CN-121990708-A - Advanced treatment process for copper smelting contaminated acid

Abstract

The invention discloses a copper smelting waste acid advanced treatment process, and belongs to the technical field of copper smelting waste acid treatment. The method comprises the steps of (1) primary copper sulfide removal, (2) secondary arsenic sulfide removal, (3) one-stage acid reduction treatment, (4) two-stage neutralization ferric salt heavy metal removal, (5) three-stage neutralization ferric salt heavy metal removal, (6) hardness reduction treatment, (7) membrane treatment and (8) evaporation crystallization. The invention truly realizes zero emission of the copper smelting waste acid wastewater by carrying out advanced treatments such as pollutant removal, product quality regulation and the like on the copper smelting waste acid wastewater.

Inventors

• PAN LI
• ZHANG JICAI
• Xie jiao
• LU WEI
• Ni Yucang
• NONG JUNHUA
• LI SHAOHUA
• WANG BAOLIANG
• CHEN JIANLONG
• BIAN YUHAO
• CHEN YING

Assignees

• 云南铜业股份有限公司西南铜业分公司

Dates

Publication Date

20260508

Application Date

20260106

Claims (10)

1. 1. The copper smelting waste acid advanced treatment process is characterized by comprising the following steps of: (1) Primary copper sulfide removal, namely performing copper sulfide removal treatment on copper-containing dirty acid of anode slime generated in a copper smelting process and copper-containing dirty acid generated in a copper electrolysis process to obtain copper sulfide removal liquid and copper sulfide slag, wherein the copper sulfide slag is conveyed to a pyrometallurgy copper smelting process for utilization; (2) Performing secondary vulcanization dearsenification, namely performing vulcanization dearsenification treatment on the solution obtained after the copper removal by vulcanization and the arsenic-containing waste acid generated in the copper smelting process in the step (1) to obtain solution obtained after the arsenic removal by vulcanization and arsenic sulfide slag; (3) Adding calcium carbonate into the liquid after the vulcanization and the dearsenification in the step (2) until the pH value of the liquid is=1-4, and then sequentially carrying out thickening treatment and centrifugal treatment on the liquid to obtain the liquid after the deacidification and byproduct gypsum; (4) Adding calcium hydroxide into the deacidification liquid obtained in the step (3) until the pH value of the liquid is 10-11.8, then adding polymeric ferric sulfate and hydrogen peroxide into the liquid until the pH value of the liquid is 8-10.5, adding polyacrylamide into the liquid for flocculation, and finally sequentially carrying out thickening and filter pressing treatment on the liquid to obtain second-stage supernatant and neutralization residues; (5) Adding calcium hydroxide to the second-stage supernatant fluid in the step (4) until the pH value of the liquid is=10-11.5, then adding polymeric ferric sulfate to the pH value of the liquid is=8-10.5, simultaneously adding hydrogen peroxide, then adding sodium hydrosulfide, finally adding polyacrylamide into the liquid for flocculation, and then carrying out thickening treatment on the liquid to obtain the third-stage supernatant fluid and thickened sediment, wherein the thickened sediment is conveyed to the step (4) for circulation treatment; (6) Adding carbon dioxide into the three-stage supernatant in the step (5) until the liquid hardness is lower than 100mg/L, adding sodium hydroxide to regulate the pH of the liquid, adding polyacrylamide and polyaluminium chloride into the liquid to flocculate, and sequentially carrying out thickening and suspension filtration treatment on the liquid to obtain low-hardness supernatant, thickening sediment and filtration sediment, wherein the thickening sediment and the filtration sediment are both conveyed into the step (3) to be circularly treated; (7) Membrane treatment, namely carrying out membrane treatment on the low-hardness supernatant in the step (6) to obtain produced water, wastewater and high-pressure reverse osmosis concentrated water, wherein the produced water is conveyed to a chemical water treatment station for use, the wastewater is conveyed to the step (6) for cyclic treatment, and the high-pressure reverse osmosis concentrated water is conveyed to an evaporation crystallization process for use; (8) And (3) evaporating and crystallizing, namely evaporating and crystallizing the high-pressure reverse osmosis concentrated water in the step (7) to finish the advanced treatment of copper smelting waste acid.
2. 2. The process according to claim 1, wherein in the step (1), sodium bisulfide is added to the copper-containing contaminated acid of the anode slime and the copper-containing contaminated acid to decopperate the copper, and the mass ratio of the sodium bisulfide to the copper in the copper-containing contaminated acid is equal to 1:1.14.
3. 3. The process according to claim 1, wherein in the step (2), sodium bisulfide is added to the arsenic-containing contaminated acid for dearsenification, and sodium bisulfide is added until the solution after the dearsenification is titrated with a sodium bisulfide solution with a concentration of 13.6%, and no yellow precipitate appears and white mist is generated.
4. 4. The process according to claim 1, wherein in the step (3), the thickened underflow of the thickening treatment is centrifuged, the filtrate obtained after the centrifugation is returned to the thickening treatment for recycling treatment, and the filtrate obtained after the acid reduction is the supernatant obtained after the thickening treatment.
5. 5. The process according to claim 1, wherein in the step (4), calcium hydroxide is added to the liquid pH=10.5-11.5, polymeric ferric sulfate is added to the liquid pH=9.5-10.5, the hydrogen peroxide is added in a mass-to-liquid volume ratio of H 2 O 2 to liquid=125 g to 1m 3 , the polyacrylamide is added in a mass-to-liquid volume ratio of polyacrylamide to liquid=2 g to 1m 3 , the underflow obtained by the thickening is subjected to pressure filtration treatment, the filtrate produced by the pressure filtration is returned to the thickening treatment for circulation treatment, the two-stage supernatant is supernatant obtained by the thickening treatment, and the neutralization slag is solid slag produced by the pressure filtration.
6. 6. The process according to claim 1, wherein in the step (5), the pH is controlled to be 10.5-11.5 by adding calcium hydroxide, the pH is controlled to be 9-10.5 by adding polymeric ferric sulfate, the hydrogen peroxide is added in a mass-to-liquid volume ratio of H 2 O 2 :liquid=125 g:1m 3 , the sodium hydrosulfide is added in a mass-to-liquid volume ratio of sodium hydrosulfide:liquid=91 g:1m 3 , and the polyacrylamide is added in a mass-to-liquid volume ratio of polyacrylamide:liquid=2 g:1m 3 .
7. 7. The process according to claim 1, wherein in the step (6), the pH value is controlled to be 10.5-11.5 by adding sodium hydroxide, the mass-to-liquid volume ratio of polyacrylamide to liquid is polyacrylamide: liquid=2g:1 m 3 , the mass-to-liquid volume ratio of polyaluminum chloride to liquid=35g:1 m 3 , and the supernatant obtained by the thickening treatment is subjected to suspension filtration.
8. 8. The process according to claim 1, wherein in the step (7), the film treatment comprises the steps of: S1, adding polyaluminium chloride into low-hardness supernatant, and then performing multi-medium filtration on liquid to obtain multi-medium filter residues and multi-medium filtrate, wherein the mass ratio of the polyaluminium chloride to the liquid is polyaluminium chloride to be liquid=30g:1 m 3 , and backwash steam washing drainage generated in the multi-medium filter residues and the multi-medium filtration process is conveyed to the step (6) for circulation treatment; S2, carrying out self-cleaning filtration on the multi-medium filtrate in the step S1 to obtain self-cleaning filter residues and self-cleaning filtrate, and conveying backwash drainage generated in the self-cleaning filter residues and the self-cleaning filtration process to the step (6) for circulation treatment; S3, carrying out ultrafiltration on the self-cleaning filtrate in the step S2 to obtain ultrafiltration produced water and ultrafiltration filter residues, and conveying the ultrafiltration filter residues, backwash wastewater generated in the ultrafiltration process and overflow of the ultrafiltration produced water to the step (6) for cyclic treatment; And S4, carrying out resin exchange treatment on the ultrafiltration produced water in the step S3 to obtain resin exchange produced water, and conveying overflow generated in the resin exchange treatment process and overflow of the resin produced water to the step (6) for recycling treatment. S5, adding a non-oxygen bactericide, a reducing agent and a membrane scale inhibitor into the resin exchange produced water in the step S4, performing primary reverse osmosis treatment on the resin exchange produced water, wherein the non-oxygen bactericide is isothiazolinone, the reducing agent is sodium bisulphite, the non-oxygen bactericide is added in a mass-to-liquid volume ratio of non-oxygen bactericide to liquid=5g:1 m 3 , the reducing agent is added in a mass-to-liquid volume ratio of reducing agent to liquid=12g:1 m 3 reaction liquid, the membrane scale inhibitor is added in a mass-to-liquid volume ratio of membrane scale inhibitor to liquid=23 g:1: 3 reaction liquid, obtaining produced water I and concentrated water I after the primary reverse osmosis treatment, returning reverse osmosis membrane cleaning water generated in the primary reverse osmosis process to the step (6) for circulation treatment, and conveying overflow of the concentrated water I to the step (6) for circulation treatment; S6, adding a non-oxygen bactericide, a reducing agent, a membrane scale inhibitor and concentrated sulfuric acid into the concentrated water I in the step S5, performing high-pressure reverse osmosis treatment on the concentrated water I, obtaining high-pressure reverse osmosis produced water and high-pressure reverse osmosis concentrated water after the high-pressure reverse osmosis treatment, conveying the high-pressure reverse osmosis concentrated water to an evaporation crystallization process for use, conveying overflow of the high-pressure reverse osmosis concentrated water to the step (6) for cyclic treatment, and combining the high-pressure reverse osmosis produced water and the water I produced in the step S5 to form mixed produced water, wherein the non-oxygen bactericide is isothiazolinone, the reducing agent is sodium bisulphite, the non-oxygen bactericide is added in a mass-liquid volume ratio of non-oxygen bactericide: liquid=2g:1 mm 3 , the reducing agent is added in a mass-liquid volume ratio of reducing agent: liquid=5g:1 m 3 , the membrane scale inhibitor is added in a mass-liquid volume ratio of membrane scale inhibitor: liquid=6g:1 m 3 , the concentrated sulfuric acid concentration is 98%, and the concentrated sulfuric acid is added until the pH value of the concentrated sulfuric acid is less than 6.5; And S7, adding a non-oxygen bactericide, a reducing agent and a membrane scale inhibitor into the mixed produced water in the step S6, performing secondary reverse osmosis treatment on the mixed produced water, obtaining produced water II and concentrated water II after the secondary reverse osmosis treatment, conveying overflow of the mixed produced water to the step (6) for circulation treatment, conveying the produced water II to a chemical water treatment station for use, conveying the concentrated water II to the step S5, and carrying out circulation treatment after the concentrated water II is combined with resin exchange produced water, wherein the non-oxygen bactericide is isothiazolinone, the reducing agent is sodium bisulphite, the non-oxygen bactericide is added in a ratio of the mass of the non-oxygen bactericide to the volume of the liquid=5g:1 mm 3 , the reducing agent is added in a ratio of the mass of the reducing agent to the volume of the liquid=13g:1 m 3 reaction liquid, and the membrane scale inhibitor is added in a ratio of the volume of the membrane scale inhibitor to the volume of the liquid=25g:1 m 3 reaction liquid.
9. 9. The process according to claim 8, wherein in the steps S1 to S7, the liquid produced by the purging operation is fed to the step (6) for recycling.
10. 10. The process according to claim 1, wherein in the step (8), the specific process of evaporative crystallization comprises the steps of: q1, sequentially carrying out triple-effect evaporation crystallization, thickening and centrifugation on the high-pressure reverse osmosis concentrated water to obtain sodium sulfate crystals and triple-effect mother liquor, and drying the sodium sulfate crystals to obtain a sodium sulfate product, wherein the saturation temperature difference of the triple-effect evaporation crystallization is controlled to be 4.5-9.5 ℃; Q2, sequentially carrying out freezing crystallization and centrifugal treatment on the triple-effect mother liquor to obtain sodium sulfate decahydrate and frozen mother liquor, and conveying the sodium sulfate decahydrate after hot melting to the step Q1 for cyclic treatment; Q3, sequentially carrying out single-effect evaporation crystallization, thickening and centrifugation on the frozen mother solution in the step Q2 to obtain sodium chloride crystals and single-effect mother solution, and drying the sodium chloride crystals to obtain sodium chloride products, wherein the saturation temperature difference of the single-effect evaporation crystallization is controlled to be 4.5-9.5 ℃; And Q4, drying the single-effect mother liquor in the step Q3 to obtain mixed salt solid waste, and carrying out solid waste treatment on the mixed salt solid waste.

Description

Advanced treatment process for copper smelting contaminated acid Technical Field The invention belongs to the technical field of copper smelting waste acid treatment, and relates to a copper smelting waste acid advanced treatment process. Background The waste acid and wastewater generated in the copper smelting process has pollutants such as high arsenic and heavy metal, cannot be directly discharged, and needs to be treated, however, the waste acid and wastewater generated in the copper smelting process has high pollutant content and complex pollutant properties, so that the waste acid and wastewater generated in the copper smelting process has the influence caused by the toxic action of the pollutants, and the quality of the waste acid and wastewater cannot meet the use or environmental protection requirements, such as high liquid hardness, high sludge density index, high turbidity and the like. Therefore, the current treatment process for copper smelting acid wastewater cannot meet the stricter environmental protection requirements. In the industrial water saving term GB/T21534-2008, it is pointed out that "zero discharge" of sewage refers to that the industrial wastewater is not discharged by the industrial water system of an enterprise or a main unit, so that the sewage and the acid wastewater generated by the production of related units are required to be recycled through resources, used as raw materials in other industries, transferred into waste residues, subjected to solid waste treatment and other means to realize "zero discharge". Therefore, it is necessary to provide a deep treatment process for copper smelting waste acid, which carries out omnibearing treatment on the copper smelting waste acid and wastewater, and truly realizes zero emission of the copper smelting waste acid and wastewater. Disclosure of Invention In order to overcome the problems in the background art, the method disclosed by the invention not only can remove pollutants such as arsenic, copper and other heavy metals in the waste acid and water thoroughly by perfecting the treatment process of the waste acid and water in the copper smelting process, but also can adjust the quality of the waste acid and water, so that the waste acid and water in the copper smelting process has lower pollution and even no pollution after being subjected to advanced treatment, and simultaneously improves the availability of substances generated in the treatment process, thereby laying a solid foundation for zero emission. In order to achieve the above purpose, the present invention is realized by the following technical scheme: The invention provides a copper smelting waste acid advanced treatment process, which comprises the following steps of: (1) And (3) primary copper sulfide removal, namely performing copper sulfide removal treatment on copper-containing dirty acid of anode slime generated in the copper smelting process and copper-containing dirty acid generated in the copper electrolysis process to obtain copper sulfide removal liquid and copper sulfide slag, and conveying the copper sulfide slag to a pyrometallurgy copper smelting process for utilization. (2) And (2) secondary sulfuration dearsenification, namely carrying out sulfuration dearsenification treatment on the sulfuration dearsenification liquid in the step (1) and arsenic-containing waste acid generated in the copper smelting process to obtain sulfuration dearsenification liquid and sulfuration arsenic slag. The arsenic sulfide slag is transferred to a special treatment mechanism for solid waste disposal. (3) And (3) carrying out one-stage acid reduction treatment, namely adding calcium carbonate into the liquid after the vulcanization and dearsenification in the step (2) until the pH value of the liquid is=1-4, and then sequentially carrying out thickening treatment and centrifugal treatment on the liquid to obtain the liquid after the acid reduction and byproduct gypsum. The byproduct gypsum can be used as a raw material in the industries of construction and the like. (4) And (3) adding calcium hydroxide into the deacidification liquid obtained in the step (3) until the pH value of the liquid is 10-11.8, adding polymeric ferric sulfate and hydrogen peroxide into the liquid until the pH value of the liquid is 8-10.5, adding polyacrylamide into the liquid for flocculation, and finally sequentially carrying out thickening and filter pressing treatment on the liquid to obtain second-stage supernatant and neutralization residues. The free radical or intermediate product generated by the hydrogen peroxide can enhance the coagulation effect of the polymeric ferric sulfate and promote the heavy metal and the polymeric ferric sulfate to generate flocculent precipitate. (5) And (3) deeply removing heavy metals by three-stage neutralization ferric salt, namely adding calcium hydroxide into the second-stage supernatant fluid in the step (4) until the pH value of the liquid is=10-11.5, th