Electrolyte for copper refining and electrolytic refining method of high-gold-silver complex copper anode plate

Abstract

The present invention belongs to the field of metallurgical technology, and discloses an electrolyte for copper refining and an electrolytic refining method for a high-gold-silver complex copper anode plate. The electrolyte for copper refining also includes an oxidative activity inhibitor; the oxidative activity inhibitor is prepared by the following method: S1. Obtain copper acetate; S2. Mix copper acetate, hydrochloric acid and copper powder, react at 120-150°C for 4-6 hours, filter after cooling, and the filtrate is the oxidative activity inhibitor. The present invention suppresses the oxidative dissolution of gold and silver in the copper anode plate during copper electrolysis by adding an oxidative activity inhibitor, thereby achieving efficient separation and recovery of copper and gold and silver in a high-gold-silver complex copper anode plate, and has the advantages of short process flow, high metal recovery rate, low processing cost, etc., and has far-reaching significance for improving the economic benefits of enterprises and taking the path of green and sustainable development.

Description

Technical Field

[0001] The invention belongs to the technical field of metallurgy, and in particular relates to an electrolyte for copper refining and an electrolytic refining method for a high-gold-silver complex copper anode plate. Background Art

[0002] The existing copper smelting processes mainly include copper concentrate smelting, matte refining, crude copper refining casting, electrolytic refining, etc. With the deterioration of competition within the copper smelting industry and the procurement of raw materials, the copper grade of existing copper raw materials is lower and the impurity composition is more complex. In order to increase production profits, some companies add a large amount of gold concentrate and silver concentrate to the raw materials, and the copper grade entering the furnace is less than 13%, resulting in the output copper anode plates containing a large amount of impurities such as gold, silver, arsenic, antimony, bismuth, etc., and the quality of the output cathode copper continues to decline.

[0003] Invention patent CN 118756248 A discloses a process for electrolysis of ultra-high impurity copper, which relates to the field of copper electrolysis technology, and includes the following steps: step 1, placing anode plates, step 2, electrolysis, step 3, maintaining the composition of electrolyte, step 4, cleaning the electrolytic cell, step 5, treatment of impurities and filtrate, step 6, recovery of waste electrolyte. The use of reverse current electrolysis in the above process can adapt to the situation of high impurities in the anode plate, and can reduce the occurrence of passivation; in the copper electrolytic refining process, impurities in anode copper mainly enter anode mud and electrolyte, and a small amount enters cathode copper, affecting the quality of cathode copper. In addition, the invention patent does not fully disclose the impurity content of the copper anode plate and the quality of cathode copper, so the process cannot guarantee the quality of the output cathode copper, and the current efficiency is low. Summary of the invention

[0004] The present invention aims to address the deficiencies of the above-mentioned prior art and provides an electrolyte for copper refining and a method for electrolytic refining of a high-gold-silver complex copper anode plate. In order to address the problem that part of the silver and gold in the high-gold-silver complex copper anode plate dissolves and precipitates at the cathode, resulting in the cathode copper containing a large amount of gold and silver, an oxidative activity inhibitor is added to the electrolyte of the present invention, which can inhibit the dissolution of gold and silver during the electrolysis of the copper anode plate, reduce the content of gold and silver in the cathode copper, and improve the purity of the cathode copper.

[0005] The specific technical solutions are as follows:

[0006] One of the purposes of the present invention is to provide an electrolyte for copper refining, comprising copper sulfate and sulfuric acid, which differs from the prior art in that it also comprises an oxidation activity inhibitor; the oxidation activity inhibitor is prepared by the following method:

[0007] S1. Obtain copper acetate;

[0008] S2. Mix cupric acetate, hydrochloric acid and copper powder, react at 120-150°C for 4-6 hours, cool and filter. The filtrate is a mixed solution of acetic acid-cuprous acetate-cuprous chloride complex-hydrochloric acid, which is the oxidation activity inhibitor.

[0009] The reaction mechanism of the present invention is as follows:

[0010] During the electrolysis process, impurities in the copper anode plate mainly enter the anode mud and electrolyte, and a small amount enters the cathode copper, affecting the quality of the cathode copper. In the actual production process, under the action of electric current, part of the silver and gold in the copper anode plate dissolves and precipitates at the cathode, causing the cathode copper to contain a large amount of gold and silver. This problem is particularly obvious when the copper anode plate contains a high content of gold and silver. In response to this phenomenon, an oxidative activity inhibitor was invented, which is generated by the reaction of copper acetate, hydrochloric acid and copper powder to form a mixed solution of acetic acid-cuprous acetate-cuprous chloride complex-hydrochloric acid; during the electrolysis of the copper anode plate, the cuprous ions in the cuprous acetate and cuprous chloride in the oxidizing agent form a weak reducing area on the surface of the copper anode plate, preventing the oxidation reaction of gold and silver in the copper anode plate, inhibiting the dissolution of gold and silver, and reducing the gold and silver content of the cathode copper.

[0011] During the copper electrolysis reaction, the main reaction is that the copper anode plate loses electrons under the action of current to generate copper ions, and the copper ions gain electrons at the cathode to generate single substances. The main chemical reaction equation is as follows:

[0012] Anodic reaction: Cu - 2e - =Cu 2+ ;

[0013] Cathode reaction: Cu 2+ + 2e=Cu.

[0014] The preparation of the oxidation activity inhibitor in the present invention mainly involves the reaction of acetic acid with copper hydroxide to form copper acetate, and the reaction of copper acetate with copper powder in a hydrochloric acid solution to form a complex of cuprous acetate and cuprous chloride. The main chemical reaction equation is as follows:

[0015] 2CH3COOH+Cu(OH)2=(CH3COO)2Cu+2H2O;

[0016] (CH3COO)2Cu+2HCl=CuCl2+2CH3COOH;

[0017] (CH3COO)2Cu+Cu=2CH3COOCu;

[0018] CuCl2+Cu=2CuCl;

[0019] CuCl+HCl=H[CuCl2].

[0020] Furthermore, in step S2: hydrochloric acid and copper powder are added in excess; preferably, the mass ratio of copper acetate, HCl in hydrochloric acid, and copper powder is 1:(1~2):(0.5~1).

[0021] Further, in step S2: after the reaction is completed, cool to room temperature in an airtight condition, and then filter.

[0022] Further, in step S2: the reaction is preferably carried out in a hydrothermal synthesis reactor.

[0023] Further, in step S1: the cupric acetate can be generated by reacting acetic acid solution with cupric hydroxide.

[0024] Specifically, the reaction conditions of step S1 are preferably: adding acetic acid to water, stirring and dissolving at 30-50° C., adding copper hydroxide after complete dissolution, reacting at 30-50° C. for 2-4 hours, and then filtering, the filtrate is a blue transparent copper acetate solution.

[0025] Among them, the mass ratio of acetic acid, water and copper hydroxide is preferably 1:(12~15):(4~6).

[0026] Furthermore, in the electrolyte, the amount of the oxidation activity inhibitor added is preferably 30-50 g / t per 1t Cu calculated based on the cuprous ions therein.

[0027] Furthermore, at least one of hydrochloric acid, gelatin and thiourea is preferably added to the electrolyte.

[0028] Among them, in the electrolyte, hydrochloric acid is preferably based on the total Cl in the electrolyte. - Add at a concentration of 0.05~0.15 g / L.

[0029] Among them, in the electrolyte, gelatin is preferably added in an amount of 50-100 g / t based on the production of 1 t of Cu.

[0030] Among them, in the electrolyte, thiourea is added in an amount of 35~65 g / t based on the production of 1t Cu.

[0031] Furthermore, in the electrolyte, Cu 2+ The preferred concentration is 45~48 g / L, and the preferred H2SO4 concentration is 180~200 g / L.

[0032] Furthermore, in the electrolyte, the Ni concentration is ≤20 g / L, the As concentration is ≤5.0 g / L, the Fe concentration is ≤3.0 g / L, and the Sb concentration is ≤0.1 g / L.

[0033] The second object of the present invention is to provide a method for electrolytic refining of high-gold and silver complex copper anode plates using the above copper refining electrolyte, comprising the following steps:

[0034] The copper anode plate is used as the anode and the stainless steel permanent cathode plate is used as the cathode to carry out continuous electrolysis, and cathode copper is obtained after the electrolysis is completed.

[0035] Among them, the anode plate is a high-gold and silver complex copper anode plate, which comes from the copper fire refining process.

[0036] Furthermore, the electrolysis conditions preferably include: controlling the electrolyte temperature to 60-65°C, controlling the current density to 300-320 A / m 2 , control the single slot voltage to 0.25~0.35V.

[0037] Furthermore, the copper anode plate preferably has: a Cu content ≥ 98.0 wt %, an Au content ≤ 500 g / t, and an Ag content ≤ 1.0 wt %.

[0038] Furthermore, in the copper anode plate, preferably: As content ≤1.0wt%, Sb content ≤0.5wt%, Se content ≤0.5wt%, Bi content ≤0.2wt%.

[0039] Furthermore, during the continuous electrolysis process, 25% to 30% of the total electrolyte circulation volume is extracted every day and filtered through a precision filter before returning to the electrolyte circulation system to ensure the cleanliness of the electrolyte.

[0040] Furthermore, during the continuous electrolysis process, according to the concentration of copper and impurities in the electrolyte, part of the electrolyte is extracted every day and sent to the liquid purification workshop for treatment to ensure that the concentration of copper and impurities in the electrolyte of the electrolysis system does not exceed the limit value.

[0041] Furthermore, when the electrolysis is completed and the tank is cleaned, the anode mud flows from the anode mud outlet at the bottom of the tank to the anode mud trough (with stirring), is pumped to the anode mud thickener, and the bottom flow is pumped to the filter press by the filter press pump. The overflow flows into the overflow liquid storage tank, is filtered through the filter press, and then filtered through the electrolyte precision filter before returning to the circulation system. The filter residue is the gold and silver-containing anode mud, and the anode mud is sent to the refining system to recover valuable metals such as gold and silver.

[0042] The beneficial effects of the present invention are as follows:

[0043] The present invention suppresses the oxidative dissolution of gold and silver in the copper anode plate during copper electrolysis by adding an oxidative activity inhibitor, thereby achieving efficient separation and recovery of copper from gold and silver in a complex copper anode plate with high gold and silver content. The invention has the advantages of short process flow, high metal recovery rate, low processing cost, etc., and has far-reaching significance for improving the economic benefits of enterprises and taking the path of green and sustainable development. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 The present invention is a process flow chart of the electrolytic refining method of high-gold and silver complex copper anode plates in a specific implementation method. DETAILED DESCRIPTION

[0045] The principles and features of the present invention are described below in conjunction with examples, which are only used to explain the present invention and are not used to limit the scope of the present invention. The experimental methods used in the following examples are conventional methods unless otherwise specified. The materials, reagents, etc. used in the following examples, unless otherwise specified, can all be obtained from commercial sources. Example 1

[0046] 1. Prepare the oxidation activity inhibitor as follows:

[0047] S1. Preparation of copper acetate: Add acetic acid to water, stir and dissolve at 30°C, slowly add copper hydroxide solid after complete dissolution, react at 30°C for 4 hours and filter, the filtrate is a blue transparent copper acetate solution; the mass ratio of acetic acid, water and copper hydroxide is 1:12:4;

[0048] S2. The copper acetate solution, hydrochloric acid and copper powder obtained in step S1 are mixed, put into a hydrothermal synthesis reactor, reacted at 120°C for 4 h, and after the reaction is completed, cooled to room temperature in an airtight state, filtered, and the filtrate is the oxidation activity inhibitor; the mass ratio of copper acetate, HCl in hydrochloric acid, and copper powder is 1:1:0.5; the concentration of the hydrochloric acid used is 36wt%.

[0049] 2. Add the above-mentioned oxidation activity inhibitor to the electrolyte and electrolytically refine the high-gold-silver complex copper anode plate. The contents of the main components of the high-gold-silver complex copper anode plate are: Cu content 98.21wt%, Au content 120.02 g / t, Ag content 0.57wt%, As content 0.39wt%, Sb content 0.32wt%, Se content 0.24wt%, Bi content 0.14wt%. The steps of the electrolytic refining method are as follows:

[0050] S1. The high-gold and silver complex copper anode plates produced by the pyrometallurgical refining workshop are transported by forklift to the anode plate three-dimensional storage warehouse, and then transported to the anode shaping unit in the electrolysis workshop.

[0051] S2. High gold and silver complex copper anode plate as anode, stainless steel permanent cathode plate as cathode, for continuous electrolysis;

[0052] In electrolyte: Cu 2+ The concentration was maintained at 45-48 g / L, the H2SO4 concentration was maintained at 180-200 g / L; the hydrochloric acid concentration was maintained at 180-200 g / L according to the total Cl -The concentration is 0.05 g / L. Gelatin is added at 55 g / t for 1 t Cu produced. Thiourea is added at 39 g / t for 1 t Cu produced. The oxidation activity inhibitor is added at 30 g / t for every 1 t Cu produced, calculated based on the cuprous ions therein. The impurity Ni concentration in the electrolyte is maintained at ≤20 g / L, As concentration at ≤5.0 g / L, Fe concentration at ≤3.0 g / L, and Sb concentration at ≤0.1 g / L.

[0053] Continuous electrolysis, interelectrode distance 100 mm, electrolyte temperature controlled at 60°C, current density controlled at 300 A / m 2 , the single tank voltage is controlled to be 0.25V. After one cathode cycle electrolysis is completed, the cathode is lifted to the cathode stripping unit by a special crane, and then transported to the cathode copper conveyor belt after washing, stripping and stacking. After weighing and packaging, it is transported to the cathode copper three-dimensional storage warehouse by a transport trolley;

[0054] During the continuous electrolysis process, a dedicated electrolyte precision filter is set up to ensure the cleanliness of the electrolyte. The electrolyte circulation system extracts 25% of the total electrolyte circulation volume every day and returns it to the electrolyte circulation system after filtering through the precision filter.

[0055] During the continuous electrolysis process, according to the concentration of copper and impurities in the electrolyte, part of the electrolyte is extracted every day and sent to the liquid purification workshop for treatment to ensure that the concentration of copper and impurities in the electrolyte of the electrolysis system does not exceed the limit value of the electrolyte.

[0056] S3. When the electrolysis is finished and the tank is cleaned, the anode mud flows from the anode mud outlet at the bottom of the tank to the anode mud trough (with stirring), is pumped to the anode mud thickener, and the bottom flow is pumped to the filter press by the filter press. The overflow flows into the overflow liquid storage tank, is filtered by the filter press, and then filtered by the electrolyte precision filter before returning to the circulation system. The filter residue is the anode mud containing gold and silver. The anode mud is sent to the refining system to recover valuable metals such as gold and silver. Example 2

[0057] 1. Prepare the oxidation activity inhibitor as follows:

[0058] S1. Preparation of copper acetate: Add acetic acid to water, stir and dissolve at 50°C, slowly add copper hydroxide solid after complete dissolution, react at 50°C for 2 h and filter, the filtrate is a blue transparent copper acetate solution; the mass ratio of acetic acid, water and copper hydroxide is 1:15:6;

[0059] S2. The copper acetate solution, hydrochloric acid and copper powder obtained in step S1 are mixed, placed in a hydrothermal synthesis reactor, reacted at 150°C for 6 h, and after the reaction is completed, cooled to room temperature in an airtight manner, filtered, and the filtrate is the oxidation activity inhibitor; the mass ratio of copper acetate, HCl in hydrochloric acid, and copper powder is 1:2:1; the concentration of the hydrochloric acid used is 36wt%.

[0060] 2. Add the above-mentioned oxidation activity inhibitor to the electrolyte and electrolytically refine the high-gold-silver complex copper anode plate. The contents of the main components of the high-gold-silver complex copper anode plate are: Cu content 98.19wt%, Au content 498.21 g / t, Ag content 0.97wt%, As content 0.18wt%, Sb content 0.12wt%, Se content 0.19wt%, Bi content 0.18wt%. The steps of the electrolytic refining method are as follows:

[0061] S1. The high-gold and silver complex copper anode plates produced by the pyrometallurgical refining workshop are transported by forklift to the anode plate three-dimensional storage warehouse, and then transported to the anode shaping unit in the electrolysis workshop.

[0062] S2. High gold and silver complex copper anode plate as anode, stainless steel permanent cathode plate as cathode, for continuous electrolysis;

[0063] In electrolyte: Cu 2+ The concentration was maintained at 45-48 g / L, the H2SO4 concentration was maintained at 180-200 g / L; the hydrochloric acid concentration was maintained at 180-200 g / L according to the total Cl - The concentration is 0.15 g / L. Gelatin is added at 60 g / t for 1 t Cu produced. Thiourea is added at 39 g / t for 1 t Cu produced. Oxidation inhibitor is added at 50 g / t for every 1 t Cu produced, calculated based on the cuprous ions therein. The Ni concentration in the electrolyte is maintained at ≤20 g / L, the As concentration at ≤5.0 g / L, the Fe concentration at ≤3.0 g / L, and the Sb concentration at ≤0.1 g / L.

[0064] Continuous electrolysis, interelectrode distance 100 mm, electrolyte temperature controlled at 64 °C, current density controlled at 300 A / m 2 , the single tank voltage is controlled at 0.35V. After one cathode cycle electrolysis is completed, the cathode is lifted to the cathode stripping unit by a special crane, and then transported to the cathode copper conveyor belt after washing, stripping and stacking. After weighing and packaging, it is transported to the cathode copper three-dimensional storage warehouse by a transport trolley; in the continuous electrolysis process, in order to ensure the cleanliness of the electrolyte, a special electrolyte precision filter is set up. The electrolyte circulation system extracts 25% of the total electrolyte circulation volume every day, which is filtered by the precision filter and returned to the electrolyte circulation system;

[0065] During the continuous electrolysis process, according to the concentration of copper and impurities in the electrolyte, part of the electrolyte is extracted every day and sent to the liquid purification workshop for treatment to ensure that the concentration of copper and impurities in the electrolyte of the electrolysis system does not exceed the limit value of the electrolyte.

[0066] S3. When the electrolysis is finished and the tank is cleaned, the anode mud flows from the anode mud outlet at the bottom of the tank to the anode mud trough (with stirring), is pumped to the anode mud thickener, and the bottom flow is pumped to the filter press by the filter press. The overflow flows into the overflow liquid storage tank, is filtered by the filter press, and then filtered by the electrolyte precision filter before returning to the circulation system. The filter residue is the anode mud containing gold and silver. The anode mud is sent to the refining system to recover valuable metals such as gold and silver. Example 3

[0067] 1. Prepare the oxidation activity inhibitor as follows:

[0068] S1. Preparation of copper acetate: Add acetic acid to water, stir and dissolve at 40°C, slowly add copper hydroxide solid after complete dissolution, react at 40°C for 3 hours and filter, the filtrate is a blue transparent copper acetate solution; the mass ratio of acetic acid, water and copper hydroxide is preferably 1:13:5;

[0069] S2. The copper acetate solution, hydrochloric acid and copper powder obtained in step S1 are mixed, put into a hydrothermal synthesis reactor, reacted at 140°C for 3 h, and after the reaction is completed, cooled to room temperature in an airtight state, filtered, and the filtrate is the oxidation activity inhibitor; the mass ratio of copper acetate, HCl in hydrochloric acid, and copper powder is 1:1.5:0.8; the concentration of the hydrochloric acid used is 36wt%.

[0070] 2. Add the above-mentioned oxidation activity inhibitor to the electrolyte and electrolytically refine the high-gold-silver complex copper anode plate. The contents of the main components of the high-gold-silver complex copper anode plate are: Cu content 98.09wt%, Au content 425 g / t, Ag content 0.89wt%, As content 0.28wt%, Sb content 0.23wt%, Se content 0.26wt%, Bi content 0.14wt%. The steps of the electrolytic refining method are as follows:

[0071] S1. The high-gold and silver complex copper anode plates produced by the pyrometallurgical refining workshop are transported by forklift to the anode plate three-dimensional storage warehouse, and then transported to the anode shaping unit in the electrolysis workshop.

[0072] S2. High gold and silver complex copper anode plate as anode, stainless steel permanent cathode plate as cathode, for continuous electrolysis;

[0073] In electrolyte: Cu 2+ The concentration was maintained at 45-48 g / L, the H2SO4 concentration was maintained at 180-200 g / L; the hydrochloric acid concentration was maintained at 180-200 g / L according to the total Cl -The concentration is 0.08 g / L. Gelatin is added at 95 g / t for 1 t Cu produced. Thiourea is added at 64 g / t for 1 t Cu produced. Oxidation inhibitor is added at 40 g / t for every 1 t Cu produced, calculated based on the cuprous ions therein. The impurity Ni concentration in the electrolyte is maintained at ≤20 g / L, As concentration at ≤5.0 g / L, Fe concentration at ≤3.0 g / L, and Sb concentration at ≤0.1 g / L.

[0074] Continuous electrolysis, interelectrode distance 100 mm, electrolyte temperature controlled at 65°C, current density controlled at 320 A / m 2 , the single tank voltage is controlled to be 0.33V. After one cathode cycle electrolysis is completed, the cathode is lifted to the cathode stripping unit by a special crane, and then transported to the cathode copper conveyor belt after washing, stripping and stacking. After weighing and packaging, it is transported to the cathode copper three-dimensional storage warehouse by a transport trolley;

[0075] During the continuous electrolysis process, a dedicated electrolyte precision filter is set up to ensure the cleanliness of the electrolyte. The electrolyte circulation system extracts 30% of the total electrolyte circulation volume every day and returns it to the electrolyte circulation system after filtering through the precision filter.

[0076] During the continuous electrolysis process, according to the concentration of copper and impurities in the electrolyte, part of the electrolyte is extracted every day and sent to the liquid purification workshop for treatment to ensure that the concentration of copper and impurities in the electrolyte of the electrolysis system does not exceed the limit value of the electrolyte.

[0077] S3. When the electrolysis is finished and the tank is cleaned, the anode mud flows from the anode mud outlet at the bottom of the tank to the anode mud trough (with stirring), is pumped to the anode mud thickener, and the bottom flow is pumped to the filter press by the filter press. The overflow flows into the overflow liquid storage tank, is filtered by the filter press, and then filtered by the electrolyte precision filter before returning to the circulation system. The filter residue is the anode mud containing gold and silver. The anode mud is sent to the refining system to recover valuable metals such as gold and silver.

[0078] Comparative Example 1-1

[0079] Referring to Example 1, electrolytic refining was performed on a high-gold-silver complex copper anode plate. The difference from Example 1 is that no oxidation activity inhibitor was added to the electrolyte.

[0080] Comparative Example 1-2

[0081] Referring to Example 1, electrolytic refining is performed on a high-gold-silver complex copper anode plate. The difference from Example 1 is that the cuprous ion content such as the oxidation activity inhibitor in the electrolyte is replaced by cuprous chloride.

[0082] Comparative Example 2-1

[0083] Referring to Example 2, electrolytic refining was performed on a high-gold-silver complex copper anode plate. The difference from Example 2 is that no oxidation activity inhibitor was added to the electrolyte.

[0084] Comparative Example 2-2

[0085] Referring to Example 2, electrolytic refining is performed on a high-gold-silver complex copper anode plate. The difference from Example 2 is that the cuprous ion content such as the oxidation activity inhibitor in the electrolyte is replaced by cuprous chloride.

[0086] Comparative Example 3-1

[0087] Referring to Example 3, electrolytic refining was performed on a high-gold-silver complex copper anode plate. The difference from Example 3 is that no oxidation activity inhibitor was added to the electrolyte.

[0088] Comparative Example 3-2

[0089] Referring to Example 3, electrolytic refining is performed on a high-gold-silver complex copper anode plate. The difference from Example 3 is that the cuprous ion content such as the oxidation activity inhibitor in the electrolyte is replaced by cuprous chloride.

[0090] Test 1

[0091] The cathode copper obtained in each embodiment and each comparative example was tested to determine whether it met the Grade A copper standard. The results are shown in Table 1. The contents of gold, silver and copper in the anode mud of each embodiment and each comparative example were tested. The results are shown in Table 2. The gold, silver and copper recovery rates of each embodiment and each comparative example are shown in Table 3.

[0092] Cathode copper is tested in accordance with the Chemical Analysis Methods for Copper and Copper Alloys Part 1: Determination of Copper Content (GB / T 5121.1-2008). Gold and silver in anode mud are tested in accordance with the Chemical Analysis Methods for Copper Anode Mud Part 2: Determination of Gold and Silver Contents by Fire Assay Gravimetric Method (YS / T 745.2-2016); copper in anode mud is tested in accordance with the Chemical Analysis Methods for Copper Anode Mud Part 1: Determination of Copper Content by Iodine Assay (YS / T 745.1-2010).

[0093] Table 1 Contents that meet Grade A copper standards

[0094] name Comparative Example 1-1 Comparative Example 1-2 Example 1 Comparative Example 2-1 Comparative Example 2-2 Example 2 Comparative Example 3-1 Comparative Example 3-2 Example 3 A-grade copper ratio (%) 35.25 82.53 95.35 42.21 80.69 95.58 48.25 81.36 95.21

[0095] As can be seen from Table 1, more than 95% of the cathode copper produced in Examples 1 to 3 meets the Grade A copper standard, less than 50% of the cathode copper produced in Comparative Examples 1-1, 2-1, and 3-1 meets the Grade A copper standard, and less than 85% of the cathode copper produced in Comparative Examples 1-2, 2-2, and 3-2 meets the Grade A copper standard.

[0096] Table 2 Gold, silver and copper content of copper anode mud

[0097] name Comparative Example 1-1 Comparative Example 1-2 Example 1 Comparative Example 2-1 Comparative Example 2-2 Example 2 Comparative Example 3-1 Comparative Example 3-2 Example 3 Au (wt%) 0.85 0.92 1.21 0.91 0.95 1.05 0.84 0.98 1.34 Ag (wt%) 19.21 22.31 26.21 18.24 21.98 25.89 19.02 22.65 27.01 Cu (wt%) 18.24 15.23 12.24 19.57 15.05 14.02 17.65 15.34 13.52

[0098] As can be seen from Table 2, the Au content in the copper anode mud produced by Examples 1 to 3 is all above 1wt%, the Ag content is all above 25wt%, and the Cu content is all below 15wt%; the Au content in the copper anode mud produced by Comparative Example 1-1, Comparative Example 2-1, and Comparative Example 3-1 is all below 1%, the Ag content is all below 20%, and the Cu content is all above 15%; the Au content in the copper anode mud produced by Comparative Example 1-2, Comparative Example 2-2, and Comparative Example 3-2 is all below 1%, the Ag content is all below 23%, and the Cu content is all above 15%.

[0099] Table 3 Recovery rates of gold, silver and copper

[0100] name Comparative Example 1-1 Comparative Example 1-2 Example 1 Comparative Example 2-1 Comparative Example 2-2 Example 2 Comparative Example 3-1 Comparative Example 3-2 Example 3 Au(%) 83.21 92.35 99.52 82.94 93.24 99.58 84.25 92.87 99.54 Ag(%) 86.24 93.56 99.54 87.21 94.68 99.51 85.19 93.57 99.54 Cu (%) 99.42 99.49 99.82 99.35 99.48 99.85 99.26 99.46 99.83

[0101] As can be seen from Table 3, in Examples 1 to 3, the Au and Ag recovery rates are all above 99.5%, and the Cu recovery rates are all above 99.8%; in Comparative Example 1-1, Comparative Example 2-1, and Comparative Example 3-1, the Au recovery rates are all below 85%, the Ag recovery rates are all below 90%, and the Cu recovery rates are all below 99.5%; in Comparative Example 1-2, Comparative Example 2-2, and Comparative Example 3-2, the Au recovery rates are all below 95%, the Ag recovery rates are all below 95%, and the Cu recovery rates are all below 99.5%.

[0102] Test 2

[0103] The current efficiency of each embodiment and each comparative example was tested, and the results are shown in Table 4.

[0104] Table 4 Current efficiency

[0105] name Comparative Example 1-1 Comparative Example 1-2 Example 1 Comparative Example 2-1 Comparative Example 2-2 Example 2 Comparative Example 3-1 Comparative Example 3-2 Example 3 Current efficiency (%) 94.89 95.68 97.21 94.25 95.34 97.02 94.62 95.92 97.15

[0106] It can be seen from Table 4 that the current efficiencies of Examples 1 to 3 are all above 97%, the current efficiencies of Comparative Examples 1-1, 2-1, and 3-1 are all below 95%, and the current efficiencies of Comparative Examples 1-2, 2-2, and 3-2 are all below 96%.

[0107] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. An electrolyte for copper refining, comprising copper sulfate and sulfuric acid, characterized in that: Also included is an oxidative activity inhibitor; the oxidative activity inhibitor is prepared by the following method: S1. Obtain copper acetate; S2. Mix copper acetate, hydrochloric acid and copper powder, react at 120-150 °C for 4-6 h, filter after cooling, and the filtrate is the oxidation activity inhibitor; the mass ratio of copper acetate, HCl in hydrochloric acid, and copper powder is 1:(1-2):(0.5-1).

2. The copper refining electrolyte according to claim 1, characterized in that: In step S1: the cupric acetate is generated by reacting acetic acid solution with cupric hydroxide.

3. The copper refining electrolyte according to claim 1 or 2, characterized in that: In the electrolyte, the amount of the oxidation activity inhibitor added is 30-50 g / t per 1t Cu calculated based on the cuprous ions therein.

4. The copper refining electrolyte according to claim 1 or 2, characterized in that: At least one of hydrochloric acid, gelatin and thiourea is also added.

5. A method for electrolytic refining of high-gold and silver complex copper anode plates, using the copper refining electrolyte as claimed in claim 1 or 2, characterized in that: The steps include: The copper anode plate is used as the anode and the stainless steel permanent cathode plate is used as the cathode to carry out continuous electrolysis to obtain cathode copper.

6. The electrolytic refining method of high-gold and silver complex copper anode plate according to claim 5 is characterized in that: The electrolysis conditions include: controlling the electrolyte temperature to 60-65 °C and the current density to 300-320 A / m 2 , control the single slot voltage to 0.25~0.35V.

7. The electrolytic refining method of high-gold and silver complex copper anode plate according to claim 5 or 6, characterized in that: In the copper anode plate: Cu content ≥ 98.0wt%, Au content ≤ 500 g / t, Ag content ≤ 1.0wt%.

8. The electrolytic refining method of high-gold-silver complex copper anode plate according to claim 7, characterized in that: In the copper anode plate: As content ≤1.0wt%, Sb content ≤0.5wt%, Se content ≤0.5wt%, Bi content ≤0.2wt%.

9. The electrolytic refining method of high-gold and silver complex copper anode plate according to claim 5 or 6, characterized in that: During the continuous electrolysis process, 25% to 30% of the total electrolyte circulation volume is extracted every day, filtered through a precision filter, and returned to the electrolyte circulation system.

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