Method for synchronously removing arsenic, antimony and bismuth impurities from copper electrolyte

Abstract

The invention belongs to the field of copper electrolyte purification, and particularly relates to a method for synchronously removing arsenic, antimony and bismuth impurities from a copper electrolyte, which comprises the following steps: putting a copper-based impurity removal agent into a to-be-treated copper electrolyte containing the arsenic, antimony and bismuth impurities, and carrying out impurity removal treatment to obtain a purified copper electrolyte; the copper-based impurity removal agent is cuprous oxide and / or a modified copper material, and the modified copper material is obtained by carrying out acid modification treatment and / or alkali modification treatment on a copper raw material; the copper raw material is at least one of metal copper powder and cuprous oxide powder; and the D50 of the copper-based impurity removal agent is 0.5 to 75 [mu] m. According to the method, arsenic, antimony and bismuth impurities in the copper electrolyte can be synchronously removed in a high-selectivity mode, and especially the effect of deeply purifying antimony and bismuth is achieved.

Description

Technical Field

[0001] The invention relates to a method for simultaneously removing arsenic, antimony and bismuth impurities from a copper electrolyte, and belongs to the field of nonferrous metal metallurgy. Technical Background

[0002] Copper electrolysis is a key link in copper smelting, and its operation effect has a significant impact on the quality and technical and economic indicators of cathode copper. Studies have shown that the concentration of arsenic, antimony and bismuth impurities in copper electrolyte has an important influence on the copper electrolysis process. When the concentration of arsenic, antimony and bismuth is too high, not only will the electrolyte be turbid and the pipeline be blocked, but they will also precipitate on the cathode, and the surface of the cathode copper plate will be granulated, resulting in unqualified cathode copper purity. For this reason, copper smelters have strict limits on arsenic, antimony and bismuth impurities in copper electrolyte, usually requiring arsenic, antimony and bismuth concentrations not to exceed 8g / L, 0.7g / L and 0.5g / L respectively. However, with the increasing complexity of copper smelting raw materials and the large-scale use of high-impurity copper concentrates, the arsenic, antimony and bismuth impurities in the copper smelting electrolysis system have risen rapidly, resulting in poor technical and economic indicators of copper electrolysis. Therefore, how to efficiently open the circuit electrolysis system of arsenic, antimony and bismuth impurities has attracted much attention.

[0003] The reported processes for removing arsenic, antimony and bismuth from copper electrolytes include self-purification precipitation, adsorption, and ion exchange. Among them, the self-purification precipitation method is the most widely studied and applied. The self-purification precipitation method uses the arsenic, antimony and bismuth in the copper electrolyte to undergo a co-precipitation reaction under certain conditions, so that arsenic, antimony and bismuth are removed. This method is simple and low-cost, but it has strict restrictions on the concentration and proportion of arsenic, antimony and bismuth in the electrolyte, otherwise the impurities cannot be removed. In addition, this method has a good effect on the removal of antimony under appropriate conditions, but not on bismuth. Therefore, the effect of this method is very limited, especially when the concentration of antimony and bismuth is high. To solve this problem, researchers have developed adsorption and ion exchange methods. The basic principles of these two methods for removing arsenic, antimony and bismuth are the same, but the active materials used are different. The adsorption method usually uses antimony salts, zirconium salts or titanium salts, while the ion exchange method uses resins for adsorption. Although adsorption or ion exchange can remove a certain amount of arsenic, antimony, and bismuth, the copper loss is high and impurities are easily introduced, causing the electrolyte to be contaminated. Therefore, these two methods have not been widely used.

[0004] With the continuous enhancement of environmental awareness, technicians have carried out a lot of work on copper electrolyte purification methods and have made some progress. For example, the Chinese patent document with publication number CN117585711A discloses a green purification agent for copper electrolyte and its synthesis method, specifically grinding antimony pentoxide and antimony sulfate and fully mixing them and pre-treating them with hydrogen peroxide to obtain a green purification agent. For another example, the Chinese patent document with publication number CN109022784A discloses a method for removing arsenic, antimony and bismuth from copper electrolyte, specifically disclosing a method for converting a titanium antimony mixture into an active impurity remover by hydrogen peroxide activation treatment. The basic principles of the above two schemes are the same, that is, by increasing pentavalent antimony in the solution and using antimony acid precipitation to adsorb bismuth, the removal effect of bismuth is improved.

[0005] The existing technical methods have some inherent deficiencies, such as high cost, easy introduction of impurities, high copper loss, and inability to remove antimony and bismuth simultaneously, and still need to be further improved. The industry urgently needs to develop a method for removing arsenic, antimony and bismuth from copper electrolyte with simple process, low cost and no introduction of impurities. Summary of the invention

[0006] In view of the problems of low efficiency of impurity removal methods for removing arsenic, antimony and bismuth from copper electrolyte and unsatisfactory effect of simultaneous impurity removal, the present invention aims to provide a method for simultaneously removing arsenic, antimony and bismuth impurities from copper electrolyte, aiming to improve the efficiency and effect of simultaneous removal of arsenic, antimony and bismuth impurities in copper electrolyte.

[0007] Due to the high acidity of copper electrolyte, and the fact that the copper concentration in the solution is much higher than that of arsenic, antimony and bismuth, the existing self-purification precipitation method, adsorption method or ion exchange method all have obvious limitations. To this end, the inventors have proposed the idea of ​​removing arsenic, antimony and bismuth from the electrolyte by copper salt reduction method through a large number of investigations and experimental studies. However, although the theoretical analysis results have confirmed the feasibility of this technical route, the removal effect of arsenic, antimony and bismuth is not good in practice. Even if the particle size of the treatment agent is refined, it is still difficult to achieve the desired result. In view of this problem, the present invention has been studied in depth and provides the following solution:

[0008] A method for simultaneously removing arsenic, antimony and bismuth impurities from a copper electrolyte, wherein a copper-based impurity remover is placed in a copper electrolyte to be treated containing arsenic, antimony and bismuth impurities, and an impurity removal treatment is performed to obtain a purified copper electrolyte;

[0009] The copper-based impurity remover is cuprous oxide and / or modified copper material, and the modified copper material is obtained by subjecting copper raw materials to acid modification and / or alkali modification, wherein the copper raw materials are at least one of metallic copper powder and cuprous oxide powder; and the D50 of the copper-based impurity remover is 0.5 to 75 μm.

[0010] In view of the problem that the efficiency and effect of the copper-based reduction method for simultaneously removing arsenic, antimony and bismuth from the electrolyte are not ideal, the present invention innovatively adopts cuprous oxide or modified copper-based materials as impurity removers, so that arsenic, antimony and bismuth in the waste copper electrolyte can be removed simultaneously without introducing new impurities, and has excellent purification performance.

[0011] The research of the present invention shows that it is difficult to obtain an ideal simultaneous impurity removal effect by using metallic copper alone, but after the modification treatment described in the present invention, it is possible to optimize the physical and chemical characteristics of the surface of the treatment agent, optimize its surface activity, and use the pre-modified copper-based material for the removal of arsenic, antimony and bismuth impurities in copper electrolyte, thereby improving the simultaneous removal efficiency and effect of arsenic, antimony and bismuth therein, and in addition, no new impurities will be introduced, which has excellent industrial advantages.

[0012] The technical scheme of the present invention, taking into account the effect and economic value, may include the following optional schemes: Scheme 1: directly using low-carbon content cuprous oxide as an impurity remover, or high-carbon content cuprous oxide (cuprous oxide with a carbon content of more than 0.5wt.%) treated with alkali as an impurity remover. Scheme 2: using the modified copper-based material as an impurity remover; Scheme 3: using a combination of cuprous oxide and modified copper materials as an impurity remover. Among them, in Scheme 2, it can be divided into a low-carbon modified scheme (Scheme 2-A) and a high-carbon first alkali and then acid modified scheme (Scheme 2-B) according to the carbon content of the raw materials.

[0013] In Scheme 2-A of the present invention, the low-carbon raw material refers to a copper raw material with a carbon content of less than or equal to 0.25%. The low-carbon raw material can be subjected to acid modification treatment to obtain the modified copper raw material.

[0014] Preferably, the carbon content of the low-carbon raw material is less than 0.2 wt.% and the D50 is 5-25 μm. For example, the D50 of the metal copper powder is 5-25 μm, the oxygen content is less than 0.5%, and the carbon content is less than 0.2%. The D50 of the cuprous oxide powder is 5-25 μm and the carbon content is less than 0.1%.

[0015] In the present invention, the acid solution used in the acid modification treatment step is an aqueous solution of an inorganic strong acid;

[0016] In the present invention, the inorganic strong acid includes at least one of hydrochloric acid and sulfuric acid; preferably a mixed acid of hydrochloric acid and sulfuric acid in a molar ratio of 0.03-0.1:1. The present invention unexpectedly shows that under the same acid solute solubility, the use of the mixed acid can unexpectedly further optimize the surface physicochemical characteristics of the copper-based material, so that it can give more physicochemical characteristics and active sites suitable for the simultaneous removal of arsenic, antimony and bismuth impurities in the copper electrolyte, and can unexpectedly further enhance the efficiency and effect of the simultaneous removal of arsenic, antimony and bismuth impurities in the copper electrolyte.

[0017] In the present invention, the concentration of the solute in the acid solution is 1 to 2 mol / L;

[0018] Preferably, the liquid-to-solid ratio in the acid modification treatment stage is 3 to 6:1;

[0019] Preferably, the temperature in the acid modification treatment stage is above 20°C, further 50-90°C;

[0020] Preferably, the acid modification treatment time is more than 10 min, preferably 15-50 min.

[0021] In the scheme 2-B of the present invention, the high-carbon raw material may refer to a copper raw material with a carbon content greater than 0.25% (or further 0.3-0.9 wt.%), which may be pre-treated with an alkali and then treated with an acid to obtain the modified copper raw material. In the present invention, the combined process may be used to obtain a better effect for the high-carbon raw material.

[0022] In the present invention, the alkali solution used in the alkali treatment step is an aqueous solution of at least one alkaline solute selected from the group consisting of alkali metal hydroxides and carbonates;

[0023] Preferably, the alkaline solute includes at least one of sodium hydroxide and potassium hydroxide.

[0024] In the present invention, the concentration of the solute in the alkali solution is 0.5 to 1 mol / L;

[0025] Preferably, the liquid-to-solid ratio in the alkali treatment stage is 3 to 6:1;

[0026] Preferably, the temperature of the alkali treatment stage is above 20°C, further 50 to 90°C;

[0027] Preferably, the alkali treatment time is 10 minutes or more, preferably 15 to 50 minutes.

[0028] In the present invention, in Scheme 2-B, after the alkali modification treatment, a subsequent acid modification treatment can be performed using the acid modification process of Scheme 2-A.

[0029] In the present invention, the copper electrolyte to be treated can be any waste copper electrolyte with treatment value, for example, wherein the concentration of arsenic, antimony and bismuth is above 100 mg / L; and the acidity is controlled below 320 g / L.

[0030] In the present invention, the modified copper-based impurity remover is 2-8 times the mass of arsenic, antimony and bismuth in the copper electrolyte to be treated.

[0031] In the present invention, the temperature in the impurity removal stage is between 35°C and 85°C;

[0032] Preferably, the time for the impurity removal treatment is 30 to 90 minutes.

[0033] Beneficial effects:

[0034] (1) The process flow of the present invention is short and the cost of removing arsenic, antimony and bismuth from the electrolyte is low.

[0035] (2) The reaction conditions of the present invention are mild, no special equipment is required, the copper salt materials used are widely available, and industrialization is easy to achieve.

[0036] (3) The impurity removal agent used in the present invention is a copper salt material, and no impurities will be introduced during the use process, and no pollution will be caused to the existing production system.

[0037] (4) The impurity-removing slag obtained by the present invention has simple composition and high antimony-bismuth content, and can be sold as an antimony-bismuth byproduct.

[0038] (5) The present invention is environmentally friendly, does not generate waste gas or waste residue, has low energy consumption, and does not require pyrolysis or high temperature and high pressure processes. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Attached Figure 1 The XRD pattern of the reaction product obtained in Example 1

[0040] Attached Figure 2 This is the SEM-EDS analysis spectrum of the precipitate obtained by removing impurities in Example 6 DETAILED DESCRIPTION

[0041] The following examples are intended to further illustrate the present invention, rather than to limit the scope of the claims of the present invention.

[0042] Embodiment 1:

[0043] Take metal copper powder (O: 1.35%, C: 0.12%, D50: 16.64um) as an impurity removal agent to purify copper electrolyte (Cu: 48.55g / L, As: 9.12g / L, Sb: 0.45g / L, Bi: 1.67g / L, H2SO4: 185g / L) as an example. First weigh 20g of the above metal copper powder, add it to 80mL 1.2mol / L mixed acid (H2SO4: 1.15mol / L, HCl: 0.05mol / L) activation solution, and stir at 75℃ for 35min. After activation, filter and collect the filter residue, and the obtained filter residue is the activated copper powder. The activated copper powder was added to 2.5L of waste electrolyte, and the reaction was terminated after 45 minutes at 60°C. The filtrate and the residue were collected respectively. The filtrate was the purified copper electrolyte. The arsenic, antimony and bismuth concentrations were 6.56, 0.17 and 0.12 g / L respectively. The above results show that the activated copper powder has a good removal effect on arsenic, antimony and bismuth in the electrolyte, and the arsenic, antimony and bismuth concentrations of the purified copper electrolyte can fully meet the technical requirements of the copper electrolyte.

[0044] Depend on Figure 1 It can be seen that in addition to Cu and Cu2O, the obtained product also has a characteristic diffraction peak of Bi2O3, indicating that in the reaction process, metallic copper can reduce and remove bismuth. No characteristic diffraction peak is observed for antimony due to its low content.

[0045] Comparative Example 1:

[0046] Compared with Example 1, the only difference is that the copper powder is not subjected to the acid activation treatment, that is, the metal copper powder is directly subjected to the waste copper electrolyte treatment, and the other operations and parameters are the same as Example 1. The results after treatment are: arsenic, antimony and bismuth concentrations are 8.74, 0.41 and 1.13 g / L respectively. The above results show that the unactivated copper powder has a poor effect on removing arsenic, antimony and bismuth from the electrolyte, and the arsenic, antimony and bismuth concentrations of the purified copper electrolyte are still high, which cannot meet the technical requirements of the copper electrolyte.

[0047] Embodiment 2:

[0048] The purification and impurity removal of copper electrolyte (same as Example 1) is carried out by taking metal copper powder (O: 2.15%, C: 0.76%, D50: 5.48um) as an impurity removal agent as an example.

[0049] First weigh 25g of the above-mentioned metal copper powder, add it to 90mL 0.85mol / LNaOH solution and stir and react for 35min at 80. After alkali washing is completed, filter, add the alkali washing residue to 90mL 1.85mol / L mixed acid (H2SO4: 1.70mol / L, HCl: 0.15mol / L) activation solution and stir and activate for 35min at 75°C. After the acid washing activation is completed, filter and collect the acid washing residue, and the obtained residue is the activated copper powder. Add the activated copper powder to 2.5L waste electrolyte, react at 55°C for 45min, end the reaction filtration, collect the filtrate and the residue respectively, the filtrate is the purified copper electrolyte, and the sampling analysis shows that the concentrations of arsenic, antimony and bismuth are 6.38, 0.17 and 0.16g / L respectively.

[0050] Embodiment 3:

[0051] Compared with Example 2, the only difference is that the metal copper powder is only subjected to acid activation treatment, and the steps are: first weigh 25g of the above-mentioned metal copper powder, add it to 90mL 1.85mol / L mixed acid (H2SO4: 1.70mol / L, HCl: 0.15mol / L) activation solution and stir and activate for 35min at 75°C. After the acid washing activation is completed, the acid washing residue is filtered and collected, and the obtained residue is the activated copper powder. The activated copper powder is added to 2.5L of waste electrolyte, reacted at 55°C for 45min, and then the reaction is terminated and filtered, and the filtrate and the residue are collected respectively. The filtrate is the purified copper electrolyte, and the sampling analysis shows that the concentrations of arsenic, antimony and bismuth are 8.49, 0.34 and 0.87g / L respectively.

[0052] It can be seen from Examples 2 and 3 that for metallic copper with a high C content (e.g., above 0.5 wt.%), alkali activation followed by acid activation can further achieve synergy and further improve the simultaneous removal of arsenic, antimony and bismuth in the waste copper electrolyte.

[0053] Embodiment 4:

[0054] Take metal copper powder (O: 1.35%, C: 0.12%, D50: 16.64um) as an impurity removal agent to purify copper electrolyte (Cu: 50.27g / L, As: 10.18g / L, Sb: 0.62g / L, Bi: 1.33g / L, H2SO4: 176g / L) as an example. First weigh 20g of the above metal copper powder, add it to 110mL 1.15mol / L mixed acid (H2SO4: 1.07mol / L, HCl: 0.08mol / L) activation solution and stir at 60℃ for 45min. After the acid washing activation is completed, filter and collect the acid washing residue, and the obtained residue is the activated copper powder. The activated copper powder was added to 2L of waste electrolyte, and the reaction was terminated after 45 minutes at 40°C. The filtrate and the residue were collected respectively. The filtrate was the purified copper electrolyte. The arsenic, antimony and bismuth concentrations were 5.82, 0.20 and 0.17 g / L respectively. The above results show that the activated copper powder has a good removal effect on arsenic, antimony and bismuth in the electrolyte, and the arsenic, antimony and bismuth concentrations of the purified copper electrolyte can fully meet the technical requirements of the copper electrolyte.

[0055] Embodiment 5:

[0056] Compared with Example 1, the only difference is that cuprous oxide powder (C: 0.07%, D50: 16.8 um) is used to replace the activated copper powder as an impurity remover for purification of waste copper electrolyte. Other operations and parameters are the same as those in Example 1. The purified electrolyte is sampled and analyzed, and the concentrations of arsenic, antimony and bismuth are 5.47, 0.22 and 0.28 g / L, respectively.

[0057] It can be seen from Examples 1 and 5 that cuprous oxide can also be used to achieve a good combined removal effect of arsenic, antimony and bismuth.

[0058] Comparative Example 2:

[0059] Compared with Example 5, the only difference is that copper oxide powder (Cu: 79.24%, D50: 16.6um) is used instead of cuprous oxide as an impurity removal agent to purify and remove impurities in copper electrolyte. Other operations and parameters are the same as those in Example 1. The purified electrolyte is sampled and analyzed, and its arsenic, antimony and bismuth concentrations are 9.08, 0.46 and 1.66 g / L respectively. The above results show that copper oxide powder has no effect on removing arsenic, antimony and bismuth in the electrolyte, and the concentrations of arsenic, antimony and bismuth in the copper electrolyte after the reaction are much higher than the technical requirements of the copper electrolyte.

[0060] Embodiment 6:

[0061] Take cuprous oxide powder (C: 0.58%, D50: 11.18um) as an impurity removal agent to purify and remove impurities from copper electrolyte (Cu: 50.27g / L, As: 10.18g / L, Sb: 0.62g / L, Bi: 1.33g / L, H2SO4: 176g / L) as an example. First weigh 20g of the above cuprous oxide powder, add it to 100mL 0.65mol / L NaOH solution, and stir and activate it at 65℃ for 40min. After the alkali washing activation is completed, filter and collect the alkali washing residue, and the obtained residue is the activated copper powder. Add the activated copper powder to 1.5L of waste electrolyte, react at 80℃ for 80min, end the reaction and filter, collect the filtrate and residue respectively, the filtrate is the purified copper electrolyte, sample and analyze, and the concentrations of arsenic, antimony and bismuth are 6.38, 0.24 and 0.29g / L respectively. The above results show that the activated copper powder has a good removal effect on arsenic, antimony and bismuth in the electrolyte, and the concentrations of arsenic, antimony and bismuth in the purified copper electrolyte can fully meet the technical requirements of the copper electrolyte.

[0062] Depend on Figure 2 It can be seen that the precipitated slag obtained after impurity removal contains, in addition to copper, impurities such as arsenic, antimony and bismuth, with contents of 6.04%, 0.27% and 12.36% respectively.

[0063] Embodiment 7:

[0064] Take metal copper powder (O: 1.35%, C: 0.12%, D50: 16.64um) as an impurity removal agent to purify copper electrolyte (Cu: 50.27g / L, As: 10.18g / L, Sb: 0.62g / L, Bi: 1.33g / L, H2SO4: 176g / L) as an example. First weigh 25g of the above metal copper powder, add it to 90mL 1.25mol / L mixed acid (H2SO4: 1.20mol / L, HCl: 0.05mol / L) activation solution and stir at 85℃ for 25min. After the acid washing activation is completed, filter and collect the acid washing residue, and the obtained residue is the activated copper powder. The activated copper powder was added to 3L of waste electrolyte, and the reaction was terminated after 50 minutes at 65°C. The filtrate and the residue were collected respectively. The filtrate was the purified copper electrolyte. The arsenic, antimony and bismuth concentrations were 6.07, 0.12 and 0.09 g / L respectively. The above results show that the activated copper powder has a good removal effect on arsenic, antimony and bismuth in the electrolyte, and the arsenic, antimony and bismuth concentrations of the purified copper electrolyte can fully meet the technical requirements of the copper electrolyte.

[0065] Comparative Example 3:

[0066] Compared with Example 7, the only difference is that the D50 of the metal copper powder is 0.24 um, and the other operations and parameters are the same as those in Example 1.

[0067] After the purification, the copper electrolyte was sampled and analyzed, and the concentrations of arsenic, antimony and bismuth were 7.86, 0.43 and 0.71 g / L respectively. The above results show that the activated fine-particle copper powder has a poor effect on the removal of arsenic, antimony and bismuth in the electrolyte, and the concentrations of arsenic, antimony and bismuth in the purified copper electrolyte cannot meet the technical requirements of the copper electrolyte.

[0068] Comparative Example 4:

[0069] Compared with Example 7, the only difference is that the D50 of the metal copper powder is 122.83 um, and the other operations and parameters are the same as Example 1. The purified copper electrolyte was sampled and analyzed, and the concentrations of arsenic, antimony and bismuth were 9.78, 0.51 and 0.94 g / L, respectively. The above results show that the activated coarse-grained copper powder has a poor effect on removing arsenic, antimony and bismuth from the electrolyte, and the concentrations of arsenic, antimony and bismuth in the purified copper electrolyte cannot meet the technical requirements of the copper electrolyte.

[0070] It can be seen from Example 7 and Comparative Examples 3 and 4 that the particle size control of the present invention is within the required range, which can unexpectedly achieve synergy with the process and further enhance the removal effect of arsenic, antimony and bismuth.

Claims

1. A method for simultaneously removing arsenic, antimony and bismuth impurities from a copper electrolyte, characterized in that: placing a copper-based impurity remover in a copper electrolyte to be treated containing arsenic, antimony and bismuth impurities to perform impurity removal treatment to obtain a purified copper electrolyte; The copper-based impurity remover is cuprous oxide and / or modified copper material, the modified copper material is obtained by subjecting copper raw material to acid modification and / or alkali modification; the copper raw material is at least one of metallic copper powder and cuprous oxide powder; the D50 of the copper-based impurity remover is 0.5-75 μm.

2. The method for simultaneously removing arsenic, antimony and bismuth impurities from a copper electrolyte according to claim 1, characterized in that: The copper raw material is a low-carbon raw material with a carbon content of less than or equal to 0.25%, which is subjected to acid modification treatment to obtain the modified copper raw material; Preferably, the carbon content of the low-carbon raw material is below 0.2 wt.% and D50 is 5 to 25 μm.

3. The method for simultaneously removing arsenic, antimony and bismuth impurities from a copper electrolyte according to claim 2, characterized in that: The acid solution used in the acid modification treatment step is an aqueous solution of an inorganic strong acid; Preferably, the inorganic strong acid comprises at least one of hydrochloric acid and sulfuric acid; preferably, it is a mixed acid of hydrochloric acid and sulfuric acid in a molar ratio of 0.03-0.1:

1.

4. The method for simultaneously removing arsenic, antimony and bismuth impurities from a copper electrolyte according to claim 3, characterized in that: The concentration of the solute in the acid solution is 1 to 2 mol / L; Preferably, the liquid-to-solid ratio in the acid modification treatment stage is 3 to 6:1; Preferably, the temperature in the acid modification treatment stage is above 20°C, further 50 to 90°C; Preferably, the acid modification treatment time is 10 minutes or more, preferably 15 to 50 minutes.

5. The method for simultaneously removing arsenic, antimony and bismuth impurities from a copper electrolyte according to any one of claims 1 to 4, characterized in that: The copper raw material is a high-carbon raw material with a carbon content greater than 0.25%, which is preliminarily subjected to an alkali modification treatment and then subjected to the acid modification treatment to obtain the modified copper raw material; Preferably, in the high-carbon raw material, the carbon content is 0.3-0.9wt.%.

6. The method for simultaneously removing arsenic, antimony and bismuth impurities from a copper electrolyte according to claim 5, characterized in that: The alkali solution used in the alkali treatment step is an aqueous solution of at least one alkaline solute selected from the group consisting of alkali metal hydroxides and carbonates; Preferably, the alkaline solute includes at least one of sodium hydroxide and potassium hydroxide.

7. The method for simultaneously removing arsenic, antimony and bismuth impurities from a copper electrolyte according to claim 6, characterized in that: The concentration of the solute in the alkali solution is 0.5 to 1 mol / L; Preferably, the liquid-to-solid ratio in the alkali treatment stage is 3 to 6:1; Preferably, the temperature of the alkali treatment stage is above 20°C, further 50 to 90°C; Preferably, the alkali treatment time is 10 minutes or more, preferably 15 to 50 minutes.

8. The method for simultaneously removing arsenic, antimony and bismuth impurities from a copper electrolyte according to claim 1, characterized in that: The concentrations of arsenic, antimony and bismuth in the copper electrolyte to be treated are above 100 mg / L; and the acidity is controlled below 320 g / L.

9. The method for simultaneously removing arsenic, antimony and bismuth impurities from a copper electrolyte according to claim 1, characterized in that: The modified copper-based impurity remover is 2 to 8 times the mass of arsenic, antimony and bismuth in the copper electrolyte to be treated.

10. The method for simultaneously removing arsenic, antimony and bismuth impurities from a copper electrolyte according to claim 1, characterized in that: The temperature during the impurity removal stage is between 35°C and 85°C; Preferably, the time for the impurity removal treatment is 30 to 90 minutes.

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