CN118308603A - Method for separating arsenic from copper sulfate solution - Google Patents

Abstract

The invention discloses a method for separating arsenic from a copper sulfate solution. The method for separating arsenic from the copper sulfate solution comprises the steps of pretreatment, oxidation, arsenic removal and post-treatment, and specifically comprises the following steps: adding water into the crude copper sulfate to dissolve the crude copper sulfate to obtain a crude copper sulfate solution a; adding an oxidant to react to obtain a reaction solution b; adding an dearsenization agent to carry out dearsenization reaction to obtain a reaction liquid c; adding a flocculating agent into the reaction liquid c for sedimentation, and obtaining a copper sulfate solution and purified slag after arsenic removal through liquid-solid separation; the copper sulfate solution after arsenic removal can be crystallized to produce copper sulfate products or electrodeposited copper; and returning the purified slag to the pyrometallurgical copper smelting system to recycle copper. The method of the invention enables arsenic in the crude copper sulfate solution to be efficiently removed in the form of ferric arsenate, the arsenic removal rate is more than 99%, the arsenic removal rate is less than 1mg/L, no impurity ions are introduced in the whole process, no waste residue and waste liquid are generated, the operation is simple, the running cost is low, the whole process is green and efficient, and the method has good application prospect.

Description

A method for separating arsenic from copper sulfate solution

Technical Field

The invention belongs to the technical field of metallurgy, and in particular relates to a method for separating arsenic from a copper sulfate solution.

Background technique

Crude copper sulfate crystals are the intermediate products of current copper hydrometallurgy. In the copper electrolytic refining process, in order to ensure the output of qualified cathode copper, it is necessary to control the copper, acid and impurity concentrations in the electrolyte within the specified range, and the electrolyte needs to be purified and opened to ensure the balance of impurities and acids in the system. The electrolyte is neutralized by copper addition or direct concentration to make the copper sulfate concentration in the electrolyte reach a saturated state, and the copper sulfate crystal form is output after cooling and crystallization to obtain a crude copper sulfate product, and the product added value is relatively low. At present, people have studied the preparation of various copper sulfate products by removing impurities from crude copper sulfate solutions, but arsenic in the obtained products is easily exceeded, and the requirements of qualified high-purity copper sulfate products are not met. There are few studies on the deep removal of arsenic elements in the crude copper sulfate purification process, and arsenic is difficult to remove, and the removal cost is high. How to achieve deep removal of arsenic impurities in crude copper sulfate solutions and obtain higher purity copper sulfate products is a problem both at home and abroad. Therefore, developing a method that can deeply remove arsenic from crude copper sulfate has become a technical problem that needs to be solved urgently.

Summary of the invention

The object of the present invention is to provide a method for separating arsenic from a copper sulfate solution.

The object of the present invention is achieved in that the method for separating arsenic from a copper sulfate solution comprises pre-treatment, oxidation, arsenic removal and post-treatment steps, specifically comprising:

A. Pretreatment: Add water with a liquid-to-solid volume ratio of (2-4):1 to the crude copper sulfate, and dissolve under uniform stirring to obtain a crude copper sulfate solution a;

B. Oxidation: Add an oxidant to the crude copper sulfate solution a, and react at a temperature of 45-55°C for 30-60 minutes to obtain a reaction solution b;

C. Arsenic removal: adding an arsenic removal agent to the reaction solution b to carry out arsenic removal reaction to obtain a reaction solution c;

D. Post-treatment: Add flocculants to the reaction solution c for sedimentation, and obtain the dearsenicated copper sulfate solution and purified slag through liquid-solid separation; the dearsenicated copper sulfate solution can be crystallized to produce copper sulfate products or electrolytic copper; the purified slag is returned to the pyrometallurgical copper smelting system to recover copper.

The raw materials of the invention include: _{Na2S2O8 ,} Fe(OH) ₃ , NaOH, flocculant PAM, etc., which are all general industrial-grade chemical raw materials _and are easy to purchase; the materials provided by the invention have the advantages of good oxidation effect, high neutralization precipitation efficiency, etc., so the scheme has good oxidation and neutralization removal of As, improves the effect of As in the crude copper sulfate solution, has a significant removal effect, can achieve one-time removal, realizes industrial application, fundamentally avoids the problem of As exceeding the standard in the produced copper sulfate product due to incomplete As removal in the crude copper sulfate solution, and improves the As removal capacity in the crude copper sulfate solution without increasing the labor intensity of workers, thereby reducing production costs.

In the present invention, Na ₂ S ₂ O ₈ is industrial grade Na ₂ S ₂ O ₈ well known to those skilled in the art, and there is no particular limitation on its source in the present invention. However, in order to ensure the oxidation removal effect of As in the crude copper sulfate solution and not affect the normal production capacity, the content of Na ₂ S ₂ O ₈ used in the embodiment is greater than 98%; the amount of Na ₂ S ₂ O ₈ added is Na ₂ S ₂ O ₈ :As=(1.0~1.5):1 in molar ratio, and the trivalent arsenic in the solution is completely oxidized into pentavalent arsenic.

In the present invention, Fe(OH) ₃ is industrial grade Fe(OH) ₃ well known to those skilled in the art, and there is no particular limitation on its source in the present invention. However, in order to ensure the removal effect of As in the crude copper sulfate solution and not affect the normal production capacity, the content of Fe(OH) ₃ used in the embodiment is greater than 99%; the amount of Fe(OH) ₃ added is Fe(OH) ₃ :As=(1.0~1.5):1 in molar ratio, so that the pentavalent arsenic in the solution is completely reacted to form FeAsO ₄ precipitate.

In the present invention, NaOH is an industrial grade NaOH well known to those skilled in the art, and there is no particular limitation on its source. However, in order to ensure the removal effect of As in the crude copper sulfate solution and not affect the normal production capacity, the content of NaOH used in the embodiment is greater than 98%; the amount is not limited, and the pH value at the reaction endpoint is controlled to be stable between 3.0 and 4.0, and NaOH plays a role in adjusting the pH value.

In the present invention, the flocculant polyacrylamide (PAM) is an industrial grade polyacrylamide (PAM) well known to those skilled in the art, and there is no particular limitation on its source. However, in order to ensure the removal effect of As in the crude copper sulfate solution and not affect the normal production capacity, the flocculant polyacrylamide (PAM) used in the embodiment has a solid content greater than 90%; the concentration ratio is 0.5-1.5‰, and the amount added per liter of solution is 1-3 ml. The flocculant promotes the aggregation of ferric arsenate into large particles and rapid sedimentation, ensuring that ferric arsenate will not be suspended in the filtrate during the liquid-solid separation process, thereby preventing incomplete separation.

The method for separating arsenic from a copper sulfate solution of the present invention is specifically performed as follows:

The crude copper sulfate is dissolved in water at a liquid-solid ratio of (2-4):1 under uniform stirring to obtain a crude copper sulfate solution; then, an oxidant Na ₂ S ₂ O ₈ is added at a molar ratio of Na ₂ S ₂ O ₈ :As=(1.0-1.5):1, the oxidant addition time is controlled at 10-15 min, the reaction temperature is controlled at 45-55°C, and the reaction time is 30-60 min; the trivalent arsenic in the solution is completely oxidized to pentavalent arsenic; the dearsenicating agent Fe(OH) ₃ is added at a molar ratio of Fe(OH) 3 :As=(1.0-1.5): ₁ , and the end point pH is 3.0-4.0; the reaction time is controlled at 60-90 min; the pH is adjusted to 3.0-4.0 with a NaOH solution, so that the pentavalent arsenic in the solution is completely reacted to form FeAsO ₄ precipitation; then add 1-3 ml of polyacrylamide (PAM) with a concentration of 0.5-1.5‰ per liter of solution to promote the aggregation of ferric arsenate into large particles and rapid sedimentation; finally, perform liquid-solid separation, filter and remove the purification residue to obtain the de-arsenified copper sulfate solution; the de-arsenicated liquid can be crystallized to produce copper sulfate products or electrolytic copper; the purification residue is returned to the pyrometallurgical copper smelting system to recover copper. This method can reduce the arsenic concentration in the crude copper sulfate solution from 20-100 mg/L to below 1 mg/L, the arsenic removal rate is greater than 99%, the removal effect is significant, and it can achieve one-time removal, which can ensure the production of high-purity copper sulfate products, with a short process flow, simple operation, and easy industrial application.

Preferably, the uniform stirring speed is 250-400 r/min.

Preferably, the As content in the crude CuSO ₄ ·5H ₂ O crystals is 0.01% to 0.05%.

Preferably, the oxidant is industrial grade Na ₂ S ₂ O ₈ with a content greater than 98%.

Preferably, the arsenic removal agent is industrial grade Fe(OH) ₃ with a content greater than 99%.

Preferably, the oxidizing agent Na ₂ S ₂ O ₈ and the dearsenicizing agent Fe(OH) ₃ are added in a molar ratio of Na ₂ S ₂ O ₈ (Fe(OH) ₃ ):As=(1.0-1.5):1.

Preferably, the oxidant addition time is controlled within 10 to 15 minutes.

Preferably, the oxidation reaction temperature is controlled at 45-55°C, and the reaction time is controlled at 30-60 min.

Preferably, the NaOH solution is a 10% to 30% industrial grade NaOH solution.

Preferably, the arsenic removal endpoint pH is controlled at 3.0-4.0, and the reaction time is controlled at 60-90 min.

Preferably, the flocculant is industrial-grade polyacrylamide (PAM) with a solid content greater than 90%, a concentration ratio of 0.5 to 1.5‰, and an addition amount of 0.5 to 3 ml per liter of solution.

The present invention adopts _{Na2S2O8 to} oxidize As in a crude copper sulfate solution, and then adds Fe ₍ OH) ₃ to remove arsenic, so that arsenic is removed in the form of ferric arsenate. The method of the present invention can reduce the As concentration in the crude copper sulfate solution from 20 to 100 mg/L to below 1 mg/L, and the arsenic removal rate is greater than 99%. The removal effect is significant, and one-time removal can be achieved, which can ensure the production of high-purity copper sulfate products. The process flow is short, the operation is simple, and industrial application is easy to achieve. Moreover, _the raw materials _Na2S2O8 , Fe(OH) ₃ , NaOH, flocculant PAM, etc. used in the method of the present invention are all general industrial-grade chemical raw materials, which _are easy to purchase, have low operating costs, are economical and efficient, are suitable for removing As in a crude copper sulfate solution, and have good application prospects.

The beneficial effects of the present invention are:

1. The method of the present invention is used to directly remove As in a crude copper sulfate solution, has a significant removal effect, can achieve one-time removal, and realize industrial application, fundamentally avoiding the problem of incomplete As removal in a crude copper sulfate solution, which leads to excessive As in the produced copper sulfate product, and can reduce the As concentration in the crude copper sulfate solution from 20 to 100 mg/L to below 1 mg/L, with an arsenic removal rate of more than 99%.

2. The raw materials Na ₂ S ₂ O ₈ , Fe(OH) ₃ , NaOH, flocculant PAM, etc. used in the method of the present invention are all general industrial-grade chemical raw materials, which are easy to purchase, economical and efficient, and will not introduce other harmful impurities. They are suitable for removing As in crude copper sulfate solution.

3. The main component of the purified slag produced by the present invention is FeAsO ₄ , which can be returned to the pyrometallurgical copper smelting system to recycle the copper in the purified slag. The whole process does not introduce impurity ions, does not generate waste slag and waste liquid, is simple to operate, has low operating costs, is green and efficient throughout the process, and has good application prospects.

4. The conventional hydrometallurgical equipment used in the present invention has a simple structure, low cost and easy maintenance.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic diagram of the process flow of the present invention.

Detailed ways

The present invention is further described below in conjunction with the embodiments, but the present invention is not limited in any way. The examples described in the present invention are only descriptions of the preferred test methods of the present invention, and are not intended to limit the concept and scope of the present invention. Without departing from the design concept of the present invention, any modifications and improvements made based on the teachings of the present invention should fall within the scope of the present invention.

The method for separating arsenic from a copper sulfate solution of the present invention comprises pre-treatment, oxidation, arsenic removal and post-treatment steps, specifically comprising:

A. Pretreatment: Add water with a liquid-to-solid volume ratio of (2-4):1 to the crude copper sulfate, and dissolve under uniform stirring to obtain a crude copper sulfate solution a;

B. Oxidation: Add an oxidant to the crude copper sulfate solution a, and react at a temperature of 45-55°C for 30-60 minutes to obtain a reaction solution b;

C. Arsenic removal: adding an arsenic removal agent to the reaction solution b to carry out arsenic removal reaction to obtain a reaction solution c;

D. Post-treatment: Add flocculants to the reaction solution c for sedimentation, and obtain the dearsenicated copper sulfate solution and purified slag through liquid-solid separation; the dearsenicated copper sulfate solution can be crystallized to produce copper sulfate products or electrolytic copper; the purified slag is returned to the pyrometallurgical copper smelting system to recover copper.

The As content in the crude copper sulfate is 0.01-0.1%.

The amount of the oxidant added in step B is a molar ratio of oxidant:As = (1.0~1.5):1.

The oxidant is industrial grade Na ₂ S ₂ O ₈ with a content greater than 98%.

The amount of the arsenic removal agent added in step C is a molar ratio of arsenic removal agent: As = (1.0~1.5): 1.

The arsenic removal agent is industrial grade Fe(OH) ₃ with a content greater than 99%.

The reaction time of the arsenic removal reaction in step C is 60 to 90 minutes.

The reaction endpoint pH value of the arsenic removal reaction in step C is controlled at 3.0-4.0.

The pH value at the reaction endpoint is controlled by adjusting the pH value using an industrial NaOH solution with a mass concentration of 10%.

The flocculant described in step D is polyacrylamide PAM with an industrial grade content greater than 90%.

The present invention will be further described below with specific embodiments:

Example 1

As shown in FIG1 , crude CuSO ₄ ·5H ₂ O crystals with the composition of 24% Cu, 0.03% As, and 0.04% Fe were dissolved in water at a liquid-to-solid ratio of 4:1 under a uniform stirring speed of 250 r/min.

Then, an oxidant is added at a molar ratio of Na ₂ S ₂ O ₈ :As=1.5:1. The oxidant addition time is controlled at 10-15 min, the oxidation reaction temperature is controlled at 50°C, and the reaction time is 60 min, so that the trivalent arsenic in the solution is completely oxidized to pentavalent arsenic.

Then add arsenic removal agent at a molar ratio of Fe(OH) ₃ :As=1:1, adjust the endpoint pH value of industrial NaOH solution with a concentration of 10% to 3.0, and control the reaction time to 60min, so that the pentavalent arsenic in the solution reacts completely to form FeAsO ₄ precipitation.

Then, 3 ml of 1‰ flocculant polyacrylamide (PAM) was added to each liter of solution to promote the aggregation of ferric arsenate into large particles and rapid sedimentation.

Finally, liquid-solid separation is carried out, and the purified slag is filtered to remove the arsenic removal, and the copper sulfate solution after arsenic removal is obtained. The arsenic content is 0.58 mg/L, and the removal rate is 99.53%. The removal effect is significant. The arsenic removal liquid can be crystallized to produce copper sulfate products or electrolytic copper; the purified slag is returned to the pyrometallurgical copper smelting system to recover copper, and the effect of no waste slag discharge is achieved.

Example 2

As shown in FIG1 , crude CuSO ₄ ·5H ₂ O crystals with the composition of 25% Cu, 0.03% As, and 0.02% Fe were dissolved in water at a liquid-to-solid ratio of 3:1 under a uniform stirring speed of 250 r/min.

Then, an oxidant is added at a molar ratio of Na ₂ S ₂ O ₈ :As=1.25:1. The oxidant addition time is controlled at 10-15 min, the oxidation reaction temperature is controlled at 45°C, and the reaction time is 60 min, so that the trivalent arsenic in the solution is completely oxidized to pentavalent arsenic.

Then, a dearsenicizing agent was added at a molar ratio of Fe(OH) ₃ :As=1.5:1, and the endpoint pH value of the industrial NaOH solution with a concentration of 30% was adjusted to 3.5. The reaction time was controlled to 90 min, so that the pentavalent arsenic in the solution was completely reacted to form FeAsO ₄ precipitation.

Then, 2 ml of polyacrylamide (PAM) flocculant with a concentration of 0.5‰ was added to each liter of solution to promote the aggregation of ferric arsenate into large particles and rapid sedimentation.

Finally, liquid-solid separation is carried out, and the purified slag is filtered to obtain a dearsenified copper sulfate solution with an arsenic content of 0.75 mg/L and a removal rate of 99.32%. The removal effect is significant. The dearsenicized liquid can be crystallized to produce copper sulfate products or electrolytic copper; the purified slag is returned to the pyrometallurgical copper smelting system to recover copper, and the effect of no waste slag discharge is achieved.

Example 3

As shown in FIG1 , crude CuSO ₄ ·5H ₂ O crystals with the composition of 24% Cu, 0.02% As, and 0.01% Fe were dissolved in water at a liquid-to-solid ratio of 2:1 under a uniform stirring speed of 250 r/min.

Then, an oxidant is added at a molar ratio of Na ₂ S ₂ O ₈ :As=1.0:1. The oxidant addition time is controlled at 10-15 min, the oxidation reaction temperature is controlled at 50°C, and the reaction time is 45 min, so that the trivalent arsenic in the solution is completely oxidized to pentavalent arsenic.

Then, a dearsenicizing agent was added at a molar ratio of Fe(OH) ₃ :As=1.25:1, and the endpoint pH value of the industrial NaOH solution with a concentration of 20% was adjusted to 4.0. The reaction time was controlled to 75 min, so that the pentavalent arsenic in the solution was completely reacted to form FeAsO ₄ precipitation.

Then, 1.5 ml of 1‰ flocculant polyacrylamide (PAM) was added to each liter of solution to promote the aggregation of ferric arsenate into large particles and rapid sedimentation.

Finally, liquid-solid separation is carried out, and the purified slag is filtered to obtain a dearsenified copper sulfate solution with an arsenic content of 0.62 mg/L and a removal rate of 99.39%. The removal effect is significant. The dearsenicized liquid can be crystallized to produce copper sulfate products or electrolytic copper; the purified slag is returned to the pyrometallurgical copper smelting system to recover copper, and the effect of no waste slag discharge is achieved.

Example 4

As shown in FIG1 , crude CuSO ₄ ·5H ₂ O crystals with the composition of 25% Cu, 0.05% As, and 0.05% Fe were dissolved in water at a liquid-to-solid ratio of 3:1 under a uniform stirring speed of 300 r/min.

Then, an oxidant is added at a molar ratio of Na ₂ S ₂ O ₈ :As=1.5:1. The oxidant addition time is controlled at 10-15 min, the oxidation reaction temperature is controlled at 55°C, and the reaction time is 60 min, so that the trivalent arsenic in the solution is completely oxidized to pentavalent arsenic.

Then, a dearsenicizing agent was added at a molar ratio of Fe(OH) ₃ :As=1.5:1, and the endpoint pH value of the industrial NaOH solution with a concentration of 15% was adjusted to 3.5. The reaction time was controlled to 80 min, so that the pentavalent arsenic in the solution was completely reacted to form FeAsO ₄ precipitation.

Then, 1 ml of 1.5‰ flocculant polyacrylamide (PAM) was added to each liter of solution to promote the aggregation of ferric arsenate into large particles and rapid sedimentation.

Finally, liquid-solid separation is carried out, and the purified slag is filtered to remove the arsenic removal, and the copper sulfate solution after arsenic removal is obtained. The arsenic content is 0.49 mg/L, and the removal rate is 99.43%. The removal effect is significant. The arsenic removal liquid can be crystallized to produce copper sulfate products or electrolytic copper; the purified slag is returned to the pyrometallurgical copper smelting system to recover copper, and the effect of no waste slag discharge is achieved.

Example 5

As shown in FIG1 , crude CuSO ₄ ·5H ₂ O crystals with the composition of 24.5% Cu, 0.08% As, and 0.03% Fe were dissolved in water at a liquid-to-solid ratio of 3.5:1 under a uniform stirring speed of 350 r/min.

Then, an oxidant is added at a molar ratio of Na ₂ S ₂ O ₈ :As=1.25:1. The oxidant addition time is controlled at 10-15 min, the oxidation reaction temperature is controlled at 45°C, and the reaction time is 60 min, so that the trivalent arsenic in the solution is completely oxidized to pentavalent arsenic.

Then, a dearsenicizing agent was added at a molar ratio of Fe(OH) ₃ :As=1.5:1, and the endpoint pH value of the industrial NaOH solution with a concentration of 15% was adjusted to 3.5. The reaction time was controlled to 65 min, so that the pentavalent arsenic in the solution was completely reacted to form FeAsO ₄ precipitation.

Then, 0.5 ml of 1.5‰ flocculant polyacrylamide (PAM) was added to each liter of solution to promote the aggregation of ferric arsenate into large particles and rapid sedimentation.

Finally, liquid-solid separation is carried out, and the purified slag is filtered to remove the arsenic removal, and the copper sulfate solution after arsenic removal is obtained. The arsenic content is 0.51 mg/L, and the removal rate is 99.58%. The removal effect is significant. The arsenic removal liquid can be crystallized to produce copper sulfate products or electrolytic copper; the purified slag is returned to the pyrometallurgical copper smelting system to recover copper, and the effect of no waste slag discharge is achieved.

Example 6

As shown in FIG1 , crude CuSO ₄ ·5H ₂ O crystals with the composition of 24.8% Cu, 0.1% As, and 0.04% Fe were dissolved in water at a liquid-to-solid ratio of 3:1 under a uniform stirring speed of 400 r/min.

Then, an oxidant is added at a molar ratio of Na ₂ S ₂ O ₈ :As=1.5:1. The oxidant addition time is controlled at 10-15 min, the oxidation reaction temperature is controlled at 50°C, and the reaction time is 45 min, so that the trivalent arsenic in the solution is completely oxidized to pentavalent arsenic.

Then, a dearsenicizing agent was added at a molar ratio of Fe(OH) ₃ :As=1.25:1, and the endpoint pH value of the industrial NaOH solution with a concentration of 15% was adjusted to 4.0. The reaction time was controlled to 65 min, so that the pentavalent arsenic in the solution was completely reacted to form FeAsO ₄ precipitation.

Then, 2.5 ml of 1.5‰ flocculant polyacrylamide (PAM) was added to each liter of solution to promote the aggregation of ferric arsenate into large particles and rapid sedimentation.

Finally, liquid-solid separation is carried out, and the purified slag is filtered to obtain a dearsenified copper sulfate solution with an arsenic content of 0.45 mg/L and a removal rate of 99.45%. The removal effect is significant. The dearsenicized liquid can be crystallized to produce copper sulfate products or electrolytic copper; the purified slag is returned to the pyrometallurgical copper smelting system to recover copper, and the effect of no waste slag discharge is achieved.

The specific implementation modes of the present invention are described in detail above, but the present invention is not limited to the above implementation modes, and various changes can be made within the knowledge scope of ordinary technicians in this field without departing from the purpose of the present invention.

Claims (11)

1. A method for separating arsenic from a copper sulfate solution, characterized in that the method for separating arsenic from a copper sulfate solution comprises pretreatment, oxidation, arsenic removal and post-treatment steps, specifically comprising: A. Pretreatment: Add water with a liquid-to-solid volume ratio of (2-4):1 to the crude copper sulfate, and dissolve under uniform stirring to obtain a crude copper sulfate solution a; B. Oxidation: Add an oxidant to the crude copper sulfate solution a, and react at a temperature of 45-55°C for 30-60 minutes to obtain a reaction solution b; C. Arsenic removal: adding an arsenic removal agent to the reaction solution b to carry out arsenic removal reaction to obtain a reaction solution c; D. Post-treatment: Add flocculants to the reaction solution c for sedimentation, and obtain the dearsenicated copper sulfate solution and purified slag through liquid-solid separation; the dearsenicated copper sulfate solution can be crystallized to produce copper sulfate products or electrolytic copper; the purified slag is returned to the pyrometallurgical copper smelting system to recover copper. 2. The method for separating arsenic from a copper sulfate solution according to claim 1, wherein the As content in the crude copper sulfate is 0.01-0.1%. 3. The method for separating arsenic from a copper sulfate solution according to claim 1, characterized in that the amount of the oxidant added in step B is a molar ratio of oxidant: As = (1.0~1.5): 1. 4. The method _for separating _arsenic from a copper sulfate solution according to claim 1 or 3, characterized in that the oxidant is industrial grade _Na2S2O8 with a content greater than 98%. 5. The method for separating arsenic from a copper sulfate solution according to claim 1, characterized in that the oxidation reaction temperature is 45-55° C. and the reaction time is 30-60 min. 6. The method for separating arsenic from a copper sulfate solution according to claim 1, characterized in that the amount of the arsenic removal agent added in step C is a molar ratio of arsenic removal agent: As = (1.0-1.5): 1. 7. The method for separating arsenic from a copper sulfate solution according to claim 1 or 6, characterized in that the dearsenicating agent is industrial grade Fe(OH) ₃ with a content greater than 99%. 8. The method for separating arsenic from a copper sulfate solution according to claim 1, characterized in that the reaction time of the arsenic removal reaction in step C is 60 to 90 minutes. 9. The method for separating arsenic from a copper sulfate solution according to claim 1, characterized in that the reaction endpoint pH value of the arsenic removal reaction in step C is controlled at 3.0-4.0. 10. The method for separating arsenic from a copper sulfate solution according to claim 7, characterized in that the pH value at the reaction endpoint is controlled by adjusting the pH value using an industrial NaOH solution with a mass concentration of 10%. 11. The method for separating arsenic from a copper sulfate solution according to claim 1, characterized in that the flocculant in step D is polyacrylamide (PAM) with an industrial grade content greater than 90%.