CN112359213A - Method for copper smelting hazardous waste co-processing and valuable metal comprehensive recovery - Google Patents

Abstract

The invention provides a method for the cooperative disposal of copper smelting hazardous waste and the comprehensive recovery of valuable metals, which comprises the following steps: carrying out normal pressure-pressurization two-stage countercurrent leaching on copper smelting smoke dust to obtain normal pressure leaching liquid and lead-silver-bismuth slag, and carrying out electrodeposition pre-copper removal on the normal pressure leaching liquid to obtain electro-copper and pre-copper removal liquid; then adding arsenic sulfide slag into the pre-decoppered solution for displacement copper precipitation to obtain copper sulfide concentrate and a copper precipitation solution; introducing SO into the copper precipitation solution₂And (4) reducing the flue gas to precipitate arsenic to obtain arsenic trioxide and arsenic precipitation liquid. The present invention providesThe method for the cooperative treatment of the hazardous waste in copper smelting and the comprehensive recovery of valuable metals has the advantages of high recycling and harmless treatment degree of waste residues, good comprehensive recovery effect of the valuable metals, no generation of waste acid, waste water and dangerous solid waste in the whole process, provides a new path for the cooperative treatment of the hazardous waste in copper smelting, and has wide application prospect.

Description

Method for copper smelting hazardous waste co-processing and valuable metal comprehensive recovery

Technical Field

The invention relates to the field of non-ferrous metal smelting and environmental protection, in particular to a method for the cooperative treatment of copper smelting hazardous waste and the comprehensive recovery of valuable metals.

Background

The rapid development of the non-ferrous metal industry not only faces the problem of the lack of primary mineral products, but also increasingly increases the discharge amount of dangerous wastes generated in the smelting process. The method is characterized in that copper smelting smoke (white smoke) produced in the copper pyrometallurgical smelting and converting processes, lead-zinc ash produced by smelting slag pyrometallurgy, arsenic sulfide slag, lead filter cake and gypsum slag produced by waste acid treatment, and hazardous wastes such as lead sulfate slag, silver separating slag produced in the anode mud treatment process contain a large amount of valuable metal elements, and the comprehensive and efficient recovery of the valuable elements has important significance for driving the comprehensive utilization of renewable resources in the nonferrous metal industry and environmental management.

At present, the copper smelting smoke (white smoke) is mainly treated by a wet method-fire method combined process, the wet method process mainly adopts low-acid normal-pressure leaching, leaching slag is reduced and smelted to recover lead, but because the leaching is carried out under normal pressure and low acid, the leaching rate of the valuable metals in the ash is low, particularly the leaching rate of arsenic is low, and the dispersion of the arsenic in the process brings great secondary pollution risk; the treatment of arsenic in the leachate is usually solidified by adopting a calcium salt or iron salt precipitation method, the arsenic-containing waste residues produced in the arsenic precipitation process are large in amount, the entrainment loss of valuable metals is high, the reduction effect of hazardous wastes is poor, and serious potential safety hazards exist in the stacking or landfill of the arsenic-containing residues; and the leaching slag produces a large amount of arsenic matte in the reduction smelting process due to high arsenic content, and the leaching slag is generally directly returned to the copper pyrometallurgy process, so that the ineffective circulation amount of Cu, Pb, As and the like is large, and the direct metal yield is low. Particularly, the pyro-copper smelting process and control are different, and for smoke dust with high arsenic content and poor leaching performance, the leaching rate of arsenic leached at normal pressure is only 50-60%, so that the requirements of recycling and harmless treatment of the smoke dust cannot be met.

The method for treating the arsenic sulfide slag mainly comprises a pyrogenic process and a wet process, wherein the pyrogenic process is a direct roasting method, arsenic trioxide is produced, but the recovery rate of arsenic is low, secondary pollution is serious, and the product quality is poor; the wet process mainly comprises an alkaline leaching method, an iron sulfate method and the likeAlthough crude arsenic trioxide, sodium arsenate and other products can be prepared, the purity of the product is low, and the consumption of auxiliary materials is large. Patent CN103911508B adopts pressurized oxygen leaching-SO₂The reduction-extraction process prepares arsenic trioxide and recovers rhenium in the arsenic sulfide slag, but S element in the arsenic sulfide slag is finally converted into dilute sulfuric acid or sulfate, the solution purification cost is high, and the wastewater treatment capacity is large.

Resource utilization of white smoke and arsenic sulfide slag has also been proposed in the prior art, for example, CN110983060A, which discloses leaching white smoke to obtain lead-rich slag and a white smoke leachate, mixing the white smoke leachate with an arsenic filter cake (i.e., arsenic sulfide slag), then pressure leaching, returning the leached slag to a smelting system, introducing SO into the leachate₂Reducing the gas to obtain coarse As₂O₃And (4) crystallizing. However, the method finally changes the S element from-2 valence into sulfate radical, so that the treatment capacity of waste acid is large, and the solution purification cost is high.

For example, CN 108624759A, it mixes white smoke with arsenic sulfide slag, adds sulfuric acid, mixes and pastes, and then carries on low temperature indirect roasting, gets arsenic trioxide and dearsenized calcine, then carries on acid leaching to dearsenized calcine, then processes leaching liquid and leaching slag separately, finally gets products such As bismuth, copper, lead slag, etc., this method converts arsenic into As through sulfuric acid curing and roasting conversion₂O₃The flue dust enters the roasting sand to be recycled, arsenic is preferentially extracted, the roasted sand is leached by dilute sulfuric acid, the leaching rate of metals such as Cu, Zn and the like is high, but the subsequent leaching solution separation and extraction process is an acid production process, sulfuric acid is added in the curing and leaching processes, the system is expanded by acid, a large amount of waste acid is generated as a by-product of concentrated crystalline zinc sulfate, the waste acid is converted into pure sulfuric acid through high-cost membrane separation, the treatment cost is high, the concentration of purified dilute sulfuric acid is low, the waste acid cannot be directly returned to the curing process, and the actual industrial production is difficult to popularize.

Disclosure of Invention

Aiming at the defects in the prior art, the embodiment of the invention provides a method for the cooperative treatment of copper smelting hazardous waste and the comprehensive recovery of valuable metals, which realizes high degrees of waste residue recycling and harmless treatment and good comprehensive recovery effect of the valuable metals and is suitable for large-scale industrial production.

The embodiment of the invention provides a method for the cooperative disposal of copper smelting hazardous waste and the comprehensive recovery of valuable metals, which comprises the following steps:

carrying out normal pressure-pressurization two-stage countercurrent leaching on copper smelting smoke dust to obtain normal pressure leaching liquid and lead-silver-bismuth slag, and carrying out electrodeposition pre-copper removal on the normal pressure leaching liquid to obtain electro-copper and pre-copper removal liquid;

then adding arsenic sulfide slag into the pre-decoppered solution for displacement copper precipitation to obtain copper sulfide concentrate and a copper precipitation solution;

introducing SO into the copper precipitation solution₂And (4) reducing the flue gas to precipitate arsenic to obtain arsenic trioxide and arsenic precipitation liquid.

The copper smelting smoke dust is copper-arsenic-containing smoke dust produced by copper smelting and converting, and particularly high-copper and high-arsenic refractory smoke dust which is poor in leaching performance and poor in direct normal-pressure leaching and separating effect. According to the invention, the normal-pressure leachate is subjected to electrodeposition pre-decoppering-arsenic sulfide residue replacement to extract copper step by step, and high-concentration copper liquid is subjected to electrodeposition recovery to obtain 2# cathode copper and pre-decoppered liquid; because the liquid after pre-decoppering has low copper concentration and high arsenic concentration, the electrodeposition can not produce cathode copper which meets the product requirement, usually black copper powder, the copper in the liquid after pre-decoppering is replaced by arsenic sulfide slag, copper sulfide concentrate is co-produced, and the loss of S is reduced while the arsenic is recovered.

The obtained arsenic trioxide contains certain moisture, and can be dried by microwave or infrared, wherein the drying temperature is 105-200 ℃. The dried arsenic trioxide can be reduced by charcoal to obtain metallic arsenic, and the reduction temperature is 350-600 ℃.

The method for the cooperative disposal of the copper smelting hazardous waste and the comprehensive recovery of valuable metals, provided by the embodiment of the invention, further comprises the following steps:

and returning part of the arsenic-precipitated liquid to the pressure leaching process of copper smelting smoke dust, and opening a circuit to perform sulfuration arsenic removal on part of the arsenic-precipitated liquid to obtain arsenic-removed liquid and arsenic-removed slag, wherein the arsenic-removed slag is returned to the displacement copper precipitation process.

The invention utilizes the arsenic precipitation liquid (which contains acid production of the working procedures of electro-deposition pre-copper removal, replacement copper precipitation and reduction arsenic precipitation) to leach the copper smelting smoke dust, the whole process has no waste liquid discharge, but the prior art is difficult to realize that the sulfate radical quantity which can be taken away by lead and bismuth in the leaching slag is more than or equal to the sulfate radical quantity in the existing copper, zinc and other sulfates in the copper smelting smoke dust, so the invention has the advantage of saving the cost compared with the cost of specially processing the waste acid in the prior art. However, if all of the arsenic-precipitated solution is returned to the pressure leaching step of the copper smelting fumes, the problems of zinc, cadmium and acid swell are not solved. Therefore, preferably, 50-80% of the arsenic-precipitated liquid is returned to the pressure leaching process of the copper smelting smoke dust, and the rest is opened to remove arsenic by vulcanization, so that the subsequent solution of the problems of zinc, cadmium and acid swelling is facilitated.

In the step of removing arsenic by vulcanization, adding a vulcanizing agent to remove arsenic, wherein the reaction temperature is 0-50 ℃ and the reaction time is 0.5-3 h; the vulcanizing agent is H₂One or more of S, ZnS, CaS, CdS and BaS, the addition amount of which is 1.0-2.0 times of the molar amount of the As in the solution. The main component of the arsenic-removed slag is arsenic sulfide.

The method for the cooperative disposal of the copper smelting hazardous waste and the comprehensive recovery of valuable metals, provided by the embodiment of the invention, further comprises the following steps:

adding lead-zinc ash into the arsenic-removed liquid, neutralizing and reducing acid to obtain neutralized slag and acid-reduced liquid, adding zinc powder into the acid-reduced liquid to perform displacement cadmium precipitation to obtain crude cadmium and cadmium-precipitated liquid, and concentrating and crystallizing the cadmium-precipitated liquid to obtain zinc sulfate monohydrate.

The lead-zinc ash is produced by pyrogenic depletion of copper smelting slag, processing of scrap copper and the like, and the lead-zinc ash belongs to hazardous waste due to the fact that the lead-zinc ash contains harmful elements such As As, Cd and the like, the lead-zinc ash is generally treated by sulfuric acid, hydrochloric acid and the like in steps, and the lead-zinc ash is treated by a solution separation method or directly treated by solidification and landfill.

The method for the cooperative disposal of the copper smelting hazardous waste and the comprehensive recovery of valuable metals, provided by the embodiment of the invention, further comprises the following steps:

and carrying out reduction smelting on the lead-silver-bismuth slag, the silver separating slag, the lead sulfate slag, the lead filter cake and the neutralization slag to obtain a lead-bismuth alloy, smelting slag, smelting smoke and copper removing slag, directly returning part of the smelting smoke to the reduction smelting, returning part of the smelting smoke to the copper smelting smoke leaching process, and mixing the part of the smelting smoke with the copper smelting smoke to leach.

Hazardous wastes such as lead sulfate slag, silver separating slag and the like can be produced in the anode slime treatment process, and valuable metal elements such as Pb, Bi, Ag and the like are also contained in the hazardous wastes. The treatment method of the silver slag in the prior art mainly comprises a fire method and a wet method, wherein the fire method mainly adopts reduction smelting to produce precious lead, and then ash blows off the lead, so that the energy consumption is high; the wet process mostly adopts a leaching-step enrichment extraction process, the consumption of auxiliary materials in the process is large, the variety of intermediate waste residues is large, and the treatment capacity of waste water is large. According to the invention, multi-source lead-containing materials such as lead-silver-bismuth slag, silver separating slag, lead sulfate slag, lead filter cake, neutralization slag and the like are cooperatively smelted, and the final slag (reduction smelting slag) in the whole process is common solid waste, so that harmless treatment of various hazardous wastes and efficient recovery of valuable metals in the copper smelting process are realized. The invention returns a part of the open circuit of the smelting smoke dust to the leaching process of the copper smelting smoke dust, can effectively avoid the higher arsenic content in the smelting slag caused by the accumulation of arsenic, and can further recover the arsenic.

The copper removing slag mainly comprises copper sulfide, namely, the crude lead has a copper sulfide removing process, namely, sulfur is added into a lead pot, the mixture is stirred, copper in lead liquid is removed, and a small amount of copper in the lead liquid is enriched in the copper sulfide slag.

According to the method for the synergistic treatment of the hazardous waste from copper smelting and the comprehensive recovery of valuable metals, provided by the embodiment of the invention, the atmospheric-pressure two-stage countercurrent leaching specifically comprises the following steps:

the normal pressure leaching process comprises the steps of leaching copper smelting dust and reduction smelting return dust by using a pressurized leaching solution, wherein the liquid-solid ratio ml/g is 2: 1-8: 1, the temperature is 20-80 ℃, the time is 0.5-6 h, and the sulfuric acid concentration at the leaching end point is 15-60 g/L;

and a pressure leaching step, wherein the normal pressure leaching residue is leached by using the arsenic-precipitated liquid, the liquid-solid ratio ml/g is 3: 1-10: 1, the temperature is 105-150 ℃, the oxygen partial pressure is 0.1-0.6 MPa, the time is 0.5-5 h, the final sulfuric acid concentration is 60-120 g/L, and the pressure leaching liquid returns to the normal pressure leaching step to consume residual acid.

The invention adopts two-stage countercurrent leaching of normal pressure and pressurization under proper conditions, has good material leaching and separating effects, particularly greatly improves the leaching rate of arsenic, avoids the dispersion of arsenic, and solves the problems of high arsenic content and arsenic matte production of the reduction smelting slag of the leaching slag at the source.

According to the method for the cooperative disposal of the copper smelting hazardous waste and the comprehensive recovery of valuable metals, provided by the embodiment of the invention, in the electrodeposition pre-decoppering process, the pre-decoppering liquid Cu is used²⁺A concentration of 25 to 55g/L and a current density of 100 to 200A/m²The electrodeposition temperature is 30-55 ℃, and the copper is removed in advance to obtain Cu liquid²⁺The concentration is 15-30 g/L.

According to the method for the cooperative disposal of the copper smelting hazardous waste and the comprehensive recovery of valuable metals, provided by the embodiment of the invention, in the replacement and copper deposition process, the addition amount of the arsenic sulfide slag is 20-300 kg/m³Pre-decoppering liquid, and blowing compressed air into a reaction system, wherein the air filling amount is 5-50 m³/m³Ore pulp, the reaction temperature is 25-80 ℃, and the reaction time is 0.5-4 h.

The technological parameters of the displacement copper deposition process and the electrodeposition copper pre-removal process are closely related, and the inventor finds the most appropriate conditions through a large number of experiments, so that the addition amount of the arsenic sulfide slag and the Cu of the liquid after the copper pre-removal are ensured²⁺The concentration is matched, so that qualified electrolytic copper can be obtained, and Cu can be realized after replacement copper deposition²⁺Down to<0.5g/L, while reducing As much As possible the entrainment of As.

According to the method for the cooperative disposal of the copper smelting hazardous waste and the comprehensive recovery of the valuable metal, provided by the embodiment of the invention, SO is introduced into the process of reduction and arsenic precipitation₂The concentration of the flue gas is 5-20%, the reduction temperature is 50-90 ℃, and the reaction time is 2-4 h; and (4) cooling and crystallizing after the reduction is finished, wherein the crystallization temperature is 0-30 ℃.

According to the method for the cooperative disposal of the copper smelting hazardous waste and the comprehensive recovery of valuable metals, provided by the embodiment of the invention, in the neutralization and deacidification process, the liquid-solid ratio ml/g of the arsenic-removed liquid to the lead-zinc ash is 4: 1-15: 1, an oxidant is added, the reaction temperature is 30-95 ℃, the reaction time is 1-6 h, and the end point pH is 3.0-5.5;

the oxidant is one or more of hydrogen peroxide, persulfuric acid, sodium persulfate, potassium persulfate and sodium peroxide, and the addition amount of the oxidant is 1.0-2.0 times of the molar amount of iron in the solution.

According to the method for the cooperative disposal of the hazardous waste in copper smelting and the comprehensive recovery of valuable metals, provided by the embodiment of the invention, in the reduction smelting process, iron-based solid waste and calcium-based solid waste are used as slag formers, and the reaction temperature is 900-1200 ℃; the invention adjusts the slag type and simultaneously (scrap iron, quartz and lime are conventional), and the relevant solid wastes are absorbed and treated.

The iron-based solid waste is one or more of waste scrap iron, cyanided tailings, copper smelting slag and slag dressing tailings, and the addition amount of the iron-based solid waste is 2-10% of the mixture; the calcium-based solid waste is one or two of calcium sulfate slag and gypsum slag, and the addition amount of the calcium-based solid waste is 1-10% of the mixture.

In a preferred embodiment of the invention, the method for the cooperative disposal of the hazardous waste from copper smelting and the comprehensive recovery of valuable metals specifically comprises the following steps:

(1) copper smelting dust and reduction smelting return dust are subjected to normal pressure-pressurization two-stage countercurrent leaching, and solid-liquid separation is carried out to obtain normal pressure leaching liquid and pressurized leaching slag (lead, silver and bismuth slag);

(2) carrying out electrodeposition pre-decoppering on the normal-pressure leaching solution obtained in the step (1) to produce electro-copper and a pre-decoppering solution;

(3) adding arsenic sulfide slag into the pre-decoppered liquid obtained in the step (2) to replace precipitated copper, and performing solid-liquid separation to obtain copper sulfide concentrate and a liquid after copper precipitation;

(4) introducing SO-containing liquid obtained after copper precipitation in the step (3)₂Reducing and precipitating arsenic in the flue gas, and performing centrifugal separation to obtain arsenic trioxide and an arsenic precipitation solution;

(5) drying the arsenic trioxide obtained in the step (4), and reducing by using charcoal to obtain metal arsenic;

(6) returning part of the arsenic-precipitated liquid obtained in the step (4) to the pressure leaching process in the step (1), opening a circuit to remove arsenic through sulfuration, and performing solid-liquid separation to obtain arsenic-removed slag and arsenic-removed liquid, wherein the arsenic-removed slag is returned to the step (3) for replacing the copper precipitation process;

(7) adding lead-zinc ash into the arsenic-removed liquid obtained in the step (6) for neutralization and deacidification, adding an oxidant for oxidation and iron removal, and performing solid-liquid separation to obtain neutralized slag and deacidified liquid;

(8) adding zinc powder into the deacidified solution obtained in the step (7) to perform displacement cadmium precipitation, and performing solid-liquid separation to obtain crude cadmium and a solution after cadmium precipitation;

(9) concentrating and crystallizing the cadmium-precipitated liquid obtained in the step (8), and performing centrifugal separation and drying to obtain zinc sulfate monohydrate;

(10) and (3) mixing the lead-silver-bismuth slag obtained in the step (1) with the silver separating slag, the lead sulfate slag, the lead filter cake, the neutralization slag obtained in the step (7) and the charcoal ash obtained in the step (5), carrying out reduction smelting/refining to obtain a lead-bismuth alloy, smelting slag, smelting smoke and copper removing slag, directly returning part of the smelting smoke to the reduction smelting, returning part of the smelting smoke to the normal-pressure leaching process in the step (1), and mixing the smelting smoke with the copper smelting smoke to leach.

The method for the cooperative treatment of the dangerous waste in copper smelting and the comprehensive recovery of valuable metals, provided by the embodiment of the invention, has the advantages of high recycling and harmless treatment degree of waste residues, good comprehensive recovery effect of valuable metals, no generation of waste acid, waste water and dangerous solid waste in the whole process, provides a new path for the cooperative treatment of the dangerous waste in copper smelting, and has wide application prospect.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and those skilled in the art can also obtain other drawings according to the drawings without creative efforts.

FIG. 1 is a process flow chart of the method for the co-disposal of hazardous waste from copper smelting and the comprehensive recovery of valuable metals in example 1 of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1

The embodiment provides a method for the cooperative disposal of copper smelting hazardous waste and the comprehensive recovery of valuable metals, wherein the main components of the copper smelting hazardous waste are shown in table 1, the specific process flow is shown in fig. 1, and the steps are as follows:

TABLE 1 major components (wt%, Au, Ag in g/t) of several hazardous wastes for copper smelting

Element(s)	Cu	Pb	Bi	As	Zn	Au	Ag	Cd	S	Sb
											Copper smelting smoke dust	15.75	17.86	2.46	6.44	5.84	4.38	0.04	0.91	7.46	0.45
Arsenic sulfide slag	10.82	3.45	2.36	29.96	4.045	0.16	16.45	0.395	30.8	0.097
											Silver separating slag	0.08	21.63	14.46	0.62	0.022	5.79	1003	/	7.01	9.39
Lead filter cake	3.36	47.59	2.65	0.47	1.48	3.44	163.6	0.49	8.89	0.018
											Lead-zinc ash	0.41	40.75	1.72	3.68	31.93	0.31	421.3	0.90	3.81	0.17
Lead sulfate slag	0.06	64.5	2.13	0.11	/	/	0.72	/	10.01	/

(1) Carrying out two-stage countercurrent leaching on copper smelting smoke dust by using residual acid (sulfuric acid is 160g/L, As is 12g/L, Zn is 58g/L and Cd is 8g/L) of a solution after arsenic precipitation, wherein the solution has a normal pressure-pressurization solid ratio (ml: g, the same below) of 4:1, the leaching time is 2h at the temperature of 80 ℃, the pressure leaching solution has a solid ratio of 4:1, and the leaching time is 1.5h at the temperature of 120 ℃ and the oxygen partial pressure of 0.5MPa, so that a normal-pressure leaching solution (a fine leaching solution obtained after overflow fine filtration) rich in Cu, Zn, As and Cd and a pressure leaching residue (lead silver bismuth residue) rich in Pb, Bi, Au and Ag are obtained, wherein the total residue leaching rate of the two stages is 40.03%, and the total residue leaching rates of Cu, Zn, As and Cd are 97.5%, 99%, 96.8% and 94.3% respectively;

(2) leaching the normal pressure leaching solution at 50 ℃ and the current density of 150A/m²Carrying out electrodeposition copper pre-removal at the same-grade distance of 100mm, and obtaining national standard No. 2 cathode copper with the concentration of liquid Cu of 21.12g/L after copper pre-removal, wherein the current efficiency is 98.5%;

(3) the pre-decoppered solution is added according to the proportion of 58.7kg/m³Adding arsenic sulfide slag, and adding 5m³/m³Introducing compressed air into the ore pulp, and replacing and precipitating copper for 3 hours at the temperature of 60 ℃ to obtain copper sulfide concentrate containing Cu50.28% and As2.39% and copper precipitation solution containing As41.30g/L, Cu0.5g/L, Zn59.64g/L and Cd8.44g/L;

(4) introducing SO into the copper precipitation solution₂Reducing smelting smoke with the concentration of 9.2%, reducing and precipitating arsenic for 4h at 70 ℃, cooling to 15 ℃ after the reaction is finished, crystallizing for 1h, and carrying out centrifugal filtration to obtain white arsenic with the water content of 5.8% and arsenic precipitation liquid with the water content of As12.08g/L, Zn58.42g/L, Cd8.02g/L and sulfuric acid content of 158.7 g/L; returning 75% of the total amount of the arsenic-precipitated liquid directly to the copper smelting smoke dust leaching process, and opening a circuit to the arsenic sulfide removal process, wherein 25% of the total amount of the arsenic-precipitated liquid is open;

(5) drying wet white arsenic at a constant temperature of 140 ℃ to obtain white arsenic containing As75.26%, and performing charcoal reduction on the white arsenic at a temperature of 400 ℃ to obtain metal arsenic containing As99.6%, wherein the metal arsenic reduction yield is 96%;

(6) adding 25% of the total arsenic precipitation solution at a ratio of 19kg/m³Slowly adding CaS into the arsenic-precipitated solution to remove arsenic by sulfurization, reacting at 30 ℃ for 2h, and carrying out solid-liquid separation to obtain arsenic-removed slag and arsenic-removed solution, wherein the arsenic-removed slag returns to the step of displacement copper precipitation;

(7) adding lead-zinc ash into the arsenic-removed solution for neutralization and deacidification, wherein the concentration of lead-zinc ash is 3.0kg/m³Adding hydrogen peroxide (with the concentration of 30%) into the arsenic-removed liquid, reacting for 3 hours at the temperature of 80 ℃, controlling the end-point pH value to be 5.0, and carrying out solid-liquid separation to obtain a deacidified liquid and neutralization slag;

(8) reducing the acid content to 7.0kg/m³Adding zinc powder into the acid-reduced solution, performing displacement cadmium precipitation, performing solid-liquid separation to obtain crude cadmium and a cadmium-precipitated solution, and performing alkali fusion purification on the crude cadmium to obtain refined cadmium; concentrating and crystallizing the solution after cadmium precipitation, centrifugally separating, and drying at 180 ℃ to obtain zinc sulfate monohydrate;

(9) mixing lead-silver-bismuth slag, silver separating slag, lead sulfate slag, lead filter cake, neutralization slag and the like, adding 8% of cyanidation tailings, 4% of gypsum slag and 12% of coke, and carrying out reduction smelting for 2 hours at 1150 ℃ to obtain lead-bismuth alloy (Pb88.03%, Bi10.14%, Ag0.64% and Au12.4g/t), smelting slag, copper removing slag and smelting smoke, wherein part of smoke is directly returned to reduction smelting, and part of smoke is returned to the reduction smelting in the step (1) after being opened to the leaching process, so that valuable metals such As Zn, As, Pb and the like are recovered.

Full-process metal recovery/capture rate: cu97.52%, Pb98.5%, Zn97.8%, Bi98.05%, As95.8%, Cd93.8%, Au99.5%, Ag99.3%.

Therefore, the method provided by the embodiment can realize harmless treatment and efficient recovery of valuable metals of various dangerous solid wastes, which are byproducts in copper smelting processes such as copper smelting smoke dust, arsenic sulfide slag, silver separating slag, lead sulfate slag, lead-zinc smoke dust and the like, and produce products such as electrolytic copper, copper sulfide concentrate, lead-bismuth alloy, zinc sulfate monohydrate, metal arsenic and the like, wherein the lead-bismuth alloy can be further subjected to electrolytic separation, lead anode slime smelting and bismuth refining to obtain electric lead, refined bismuth and gold-silver concentrates. The whole process has no waste liquid discharge, and the final slag (reduction smelting slag) is common solid waste, thereby really realizing the harmless treatment of various dangerous wastes and the high-efficiency recovery of valuable metals in the copper smelting process.

Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.

Claims (9)

1. A method for the cooperative disposal of copper smelting hazardous waste and the comprehensive recovery of valuable metals is characterized by comprising the following steps:

carrying out normal pressure-pressurization two-stage countercurrent leaching on copper smelting smoke dust to obtain normal pressure leaching liquid and lead-silver-bismuth slag, and carrying out electrodeposition pre-copper removal on the normal pressure leaching liquid to obtain electro-copper and pre-copper removal liquid;

then adding arsenic sulfide slag into the pre-decoppered solution for displacement copper precipitation to obtain copper sulfide concentrate and a copper precipitation solution;

introducing SO into the copper precipitation solution₂And (4) reducing the flue gas to precipitate arsenic to obtain arsenic trioxide and arsenic precipitation liquid.

2. The method for the cooperative disposal of hazardous waste from copper smelting and the comprehensive recovery of valuable metals according to claim 1, further comprising:

and returning part of the arsenic-precipitated liquid to the pressure leaching process of copper smelting smoke dust, and opening a circuit to perform sulfuration arsenic removal on part of the arsenic-precipitated liquid to obtain arsenic-removed liquid and arsenic-removed slag, wherein the arsenic-removed slag is returned to the displacement copper precipitation process.

3. The method for the cooperative disposal of hazardous waste from copper smelting and the comprehensive recovery of valuable metals according to claim 2, further comprising:

adding lead-zinc ash into the arsenic-removed liquid, neutralizing and reducing acid to obtain neutralized slag and acid-reduced liquid, adding zinc powder into the acid-reduced liquid to perform displacement cadmium precipitation to obtain crude cadmium and cadmium-precipitated liquid, and concentrating and crystallizing the cadmium-precipitated liquid to obtain zinc sulfate monohydrate.

4. The method for the cooperative disposal of the hazardous waste from copper smelting and the comprehensive recovery of valuable metals according to any one of claims 1 to 3, further comprising:

and carrying out reduction smelting on the lead-silver-bismuth slag, the silver separating slag, the lead sulfate slag, the lead filter cake and the neutralization slag to obtain a lead-bismuth alloy, smelting slag, smelting smoke and copper removing slag, directly returning part of the smelting smoke to the reduction smelting, returning part of the smelting smoke to the copper smelting smoke leaching process, and mixing the part of the smelting smoke with the copper smelting smoke to leach.

5. The method for the cooperative disposal of hazardous waste from copper smelting and the comprehensive recovery of valuable metals according to claim 1, wherein the atmospheric-pressure two-stage countercurrent leaching specifically comprises:

the normal pressure leaching process comprises the steps of leaching copper smelting smoke dust and reduction smelting smoke dust by using a pressurized leaching solution, wherein the liquid-solid ratio ml/g is 2: 1-8: 1, the temperature is 20-80 ℃, the time is 0.5-6 h, and the sulfuric acid concentration at the leaching end point is 15-60 g/L;

and a pressure leaching step, wherein the normal pressure leaching residue is leached by using the arsenic-precipitated liquid, the liquid-solid ratio ml/g is 3: 1-10: 1, the temperature is 105-150 ℃, the oxygen partial pressure is 0.1-0.6 MPa, the time is 0.5-5 h, the final sulfuric acid concentration is 60-120 g/L, and the pressure leaching liquid returns to the normal pressure leaching step to consume residual acid.

6. The method for the cooperative disposal of the hazardous waste from copper smelting and the comprehensive recovery of valuable metals according to claim 1, wherein the amount of arsenic sulfide slag added in the step of replacing and depositing copper is 20-300 kg/m³Pre-decoppering liquid, and blowing compressed air into a reaction system, wherein the air filling amount is 5-50 m³/m³Ore pulp, the reaction temperature is 25-80 ℃, and the reaction time is 0.5-4 h.

7. According to the claimsThe method for the synergistic treatment of the dangerous waste from copper smelting and the comprehensive recovery of valuable metals in the step 1 is characterized in that SO is introduced into the process of reduction and arsenic precipitation₂The concentration of the flue gas is 5-20%, the reduction temperature is 50-90 ℃, and the reaction time is 2-4 h; and (4) cooling and crystallizing after the reduction is finished, wherein the crystallization temperature is 0-30 ℃.

8. The method for the cooperative disposal of the hazardous waste from copper smelting and the comprehensive recovery of valuable metals according to claim 3, wherein in the step of neutralizing and deacidifying, the liquid-solid ratio ml/g of the arsenic-removed liquid to the lead-zinc ash is 4: 1-15: 1, an oxidant is added, the reaction temperature is 30-95 ℃, the reaction time is 1-6 h, and the end-point pH value is 3.0-5.5;

the oxidant is one or more of hydrogen peroxide, persulfuric acid, sodium persulfate, potassium persulfate and sodium peroxide, and the addition amount of the oxidant is 1.0-2.0 times of the molar amount of iron in the solution.

9. The method for the cooperative disposal of the hazardous waste from copper smelting and the comprehensive recovery of valuable metals according to claim 4, wherein in the reduction smelting process, iron-based solid waste and calcium-based solid waste are used as slag formers, and the reaction temperature is 900-1200 ℃;

the iron-based solid waste is one or more of waste scrap iron, cyanided tailings, copper smelting slag and slag dressing tailings, and the addition amount of the iron-based solid waste is 2-10% of the mixture; the calcium-based solid waste is one or two of calcium sulfate slag and gypsum slag, and the addition amount of the calcium-based solid waste is 1-10% of the mixture.

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