Method for recovering valuable elements by co-disposing antimony electrodeposition barren liquid and arsenic sulfide slag

Abstract

The present invention belongs to the field of metallurgical technology, and specifically relates to a method for recovering valuable elements by co-disposing antimony electrodeposition lean liquid and arsenic sulfide slag. The method of the present invention comprises the following steps: S1. Mixing the antimony electrodeposition lean liquid with the arsenic sulfide slag, adjusting the pH value to 9.0-10.0, and reacting to obtain copper sulfide slag and rich liquid; S2. Reacting the rich liquid under aerobic conditions to obtain sodium pyroantimonate and arsenic-rich sulfur liquid; S3. Reacting the arsenic-rich sulfur liquid with sulfur dioxide to obtain sulfur slag and arsenic-rich liquid; S4. Adjusting the pH value of the arsenic-rich liquid to 1.0-3.0 with sulfuric acid, and obtaining sulfur dioxide, arsenic trioxide and low-arsenic liquid after the reaction; S5. Reacting the low-arsenic liquid with hydrogen sulfide, and obtaining arsenic sulfide slag and sodium sulfate solution after the reaction. The present invention combines the chemical properties of the antimony electrodeposition lean liquid and the arsenic sulfide slag, and jointly treats the two, thereby reducing the production cost of separate treatments, and comprehensively and effectively recovering valuable elements such as antimony, sulfur, arsenic, and sodium.

Description

Technical Field

[0001] The invention belongs to the technical field of metallurgy, and relates to a method for recovering valuable elements by co-disposing non-ferrous smelting wastewater and solid waste, and specifically relates to a method for recovering valuable elements by co-disposing antimony electrodeposition lean liquid and arsenic sulfide slag. Background Art

[0002] At present, the wet treatment of antimony-containing gold concentrate usually uses alkaline leaching and electrolytic antimony collection methods to separate gold and antimony, and recover antimony. The treatment method of the generated electrolytic lean liquid is to use frozen crystallization to obtain raw antimony crystal salt; the leached slag is then recovered by pyrometallurgy or hydrometallurgy to recover valuable metals such as gold and silver. The main component of raw antimony crystal salt is sodium sulfide, but it contains relatively high levels of sodium hydrosulfide and sodium thiosulfate, and cannot be sold directly. During long-term stacking, sodium sulfide will deliquesce in the air for a long time, and will acidify and deteriorate, and continuously release hydrogen sulfide gas, which puts great pressure on the environmental protection and safe production of enterprises.

[0003] Patent CN 114540626 B discloses a method for cascading recovery of valuable metals from waste acid using antimony electrodeposition lean liquid. Sewage acid is slowly added to the antimony electrodeposition lean liquid to obtain copper sulfide slag containing precious metals and copper removal wastewater; the copper removal wastewater is then added to the waste acid to obtain copper-containing arsenic sulfide slag and arsenic removal wastewater; the antimony electrodeposition lean liquid is then added to the arsenic removal wastewater to obtain arsenic-containing antimony sulfide slag and antimony removal wastewater. Although this patented technology realizes the comprehensive treatment of antimony electrodeposition lean liquid and waste acid, the recovery rate of valuable metals is low and the recovery cost is high. The main valuable metals sulfur and antimony need to be further treated.

[0004] In the non-ferrous metal smelting industry, metal sulfide ores are treated by pyrometallurgical methods. During the smelting process, part of the arsenic in the ore volatilizes into the sulfur dioxide flue gas in the form of arsenic trioxide. The sulfur dioxide flue gas is washed by dilute acid spray to produce arsenic-containing waste acid. Arsenic-containing waste acid uses sulfiding agents such as sodium sulfide and hydrogen sulfide to precipitate and separate the arsenic in the waste acid to obtain arsenic sulfide slag with a high arsenic grade. The arsenic content in arsenic sulfide slag is high. If it is left in the air for too long, the arsenic sulfide in it will naturally oxidize to arsenic oxide, which is easy to release and cause secondary pollution; the arsenic sulfide slag has a high moisture content and occupies a large area for storage; the gel particles are small, bright in color, and emit an unpleasant odor, causing great harm to the environment.

[0005] The treatment methods of arsenic sulfide slag mainly include resource technology and stabilization / solidification technology. Stabilization / solidification technology is to use specific additives to inert the arsenic sulfide slag to reduce the solubility, mobility and toxicity of arsenic. Although the solubility of arsenic is low in a short period of time, it will slowly increase with the extension of time, posing a serious safety hazard. Resource technology is to use certain methods to extract arsenic and arsenic compounds from the slag, such as arsenic oxide, elemental arsenic, arsenate and other products; but there are few technologies for effectively recovering sulfur resources, resulting in a waste of sulfur resources. In addition, the economic value of arsenic products is low. Therefore, it is very meaningful to develop a comprehensive method for recovering the valuable elements arsenic and sulfur in arsenic sulfide slag. Summary of the invention

[0006] In view of the deficiencies in the above-mentioned prior art, the present invention provides a method for co-disposing antimony electrodeposition lean liquid and arsenic sulfide slag to recover valuable elements, and jointly treats the antimony electrodeposition lean liquid and arsenic sulfide slag to treat waste with waste, thereby promoting the sustainable green development of the smelting industry.

[0007] The specific technical solutions are as follows:

[0008] The method for recovering valuable elements by co-disposing antimony electrodeposition barren liquid and arsenic sulfide slag comprises the following steps:

[0009] S1. Mixing the antimony electrodeposition lean solution with the arsenic sulfide slag, adjusting the pH value to 9.0-10.0, and separating after the reaction to obtain copper sulfide slag and rich solution;

[0010] S2. The rich liquid obtained in step S1 is reacted under aerobic conditions, and separated after the reaction to obtain sodium pyroantimonate and arsenic-rich sulfur liquid;

[0011] S3. reacting the arsenic-rich sulfur liquid obtained in step S2 with sulfur dioxide, and separating after the reaction to obtain sulfur slag and arsenic-rich liquid;

[0012] S4. The arsenic-rich solution obtained in step S3 is adjusted to a pH of 1.0 to 3.0 with sulfuric acid, and separated after the reaction to obtain sulfur dioxide, arsenic trioxide and a low-arsenic solution;

[0013] S5. The low-arsenic liquid obtained in step S4 is reacted with hydrogen sulfide, and separated after the reaction to obtain arsenic sulfide slag and sodium sulfate solution.

[0014] The antimony electrodeposition barren liquid may come from the wet treatment of antimony-containing gold concentrate (alkaline leaching, antimony electrodeposition), and the arsenic sulfide slag may come from the sulfidation treatment slag containing arsenic-containing waste acid produced by pyrometallurgical smelting of metal sulfide ores.

[0015] Specifically, the main component concentrations in the antimony electrodeposition lean solution are: Sb ion concentration 15-45 g / L, Na2S concentration 30-60 g / L, NaOH concentration 35-60 g / L. More specifically, the main component concentrations in the antimony electrodeposition lean solution are: Sb ion concentration 15-45 g / L, Na2S concentration 30-60 g / L, NaOH concentration 35-60 g / L, Au ion concentration 1-5 mg / L, As ion concentration 0.1-1 g / L.

[0016] Specifically, the main components of the arsenic sulfide slag are: As content 30wt%~55wt%, S content 25wt%~45wt%. More specifically, the main components of the arsenic sulfide slag are: As content 30wt%~55wt%, S content 25wt%~45wt%, Cu content 0.1wt%~2.0wt%, Ag content 1.0~50.0 g / t, and Au content 0.1~5.0 g / t.

[0017] In the above method of recovering valuable elements by co-disposing antimony electrodeposition barren liquid and arsenic sulfide slag:

[0018] The main reaction of step S1 is that the sodium hydroxide in the antimony electrodeposition lean solution reacts with arsenic sulfide to generate sodium thioarsenite, sodium arsenite and water. The main chemical reaction equation is as follows:

[0019] As2S3+6NaOH=Na3AsO3+Na3AsS3+3H2O.

[0020] The main reaction in step S2 is that sodium sulfide, sodium thioantimonite, sodium thioarsenite and sodium arsenite in the rich solution react with oxygen respectively. The main chemical reaction equations are as follows:

[0021] 2Na3S+2O2+H2O=Na2S2O3+2NaOH;

[0022] 2Na3SbS3+7O2+5H2O+2NaOH=2NaSb(OH)6↓+3Na2S2O3;

[0023] 2Na3AsS3+7O2+6NaOH=2Na3AsO4+3Na2S2O3+3H2O;

[0024] 2Na3AsO3+O2=2Na3AsO4.

[0025] The main reaction in step S3 is that the sodium thiosulfate, sodium arsenate and sodium hydroxide in the arsenic-sulfur-rich liquid react with sulfur dioxide respectively. The main chemical reaction equation is as follows:

[0026] Na2S2O3+H2O+SO2=2NaHSO3+S↓;

[0027] Na3AsO4+SO2+2NaOH=Na3AsO3+Na2SO4+H2O;

[0028] NaOH+SO2=NaHSO3.

[0029] The main reaction of step S4 is that sodium bisulfite and sodium arsenite in the arsenic-rich solution react with sulfuric acid respectively. Arsenic trioxide has low solubility under acidic conditions and precipitates out in the form of precipitation. The main chemical reaction equation is as follows:

[0030] 2NaHSO3+H2SO4=Na2SO4+2H2O+2SO2↑;

[0031] 2Na3AsO3+3H2SO4=3Na2SO4+As2O3↓+3H2O.

[0032] The main reaction of step S5 is the reaction of a small amount of arsenic trioxide (H3AsO3) dissolved in water with hydrogen sulfide. The main chemical equation is as follows:

[0033] 2H3AsO3+3H2S=As2S3↓+6H2O.

[0034] Furthermore, in step S1, the reaction conditions are preferably: reaction temperature 60-90° C., reaction time 1.0-3.0 h.

[0035] Furthermore, in step S2, the reaction conditions are preferably: reaction temperature 80-100° C., reaction time 3.0-5.0 h.

[0036] Furthermore, in step S2, the aerobic condition is preferably to introduce oxygen-enriched air into the rich liquid, and the oxygen concentration in the oxygen-enriched air is preferably 25% to 50%.

[0037] Furthermore, in step S3, the reaction conditions are preferably: controlling the pH value to be 6.0-7.0, the reaction temperature to be 40-60° C., and the reaction time to be 3.0-5.0 h.

[0038] Furthermore, in step S4, the reaction time is preferably 0.5 to 1.0 h.

[0039] Furthermore, in step S5, the reaction time is preferably 0.5 to 1.0 h.

[0040] Furthermore, in step S5, the amount of hydrogen sulfide added is preferably in a molar ratio of sulfur in hydrogen sulfide: arsenic in the low-arsenic liquid of (1.5-2.0):1.

[0041] Furthermore, in steps S1 to S5, the separation is preferably performed by filter press.

[0042] Furthermore, in steps S1 to S5, the reaction is preferably carried out under stirring.

[0043] Furthermore, the copper sulfide slag obtained in step S1 is sent to copper pyrometallurgy to recover valuable elements, wherein the valuable elements include copper, gold, silver, etc.

[0044] Furthermore, the sodium sulfate solution obtained in step S5 is added with sodium hydroxide solution for neutralization and then the sodium sulfate is recovered by multiple-effect evaporation.

[0045] Furthermore, it is preferred that the sulfur dioxide obtained in step S4 is returned to step S3 for use.

[0046] Furthermore, it is preferred that the arsenic sulfide slag obtained in step S5 is returned to step S1 for use.

[0047] Furthermore, the main components of the copper sulfide slag (dry basis) obtained in step S1 are as follows: S content ≥ 30wt%, Cu content ≥ 60wt%.

[0048] Furthermore, the purity of the sodium pyroantimonate (dry basis) obtained in step S2 is ≥95%.

[0049] Furthermore, the main component proportion of the sulfur slag (dry basis) obtained in step S3 is: S content ≥ 90wt%.

[0050] Furthermore, the purity of arsenic trioxide (dry basis) obtained in step S4 is ≥95%.

[0051] The beneficial effects of the present invention are as follows:

[0052] The present invention combines the chemical properties of antimony electrodeposition lean liquid and arsenic sulfide slag to jointly treat the two. On the one hand, it provides a method for co-processing antimony electrodeposition lean liquid and arsenic sulfide slag, which reduces the production cost of separately processing antimony electrodeposition lean liquid and arsenic sulfide slag; on the other hand, it comprehensively and effectively recovers valuable elements such as antimony, sulfur, arsenic, and sodium in antimony electrodeposition lean liquid and arsenic sulfide slag. The purpose of "using waste to treat waste and turning waste into treasure" is achieved, and it has the advantages of low investment in processing equipment, reasonable processing technology, high processing efficiency, and low processing cost; it 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

[0053] Figure 1 It is a process flow chart of the present invention. DETAILED DESCRIPTION

[0054] 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

[0055] Antimony electrodeposition barren liquid and arsenic sulfide slag are co-processed to recover valuable elements, including:

[0056] The concentrations of the main components in the antimony electrodeposition lean solution are: Sb ion concentration 15.35 g / L, Na2S concentration 32.32 g / L, NaOH concentration 37.25 g / L, Au ion concentration 1.27 mg / L, As ion concentration 0.28 g / L;

[0057] The contents of the main components in the arsenic sulfide slag are: As content is 32.54wt%, S content is 26.17wt%, Cu content is 0.18wt%, Ag content is 1.04 g / t, and Au content is 0.14 g / t.

[0058] The steps are as follows:

[0059] S1. Place the antimony electrodeposition lean liquid in a reaction tank, slowly add arsenic sulfide slag into the antimony electrodeposition lean liquid, adjust the pH of the reaction liquid to 9.0, control the reaction temperature to 60 °C, stir for 1.0 h and then filter to obtain copper sulfide slag and rich liquid; wherein, the copper sulfide slag is sent to copper pyrometallurgy to recover valuable elements such as copper, gold, and silver;

[0060] S2. The rich liquid obtained in step S1 is placed in a reactor, and then oxygen-enriched air with an oxygen concentration of 25% is continuously introduced into the reactor, the reaction temperature is controlled to 80 ° C, and after stirring for 3.0 h, the mixture is filtered to obtain sodium pyroantimonate and arsenic-rich sulfur liquid;

[0061] S3. The arsenic-rich sulfur liquid obtained in step S2 is placed in a reactor, and then sulfur dioxide gas is introduced into the reactor, the pH of the solution is controlled to be 6.0, the reaction temperature is 40 ° C, and the mixture is stirred for 3.0 h and then filtered to obtain sulfur residue and arsenic-rich liquid;

[0062] S4. The arsenic-rich solution obtained in step S3 is placed in a reactor, and then sulfuric acid is added to the reactor to adjust the pH of the solution to 1.0, and the solution is stirred at room temperature for 0.5 h and then filtered to obtain a small amount of sulfur dioxide gas, arsenic trioxide and low-arsenic solution; wherein the sulfur dioxide is returned to step S3 for use;

[0063] S5. The low-arsenic liquid obtained in step S4 is placed in a reactor, and then hydrogen sulfide gas is introduced into the reactor, with the molar ratio of sulfur in hydrogen sulfide: arsenic in the low-arsenic liquid being 1.5:1. The mixture is stirred at room temperature for 0.5 h and then filtered to obtain arsenic sulfide slag and sodium sulfate solution, wherein the arsenic sulfide slag is returned to step S1 for use, and the sodium sulfate solution is neutralized by adding 30 wt % sodium hydroxide solution and then recovered by multiple-effect evaporation. Example 2

[0064] Antimony electrodeposition barren liquid and arsenic sulfide slag are co-processed to recover valuable elements, including:

[0065] The concentrations of the main components in the antimony electrodeposition lean solution are: Sb ion concentration 32.35 g / L, Na2S concentration 44.59 g / L, NaOH concentration 46.24 g / L, Au ion concentration 2.93 mg / L, As ion concentration 0.85 g / L;

[0066] The contents of the main components in the arsenic sulfide slag are: As content is 38.44wt%, S content is 34.97wt%, Cu content is 0.95wt%, Ag content is 25.04 g / t, and Au content is 2.04 g / t.

[0067] The steps are as follows:

[0068] S1. Place the antimony electrodeposition lean liquid in a reaction tank, slowly add arsenic sulfide slag into the antimony electrodeposition lean liquid, adjust the pH of the reaction liquid to 9.5, control the reaction temperature to 75 °C, stir for 2.0 h and then filter to obtain copper sulfide slag and rich liquid; wherein the copper sulfide slag is sent to copper pyrometallurgy to recover valuable elements such as copper, gold and silver;

[0069] S2. The rich liquid obtained in step S1 is placed in a reactor, and then oxygen-enriched air with an oxygen concentration of 30% is continuously introduced into the reactor, the reaction temperature is controlled to 90 ° C, and after stirring for 4.0 h, the mixture is filtered to obtain sodium pyroantimonate and arsenic-rich sulfur liquid;

[0070] S3. The arsenic-rich sulfur liquid obtained in step S2 is placed in a reactor, and then sulfur dioxide gas is introduced into the reactor, the pH of the solution is controlled to be 7.0, the reaction temperature is 50 ° C, and the mixture is stirred for 4.0 h and then filtered to obtain sulfur residue and arsenic-rich liquid;

[0071] S4. The arsenic-rich solution obtained in step S3 is placed in a reactor, and then sulfuric acid is added to the reactor to adjust the pH of the solution to 3.0, and the solution is stirred at room temperature for 0.5 h and then filtered to obtain a small amount of sulfur dioxide gas, arsenic trioxide and low-arsenic solution; wherein the sulfur dioxide is returned to step S3 for use;

[0072] S5. The low-arsenic liquid obtained in step S4 is placed in a reactor, and then hydrogen sulfide gas is introduced into the reactor, with the molar ratio of sulfur in hydrogen sulfide: arsenic in the low-arsenic liquid being 1.8:1. After stirring at room temperature for 1 hour, the mixture is filtered to obtain arsenic sulfide slag and sodium sulfate solution, wherein the arsenic sulfide slag is returned to step S1 for use, and the sodium sulfate solution is neutralized by adding 30 wt % sodium hydroxide solution and then recovered by multiple-effect evaporation. Example 3

[0073] Antimony electrodeposition barren liquid and arsenic sulfide slag are co-processed to recover valuable elements, including:

[0074] The concentrations of the main components in the antimony electrodeposition lean solution are: Sb ion concentration 43.89 g / L, Na2S concentration 57.24 g / L, NaOH concentration 56.28 g / L, Au ion concentration 4.57 mg / L, As ion concentration 0.82 g / L;

[0075] The contents of the main components in the arsenic sulfide slag are: As content is 53.24wt%, S content is 44.21wt%, Cu content is 1.84wt%, Ag content is 48.24 g / t, and Au content is 4.74 g / t.

[0076] The steps are as follows:

[0077] S1. Place the antimony electrodeposition lean liquid in a reaction tank, slowly add arsenic sulfide slag into the antimony electrodeposition lean liquid, adjust the pH of the reaction liquid to 10.0, control the reaction temperature to 90 °C, stir for 3.0 h and then filter to obtain copper sulfide slag and rich liquid; wherein the copper sulfide slag is sent to copper pyrometallurgy to recover valuable elements such as copper, gold, and silver;

[0078] S2. The rich liquid obtained in step S1 was placed in a reactor, and then oxygen-enriched air with an oxygen concentration of 35% was continuously introduced into the reactor, the reaction temperature was controlled to 100 ° C, and the mixture was stirred for 5.0 h and then filtered to obtain sodium pyroantimonate and arsenic-rich sulfur liquid;

[0079] S3. The arsenic-rich sulfur liquid obtained in step S2 is placed in a reactor, and then sulfur dioxide gas is introduced into the reactor, the pH of the solution is controlled to be 6.5, the reaction temperature is 60 ° C, and the mixture is stirred for 5.0 h and then filtered to obtain sulfur residue and arsenic-rich liquid;

[0080] S4. The arsenic-rich solution obtained in step S3 is placed in a reactor, and then sulfuric acid is added to the reactor to adjust the pH of the solution to 2.0, and the solution is stirred at room temperature for 1 h and then filtered to obtain a small amount of sulfur dioxide gas, arsenic trioxide and low-arsenic solution; wherein the sulfur dioxide is returned to step S3 for use;

[0081] S5. The low-arsenic liquid obtained in step S4 is placed in a reactor, and then hydrogen sulfide gas is introduced into the reactor, with the molar ratio of sulfur in hydrogen sulfide: arsenic in the low-arsenic liquid being 2.0:1. After stirring at room temperature for 1 hour, filter press is performed to obtain arsenic sulfide slag and sodium sulfate solution, wherein the arsenic sulfide slag is returned to step S1 for use, and the sodium sulfate solution is neutralized by adding 30wt% sodium hydroxide solution and then recovered by multiple-effect evaporation.

[0082] test

[0083] The component content or purity of the main products obtained in Examples 1 to 3 was detected, and the results are shown in Table 1; the recovery rate of each element in Examples 1 to 3 was calculated, and the results are shown in Table 2.

[0084] The detection methods for the main products are as follows: the detection methods for copper sulfide slag are as follows: Chemical analysis method for copper concentrate - Part 1: Determination of copper content - Iodine titration method (GB / T 3884.1-2012), the determination of sulfur content in copper concentrate - High frequency combustion infrared absorption method (SN / T4363-2015), the determination of sulfur content in copper concentrate - High frequency combustion infrared absorption method (SN / T 4363-2015), the sodium pyroantimonate is as follows: Chemical analysis method for crude antimony - Part 1: Determination of antimony content - Cerium sulfate titration method (YS / T 1582.1-2022), and arsenic trioxide is as follows: Chemical analysis method for import and export arsenic trioxide - Part 1: Determination of arsenic trioxide content (SN / T 0837.1-2011).

[0085] Table 1 Content or purity of main products

[0086]

[0087] Table 2 Comprehensive recovery rate of each valuable element

[0088] Recovery rate Example 1 Example 2 Example 3 Sb(%) 98.24 98.45 98.25 S（%） 99.32 99.24 99.17 As(%) 95.24 95.12 96.07 Na (%) 99.25 99.32 99.14

[0089] As shown in Table 1, in Examples 1 to 3, the S content in the copper sulfide slag is ≥30wt%, the Cu content is ≥60wt%, the purity of sodium pyroantimonate is ≥95%, the purity of sulfur is ≥90%, and the purity of arsenic trioxide is ≥95%. The results of Tables 1 and 2 show that the antimony electrodeposition lean solution is synergistically treated with the arsenic sulfide slag, and the valuable elements are fully recovered.

[0090] 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. A method for recovering valuable elements by co-disposing antimony electrodeposition barren liquid and arsenic sulfide slag, characterized in that: The steps include: S1. Mixing the antimony electrodeposition lean solution with the arsenic sulfide slag, adjusting the pH value to 9.0-10.0, and separating after the reaction to obtain copper sulfide slag and rich solution; S2. The rich liquid obtained in step S1 is reacted under aerobic conditions, and separated after the reaction to obtain sodium pyroantimonate and arsenic-rich sulfur liquid; S3. reacting the arsenic-rich sulfur liquid obtained in step S2 with sulfur dioxide, and separating after the reaction to obtain sulfur slag and arsenic-rich liquid; S4. The arsenic-rich solution obtained in step S3 is adjusted to a pH of 1.0 to 3.0 with sulfuric acid, and separated after the reaction to obtain sulfur dioxide, arsenic trioxide and a low-arsenic solution; S5. reacting the low-arsenic solution obtained in step S4 with hydrogen sulfide, and separating after the reaction to obtain arsenic sulfide slag and sodium sulfate solution; The concentrations of main components in the antimony electrodeposition lean solution are: Sb ion concentration 15-45 g / L, Na2S concentration 30-60 g / L, and NaOH concentration 35-60 g / L.

2. The method according to claim 1, characterized in that In step S1, the reaction conditions are: reaction temperature 60-90° C., reaction time 1.0-3.0 h.

3. The method according to claim 1, characterized in that In step S2, the reaction conditions are: reaction temperature 80-100° C., reaction time 3.0-5.0 h.

4. The method according to claim 1, characterized in that: In step S3, the reaction conditions are: controlling the pH value to be 6.0-7.0, the reaction temperature to be 40-60° C., and the reaction time to be 3.0-5.0 h.

5. The method according to claim 1, characterized in that In step S4, the reaction time is 0.5-1.0 h.

6. The method according to claim 1, characterized in that In step S5, the reaction time is 0.5-1.0 h.

7. The method according to claim 1, characterized in that In step S5, the amount of hydrogen sulfide added is based on a molar ratio of sulfur in hydrogen sulfide to arsenic in the low-arsenic liquid of (1.5-2.0):

1.

8. The method according to any one of claims 1 to 7, characterized in that: The copper sulfide slag obtained in step S1 is sent to copper pyrometallurgy to recover valuable elements.

9. The method according to any one of claims 1 to 7, characterized in that: The sodium sulfate solution obtained in step S5 is added with sodium hydroxide solution for neutralization and then the sodium sulfate is recovered by multiple-effect evaporation.

10. The method according to any one of claims 1 to 7, characterized in that: The sulfur dioxide obtained in step S4 is returned to step S3 for use; The arsenic sulfide slag obtained in step S5 is returned to step S1 for use.

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