Electrolyte for preparing high-purity copper through electrolytic refining of high-silver copper plate and preparation method

Abstract

The invention belongs to the technical field of copper electrolytic refining, and particularly relates to an electrolyte for preparing high-purity copper through electrolytic refining of a high-silver copper plate and a preparation method. The electrolyte for preparing the high-purity copper through electrolytic refining of the high-silver copper plate comprises an electrolytic mother solution and an additive, the electrolytic mother solution comprises CuSO4 and H2SO4, the additive is amino-functionalized imidazole ionic liquid, the amino-functionalized imidazole ionic liquid is 1-aminoalkyl-3-methylimidazole halide salt, and the electrolyte is prepared from an electrolyte solution and a solvent. And the mass concentration of the additive in the electrolyte is 0.01-0.08 g / L. According to the method, a specific type of ionic liquid additive is added into the electrolysis mother liquor, so that the flocculation effect on fine suspended anode mud generated in the electrolysis process can be achieved, the ionic liquid additive can react with Ag < + > to generate precipitates, then the content of Ag and other impurities in cathode copper is reduced, the purity of the cathode copper is greatly improved, and the surface quality of the cathode copper is improved.

Description

Technical Field

[0001] The invention relates to the technical field of copper electrolytic refining, and in particular to an electrolyte used for electrolytic refining of high-silver copper plates to prepare high-purity copper and a preparation method thereof. Background Art

[0002] High-purity copper is a key supporting material for industries such as electronic information, high-end equipment manufacturing, and national defense and military industries. It has excellent properties such as high residual resistivity, high thermal conductivity, low softening temperature, and good machinability. It is widely used in high-end technology fields such as integrated circuits, electronic packaging, superconductivity, semiconductors, and aerospace. The main methods for preparing high-purity copper include electrolytic refining, zone smelting, anion exchange, vacuum electron beam melting, and suspension melting. As the most basic and commonly used method, electrolytic refining is widely used in industrial production due to its stable production process conditions.

[0003] At present, the electrolytic refining method for preparing high-purity copper uses 4N grade copper as the anode plate and titanium plate as the cathode plate, and prepares 5N grade and above high-purity copper through one or more electrolysis. However, due to the increasing complexity of the composition of copper concentrate in my country, the silver (Ag) impurity content in the copper plates prepared by pyrometallurgy has increased. For the electrolytic refining of high-purity copper using high-silver content copper plates as anode plates, there are technical disadvantages such as low copper quality and low production efficiency. On the one hand, the high silver content of the copper plate will cause Ag in the electrolyte during the electrolysis process. + The concentration increases, which leads to a high Ag content in the prepared cathode copper, resulting in a decrease in copper purity; on the other hand, some of the suspended anode mud produced during the electrolysis process tends to adhere to the cathode surface to form particles, affecting the quality of high-purity copper and causing a large amount of precious metal (Ag) to be seriously lost.

[0004] The prior art prevents anode mud from falling onto the cathode plate by wrapping anode bags on the anode plate, increasing the circulation speed of the electrolyte in the electrolytic cell, and increasing the current density during the electrolysis process, thereby reducing the loss of precious metals and improving the quality of the cathode copper plate. For example, a Chinese patent with the authorization announcement number CN106868543B, which was authorized on December 22, 2020, discloses a system and method for electrolytic refining of crude copper with a high precious metal content. The circulation mode of the electrolyte in the cell is modified from bottom-in and top-out in the cell, low-level cell-high-level cell-electrolytic cell-low-level cell, to a circulation mode in which the electrolyte in the cell is parallel to the arrangement direction of the plates, flows in and out from the bottom, flows out through the overflow port, and then returns to the low-level cell. The circulation speed of the electrolyte in the cell is increased, and the anode bags are wrapped on the anode plate to prevent the anode mud from falling onto the cathode, thereby reducing the loss of precious metals and improving the quality of the cathode copper plate. The current density during electrolysis is increased to 600-1000A / m 2, reducing the amount of precious metals occupied during the electrolytic refining process. However, this method requires improving the layout of the electrolytic cells and installing a circulating pump, which greatly increases the complexity of the electrolytic refining process and increases the process cost. The electricity cost caused by the high current density also increases sharply.

[0005] In the electrolytic refining process, in order to obtain electrolytic copper with a smooth surface and high purity, additives can also be added to the electrolyte. The additives can not only make the cathode copper deposit fine, clean and tough, but also reduce the impurity content in the copper deposit. In June 2012, Xu Li et al. published the article "The Effect of 1-Octyl-2,3-Dimethylimidazolium Chloride Ionic Liquid on the Surface Quality of Electrolytic Copper" in which 1-Octyl-2,3-Dimethylimidazolium Chloride Ionic Liquid (abbreviated as [OMMIm]C1) was used as an additive for electrolytic refining of copper. The electrolyte composition is: Cu 2+ 46~48g / L, H2SO4 169~171g / L, [OMMIm]C1 0~50mg / L, electrolyte temperature 62℃, current density 250A / m 2 The additive can refine the cathode copper grains, make the plate surface smooth and dense, and improve the surface quality of the cathode copper. However, the additive is still difficult to achieve the preparation of high-purity copper for electrolytic refining of copper plates with high silver content.

[0006] Therefore, in order to reduce costs and improve the quality and production efficiency of cathode copper, it is urgent to develop a method for preparing high-purity copper through one-time electrolytic refining using a high-silver content copper plate as an anode plate. Summary of the invention

[0007] The object of the present invention is to provide an electrolyte for preparing high-purity copper by electrolytic refining of high-silver copper plates, so as to solve the problems of low purity and high impurity content of cathode copper prepared by electrolytic refining of high-silver copper plates.

[0008] The second object of the present invention is to provide a method for preparing high-purity copper by electrolytic refining of high-silver copper plates, so as to solve the problem of low purity and high impurity content of cathode copper prepared by electrolytic refining of high-silver content copper plates.

[0009] In order to solve the above technical problems, the technical solution of the electrolyte for preparing high-purity copper by electrolytic refining of high-silver copper plate of the present invention is as follows:

[0010] An electrolyte for preparing high-purity copper by electrolytic refining of high-silver copper plates, the electrolyte comprising an electrolyte mother solution and an additive, the electrolyte mother solution comprising CuSO4 and H2SO4, the additive being an amino-functionalized imidazole ionic liquid, the amino-functionalized imidazole ionic liquid being a 1-aminoalkyl-3-methylimidazolium halide, and the mass concentration of the additive in the electrolyte being 0.01-0.08 g / L.

[0011] The present invention is an improvement on the prior art, and provides an electrolyte for preparing high-purity copper by electrolytic refining of high-silver copper plates. By adding amino-functionalized imidazole ionic liquid additives to the electrolytic mother liquor, the imidazole cations and amino functional groups in the additives can cooperate with the fine suspended anode mud produced during the electrolysis process to produce flocculation. The reason is that the imidazole cation is a positively charged five-membered nitrogen-containing heterocycle with strong polarity and hydrophilicity, and can react with the particles in the suspended anode mud to enhance the interaction between the particles, thereby promoting the aggregation of the particles into flocs; at the same time, the amino functional group can react with hydrogen ions under acidic conditions of the electrolyte to carry a positive charge, and can also interact with the surface of negatively charged suspended particles to promote aggregation between particles. The flocculation effect of the additives and the fine suspended anode mud can reduce the fine suspended anode mud from entering the cathode copper in the form of mechanical adhesion and inclusion, and the ionic liquid additive can react with Ag. + The reaction generates precipitation, reducing the Ag content in the electrolyte + The concentration reduces the Ag content in the cathode copper, thereby reducing the silver and other impurities in the prepared cathode copper, greatly improving the purity of the cathode copper; the obtained cathode copper has good surface quality and the surface crystal is flat and dense.

[0012] In order to further reduce impurities in cathode copper, preferably, the 1-aminoalkyl-3-methylimidazolium halide is selected from one or more of 1-aminopropyl-3-methylimidazolium chloride, 1-aminopropyl-3-methylimidazolium bromide and 1-aminoethyl-3-methylimidazolium bromide.

[0013] In order to further improve the deposition quality of cathode copper, preferably, the mass concentrations of CuSO4 and H2SO4 in the electrolyte are 20-50 g / L and 50-90 g / L, respectively.

[0014] The technical solution of the method for preparing high-purity copper by electrolytic refining of high-silver copper plate of the present invention is:

[0015] A method for preparing high-purity copper by electrolytic refining of high-silver copper plates comprises the following steps: using the high-silver copper plates as anodes, electrolytically refining copper in an electrolyte used for electrolytic refining of high-purity copper by high-silver copper plates, wherein the silver content of the high-silver copper plates is 640-820 g / t, and during the electrolytic refining of copper, the anodes are wrapped with anode bags.

[0016] The present invention adopts an electrolyte added with a specific type of ion additive to electrolyze and refine copper, and utilizes the flocculation effect of the ion additive on the fine suspended anode mud generated during the electrolysis process, and the ionic liquid additive and Ag +The precipitation effect can reduce the silver and other impurities in the prepared cathode copper, greatly improving the purity of the cathode copper; and the anode bag can prevent the anode mud from falling into the solution during the electrolysis process, thereby reducing the generation of suspended anode mud, and can reduce the suspended anode mud from entering the cathode copper in the form of mechanical adhesion and inclusion, achieving the effect of deep physical isolation of impurities, thereby avoiding the contamination of the cathode copper by the anode mud. The preparation method of electrolytic refined copper of the present invention has a silver content of 640-820g / t in the high-silver copper plate used as the anode, and a copper purity of 99.2-99.6%. High-purity copper with a copper purity of 99.9996-99.9998% and a silver content of 0.9-1.5% can be prepared, and other impurity elements are far lower than the impurity element content requirements in the national standard for high-purity copper (GB / T26017-2020).

[0017] The method for preparing high-purity copper by electrolytic refining of high-silver copper plates provided by the present invention does not require improvement of the electrolytic cell structure, nor does it require introduction of a circulating pump and a large electrolytic current. The process is simple, the cost is low, and it is easy to implement. The problem of multiple electrolysis required for preparing high-purity copper by traditional electrolytic refining is avoided, thereby greatly improving the quality of high-purity copper and the economic benefits of the enterprise.

[0018] In order to further increase the electrolysis rate of electrolytic refining, preferably, the electrolysis temperature during electrolytic refining of copper is 40-60°C.

[0019] In order to further control the electrolysis rate of the high silver content copper plate, preferably, the current density during electrolytic refining of copper is 100-200A / m 2 .

[0020] In order to further reduce the generation of suspended anode mud, prevent the anode mud from falling onto the cathode, reduce the loss of precious metals and improve the quality of the cathode copper plate, preferably, the pores of the anode bag are less than 20 μm.

[0021] In order to further improve the purity of cathode copper, preferably, the purity of the prepared high-purity copper is 99.9996-99.9998%, and the silver content in the high-purity copper is 0.9-1.5%. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is an optical photograph of the cathode copper prepared in Example 5 of the present invention;

[0023] Figure 2 This is a SEM morphology image of the cathode copper prepared in Example 5 of the present invention. DETAILED DESCRIPTION

[0024] The technical concept of the electrolyte for preparing high-purity copper by electrolytic refining of high-silver copper plates of the present invention is as follows:

[0025] The electrolyte provided by the present invention for preparing high-purity copper by electrolytic refining of high-silver copper plates interacts with suspended anode mud and silver ions generated during the electrolysis process by adding a specific type of ion additive, thereby preventing the suspended anode mud from adhering to the cathode surface to form particles and the silver ions from entering the cathode copper, thereby greatly reducing impurities such as silver in the prepared cathode copper and improving the purity of the cathode copper.

[0026] The method for preparing high-purity copper by electrolytic refining of high-silver copper plate of the present invention comprises the following steps: using the high-silver copper plate as an anode, wrapping an anode bag on the anode, and using titanium as a cathode; electrolytic refining of copper is carried out in the electrolyte used for electrolytic refining of high-purity copper by high-silver copper plate, wherein the silver content in the high-silver copper plate is 640-820 g / t; wherein the electrolyte consists of an electrolytic mother liquor and an additive, the electrolytic mother liquor comprises CuSO4 and H2SO4, the additive is an amino-functionalized imidazole ionic liquid, and the mass concentrations of CuSO4, H2SO4 and the additive in the electrolyte are 20-50 g / L, 50-90 g / L and 0.04-0.1 g / L, respectively.

[0027] In a specific embodiment, the copper purity of the high-silver copper plate used in the electrolytic copper refining process is 99.2-99.6%.

[0028] In a specific embodiment, the anode bag is made of polypropylene.

[0029] In a specific embodiment, the electrolyte mother solution is prepared from analytical pure copper sulfate, sulfuric acid and water, and the electrolyte is obtained by adding ionic liquid to the electrolyte mother solution; the copper concentration in the electrolyte is the mass of commercially available analytical pure copper sulfate added to a certain volume of water, and similarly, the sulfuric acid concentration is the mass of commercially available concentrated sulfuric acid (mass fraction 98%) added to water.

[0030] In a specific embodiment, a direct current power supply is used for electrolysis during the electrolytic refining of copper; the method for preparing high-purity copper by electrolytic refining of high-silver copper plates is specifically as follows: a high-silver content copper plate and titanium are used as the anode and cathode of the electrolytic cell, respectively, the anode and cathode are respectively loaded into the anode area and cathode area of ​​the electrolytic cell, and the electrolysis cycle is started to perform direct current electrolysis.

[0031] In a specific embodiment, the prepared cathode copper is washed and then dried; the washing is carried out using 5-10 g / L dilute sulfuric acid as a cleaning medium, and the cleaning is carried out under the action of ultrasound with a frequency of 30-50 kHz, and the cleaning time is 5-20 minutes; the drying is carried out in a vacuum drying oven at 65-70°C.

[0032] In order to more clearly understand the purpose, technical solutions and advantages of the present invention, the following is a further description of the embodiments of the present invention in conjunction with specific examples, and the protection scope of the present invention is not limited by the following examples. The raw materials used in the following examples are all conventional commercial products and are well known to those skilled in the art.

[0033] 1. Specific embodiments of the electrolyte for preparing high-purity copper by electrolytic refining of high-silver copper plates of the present invention

[0034] The formula composition of the electrolyte for preparing high-purity copper by electrolytic refining of high-silver copper plates of the present invention is shown in Table 1.

[0035] Table 1 Electrolyte formulation composition

[0036]

[0037] The electrolyte for electrolytic refining of high-silver copper plates to prepare high-purity copper in Example 1 is composed of an electrolytic mother liquor and an additive. The electrolytic mother liquor is composed of CuSO4, H2SO4 and water, and the additive is 1-aminoethyl-3-methylimidazolium bromide. The mass concentrations of CuSO4, H2SO4 and 1-aminoethyl-3-methylimidazolium bromide in the electrolyte are 20 g / L, 50 g / L and 0.04 g / L, respectively.

[0038] The electrolyte for preparing high-purity copper by electrolytic refining of high-silver copper plates in Example 2 is composed of an electrolytic mother liquor and an additive. The electrolytic mother liquor is composed of CuSO4, H2SO4 and water, and the additive is 1-aminopropyl-3-methylimidazolium chloride. The mass concentrations of CuSO4, H2SO4 and 1-aminopropyl-3-methylimidazolium chloride in the electrolyte are 40 g / L, 70 g / L and 0.08 g / L, respectively.

[0039] The electrolyte used for electrolytic refining of high-silver copper plates to prepare high-purity copper in Example 3 is composed of an electrolytic mother liquor and an additive. The electrolytic mother liquor is composed of CuSO4, H2SO4 and water, and the additive is 1-aminopropyl-3-methylimidazolium bromide. The mass concentrations of CuSO4, H2SO4 and 1-aminopropyl-3-methylimidazolium bromide in the electrolyte are 50 g / L, 90 g / L and 0.01 g / L, respectively.

[0040] 2. Specific embodiments of the method for preparing high-purity copper by electrolytic refining of high-silver copper plates of the present invention

[0041] Example 4

[0042] The method for preparing high-purity copper by electrolytic refining of high-silver copper plate in this embodiment is as follows:

[0043] (1) A high-silver content copper plate is used as an anode and titanium is used as a cathode. The Ag content in the high-silver content copper plate is 640.7 g / t and the copper purity is 99.2%. Electrolytic refining of copper is performed in the electrolyte of Example 1;

[0044] (2) Turn on the DC power supply to conduct electrolysis, and the DC current density is 100A / m 2 , the electrolysis temperature is 50℃.

[0045] (3) During the electrolysis process, the anode is wrapped with an anode bag, and the pores of the anode bag are less than 20 μm.

[0046] (4) The cathode copper obtained by electrolytic refining is washed and dried. The washing is carried out using 5 g / L dilute sulfuric acid as the cleaning medium and is cleaned for 5 minutes under the action of ultrasound at a frequency of 30 kHz. After the cleaning is completed, the copper is dried in a vacuum drying oven at 65°C.

[0047] Example 5

[0048] The method for preparing high-purity copper by electrolytic refining of high-silver copper plate in this embodiment is as follows:

[0049] (1) using a high-silver content copper plate as an anode and titanium as a cathode, wherein the Ag content in the high-silver content copper plate is 769.3 g / t and the copper purity is 99.5%; electrolytic refining of copper is performed in the electrolyte of Example 2;

[0050] (2) Turn on the DC power supply to conduct electrolysis, and the DC current density is 150A / m 2 , the electrolysis temperature is 40℃.

[0051] (3) During the electrolysis process, the anode is wrapped with an anode bag, and the pores of the anode bag are less than 20 μm.

[0052] (4) The cathode copper obtained by electrolytic refining is washed and then dried. The washing is carried out using 8 g / L dilute sulfuric acid as the cleaning medium and is cleaned for 15 minutes under the action of ultrasound at a frequency of 40 kHz. After the cleaning is completed, the copper is dried in a vacuum drying oven at 65°C.

[0053] Example 6

[0054] The method for preparing high-purity copper by electrolytic refining of high-silver copper plate in this embodiment is as follows:

[0055] (1) using a high-silver content copper plate as an anode and titanium as a cathode, wherein the Ag content in the high-silver content copper plate is 810.5 g / t and the copper purity is 99.6%; electrolytic refining of copper is performed in the electrolyte of Example 3;

[0056] (2) Turn on the DC power supply to conduct electrolysis, and the DC current density is 200A / m 2 , the electrolysis temperature is 60℃.

[0057] (3) During the electrolysis process, the anode is wrapped with an anode bag, and the pores of the anode bag are less than 20 μm.

[0058] (4) The cathode copper obtained by electrolytic refining is washed and then dried. The washing is carried out using 10 g / L dilute sulfuric acid as the cleaning medium and is cleaned for 20 minutes under the action of ultrasound at a frequency of 30 kHz. After the cleaning is completed, the copper is dried in a vacuum drying oven at 65°C.

[0059] 3. Comparison

[0060] Comparative Example 1

[0061] The method for preparing high-purity copper by electrolytic refining of high-silver copper plates in this comparative example is basically the same as that in Example 5, except that no ionic liquid is added to the electrolyte.

[0062] Comparative Example 2

[0063] The method for preparing high-purity copper by electrolytic refining of high-silver copper plate in this comparative example is basically the same as that in Example 5, except that: the anode is not coated with an anode bag during the electrolysis process.

[0064] Comparative Example 3

[0065] The method for preparing high-purity copper by electrolytic refining of high-silver copper plates in this comparative example is basically the same as that in Example 5, except that the ionic liquid added to the electrolyte is 1-octyl-2,3-dimethylimidazolium chloride.

[0066] IV. Experimental Examples

[0067] Experimental Example 1

[0068] In this experimental example, the surface quality of the cathode copper was evaluated by observing the surface morphology of the prepared cathode copper. Figure 1 and Figure 2 The optical photograph and SEM morphology of the cathode copper prepared in Example 5 are shown in Figure 1. Figure 1-2 It can be seen that the cathode copper obtained by the method for electrolytic refining of copper provided by the present invention has good surface quality and a smooth and dense surface crystal.

[0069] Experimental Example 2

[0070] In this experimental example, the element content of the cathode copper obtained in the embodiment and the comparative example was tested by glow discharge mass spectrometry. The test results are shown in Table 2.

[0071] Table 2 Element content of cathode copper

[0072]

[0073]

[0074] It can be seen from Table 2 that the cathode copper prepared in Comparative Example 1 using an electrolyte without adding ionic liquid has a copper purity of 99.9983%; the cathode copper prepared without adding an anode bag in Comparative Example 2 has a copper purity of 99.9978%, and the cathode copper prepared by adding 1-octyl-2,3-dimethylimidazolium chloride as the ionic liquid in Comparative Example 3 has a copper purity of 99.9965%, which does not reach 5N grade high-purity copper (GB / T 26017-2020).

[0075] The copper content in the cathode copper obtained by the method for preparing high-purity copper by electrolytic refining provided by the present invention is greater than 99.9996%, reaching 5N grade high-purity copper, and the content of impurity elements such as Ag, S, Sb, As, Pb, Fe, etc. is much lower than the content of impurity elements in 5N grade copper in the national standard, indicating that the amino-functionalized imidazole ionic liquid of the present invention can effectively reduce the content of silver and other impurity elements in the cathode copper, thereby improving the purity of the cathode copper.

[0076] Moreover, compared with the comparative example 1 in which the ionic liquid is not introduced, the copper purity of the cathode copper obtained by the electrolyte with the added ionic liquid in the embodiment 2 is 99.99977%, reaching 5N grade high purity copper, and the content of impurity elements such as Ag, Sb, As, Pb, S, etc. is significantly reduced, indicating that the ionic liquid can effectively reduce the content of silver and other impurity elements in the cathode copper, thereby improving the purity of the cathode copper; compared with the comparative example 2 in which the anode bag is not used for coating, the content of impurity elements such as Ag, Sb, As, Pb, S, etc. is significantly reduced, indicating that the anode bag has the effect of deeply blocking insoluble impurities, thereby reducing the cathode The content of harmful impurity elements in copper; compared with the conventional imidazole ionic liquid used in Comparative Example 3, the use of the amino-functionalized imidazole ionic liquid of the present invention can reduce the content of Ag impurities in the prepared cathode copper to a greater extent, indicating that the amino-functionalized imidazole ionic liquid of the present invention is more capable of inhibiting the migration and co-deposition of Ag impurity ions during copper electrolysis than conventional ionic liquids, thereby reducing the content of Ag impurities in cathode copper and improving the purity of copper, highlighting the superiority of the amino-functionalized imidazole ionic liquid of the present invention and proving the synergistic effect of its amino group and imidazole cation.

[0077] Comprehensive analysis shows that the effect of adding ionic liquid and anode bag at the same time is better than the effect of adding ionic liquid alone; this shows that ionic liquid and anode bag have a synergistic effect in improving the purity of cathode copper.

[0078] Finally, it should be noted that the above embodiments are intended to illustrate the technical solution of the present invention rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention may be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. An electrolyte for preparing high-purity copper by electrolytic refining of high-silver copper plates, characterized in that: The electrolyte comprises an electrolyte mother solution and an additive, wherein the electrolyte mother solution comprises CuSO4 and H2SO4, the additive is an amino-functionalized imidazole ionic liquid, the amino-functionalized imidazole ionic liquid is a 1-aminoalkyl-3-methylimidazolium halide, and the mass concentration of the additive in the electrolyte is 0.01-0.08 g / L.

2. The electrolyte for preparing high-purity copper by electrolytic refining of high-silver copper plate according to claim 1, characterized in that: The 1-aminoalkyl-3-methylimidazolium halide is selected from one or more of 1-aminopropyl-3-methylimidazolium chloride, 1-aminopropyl-3-methylimidazolium bromide and 1-aminoethyl-3-methylimidazolium bromide.

3. The electrolyte for preparing high-purity copper by electrolytic refining of high-silver copper plate according to claim 1, characterized in that: The mass concentrations of CuSO4 and H2SO4 in the electrolyte are 20~50 g / L and 50~90 g / L, respectively.

4. A method for preparing high-purity copper by electrolytic refining of high-silver copper plates, characterized in that: The following steps are involved: A high-silver copper plate is used as an anode, and copper is electrolytically refined in the electrolyte for preparing high-purity copper by electrolytic refining of high-silver copper plates as described in any one of claims 1 to 3, wherein the silver content in the high-silver copper plate is 640-820 g / t, and the anode is wrapped in an anode bag during the electrolytic refining of copper.

5. The method for preparing high-purity copper by electrolytic refining of high-silver copper plate as claimed in claim 4, characterized in that: The electrolysis temperature during electrolytic refining of copper is 40~60℃.

6. The method for preparing high-purity copper by electrolytic refining of high-silver copper plate as claimed in claim 4, characterized in that: The current density during electrolytic refining of copper is 100~200 A / m 2 .

7. The method for preparing high-purity copper by electrolytic refining of high-silver copper plate as claimed in claim 4, characterized in that: The pores of the anode bag are less than 20 μm.

8. The method for preparing high-purity copper by electrolytic refining of high-silver copper plate as claimed in claim 4, characterized in that: The copper purity of the prepared high-purity copper is 99.9996-99.9998%, and the silver content in the high-purity copper is 0.9-1.5%.

Images