melting-point oxygen-containing inclusions from highly conductive pure copper. The high-conductivity pure copper raw material is 500g of national standard TU2 oxygen-free copper rod. The method for removing high-melting-point oxygen-containing inclusions from highly conductive pure copper includes the following steps:

[0078] S1. Heating and Melting: Place the highly conductive pure copper raw material in a high-purity graphite crucible; then place the high-purity graphite crucible containing the highly conductive pure copper raw material into the heating furnace of a centrifuge with ultragravity, and evacuate to 10°C. -2 After Pa, high-purity argon gas is introduced; the furnace temperature is heated to 1150℃ and held for 30 minutes, with a heating rate of 7℃ / min, to ensure that the copper material is completely melted and the temperature is uniform, thus obtaining molten, highly conductive pure copper raw material;

[0079] S2. Hypergravity field isothermal treatment: Under constant temperature of 1150℃ and argon protection, the high-speed centrifuge device of the hypergravity centrifuge is started, so that the molten high-conductivity pure copper raw material in S1 undergoes short-term isothermal centrifugation treatment in the hypergravity field formed by the high-speed centrifuge device. The centrifugation time in the isothermal centrifugation treatment is 10s, 30s, and 60s, and the gravity coefficient is 1000, so as to obtain the treated high-conductivity pure copper raw material melt.

[0080] S3. Cooling and solidification control: After the isothermal treatment in the hypergravity field is completed, the rotation is stopped, and the highly conductive pure copper raw material melt treated in S2 is cooled and solidified at a controllable rate of 10℃ / min to obtain a copper ingot with uniform composition and extremely low inclusion content.

[0081] S4. Detection of Removal Methods: Samples were taken from different axial positions (5mm, 15mm, 25mm from the bottom) of copper ingots with uniform composition and extremely low inclusion content for oxygen content analysis. For example... Figure 5 As shown, the O content at the three positions corresponding to a centrifugation time of 10s was 9.31ppm, 11.77ppm, and 13.36ppm, respectively, and the calculated average oxygen removal rate of the highly conductive pure copper raw material was 63.4%; the O content at the three positions corresponding to a centrifugation time of 30s was 3.52ppm, 6.11ppm, and 7.06ppm, respectively, and the calculated average oxygen removal rate of the highly conductive pure copper raw material was 82.3%; the O content at the three positions corresponding to a centrifugation time of 60s was 2.47ppm, 2.48ppm, and 2.50ppm, respectively, and the calculated average oxygen removal rate of the highly conductive pure copper raw material was 92.1%.

[0082] Example 4

[0083] This embodiment describes a method for removing high-melting-point oxygen-containing inclusions from highly conductive pure copper. The high-conductivity pure copper raw material is 500g of national standard TU1 oxygen-free copper rod. The method for removing high-melting-point oxygen-containing inclusions from highly conductive pure copper includes the following steps:

[0084] S1. Heating and Melting: Place the highly conductive pure copper raw material in a high-purity graphite crucible; then place the high-purity graphite crucible containing the highly conductive pure copper raw material into the heating furnace of a centrifuge with ultragravity, and evacuate to 10°C. -2 After Pa, high-purity argon gas is introduced; the furnace temperature is heated to 1100℃ and held for 60 minutes, with a heating rate of 7℃ / min, to ensure that the copper material is completely melted and the temperature is uniform, thus obtaining molten, highly conductive pure copper raw material;

[0085] S2. Hypergravity field isothermal treatment: Under constant temperature of 1100℃ and argon protection, the high-speed centrifuge device of the hypergravity centrifuge is started, so that the molten high-conductivity pure copper raw material in S1 undergoes short-term isothermal centrifugation treatment in the hypergravity field formed by the high-speed centrifuge device; the centrifugation time of the isothermal centrifugation treatment is 60s, the gravity coefficient is 1000, and the treated high-conductivity pure copper raw material melt is obtained.

[0086] The top 4mm thickness of the processed high-conductivity pure copper raw material melt contains inclusions that account for 89.79% of the mass of the high-conductivity pure copper raw material.

[0087] S3. Cooling and solidification control: After the isothermal treatment in the hypergravity field is completed, the rotation is stopped, and the highly conductive pure copper raw material melt treated in S2 is cooled and solidified at a controllable rate of 15℃ / min to obtain a copper ingot with uniform composition and extremely low inclusion content.

[0088] S4. Detection of removal method: Samples of copper ingot shafts with uniform composition and extremely low inclusion content from 5mm from the bottom were taken for oxygen content analysis. The oxygen content was uniformly reduced to 2.7ppm. The average oxygen removal rate of the highly conductive pure copper raw material was calculated, and the conductivity was tested.

[0089] In this embodiment, the average oxygen removal rate of the highly conductive pure copper raw material is 89.36%, and the conductivity is 106.64% IACS.

[0090] Example 5

[0091] This embodiment describes a method for removing high-melting-point oxygen-containing inclusions from highly conductive pure copper. The high-conductivity pure copper raw material is 500g of national standard TU1 oxygen-free copper rod. The method for removing high-melting-point oxygen-containing inclusions from highly conductive pure copper includes the following steps:

[0092] S1. Heating and Melting: Place the highly conductive pure copper raw material in a high-purity graphite crucible; then place the high-purity graphite crucible containing the highly conductive pure copper raw material into the heating furnace of a centrifuge with ultragravity, and evacuate to 10°C. -2 After Pa, high-purity argon gas is introduced; the furnace temperature is heated to 1150℃ and held for 40 minutes, with a heating rate of 7℃ / min, to ensure that the copper material is completely melted and the temperature is uniform, thus obtaining molten, highly conductive pure copper raw material;

[0093] S2. Hypergravity field isothermal treatment: Under constant temperature of 1150℃ and argon protection, the high-speed centrifuge device of the hypergravity centrifuge is started, so that the molten high-conductivity pure copper raw material in S1 undergoes short-term isothermal centrifugation treatment in the hypergravity field formed by the high-speed centrifuge device; the centrifugation time of the isothermal centrifugation treatment is 30s, the gravity coefficient is 500, and the treated high-conductivity pure copper raw material melt is obtained.

[0094] The top 4mm thickness of the processed high-conductivity pure copper raw material melt contains inclusions that account for 90.66% of the mass of the high-conductivity pure copper raw material.

[0095] S3. Cooling and solidification control: After the isothermal treatment in the hypergravity field is completed, the rotation is stopped, and the highly conductive pure copper raw material melt treated in S2 is cooled and solidified at a controllable rate of 10℃ / min to obtain a copper ingot with uniform composition and extremely low inclusion content.

[0096] S4. Detection of removal method: Samples of copper ingot shafts with uniform composition and extremely low inclusion content were taken from 5 mm from the bottom for oxygen content analysis. The oxygen content was uniformly reduced to 2.45 ppm. The average oxygen removal rate of the highly conductive pure copper raw material was calculated, and the conductivity was tested.

[0097] In this embodiment, the average oxygen removal rate of the highly conductive pure copper raw material is 90.27%, and the conductivity is 106.85% IACS.

[0098] Example 6

[0099] This embodiment describes a method for removing high-melting-point oxygen-containing inclusions from highly conductive pure copper. The high-conductivity pure copper raw material is 500g of national standard TU1 oxygen-free copper rod. The method for removing high-melting-point oxygen-containing inclusions from highly conductive pure copper includes the following steps:

[0100] S1. Heating and Melting: Place the highly conductive pure copper raw material in a high-purity graphite crucible; then place the high-purity graphite crucible containing the highly conductive pure copper raw material into the heating furnace of a centrifuge with ultragravity, and evacuate to 10°C. -2 After Pa, high-purity argon gas is introduced; the furnace temperature is heated to 1150℃ and held for 60 minutes, with a heating rate of 7℃ / min, to ensure that the copper material is completely melted and the temperature is uniform, thus obtaining molten, highly conductive pure copper raw material;

[0101] S2. Hypergravity field isothermal treatment: Under constant temperature of 1150℃ and argon protection, the high-speed centrifuge device of the hypergravity centrifuge is started, so that the molten high-conductivity pure copper raw material in S1 undergoes short-term isothermal centrifugation treatment in the hypergravity field formed by the high-speed centrifuge device; the centrifugation time of the isothermal centrifugation treatment is 60s, the gravity coefficient is 1000, and the treated high-conductivity pure copper raw material melt is obtained.

[0102] The top 3mm thickness of the processed high-conductivity pure copper raw material melt contains inclusions that account for 92.08% of the mass of the high-conductivity pure copper raw material.

[0103] S3. Cooling and solidification control: After the isothermal treatment in the hypergravity field is completed, the rotation is stopped, and the highly conductive pure copper raw material melt treated in S2 is cooled and solidified at a controllable rate of 5℃ / min to obtain a copper ingot with uniform composition and extremely low inclusion content.

[0104] S4. Detection of removal method: Samples of copper ingot shafts with uniform composition and extremely low inclusion content were taken from 5 mm from the bottom for oxygen content analysis. The oxygen content was uniformly reduced to 2.30 ppm. The average oxygen removal rate of the highly conductive pure copper raw material was calculated, and the conductivity was tested.

[0105] In this embodiment, the average oxygen removal rate of the highly conductive pure copper raw material is 91.84%, and the conductivity is 106.92% IACS.

[0106] The above-mentioned solution, proposed by this invention, is a method for removing high-melting-point oxygen-containing inclusions in highly conductive pure copper. It can solve the technical problems of high energy consumption, unstable quality, and environmental unfriendliness in the complex production process of existing copper refining technology. The removal of oxygen-containing inclusions by adding refining agents and slagging agents has technical problems such as high cost and low efficiency. In addition, the selection and addition of refining agents can cause uneven removal of impurities, possible side reactions, difficulty in control, and difficulty in deep removal. Moreover, it increases the risk of secondary oxidation of the melt.

[0107] The method of this invention, through heating and melting and holding at a constant temperature, enables the metallic copper in pure copper materials to melt while the oxide impurities remain in the solid phase.

[0108] This invention utilizes a hypergravity field constant temperature treatment, which greatly enhances the Stokes motion speed of inclusions, shortening the separation process that takes several hours in traditional processes to tens of seconds. The oxygen removal rate can reach up to 92.1%, resulting in a revolutionary improvement in production efficiency. It can achieve deep purification, reducing the oxygen content in oxygen-free copper from 31.37 ppm to below 2.70 ppm, reaching an ultra-high purity level. It also deeply removes oxide inclusions that act as electron scattering centers, increasing the material's conductivity to over 106.92% IACS, significantly optimizing its conductivity.

[0109] This invention precisely controls the degree of purification and the oxygen content distribution of the final product by adjusting two core parameters: gravity coefficient and centrifugation time, thereby achieving flexible control and balance between high conductivity and necessary mechanical strength.

[0110] The method of the present invention, through cooling and solidification control, can increase grain size and reduce grain boundaries, thereby improving conductivity.

[0111] The entire process of this invention does not require a complex vacuum system or long-term high-temperature insulation, and has outstanding advantages such as short process, high efficiency, low energy consumption and controllable cost, providing an innovative solution for the large-scale production of ultra-high purity and high conductivity copper materials.

[0112] In summary, compared with traditional methods, the method of this invention removes high-melting-point oxygen-containing inclusions from highly conductive pure copper at low cost and high efficiency by heating and melting, heat preservation and homogenization, constant temperature treatment in a hypergravity field, and cooling and solidification control. This method does not require a complex vacuum system or long-term high-temperature heat preservation, is simple to operate, low in cost, low in energy consumption, and high in efficiency, which is conducive to the large-scale industrial production and promotion of ultra-high purity and highly conductive copper materials.

[0113] It should be understood that the term "and / or" in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. A and B can be singular or plural. Additionally, the character " / " in this article generally indicates an "or" relationship between the preceding and following related objects, but it can also represent an "and / or" relationship. Please refer to the context for a more accurate understanding.

[0114] In this invention, "at least one" means one or more, and "more than one" means two or more. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of a single item or a plurality of items. For example, at least one of a, b, or c can represent: a, b, c, ab, ac, bc, or abc, where a, b, and c can be a single item or multiple items.

[0115] It should be understood that, in various embodiments of the present invention, the order of the above-mentioned process numbers does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0116] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for removing high-melting-point oxygen-containing inclusions from highly conductive pure copper, characterized in that, The method for removing high-melting-point oxygen-containing inclusions from highly conductive pure copper includes the following steps: S1. Heating and melting: Place the high-conductivity pure copper raw material in a crucible; then place the crucible containing the high-conductivity pure copper raw material into the heating furnace of the centrifugal device; heat to the complete melting temperature under an inert gas or reducing protective atmosphere and keep it at a uniform temperature to obtain molten high-conductivity pure copper raw material; S2, Hypergravity field isothermal treatment: Start the high-speed centrifuge device of the hypergravity centrifuge equipment to make the molten high-conductivity pure copper raw material in S1 undergo short-term isothermal centrifugation treatment in the hypergravity field formed by the high-speed centrifuge device to obtain the treated high-conductivity pure copper raw material melt. S3. Cooling and solidification control: After the isothermal treatment in the hypergravity field is completed, the rotation is stopped, and the highly conductive pure copper raw material melt treated in S2 is cooled and solidified at a controllable rate to obtain a copper ingot with uniform composition and extremely low inclusion content.

2. The method for removing high-melting-point oxygen-containing inclusions from highly conductive pure copper according to claim 1, characterized in that, The high-conductivity pure copper raw material in S1 is oxygen-free copper, and its oxygen-containing inclusions include Cu2O, Cu2S, and CuS; the crucible is a high-purity graphite crucible.

3. The method for removing high-melting-point oxygen-containing inclusions from highly conductive pure copper according to claim 1, characterized in that, The O content in the copper raw material in S1 is 5-35 ppm.

4. The method for removing high-melting-point oxygen-containing inclusions from highly conductive pure copper according to claim 1, characterized in that, The heating rate in S1 is 7℃ / min, the temperature at which complete melting occurs is 1100-1150℃, and the holding time is 20-60min.

5. The method for removing high-melting-point oxygen-containing inclusions from highly conductive pure copper according to claim 1, characterized in that, The gravity coefficient of the hypergravity field formed by the high-speed centrifuge device in S2 is 500-1000, and the centrifugation time is 30-60s.

6. The method for removing high-melting-point oxygen-containing inclusions from highly conductive pure copper according to claim 1, characterized in that, The top 3-8 mm thickness of the high-conductivity pure copper raw material melt after S2 treatment contains inclusions that account for more than 80% of the mass of the high-conductivity pure copper raw material.

7. The method for removing high-melting-point oxygen-containing inclusions from highly conductive pure copper according to claim 1, characterized in that, The controllable cooling and solidification rate in S3 is 5-15℃ / min.

8. The method for removing high-melting-point oxygen-containing inclusions from highly conductive pure copper according to claim 1, characterized in that, S4. Detection of removal method: Samples were taken from different positions along the axis of copper ingots with uniform composition and extremely low inclusion content for oxygen content analysis. The oxygen content was uniformly reduced to 2.5±0.2ppm. The average oxygen removal rate of the highly conductive pure copper raw material was calculated, and the conductivity was tested.

9. The method for removing high-melting-point oxygen-containing inclusions from highly conductive pure copper according to claim 1, characterized in that, The average oxygen removal rate of the high-conductivity pure copper raw material in S4 is over 80%, and the conductivity is increased to 106.92% IACS.

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