Method for recycling gold by cooperatively treating tailings through acid wastewater

Abstract

The invention belongs to the technical field of gold smelting wastewater treatment and resource utilization, and relates to a method for recycling gold by cooperatively treating tailings with acid wastewater, which comprises the following steps of: (1) concentrating the acid wastewater; (2) controlling the fineness of the roasting cyanidation gold extraction tailings; (3) removing impurities by acid; (4) adsorbing and recovering gold and silver by using thiourea leaching carbon; and (5) vulcanizing the acidolysis solution to recover copper and arsenic in a targeted manner. According to the method, efficient treatment is carried out through a five-stage treatment process, so that sulfuric acid in the acid wastewater is efficiently recycled, the roasting and cyaniding gold extraction tailings are comprehensively and efficiently utilized, resource high-value utilization and clean production of the acid wastewater and the roasting and cyaniding gold extraction tailings are achieved, and harm of the acid wastewater and the roasting and cyaniding gold extraction tailings to the environment is eliminated; the technological process is smooth, operability is high, the environment is excellent, and remarkable economic benefits, social benefits and environmental benefits are achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of gold smelting wastewater treatment and resource utilization, and relates to a method for recovering gold by utilizing acidic wastewater to collaboratively treat tailings. Background Art

[0002] The primary associated metallic minerals of gold and silver include pyrite and arsenopyrite, followed by galena, sphalerite, pyrrhotite, and arsenopyrite. Non-metallic minerals include quartz, feldspar, and carbonates. Currently, in the gold smelting industry, three pre-treatment processes are commonly used for difficult-to-process arsenic- and carbon-containing gold concentrates: roasting, hot pressing, and bio-oxidation. Roasting is currently the primary method for treating gold concentrates. After roasting pre-treatment, cyanidation is still used for gold extraction. During the roasting process, the sulfur, arsenic, and carbon in the gold concentrate are converted into oxide gases that enter the flue gas. Arsenic trioxide is recovered through dry dust collection, electrostatic precipitator (ESP), wet purification, and electrostatic demisting processes to produce industrial sulfuric acid. The wet purification process produces waste sulfuric acid, containing 10-20% by weight. This waste is treated with lime neutralization, resulting in a waste of sulfuric acid resources.

[0003] The cyanide gold extraction tailings from arsenic- and carbon-containing difficult-to-process gold concentrates after roasting pretreatment are difficult to dispose of effectively. In 2016, the roasting cyanide gold extraction tailings were included in the "National List of Hazardous Wastes". At the same time, the roasting cyanide gold extraction tailings contain 2 to 3 g / t of gold, which has not been effectively recovered, resulting in a waste of resources.

[0004] How to realize the resource utilization of sulfuric acid in acidic wastewater and the comprehensive recovery and utilization of precious metal gold elements in roasting cyanide gold extraction tailings has become the focus of the industry. It is also an important direction for enterprises to achieve economic growth and sustainable development. At the same time, it is an inevitable requirement to improve resource conservation and comprehensive resource utilization efficiency. Summary of the Invention

[0005] In view of the shortcomings of the above-mentioned prior art, the present invention provides a method for recovering gold by co-processing tailings with acidic wastewater, which can significantly improve the comprehensive utilization rate of sulfuric acid resources in acidic wastewater and the comprehensive utilization rate of gold resources in roasting cyanide gold extraction tailings. The specific technical solution is as follows:

[0006] A method for recovering gold by co-processing tailings with acidic wastewater comprises the following steps:

[0007] Step (1) Acidic wastewater concentration: The acidic wastewater is concentrated to a sulfuric acid content of 20 to 40 wt%;

[0008] Step (2) fineness control of roasting cyanide gold extraction tailings: grinding the roasting cyanide gold extraction tailings in a grinding machine to a particle size of -0.023mm reaching 80-90%;

[0009] Step (3) acidolysis: acid wastewater with a sulfuric acid content of 20-40 wt% and roasting cyanide gold extraction tailings after grinding are mixed and stirred at a liquid-solid mass ratio of 1:(1-6) for acidolysis, with a stirring speed of 300-500 r / min, an acidolysis temperature of 80-120° C., and an acidolysis time of 2-6 h. After the acidolysis is completed, filter pressing and dehydration are performed to obtain an acidolysis filter cake and an acidolysis filtrate;

[0010] Step (4) leaching gold and silver by thiourea and carbon adsorption: the acid hydrolysis filter cake is slurried with water or the liquid after gold and silver are recovered by carbon adsorption in a liquid-solid ratio of (1-3):1, thiourea is added as a leaching agent, and coconut shell activated carbon is added simultaneously. The pulp after leaching and extracting gold and silver is passed through a carbon screen to produce activated carbon loaded with gold and silver. The pulp after the sieve is subjected to liquid-solid separation to obtain a filter cake and the liquid after gold and silver are recovered by carbon adsorption;

[0011] Step (5) sulfidation of the acidolysis liquid for targeted recovery of copper and arsenic: the acidolysis filtrate is transported to a reaction tank, ferrous sulfide is added and stirred for reaction, and after the reaction is completed, it enters a concentrator, and the bottom flow is subjected to filter press to obtain a copper-containing copper sulfide product and an acidic waste liquid after copper recovery; the overflow liquid flows into the reaction tank by gravity, ferrous sulfide is added and stirred for reaction, and after the reaction is completed, it enters a concentrator, and the bottom flow is subjected to filter press to obtain an arsenic-containing arsenic sulfide product and an acidic waste liquid after arsenic recovery.

[0012] The process of the invention is simple and easy to implement, and is suitable for treating acidic wastewater and recovering sulfuric acid, gold element and copper element from tailings of gold concentrate roasting and cyaniding for gold extraction. In step (1), the acidic wastewater is concentrated to a sulfuric acid content of 20-40wt%, which is beneficial to the acid removal efficiency of the roasting cyanide gold extraction tailings and improves the resource utilization rate; in step (2), the fineness of the roasting cyanide gold extraction tailings is accurately controlled, which provides a powerful condition for the decomposition reaction of the compounds wrapped with gold such as copper, arsenic, iron, silicate, etc. in the acidolysis process; in step (3), the concentrated acidic wastewater and the roasting cyanide gold extraction tailings after ultrafine grinding are acidolyzed and impregnated, and the obtained acidolysis filter cake has a water content of 15-20wt%, a gold content of 3-6g / t, and an acidolysis filtrate containing 1-2g / l of copper and 0.2-0.3g / l of arsenic; in step (4), thiourea leaching of gold and silver and coconut shell carbon adsorption recovery of gold and silver are used as key processes, thereby realizing cyanide-free and environmentally friendly gold extraction and solving the output of hazardous waste of cyanide gold extraction tailings from the source. The gold content of the liquid after carbon adsorption recovery of gold and silver is 0.03-0.05g / m 3, which can be returned for acid hydrolysis filter cake slurrying and recycling. The filter cake containing 1.0-2.0 g / t of gold can be sent to pyrometallurgy as an additional auxiliary material for comprehensive utilization. In step (5), the copper and arsenic in the acid hydrolysis solution are controlled by segmented dosing. The principle of differential precipitation of different sulfide solubility products of copper and arsenic is utilized to solve the technical problem of efficient precipitation and separation of copper and arsenic. A copper sulfide product containing 20-40 wt% of copper is obtained by pressure filtration. An arsenic sulfide product containing 10-30 wt% of arsenic is obtained by pressure filtration. The arsenic sulfide product can be used for recycling in the pretreatment of gold concentrate roasting. The acidic waste liquid after copper and arsenic recovery can be used for recycling in the gold concentrate slurrying process using acidic waste liquid.

[0013] Furthermore, in the step (1), the acidic waste water with a sulfuric acid content of 20 to 40 wt% is obtained by circulating and concentrating the acidic waste liquid, that is, the gold concentrate is slurried with the acidic waste liquid, and the purified acidic waste water is produced through boiling roasting and roasting acid making processes. The purified acidic waste water is recycled in the gold concentrate slurrying process, and the purified waste acid is recycled and concentrated to a sulfuric acid content of 20 to 40 wt%.

[0014] The invention circulates and concentrates the acidic waste liquid to increase the acidity, is beneficial to the acid removal efficiency of the roasting cyanide gold extraction tailings, and improves the resource utilization rate.

[0015] Furthermore, in step (2), the roasting cyanide gold extraction tailings are produced by roasting gold concentrate, acid leaching of copper and zinc from roasted sand, and cyanide gold extraction from the acid leaching residue.

[0016] Furthermore, in step (2), the roasted cyanide gold extraction tailings contain 2.0-3.0 g / t of gold and 30-40 wt% of iron.

[0017] Furthermore, in the step (4), the amount of thiourea is 5-15 kg / t, the leaching temperature is 50-60 ° C, the time is 2-6 h, and the density of coconut shell activated carbon in the slurry is 10-30 kg / m 3 .

[0018] Furthermore, in step (5), the amount of ferrous sulfide added to the acid hydrolysis filtrate is 3 to 5 kg / m 3 , stirring speed 30~50r / min, reaction time 2~4h.

[0019] Furthermore, in step (5), the amount of ferrous sulfide added to the overflow liquid is 3-5 kg / m 3 , stirring speed 30~50r / min, reaction time 2~4h.

[0020] The beneficial effects of the present invention are:

[0021] The invention adopts a five-stage treatment process of increasing the acidity of sulfuric acid by circulating and concentrating the first-stage acidic wastewater; performing ultrafine grinding of the roasting cyanidation gold extraction tailings in the second-stage to improve the grinding fineness; performing acid decomposition and leaching of the acidic wastewater after the third-stage concentration and the roasting cyanidation gold extraction tailings after the ultrafine grinding; performing carbon adsorption recovery of gold and silver by thiourea leaching in the fourth stage; and performing targeted sulfurization recovery of copper and arsenic by the fifth-stage acidolysis liquid. The invention performs efficient treatment, so that sulfuric acid in the acidic wastewater is efficiently recovered, the roasting cyanidation gold extraction tailings are comprehensively and efficiently utilized, and high-value resource utilization and clean production of the acidic wastewater and the roasting cyanidation gold extraction tailings are realized, and the environmental hazards of the acidic wastewater and the roasting cyanidation gold extraction tailings are eliminated. The process has a smooth process flow, strong operability, and a good environment, and has significant economic, social and environmental benefits. DETAILED DESCRIPTION

[0022] The principles and features of the present invention are described below in conjunction with embodiments. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0023] Example 1

[0024] A method for recovering gold by co-processing tailings with acidic wastewater comprises the following steps:

[0025] (1) Primary acidic wastewater recycling and concentration: Gold concentrate is slurried with acidic wastewater, and the purified acidic wastewater produced by boiling roasting and roasting acid production process is recycled in the gold concentrate slurrying process. The purified waste acid is recycled and concentrated to a sulfuric acid content of 20wt% before entering the next process;

[0026] (2) Secondary roasting cyanide gold extraction tailings output and fineness control: The gold concentrate is pre-treated by roasting, the roasted sand is subjected to acid leaching to extract copper and zinc, and the acid leaching residue is subjected to a cyanide gold extraction process to produce roasting cyanide gold extraction tailings; the roasting cyanide gold extraction tailings are circulated and ground by an AL1500L grinding machine to ensure that the mineral particle size is increased to -0.023mm, reaching 80%. After filtration, the roasting cyanide gold extraction tailings contain 2.0g / t of gold and 30wt% of iron, and enter the next step;

[0027] (3) Tertiary acid removal: The acid removal process is carried out in four acid-resistant and corrosion-resistant stirring tanks of φ3500mm*4000mm connected in series, with a ceramic stirring device and a stirring speed of 300r / min. The acid wastewater concentrated to a sulfuric acid content of 20wt% and the roasting cyanide gold extraction tailings after grinding are mixed and stirred in a liquid-solid mass ratio of 1:1 for acid hydrolysis. The acid hydrolysis temperature is 80°C and the acid hydrolysis time is 2h. After the acid hydrolysis is completed, a blower washing filter press is used for filtration and dehydration to obtain an acid hydrolysis filter cake and an acid hydrolysis filtrate. The acid hydrolysis filter cake contains 15.0wt% water and 3.0g / t gold, and enters the next step of thiourea leaching carbon adsorption to recover gold and silver; the acid hydrolysis filtrate contains 1.0g / l copper and 0.2g / l arsenic, and enters the acid hydrolysis liquid sulfidation targeted recovery process of copper and arsenic;

[0028] (4) Recovery of gold and silver by adsorption of carbon using thiourea at the fourth stage of leaching: the acid-dissolved filter cake and water were slurried in a liquid-solid ratio of 1:1, thiourea was added as a leaching agent, and coconut shell activated carbon was added simultaneously. The thiourea dosage was 5 kg / t, the leaching temperature was 50 °C, the leaching time was 2 h, and the density of coconut shell activated carbon in the slurry was 10 kg / m 3 After the gold and silver are extracted, the pulp is screened with carbon to produce activated carbon loaded with gold and silver. The remaining pulp is separated by liquid and solid to obtain filter cake and carbon adsorption to recover the gold and silver liquid. The gold content of the gold and silver liquid recovered by carbon adsorption is 0.03g / m 3 It can be returned for slurry mixing with acid-dissolved filter cake for recycling. The filter cake containing 1.0g / t gold is sent to pyrometallurgy as an additional auxiliary material for comprehensive utilization.

[0029] (5) Targeted recovery of copper and arsenic by sulfidation of the fifth-stage acid hydrolysis solution: The acid hydrolysis filtrate is first transported to two φ2000mm*4000mm glass fiber reinforced plastic reaction tanks connected in series through a delivery pump, and ferrous sulfide is added at the same time. The amount of ferrous sulfide added is 3kg / m 3 , stirring speed 30r / min, reaction time 2h, after the reaction is completed, it enters the φ3000mm*6000mm concentration device, the bottom flow liquid is filtered to obtain a copper sulfide product containing 20wt% copper; the overflow liquid flows by gravity into two closed φ2000mm*4000mm glass fiber reinforced plastic reaction tanks connected in series, and ferrous sulfide is added at the same time, and the amount of ferrous sulfide added is 3kg / m 3 , stirring speed 30r / min, reaction time 2h, after the reaction is completed, enter the φ3000mm*6000mm concentration device, the bottom flow is filtered to obtain arsenic sulfide product containing 10wt% arsenic, which can be returned to step (2) gold concentrate roasting pretreatment recycling, after copper and arsenic are recovered, the acidic waste liquid can be returned to step (1) gold concentrate using acidic waste liquid slurrying process for recycling.

[0030] Example 2

[0031] A method for recovering gold by co-processing tailings with acidic wastewater comprises the following steps:

[0032] (1) Primary acid wastewater recycling and concentration: Gold concentrate is slurried with acidic wastewater, and the purified acidic wastewater produced by boiling roasting and roasting acid production process is recycled in the gold concentrate slurrying process. The purified waste acid is recycled and concentrated to a sulfuric acid content of 30wt% before entering the next process;

[0033] (2) Secondary roasting cyanide gold extraction tailings output and fineness control: The gold concentrate is pre-treated by roasting, the roasted sand is subjected to acid leaching to extract copper and zinc, and the acid leaching residue is subjected to a cyanide gold extraction process to produce roasting cyanide gold extraction tailings. The roasting cyanide gold extraction tailings are circulated and ground by an AL1500L grinding machine to ensure that the mineral particle size is increased to -0.023mm, reaching 85%. After filtration, the roasting cyanide gold extraction tailings contain 2.5g / t of gold and 35wt% of iron, and enter the next step;

[0034] (3) Tertiary acid removal: The acid removal process is carried out in five acid-resistant and corrosion-resistant stirring tanks of 3500mm*4000mm in series, with a ceramic stirring device and a stirring speed of 400r / min. The acid wastewater concentrated to a sulfuric acid content of 30wt% and the roasting cyanide gold extraction tailings after grinding are mixed and stirred at a liquid-solid mass ratio of 1:3 for acid hydrolysis. The acid hydrolysis temperature is 100°C and the acid hydrolysis time is 4h. After the acid hydrolysis is completed, the filter press is used for filtration and dehydration to obtain an acid hydrolysis filter cake and an acid hydrolysis filtrate. The acid hydrolysis filter cake contains 17.5wt% water and 4.5g / t gold, and enters the next step of thiourea leaching carbon adsorption to recover gold and silver; the acid hydrolysis filtrate contains 1.52g / l copper and 0.25g / l arsenic, and enters the acid hydrolysis liquid sulfide targeted recovery process of copper and arsenic;

[0035] (4) Four-stage thiourea leaching and carbon adsorption recovery of gold and silver: The acid solution filter cake and the liquid after carbon adsorption recovery of gold and silver were slurried in a liquid-solid ratio of 2:1, thiourea was added as a leaching agent, and coconut shell activated carbon was added simultaneously. The thiourea dosage was 10 kg / t, the leaching temperature was 55 ° C, the time was 4 h, and the density of coconut shell activated carbon in the slurry was 20 kg / m 3 After the gold and silver are extracted, the pulp is screened with carbon to produce activated carbon loaded with gold and silver. The remaining pulp is separated by liquid and solid to obtain filter cake and carbon adsorption to recover the gold and silver liquid. The gold content of the gold and silver liquid recovered by carbon adsorption is 0.04g / m 3 It can be returned for slurry mixing with acid-dissolved filter cake for recycling. The filter cake containing 1.5g / t gold is sent to pyrometallurgy as an additional auxiliary material for comprehensive utilization.

[0036] (5) Targeted recovery of copper and arsenic by sulfidation of the fifth-stage acid hydrolysis solution: The acid hydrolysis filtrate is first transported to two φ2000mm*4000mm glass fiber reinforced plastic reaction tanks connected in series through a conveying pump, and ferrous sulfide is added at the same time. The amount of ferrous sulfide added is 4kg / m 3 , stirring speed 40r / min, reaction time 3h, after the reaction is completed, it enters the φ3000mm*6000mm concentration device, the bottom flow liquid is filtered to obtain a copper sulfide product containing 30wt% copper; the overflow liquid flows by gravity into two closed φ2000mm*4000mm glass fiber reinforced plastic reaction tanks connected in series, and ferrous sulfide is added at the same time, and the amount of ferrous sulfide added is 4kg / m 3, stirring speed 40r / min, reaction time 3h, after the reaction is completed, enter the φ3000mm*6000mm concentration device, the bottom flow is filtered to obtain arsenic sulfide product containing 20wt% arsenic, which can be returned to step (2) gold concentrate roasting pretreatment recycling, and the acidic waste liquid after copper and arsenic recovery can be returned to step (1) gold concentrate using acidic waste liquid slurrying process for recycling.

[0037] Example 3

[0038] A method for recovering gold by co-processing tailings with acidic wastewater comprises the following steps:

[0039] (1) Primary acid wastewater recycling and concentration: Gold concentrate is slurried with acidic wastewater, and the purified acidic wastewater produced by boiling roasting and roasting acid production process is recycled in the gold concentrate slurrying process. The purified waste acid is recycled and concentrated to a sulfuric acid content of 40wt% before entering the next process;

[0040] (2) Secondary roasting cyanide gold extraction tailings output and fineness control: The gold concentrate is pre-treated by roasting, the roasted sand is subjected to acid leaching to extract copper and zinc, and the acid leaching residue is subjected to a cyanide gold extraction process to produce roasting cyanide gold extraction tailings. The roasting cyanide gold extraction tailings are circulated and ground by an AL1500L grinding machine to ensure that the mineral particle size is increased to -0.023mm, reaching 90%. After filtration, the roasting cyanide gold extraction tailings contain 3.0g / t of gold and 40wt% of iron, and enter the next step;

[0041] (3) Tertiary acid removal: The acid removal process is carried out in 6 acid-resistant and corrosion-resistant stirring tanks of φ3500mm*4000mm connected in series, with a ceramic stirring device and a stirring speed of 500r / min. The acid wastewater concentrated to a sulfuric acid content of 40wt% and the roasting cyanide gold extraction tailings after grinding are mixed and stirred at a liquid-solid mass ratio of 1:6 for acid hydrolysis. The acid hydrolysis temperature is 120°C and the acid hydrolysis time is 6h. After the acid hydrolysis is completed, the filter press is used for filtration and dehydration to obtain the acid hydrolysis filter cake and the acid hydrolysis filtrate. The acid hydrolysis filter cake has a water content of 20wt% and a gold content of 6g / t, and enters the next step of thiourea leaching carbon adsorption to recover gold and silver; the acid hydrolysis filtrate contains 2g / l of copper and 0.3g / l of arsenic, and enters the acid hydrolysis liquid sulfidation targeted recovery process of copper and arsenic;

[0042] (4) Four-stage thiourea leaching and carbon adsorption recovery of gold and silver: The acid solution filter cake and the liquid after carbon adsorption recovery of gold and silver were slurried in a liquid-solid ratio of 3:1, thiourea was added as a leaching agent, and coconut shell activated carbon was added simultaneously. The thiourea dosage was 15 kg / t, the leaching temperature was 60 ° C, the time was 6 h, and the density of coconut shell activated carbon in the slurry was 30 kg / m 3 After the gold and silver are extracted, the pulp is screened with carbon to produce activated carbon loaded with gold and silver. The remaining pulp is separated by liquid and solid to obtain filter cake and carbon adsorption to recover the gold and silver liquid. The gold content of the gold and silver liquid recovered by carbon adsorption is 0.05g / m3 It can be returned for slurry mixing with acid-dissolved filter cake for recycling. The filter cake containing 2.0g / t gold is sent to pyrometallurgy as an additional auxiliary material for comprehensive utilization.

[0043] (5) Targeted recovery of copper and arsenic by sulfidation of the fifth-stage acid hydrolysis solution: The acid hydrolysis filtrate is first transported to three φ2000mm*4000mm glass fiber reinforced plastic reaction tanks connected in series through a conveying pump, and ferrous sulfide is added at the same time. The amount of ferrous sulfide added is 5kg / m 3 , stirring speed 50r / min, reaction time 4h, after the reaction is completed, it enters the φ3000mm*6000mm concentration device, the bottom flow liquid is filtered to obtain a copper sulfide product containing 40wt% copper; the overflow liquid flows by gravity into three φ2000mm*4000mm glass fiber reinforced plastic reaction tanks connected in series, and ferrous sulfide is added at the same time, and the amount of ferrous sulfide added is 5kg / m 3 , stirring speed 50r / min, reaction time 4h, after the reaction is completed, enter the φ3000mm*6000mm concentration device, the bottom flow is filtered to obtain arsenic sulfide product containing 30wt% arsenic, which can be returned to step (2) gold concentrate roasting pretreatment recycling, after copper and arsenic are recovered, the acidic waste liquid can be returned to step (1) gold concentrate using acidic waste liquid slurrying process for recycling.

[0044] 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 principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for recovering gold by co-processing tailings with acidic wastewater, characterized in that: The steps include: Step (1) Acidic wastewater concentration: The acidic wastewater is concentrated to a sulfuric acid content of 20 to 40 wt%; Step (2) fineness control of roasting cyanide gold extraction tailings: grinding the roasting cyanide gold extraction tailings to a particle size of -0.023 mm to 80-90%; Step (3) acidolysis: acid wastewater with a sulfuric acid content of 20-40 wt% and roasting cyanide gold extraction tailings after grinding are mixed and stirred at a liquid-solid mass ratio of 1:(1-6) for acidolysis, with a stirring speed of 300-500 r / min, an acidolysis temperature of 80-120° C., and an acidolysis time of 2-6 h. After the acidolysis is completed, filter pressing and dehydration are performed to obtain an acidolysis filter cake and an acidolysis filtrate; Step (4) leaching gold and silver by thiourea and carbon adsorption: the acid hydrolysis filter cake is slurried with water or the liquid after gold and silver are recovered by carbon adsorption in a liquid-solid ratio of (1-3):1, thiourea is added as a leaching agent, and coconut shell activated carbon is added simultaneously. The pulp after leaching and extracting gold and silver is passed through a carbon screen to produce activated carbon loaded with gold and silver. The pulp after the sieve is subjected to liquid-solid separation to obtain a filter cake and the liquid after gold and silver are recovered by carbon adsorption; Step (5) sulfidation of the acidolysis liquid for targeted recovery of copper and arsenic: the acidolysis filtrate is transported to a reaction tank, ferrous sulfide is added and stirred for reaction, and after the reaction is completed, it enters a concentrator, and the bottom flow is subjected to filter press to obtain a copper-containing copper sulfide product and an acidic waste liquid after copper recovery; the overflow liquid flows into the reaction tank by gravity, ferrous sulfide is added and stirred for reaction, and after the reaction is completed, it enters a concentrator, and the bottom flow is subjected to filter press to obtain an arsenic-containing arsenic sulfide product and an acidic waste liquid after arsenic recovery.

2. The method for recovering gold by co-processing tailings with acidic wastewater according to claim 1, characterized in that: In the step (1), the acidic wastewater with a sulfuric acid content of 20 to 40 wt% is purified acidic wastewater produced by slurrying gold concentrate with acidic waste liquid, boiling roasting, and roasting acid production processes. The purified acidic wastewater is recycled in the gold concentrate slurrying process, and the purified waste acid is recycled and concentrated to a sulfuric acid content of 20 to 40 wt%.

3. The method for recovering gold by co-processing tailings with acidic wastewater according to claim 1, characterized in that: In the step (2), the roasting cyanide gold extraction tailings are produced by the process of pre-treating gold concentrate by roasting, leaching copper and zinc from roasted sand by acid leaching, and then subjecting the acid leaching residue to cyanide gold extraction.

4. The method for recovering gold by co-processing tailings with acidic wastewater according to claim 1, characterized in that: In the step (2), the roasting cyanide gold extraction tailings contain 2.0-3.0 g / t of gold and 30-40 wt% of iron.

5. The method for recovering gold by co-processing tailings with acidic wastewater according to claim 1, characterized in that: In the step (4), the amount of thiourea is 5-15 kg / t, the leaching temperature is 50-60 ° C, the time is 2-6 hours, and the density of coconut shell activated carbon in the slurry is 10-30 kg / m 3 .

6. The method for recovering gold by co-processing tailings with acidic wastewater according to claim 1, characterized in that: In the step (5), the amount of ferrous sulfide added to the acid hydrolysis filtrate is 3 to 5 kg / m 3 , stirring speed 30~50r / min, reaction time 2~4h.

7. The method for recovering gold by co-processing tailings with acidic wastewater according to claim 6, characterized in that: In the step (5), the amount of ferrous sulfide added to the overflow liquid is 3-5 kg / m 3 , stirring speed 30~50r / min, reaction time 2~4h.