Method for producing electronic-grade copper sulfate from high-chlorine copper residue

Abstract

The application discloses a method for producing electronic-grade copper sulfate from high-chlorine copper residue, and belongs to the technical field of comprehensive recovery of hydrometallurgy. Through core processes such as pre-oxidation dechlorination, acid leaching, copper separation and recovery, and zinc-cadmium-nickel-cobalt comprehensive recovery, on the basis of efficient separation and removal of harmful elements chlorine, safe control and stable solidification of toxic elements arsenic, copper and zinc in the high-chlorine copper residue are respectively utilized in the form of electronic-grade copper sulfate pentahydrate, cathode zinc or zinc sulfate heptahydrate, and various valuable elements such as cadmium, nickel and cobalt are comprehensively recovered, thereby completely solving the industry problems of excessive chlorine ions, difficult control of arsenic safety risk, difficulty in separation of copper, zinc, cadmium, nickel and cobalt, poor quality of valuable metal products, low recovery rate and incomplete recovery. The method forms electronic-grade copper sulfate, nickel-cobalt-containing sponge cadmium, zinc sulfate heptahydrate or zinc ingot and other product forms, realizes deep removal of chlorine in the high-chlorine copper residue, safe control of arsenic, and preparation and comprehensive recovery and utilization of high-value products of valuable metals.

Description

Technical Field

[0001] This invention belongs to the field of hydrometallurgical technology. Specifically, it relates to a method for preparing electronic-grade copper sulfate and comprehensively recovering valuable metals such as zinc, cadmium, cobalt, and nickel from high-chlorine copper slag as raw material. Background Technology

[0002] High-chlorinated copper slag is a typical high-chlorinated copper-containing secondary resource generated during pyrometallurgical copper smelting and hydrometallurgical zinc smelting purification and dechlorination processes. The copper mainly exists in the form of cuprous chloride. It typically contains 10%–60% copper, 10%–25% zinc, 2%–5% cadmium, 1%–3% cobalt, and 1%–2% nickel. It also contains 1%–20% toxic and harmful elements such as chlorine and 0.5%–10% arsenic. It is a high-value secondary hazardous waste resource that combines recycling value with environmental risks.

[0003] Currently, the main treatment processes for high-chloride copper slag are hydrometallurgical or pyrometallurgical processes. However, in the hydrometallurgical process, the Cl solution... - Excessive chlorine content causes severe corrosion to production equipment and affects the quality of cathode copper products. Pyrometallurgical processes, mainly employing roasting and smelting methods, achieve chlorine removal through high-temperature volatilization, but suffer from high costs, severe equipment corrosion, and incomplete dechlorination. Furthermore, current wet or pyrometallurgical processes also suffer from low and incomplete recovery rates of valuable metals, resulting in poor product quality and significant loss of valuable resources. Therefore, there is an urgent need for new process technologies that enable efficient dechlorination, deep impurity removal, simultaneous recovery of multiple metals, and the preparation of high-quality products. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a method for producing electronic-grade copper sulfate from high-chlorine copper slag. Through pre-oxidation dechlorination and acid leaching, copper, chlorine, and zinc are separated from the high-chlorine copper slag, ensuring high recovery rates for subsequent copper, zinc, and other valuable metals. This method effectively solves industry problems such as difficulties in separating copper, zinc, cadmium, nickel, and cobalt, poor quality and low recovery rates of valuable metal products, and incomplete recovery. Furthermore, this invention effectively solves problems such as equipment corrosion and toxic gas release present in existing wet-process recovery of high-chlorine copper slag.

[0005] To achieve the above objectives, the present invention is implemented through the following technical solution:

[0006] The method for producing electronic-grade copper sulfate from high-chlorine copper slag of the present invention includes the following steps:

[0007] (1) Pre-oxidation and dechlorination: The high-chlorine copper slag and aqueous solution are mixed at a solid-liquid ratio of 1:2-4 kg:L and then pumped into the reaction tank. Oxidant is continuously added to the reaction tank, and the oxidation temperature is controlled at 30-80 ℃ for 1-3 h to obtain pre-oxidized slurry. Alkali solution is then continuously added to the pre-oxidized slurry for alkaline leaching. After the reaction is completed, the reaction slurry is separated into liquid and solid to obtain chlorine-containing solution and dechlorinated copper slag.

[0008] (2) Acid leaching: The dechlorinated copper slag produced in step (1) is mixed with acid solution and pumped into a stirred reaction tank. Oxidizing agent is continuously added to the reaction tank to control leaching. After reacting for 1-3 hours, liquid-solid separation is carried out to obtain acid leaching solution and acid leaching residue.

[0009] (3) Copper separation and recovery: Copper is recovered from the acid leaching solution in step (2).

[0010] Furthermore, the residual chlorine content of the dechlorinated copper slag produced in step (1) is controlled to be ≤0.3%. When the residual chlorine content is >0.3%, a water immersion process is added to the dechlorinated copper slag, and the washing water is returned to step (1) for slurry preparation.

[0011] Furthermore, the copper recovery in step (3) specifically involves: 1) dilution and conditioning: adding a low-copper solution to the acid leaching solution produced in step (2) to obtain Cu. 2+ 1) Conditioning solution with a concentration <25 g / L; 2) Extraction: Prepare an organic phase using an extractant, diluent, and modifier, mix it thoroughly with the conditioning solution in the extraction tank, and allow it to stand and separate into layers to obtain raffinate and loaded organic phase I; 3) Washing: Wash the loaded organic phase I with copper sulfate solution to obtain loaded organic phase II and washing solution; 4) Back-extraction: Mix the loaded organic phase II and sulfuric acid solution thoroughly in the extraction tank to obtain regenerated extractant and copper sulfate back-extraction solution; 5) Concentration and crystallization: Concentrate and crystallize the copper sulfate back-extraction solution to obtain electronic grade copper sulfate pentahydrate product.

[0012] Furthermore, the low-copper solution mentioned in step (3) is a mixture of raffinate and washing solution.

[0013] Furthermore, in step (3), the extraction process is a 2-3 stage countercurrent extraction, and the number of extraction stages depends on the residual Cu in the raffinate. 2+ Concentration, controlling the residual Cu in the raffinate 2+ <100 mg / L; the washing process is a 1-2 stage countercurrent washing, the number of washing stages depends on the concentration of impurity ions in the back-extraction solution, and the concentration of Zn in the back-extraction solution is controlled. 2+ <1 mg / L, Cd 2+ <1 mg / L, Ni 2+ <1 mg / L, Co 2+ <1mg / L, Fe 2+ <1 mg / L.

[0014] Furthermore, the method for producing electronic-grade copper sulfate from high-chlorine copper slag also includes the comprehensive recovery of zinc, cadmium, nickel, and cobalt after copper separation and recovery, specifically,

[0015] 1) Purification and arsenic removal: Neutralizing agent, arsenic precipitant and oxidant are added to the raffinate produced in step (3) to purify and remove arsenic, and arsenic removal liquid is obtained; 2) Cadmium, nickel and cobalt recovery: Displacement agent is added to the arsenic removal liquid to precipitate cadmium, cobalt and nickel in the solution, and cadmium sponge rich in cobalt and nickel and pure zinc sulfate solution are obtained; 3) Zinc recovery: Zinc in pure zinc sulfate solution is converted into cathode zinc or zinc sulfate heptahydrate product by electrowinning process or concentration crystallization process.

[0016] Furthermore, the residual arsenic concentration in the solution after arsenic removal in step 1) is controlled to be <1 mg / L.

[0017] Furthermore, the aqueous solution in step (1) is industrial production water or aqueous extract produced by the water immersion process.

[0018] Furthermore, the high-chlorine copper slag described in step (1) contains 10%–60% copper, 1%–20% chlorine, 10%–25% zinc, 2%–5% cadmium, 1%–3% cobalt, 1%–2% nickel, and 0.5%–10% arsenic.

[0019] The beneficial effects of this invention are:

[0020] The technical solution of this invention can achieve efficient chlorine removal from high-chlorine copper slag in a cascade manner, high-value recovery of copper and zinc, and full recovery of associated elements cadmium, nickel, and cobalt. Firstly, pre-oxidative dechlorination is employed, which fully oxidizes the chlorine-containing phases in the high-chlorine copper slag and dissolves them completely during alkaline leaching, achieving deep dechlorination. The resulting acidic leachate contains only 20–200 mg / L of chlorine, far lower than the 2000–10000 mg / L chlorine content in current industrial high-chlorine copper slag treatment processes, effectively eliminating the adverse effects of chlorine on the subsequent recovery of valuable metals such as copper, zinc, cadmium, nickel, and cobalt. The enhanced leaching method of oxidative acid leaching fully oxidizes and dissolves the insoluble phases in the dechlorinated copper slag, achieving efficient leaching of valuable metals such as copper, zinc, cadmium, nickel, and cobalt. A high-concentration, low-impurity copper sulfate solution and electronic-grade copper sulfate pentahydrate product are obtained sequentially through a dilution-conditioning-extraction-washing-back-extraction-concentration-crystallization technical route. The efficient purification and impurity removal process controls coexisting impurity ions to extremely low levels, ensuring the quality of the electronic-grade copper sulfate pentahydrate product and achieving high-value utilization of copper. A process route of purification and arsenic removal, cadmium, nickel, and cobalt recovery, and zinc recovery is used to comprehensively recover cadmium, nickel, and cobalt from the copper removal raffinate, and the zinc is converted into #0 cathode zinc or zinc sulfate heptahydrate product, achieving its high-value utilization. Attached Figure Description

[0021] Figure 1This is a simplified process flow diagram for producing electronic-grade copper sulfate from high-chlorine copper slag, as described in an embodiment of the present invention. Detailed Implementation

[0022] To make the objectives, technical solutions, and beneficial effects of this invention clearer, the technical solutions of this invention will be described in detail below. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are all within the scope of protection of this invention.

[0023] The method for producing electronic-grade copper sulfate from high-chlorine copper slag of the present invention includes the following steps:

[0024] (1) Pre-oxidation dechlorination: High-chlorinated copper slag containing 10%–60% copper, 1%–20% chlorine, 10%–25% zinc, 2%–5% cadmium, 1%–3% cobalt, 1%–2% nickel, and 0.5%–10% arsenic is mixed with industrial production water or water leaching solution at a solid-liquid ratio of 1:2–4 kg:L, preheated to 40–80℃, and then pumped into a stirred reaction tank. Hydrogen peroxide or oxygen is continuously pumped into the reaction tank to control the oxidation temperature at 40–80℃ and the oxidation time at 1–3 h. After the oxidation reaction is completed, liquid alkali or sodium carbonate solution is pumped in for alkaline leaching. The pH of the reaction slurry is controlled at 10–13. After the reaction is completed for 1–3 h, the reaction slurry is subjected to liquid-solid separation to obtain Cl. - A chlorine-containing solution of 3–40 g / L and dechlorinated copper slag containing 12%–75% copper and 0.1%–0.5% residual chlorine were used. When the residual chlorine content of the dechlorinated copper slag was >0.3%, the dechlorinated copper slag and water were mixed at a liquid-solid ratio of 1:2–4 kg:L and leached. The mixture was stirred and leached at 40–80 °C for 0.5–1 h, and then liquid-solid separation was performed to obtain dechlorinated copper slag containing <0.3% chlorine and water leaching solution. The water leaching solution was returned to the mixing solution.

[0025] A pre-oxidation dechlorination process employing pre-oxidation-alkali leaching-water leaching achieves efficient chlorine removal from high-chlorine copper slag while ensuring no loss of other valuable elements besides chlorine. By adding an oxidant, the sparingly soluble chloride is converted into chloride that is easily leached by alkaline leaching and water leaching, thus achieving efficient chlorine removal. Simultaneously, copper is transformed from a poorly acid-soluble cuprous phase into a more soluble divalent copper phase, achieving the dual objectives of efficient pre-dechlorination and the transformation of copper into an acid-leaching-friendly phase. The resulting water leaching solution is returned to the slurry preparation stage, increasing the chlorine concentration in the chlorine-containing solution, reducing the amount of chlorine-containing wastewater generated, and lowering the cost of safe chlorine disposal.

[0026] (2) Acid leaching: The dechlorinated copper slag produced in step (1) is mixed with sulfuric acid solution at a solid-liquid ratio of 1:3 to 10 kg:L and then pumped into a stirred reaction tank. The initial acidity is 100 to 150 g / L. Hydrogen peroxide, ferric sulfate, or oxygen is continuously added to the reaction tank. The reaction temperature is controlled at 50 to 90 °C and the reaction time is 1 to 3 h. After the reaction is completed, liquid-solid separation is performed to obtain Cu. 2+ Concentration 35–70 g / L, Cl - Acid leaching solutions with a concentration of 20–200 mg / L and acid leaching residues containing less than 0.5% copper;

[0027] High-chlorine copper slag contains 0.5% to 10% arsenic, mostly in the form of cuprous arsenide. During acid leaching, the continuous addition of hydrogen peroxide, ferric sulfate, or the introduction of oxygen can prevent the generation of hydrogen arsenide gas. At the same time, the oxidizing atmosphere can accelerate the oxidation and dissolution of valuable metal elements, thus comprehensively improving the leaching rate of valuable metals.

[0028] (3) Copper separation and recovery:

[0029] 1) Dilution and conditioning: Continuously pump the raffinate or washing solution into the acid leaching solution produced in step (2) until its Cu content reaches a certain level. 2+ Concentration <25 g / L;

[0030] Typically, copper slag from dechlorination is leached with acid to obtain copper-containing residues. 2+ High copper leaching solutions with a concentration of 35–70 g / L, Cu 2+ Excessive copper concentration will affect the subsequent copper extraction effect. Therefore, a low-copper-content raffinate or washing solution is used for dilution and conditioning to reduce the Cu content of the solution. 2+ Concentration, to obtain Cu content 2+ 15~25 g / L, Ni 2+ 200–5000 mg / L, Co 2+ 200–6000 mg / L, Fe 2+ 200–500 mg / L, Zn 2+ 2~30 g / L, Cd 2+ Conditioning solutions with concentrations of 0.4–10 g / L and TAs of 0.1–6 g / L;

[0031] 2) Extraction: An organic phase is prepared using an extractant, diluent, and modifier. This mixture is thoroughly mixed with a conditioning solution in an extraction tank and allowed to stand for separation, yielding a raffinate and a loaded organic phase I. One possible method is to use P2O4 as the extractant, sulfonated kerosene or 260# solvent oil as the diluent, and TPB as the modifier. The volume ratio of the organic phase to the conditioning solution (O / A) is 1:2–5, the temperature is 25–50 °C, and the reaction time is 1–10 min. The extraction process involves 2–3 stages of countercurrent extraction; the number of extraction stages depends on the residual Cu in the raffinate. 2+Concentration, controlling the residual Cu in the raffinate 2+ <100 mg / L;

[0032] 3) Washing: Wash the supported organic phase I with copper sulfate solution to obtain supported organic phase II and washing solution. One possible method is to use Cu... 2+ The loaded organic phase I was washed with a weakly acidic high-purity copper sulfate solution (15–35 g / L, H₂SO₄ 1–5 g / L). The washing ratio (O / A) was controlled at 4–10:1, the temperature at 30–45 °C, the washing time at 3–5 min / stage, and the phase separation time at 4–6 min / stage, yielding a two-stage loaded organic phase II and a washing solution. The washing process consisted of 1–2 stages of countercurrent washing, with the number of washing stages depending on the concentration of impurity ions in the back-extraction solution. The concentration of Zn in the back-extraction solution was controlled. 2+ <1 mg / L, Cd 2+ <1 mg / L, Ni 2+ <1 mg / L, Co 2+ <1 mg / L, Fe 2+ <1 mg / L. Cu in the washing solution 2+ 20–40 g / L, Ni 2+ 2–20 mg / L, Co 2+ 2–20 mg / L, Fe 2+ 5–40 mg / L, Zn 2+ 50–300 mg / L, Cd 2+ The concentration is 5–50 mg / L.

[0033] 4) Back-extraction: The loaded organic phase II and sulfuric acid solution are thoroughly mixed in the extraction tank to obtain the regenerated extractant and copper sulfate back-extraction solution. One possible method is to use a high-purity sulfuric acid solution of 150-200 g / L as the back-extraction agent, control the back-extraction ratio (O / A) to be 1-2:1, the temperature to be 35-45 ℃, the back-extraction time to be 2-3 min / stage, and the phase separation time to be 3-5 min / stage.

[0034] 5) Concentration and Crystallization: The copper sulfate back-extraction solution is added to an evaporation and concentration apparatus. Concentration is carried out under reduced pressure at 60–80°C with a stirring speed of 100–300 rpm and a vacuum degree controlled at -0.06–-0.09 MPa for 1–2 hours until the solution reaches supersaturation. Subsequently, cooling crystallization is performed by slowly lowering the temperature from 65–75°C to 25–30°C and continuing stirring and aging for 1–3 hours to allow for sufficient crystal growth. Finally, filtration, washing, and drying are carried out. Filtration is performed using a centrifuge. Washing is done with a low-temperature saturated copper sulfate solution at a temperature of 0–10°C, with the washing solution added at 5–15% of the crystal mass. Drying is performed under vacuum at a temperature of 30–40°C and a vacuum degree controlled at -0.06–-0.09 MPa for 6–12 hours. Electronic-grade copper sulfate pentahydrate product is obtained.

[0035] (4) Comprehensive recycling of zinc, cadmium, nickel and cobalt:

[0036] 1) Purification and arsenic removal: Neutralizing agent, arsenic precipitant, and oxidant are continuously added to the raffinate produced in step (3) to purify and remove arsenic, and arsenic removal liquid is obtained. One possible method is to use zinc oxide as neutralizing agent, ferrous sulfate as arsenic precipitant, and hydrogen peroxide or oxygen as oxidant. Throughout the process, the solution pH is controlled at 2-3, the iron-arsenic molar ratio is 1.0-1.2, the reaction temperature is 50-85℃, and the reaction time is 1-4 h. After the reaction, solid arsenic residue and arsenic removal liquid with residual arsenic concentration <1 mg / L are obtained.

[0037] 2) Cadmium, Nickel, and Cobalt Recovery: A displacement agent is continuously added to the arsenic-removed solution, causing cadmium, cobalt, and nickel to precipitate out, resulting in cobalt- and nickel-rich sponge cadmium and a pure zinc sulfate solution. One possible method is to use zinc powder as the displacement agent. The amount of zinc powder added depends on the residual concentrations of cadmium, cobalt, and nickel in the solution, controlling residual cadmium <2 mg / L, cobalt <2 mg / L, and nickel <1 mg / L. The reaction temperature is 50–70℃, and the reaction time is 0.5–2 h.

[0038] 3) Zinc recovery: Zinc in a pure zinc sulfate solution is converted into cathode zinc or zinc sulfate heptahydrate product using electrowinning or concentration crystallization processes. The cathode zinc meets the quality standard of #0 zinc, and the zinc sulfate heptahydrate product meets the first-class standard of the chemical industry.

[0039] To illustrate the present invention more clearly, the following specific embodiments will be described in detail.

[0040] Example 1

[0041] A method for producing electronic-grade copper sulfate from high-chlorine copper slag includes the following steps:

[0042] (1) Pre-oxidation dechlorination: High-chlorinated copper slag containing 35% copper, 1% chlorine, 25% zinc, 3% cadmium, 2% cobalt, 1.6% nickel, and 6% arsenic is mixed with industrial production water at a solid-liquid ratio of 1:3 kg:L, preheated to 60 ℃, and then pumped into a stirred reaction tank. Hydrogen peroxide is continuously pumped into the reaction tank, with the amount of hydrogen peroxide added being 10% of the mass of the high-chlorinated copper slag. The oxidation temperature is controlled at 60 ℃, and the oxidation time is 1 h. After the oxidation reaction is completed, sodium carbonate solution is pumped in for alkaline leaching. The pH of the reaction slurry is controlled at 10. After the reaction is carried out for 2 h, the reaction slurry is separated into liquid and solid to obtain Cl. - A chlorine-containing solution of 3 g / L and dechlorinated copper slag containing 37% copper and 0.1% residual chlorine.

[0043] (2) Acid leaching: The dechlorinated copper slag produced in step (1) is mixed with sulfuric acid solution at a solid-liquid ratio of 1:6 kg:L and then pumped into a stirred reaction tank. The initial acidity is 150 g / L. Ferric sulfate is continuously added to the reaction tank, with the amount of ferric sulfate added being 12% of the desulfurized slag. The reaction temperature is controlled at 90 ℃ and the reaction time is 1 h. After the reaction is completed, liquid-solid separation is performed to obtain Cu. 2+ Concentration 60g / L, Cl - Acid leaching solution with a concentration of 150 mg / L and acid leaching residue containing 0.07% copper;

[0044] (3) Copper separation and recovery:

[0045] 1) Dilution and conditioning: Washing solution and raffinate are continuously pumped into the acid leaching solution produced in step (2) to obtain Cu 2+ Concentration 25 g / L, also contains Ni 2+ 1180 mg / L, Co 2+ 1380 mg / L, Fe 2+ 200 mg / L, Zn 2+ 17 g / L, Cd 2+ 2.08 g / L, TAs 1.25 g / L, Cl - A conditioning solution of 60 mg / L;

[0046] 2) Extraction: An organic phase was prepared using an extractant, diluent, and modifier. This phase was thoroughly mixed with the conditioning solution in an extraction tank and allowed to stand for stratification, yielding a raffinate and a loaded organic phase I. P2O4 was used as the extractant, sulfonated kerosene as the diluent, and TPB as the modifier. The volume ratio of the organic phase to the conditioning solution (O / A) was 1:2, the temperature was 25 ℃, and the reaction time was 10 min. The extraction process was a three-stage countercurrent extraction to control the residual Cu in the raffinate. 2+ 60 mg / L;

[0047] 3) Washing: The supported organic phase I was washed with copper sulfate solution using a two-stage countercurrent washing process to obtain the supported organic phase II and the washing solution. Cu 2+ The supported organic phase I was washed with a weakly acidic high-purity copper sulfate solution (15 g / L, H2SO4 5 g / L). The washing ratio (O / A) was controlled at 6:1, the temperature at 35℃, the washing time at 4 min / stage, and the phase separation time at 5 min / stage, resulting in a two-stage supported organic phase II and a washing solution. The Cu in the washing solution... 2+ 20 g / L, Ni 2+ 14 mg / L, Co 2+ 2 mg / L, Fe 2+ 23 mg / L, Zn 2+ 300 mg / L, Cd 2+ 50 mg / L.

[0048] 4) Back-extraction: The loaded organic phase II and sulfuric acid solution are thoroughly mixed in the extraction tank to obtain the regenerated extractant and copper sulfate back-extraction solution. A high-purity sulfuric acid solution of 180 g / L is used as the back-extraction agent. The back-extraction ratio (O / A) is controlled at 2:1, the temperature at 45℃, the back-extraction time at 3 min / stage, and the phase separation time at 3 min / stage. The obtained copper sulfate back-extraction solution contains Zn. 2+ 0.7 mg / L, Cd 2+ 0.4 mg / L, Ni 2+ 0.8 mg / L, Co 2+ 0.7 mg / L, Fe 2+ 0.4 mg / L.

[0049] 5) Concentration and Crystallization: The copper sulfate back-extraction solution was added to an evaporation and concentration apparatus. Concentration was carried out under reduced pressure at 80 °C with a stirring speed of 300 rpm and a vacuum degree controlled at -0.06 MPa for 1 h until the solution reached supersaturation. Subsequently, cooling crystallization was performed by slowly cooling from 75 °C to 30 °C and continuing stirring and aging for 1 h to allow for sufficient crystal growth. Finally, filtration, washing, and drying were performed. Filtration was carried out using a centrifuge. Washing was done using a low-temperature saturated copper sulfate solution at 10 °C, with the washing solution added at 15% of the crystal mass. Drying was performed under vacuum at 40 °C with a vacuum degree controlled at -0.09 MPa for 12 h. Finally, electronic-grade copper sulfate pentahydrate was obtained.

[0050] (4) Comprehensive recycling of zinc, cadmium, nickel and cobalt:

[0051] 1) Purification and arsenic removal: Neutralizing agent, arsenic precipitant, and oxidant are continuously added to the raffinate produced in step (3) to purify and remove arsenic, resulting in a arsenic-removed liquid. Zinc oxide is used as the neutralizing agent, ferrous sulfate as the arsenic precipitant, and hydrogen peroxide as the oxidant. The solution pH is controlled at 2, the iron-arsenic molar ratio at 1.2, the reaction temperature at 70 ℃, and the reaction time at 4 h throughout the process. After the reaction, solid arsenic residue and a arsenic-removed liquid with a residual arsenic concentration of 0.8 mg / L are obtained.

[0052] 2) Cadmium, Nickel, and Cobalt Recovery: A displacement agent is continuously added to the arsenic-removed solution, causing cadmium, cobalt, and nickel to precipitate out, resulting in cobalt- and nickel-rich sponge cadmium and a pure zinc sulfate solution. Zinc powder is used as the displacement agent, with a molar ratio of zinc powder added to the sum of cadmium, cobalt, and nickel in the solution of 1.1. The reaction temperature is 70 ℃, and the reaction time is 2 h. The pure zinc sulfate solution contains 1 mg / L cadmium, 1.2 mg / L cobalt, and 0.7 mg / L nickel.

[0053] 3) Zinc recovery: The zinc in the pure zinc sulfate solution is converted into cathode zinc using an electrowinning process, and the cathode zinc reaches the quality of 0# zinc.

[0054] Example 2

[0055] A method for producing electronic-grade copper sulfate from high-chlorine copper slag includes the following steps:

[0056] (1) Pre-oxidation dechlorination: High-chlorinated copper slag containing 10% copper, 8% chlorine, 15% zinc, 5% cadmium, 3% cobalt, 2% nickel, and 10% arsenic was mixed with water leaching solution at a solid-liquid ratio of 1:2 kg:L, preheated to 40 ℃, and then pumped into a stirred reaction tank. Oxygen was continuously introduced into the reaction tank at a rate of 12 L / h per kilogram of high-chlorinated copper slag. The oxidation temperature was controlled at 40 ℃ and the oxidation time was 2 h. After the oxidation reaction was completed, liquid alkali was pumped in for alkaline leaching. The pH of the reaction slurry was controlled at 12. After 1 h of reaction, the reaction slurry was subjected to liquid-solid separation to obtain Cl. - A chlorine-containing solution of 15 g / L and dechlorinated copper slag containing 12% copper and 0.95% residual chlorine were prepared by mixing the dechlorinated copper slag with water at a liquid-solid ratio of 1:2 kg:L and leaching. After stirring and leaching at 40 °C for 0.5 h, liquid-solid separation was performed to obtain dechlorinated copper slag containing 0.15% chlorine and water leaching solution. The water leaching solution was returned to the slurry preparation process in step (1).

[0057] (2) Acid leaching: The dechlorinated copper slag produced in step (1) is mixed with sulfuric acid solution at a solid-liquid ratio of 1:3 kg:L and then pumped into a stirred reaction tank. The initial acidity is 100 g / L. Hydrogen peroxide is continuously added to the reaction tank at a concentration of 6% of the dechlorinated copper slag. The reaction temperature is controlled at 70 °C and the reaction time is 2 h. After the reaction is completed, liquid-solid separation is performed to obtain Cu. 2+ Concentration 35 g / L, Cl -Acid leaching solution with a concentration of 200 mg / L and acid leaching residue containing less than 0.09% copper;

[0058] (3) Copper separation and recovery:

[0059] 1) Dilution and conditioning: Continuously pump washing liquid and raffinate into the acid leaching solution produced in step (2) until the Cu content reaches a certain level. 2+ Concentration 20 g / L, also containing Ni 2+ 3800 mg / L, Co 2+ 5700 mg / L, Fe 2+ 480 mg / L, Zn 2+ 28.5 g / L, Cd 2+ 9.50 g / L, TAs 5.7 g / L, Cl - A conditioning solution of 110 mg / L.

[0060] 2) Extraction: An organic phase is prepared using an extractant, diluent, and modifier. This mixture is thoroughly mixed with a conditioning solution in an extraction tank and allowed to stand for separation, yielding a raffinate and a loaded organic phase I. P2O4 can be used as the extractant, sulfonated kerosene as the diluent, and TPB as the modifier. The volume ratio of the organic phase to the conditioning solution (O / A) is 1:3, the temperature is 30 ℃, and the reaction time is 6 min. The extraction process is a three-stage countercurrent extraction to control the residual Cu in the raffinate. 2+ 75 mg / L;

[0061] 3) Washing: The supported organic phase I was washed with copper sulfate solution using a two-stage countercurrent washing process to obtain the supported organic phase II and the washing solution. Cu 2+ The supported organic phase I was washed with a weakly acidic high-purity copper sulfate solution of 35 g / L and 1 g / L H2SO4. The washing ratio (O / A) was controlled at 4:1, the temperature at 45 ℃, the washing time at 5 min / stage, and the phase separation time at 6 min / stage, resulting in a two-stage supported organic phase II and a washing solution. The Cu in the washing solution... 2+ 32 g / L, Ni 2+ 2 mg / L, Co 2+ 16 mg / L, Fe 2+ 40 mg / L, Zn 2+ 120 mg / L, Cd 2+ The concentration is 5 mg / L.

[0062] 4) Back-extraction: The loaded organic phase II and sulfuric acid solution are thoroughly mixed in the extraction tank to obtain the regenerated extractant and copper sulfate back-extraction solution. A 150 g / L high-purity sulfuric acid solution is used as the back-extraction agent. The back-extraction ratio (O / A) is controlled at 1:1, the temperature at 40℃, the back-extraction time at 2 min / stage, and the phase separation time at 4 min / stage. The obtained copper sulfate back-extraction solution contains Zn.2+ 0.4 mg / L, Cd 2+ 0.5 mg / L, Ni 2+ 0.7 mg / L, Co 2+ 0.8 mg / L, Fe 2+ 0.6 mg / L.

[0063] 5) Concentration and Crystallization: The copper sulfate back-extraction solution was added to an evaporation and concentration apparatus. Concentration was carried out under reduced pressure at 70 °C with a stirring speed of 100 rpm and a vacuum degree controlled at -0.08 MPa for 2 hours until the solution reached supersaturation. Subsequently, cooling crystallization was performed by slowly cooling from 70 °C to 27 °C and continuing stirring and aging for 3 hours to allow for sufficient crystal growth. Finally, filtration, washing, and drying were carried out. Filtration was performed using a centrifuge. Washing was done using a low-temperature saturated copper sulfate solution at 0 °C, with the washing solution added at 5% of the crystal mass. Drying was performed under vacuum at 35 °C with a vacuum degree controlled at -0.06 MPa for 9 hours. Finally, electronic-grade copper sulfate pentahydrate was obtained.

[0064] (4) Comprehensive recycling of zinc, cadmium, nickel and cobalt:

[0065] 1) Purification and arsenic removal: Neutralizing agent, arsenic precipitant, and oxidant are continuously added to the raffinate produced in step (3) to purify and remove arsenic, resulting in a arsenic-removed liquid. Zinc oxide is used as the neutralizing agent, ferrous sulfate as the arsenic precipitant, and oxygen as the oxidant. The solution pH is controlled at 3, the iron-arsenic molar ratio at 1.0, the reaction temperature at 85 ℃, and the reaction time at 3 h throughout the process. After the reaction, solid arsenic residue and a arsenic-removed liquid with a residual arsenic concentration of 0.6 mg / L are obtained.

[0066] 2) Cadmium, Nickel, and Cobalt Recovery: A displacement agent is continuously added to the arsenic-removed solution, causing cadmium, cobalt, and nickel to precipitate out, resulting in cobalt- and nickel-rich sponge cadmium and a pure zinc sulfate solution. Zinc powder is used as the displacement agent, with a molar ratio of zinc powder added to the sum of cadmium, cobalt, and nickel in the solution of 1.3. The reaction temperature is 50 ℃, and the reaction time is 1 h. The pure zinc sulfate solution contains 0.7 mg / L cadmium, 0.9 mg / L cobalt, and 0.6 mg / L nickel.

[0067] 3) Zinc recovery: The zinc in the pure zinc sulfate solution is converted into zinc sulfate heptahydrate product using a concentration and crystallization process. The zinc sulfate heptahydrate product meets the first-class standard of the chemical industry.

[0068] Example 3

[0069] A method for producing electronic-grade copper sulfate from high-chlorine copper slag includes the following steps:

[0070] (1) Pre-oxidation dechlorination: High-chlorinated copper slag containing 60% copper, 20% chlorine, 10% zinc, 2% cadmium, 1% cobalt, 1% nickel, and 0.5% arsenic was mixed with water leaching solution at a solid-liquid ratio of 1:4 kg:L, preheated to 80 ℃, and then pumped into a stirred reaction tank. Hydrogen peroxide was continuously pumped into the reaction tank, with the amount of hydrogen peroxide added being 10% of the mass of the high-chlorinated copper slag. The oxidation temperature was controlled at 80 ℃, and the oxidation time was 3 h. After the oxidation reaction was completed, liquid alkali was pumped in for alkaline leaching. The pH of the reaction slurry was controlled at 13. After the reaction was carried out for 3 h, the reaction slurry was separated into liquid and solid to obtain Cl. - A chlorine-containing solution of 40 g / L and dechlorinated copper slag containing 75% copper and 2.5% residual chlorine were prepared by mixing the dechlorinated copper slag with water at a liquid-solid ratio of 1:4 kg:L and leaching. After stirring and leaching at 80 °C for 1 h, liquid-solid separation was performed to obtain dechlorinated copper slag containing 0.1% chlorine and water leaching solution. The water leaching solution was returned to the slurry preparation process in step (1).

[0071] (2) Acid leaching: The dechlorinated copper slag produced in step (1) is mixed with sulfuric acid solution at a solid-liquid ratio of 1:10 kg:L and then pumped into a stirred reaction tank. The initial acidity is 130 g / L. Oxygen is continuously introduced into the reaction tank at a rate of 5 L / h per kilogram of dechlorinated copper slag. The reaction temperature is controlled at 50℃ and the reaction time is 3 hours. After the reaction is completed, liquid-solid separation is performed to obtain Cu. 2+ Concentration 70g / L, Cl - Acid leaching solution with a concentration of 20 mg / L and acid leaching residue containing 0.08% copper;

[0072] (3) Copper separation and recovery:

[0073] 1) Dilution and conditioning: Continuously pump the raffinate or washing solution into the acid leaching solution produced in step (2) until its Cu content reaches a certain level. 2+ Concentration 15 g / L, also containing Ni 2+ 200 mg / L, Co 2+ 210 mg / L, Fe 2+ 430 mg / L, Zn 2+ 2.14 g / L, Cd 2+ 0.43 g / L, TAs 75 mg / L, Cl - 4 mg / L conditioning solution;

[0074] 2) Extraction: An organic phase was prepared using an extractant, diluent, and modifier. This mixture was thoroughly mixed with a conditioning solution in an extraction tank and allowed to stand for separation, yielding a raffinate and a loaded organic phase I. P204 was used as the extractant, 260# solvent oil as the diluent, and TPB as the modifier. The volume ratio of the organic phase to the conditioning solution (O / A) was 1:5, the temperature was 50 ℃, and the reaction time was 1 min. The extraction process was a two-stage countercurrent extraction to control the residual Cu in the raffinate. 2+90 mg / L;

[0075] 3) Washing: The supported organic phase I was washed with copper sulfate solution using a single-stage washing process to obtain the supported organic phase II and the washing solution. Cu 2+ The supported organic phase I was washed with a weakly acidic high-purity copper sulfate solution of 28 g / L and 3 g / L H2SO4. The washing ratio (O / A) was controlled at 10:1, the temperature at 30 ℃, the washing time at 3 min / stage, and the phase separation time at 4 min / stage, resulting in a two-stage supported organic phase II and a washing solution. The Cu in the washing solution... 2+ 40 g / L, Ni 2+ 20 mg / L, Co 2+ 20 mg / L, Fe 2+ 5mg / L, Zn 2+ 50 mg / L, Cd 2+ It is 23 mg / L.

[0076] 4) Back-extraction: The loaded organic phase II and sulfuric acid solution are thoroughly mixed in the extraction tank to obtain the regenerated extractant and copper sulfate back-extraction solution. A 200 g / L high-purity sulfuric acid solution is used as the back-extraction agent. The back-extraction ratio (O / A) is controlled at 2:1, the temperature at 35℃, the back-extraction time at 3 min / stage, and the phase separation time at 5 min / stage. The obtained copper sulfate back-extraction solution contains Zn. 2+ 0.7 mg / L, Cd 2+ 0.4 mg / L, Ni 2+ 0.6 mg / L, Co 2+ 0.6 mg / L, Fe 2+ 0.9 mg / L.

[0077] 5) Concentration and Crystallization: The copper sulfate back-extraction solution was added to an evaporation and concentration apparatus. Concentration was carried out under reduced pressure at 60 °C with a stirring speed of 200 rpm and a vacuum degree controlled at -0.09 MPa for 1.5 h until the solution reached supersaturation. Subsequently, cooling crystallization was performed by slowly cooling from 65 °C to 25 °C and continuing stirring and aging for 2 h to allow for sufficient crystal growth. Finally, filtration, washing, and drying were carried out. Filtration was performed using a centrifuge. Washing was done using a low-temperature saturated copper sulfate solution at 6 °C, with the washing solution added at 10% of the crystal mass. Drying was performed under vacuum at 30 °C with a vacuum degree controlled at -0.07 MPa for 6 h. Finally, electronic-grade copper sulfate pentahydrate was obtained.

[0078] (4) Comprehensive recycling of zinc, cadmium, nickel and cobalt:

[0079] 1) Purification and arsenic removal: Neutralizing agent, arsenic precipitant, and oxidant are continuously added to the raffinate produced in step (3) to purify and remove arsenic, resulting in a arsenic-removed liquid. Zinc oxide is used as the neutralizing agent, ferrous sulfate as the arsenic precipitant, and hydrogen peroxide as the oxidant. The solution pH is controlled at 3, the iron-arsenic molar ratio is 1.1, the reaction temperature is 50 ℃, and the reaction time is 1 h. After the reaction, solid arsenic residue and a arsenic-removed liquid with a residual arsenic concentration of 0.9 mg / L are obtained.

[0080] 2) Cadmium, Nickel, and Cobalt Recovery: A displacement agent is continuously added to the arsenic-removed solution, causing cadmium, cobalt, and nickel to precipitate out, resulting in cobalt- and nickel-rich sponge cadmium and a pure zinc sulfate solution. Zinc powder is used as the displacement agent, with a molar ratio of zinc powder added to the sum of cadmium, cobalt, and nickel in the solution of 1.2. The reaction temperature is 60 ℃, and the reaction time is 0.5 h. The pure zinc sulfate solution contains 1.0 mg / L cadmium, 0.9 mg / L cobalt, and 0.5 mg / L nickel.

[0081] 3) Zinc recovery: The zinc in the pure zinc sulfate solution is converted into cathode zinc using an electrowinning process, and the cathode zinc reaches the quality of 0# zinc.

[0082] Comparative Example 1

[0083] Compared with Example 1, this comparative example omits step (1) pre-oxidative dechlorination, but is otherwise the same as Example 1:

[0084] A method for producing electronic-grade copper sulfate from high-chlorine copper slag includes the following steps:

[0085] (1) Acid leaching: The high-chlorine copper slag was mixed with sulfuric acid solution and reacted under the controlled conditions of Example 1 to obtain Cu. 2+ Concentration 41 g / L, Cl - Acid leaching solution with a concentration of 1490 mg / L and acid leaching residue containing 3.7% copper;

[0086] (2) Copper separation and recovery:

[0087] 1) Dilution and conditioning: Washing solution and raffinate are continuously pumped into the acid leaching solution produced in step (2) to obtain Cu 2+ Concentration 25 g / L, also contains Ni 2+ 390 mg / L, Co 2+ 460 mg / L, Fe 2+ 190 mg / L, Zn 2+ 14 g / L, Cd 2+ 1.6 g / L, TAs 4.20 g / L, Cl - A conditioning solution of 910 mg / L;

[0088] 2) Extraction: Obtain the raffinate and supported organic phase I, and control the residual Cu in the raffinate.2+ 60 mg / L;

[0089] 3) Washing: Two-stage supported organic phase II and washing solution are obtained. Cu in the washing solution 2+ 12 g / L, Ni 2+ 6 mg / L, Co 2+ 1 mg / L, Fe 2+ 11 mg / L, Zn 2+ 135 mg / L, Cd 2+ 25 mg / L.

[0090] 4) Back-extraction: The obtained copper sulfate back-extraction solution contains Zn 2+ 0.5 mg / L, Cd 2+ 0.2 mg / L, Ni 2+ 0.4 mg / L, Co 2+ 0.4 mg / L, Fe 2+ 0.2 mg / L, Cl - 480 mg / L.

[0091] 5) Concentration and crystallization: The copper sulfate pentahydrate product contains 1.3% chlorine, which exceeds the chlorine standard and makes it difficult to meet the quality of electronic grade products.

[0092] (3) Comprehensive recycling of zinc, cadmium, nickel and cobalt:

[0093] 1) Purification and arsenic removal: After the reaction, solidified arsenic residue and arsenic-removed liquid with a residual arsenic concentration of 0.8 mg / L were obtained;

[0094] 2) Cadmium, nickel and cobalt recovery: The pure zinc sulfate solution contains 1 mg / L cadmium, 1.2 mg / L cobalt, 0.7 mg / L nickel and 1270 mg / L chlorine.

[0095] 3) Zinc recovery: Severe anode corrosion makes it difficult for the zinc electrowinning process to operate smoothly.

[0096] Comparing Example 1 and Comparative Example 1, it can be found that when pre-oxidation dechlorination is omitted and high-chlorine copper slag is directly acidically leached, the Cl in the acidic leachate is... - The concentration jumped from 150 mg / L to 1490 mg / L, Cu 2+ Reducing the concentration from 60 g / L to 41 g / L yields a perchloric acidic leachate, but this also reduces the copper leaching rate by approximately 20%. The perchloric acidic system causes severe corrosion to equipment, pipes, and agitators, posing a very high potential safety risk. The high concentration of chlorine entering the acidic leachate will have a chain reaction on subsequent processes. The pentahydrate copper sulfate product contains 1.3% chlorine, exceeding the chlorine limit and making it difficult to meet electronic-grade product quality. The zinc electrowinning process contains 1270 mg / L of chlorine, directly corroding the anode and making it impossible to continue the electrowinning process.

[0097] In summary, after omitting step (1) of the present invention, the recovery of valuable metals such as copper is significantly reduced, and the high concentration of Cl in the solution also affects the recovery. - The resulting effects prevent the production of electronic-grade copper sulfate, 0# cathode zinc, and other products, which contradicts the intended objectives of this invention.

[0098] Comparative Example 2

[0099] Compared with Example 1, this comparative example differs from Example 1 in that step (2) acid leaching is performed without the addition of an oxidizing agent, while all other steps are the same.

[0100] A method for producing electronic-grade copper sulfate from high-chlorine copper slag includes the following steps:

[0101] (1) Pre-oxidative dechlorination: to obtain Cl - A chlorine-containing solution of 3 g / L and dechlorinated copper slag containing 37% copper and 0.1% residual chlorine.

[0102] (2) Acid leaching: This process is the same as in Example 1, except that ferric sulfate is not added. Cu is obtained. 2+ Concentration 45g / L, Cl - Acid leaching solution with a concentration of 150 mg / L and acid leaching residue containing 2.6% copper;

[0103] (3) Copper separation and recovery:

[0104] 1) Dilution and conditioning: to obtain Cu 2+ Concentration 25 g / L, also containing Ni 2+ 920 mg / L, Co 2+ 1170 mg / L, Fe 2+ 170mg / L, Zn 2+ 14 g / L, Cd 2+ A conditioning solution with 1.8 g / L TAs and 0.8 g / L TAs;

[0105] 2) Extraction: Raffinate and supported organic phase I are obtained. The residual Cu in the raffinate... 2+ 60 mg / L;

[0106] 3) Washing: Two-stage supported organic phase II and washing solution are obtained. Cu in the washing solution 2+ 12 g / L, Ni 2+ 8 mg / L, Co 2+ 1 mg / L, Fe 2+ 15 mg / L, Zn 2+ 230 mg / L, Cd 2+ 40 mg / L.

[0107] 4) Back-extraction: The obtained copper sulfate back-extraction solution contains Zn 2+0.6 mg / L, Cd 2+ 0.3 mg / L, Ni 2+ 0.5 mg / L, Co 2+ 0.4 mg / L, Fe 2+ 0.1 mg / L.

[0108] 5) Concentration and crystallization: electronic grade copper sulfate pentahydrate product is obtained.

[0109] (4) Comprehensive recycling of zinc, cadmium, nickel and cobalt:

[0110] 1) Purification and arsenic removal: Arsenic-fixed slag and arsenic-removed liquid with a residual arsenic concentration of 0.8 mg / L were obtained;

[0111] 2) Cadmium, nickel and cobalt recovery: Pure zinc sulfate solution contains 1 mg / L cadmium, 1.2 mg / L cobalt and 0.7 mg / L nickel.

[0112] 3) Zinc recovery: The zinc in the pure zinc sulfate solution is converted into cathode zinc using an electrowinning process, and the cathode zinc reaches the quality of 0# zinc.

[0113] It should be noted that the purpose of adding an oxidant in step (2) of acid leaching is to further improve the leaching rate and overall recovery rate of the difficult-to-dissolve cuprous oxide, as well as the insoluble alloy phases and elements such as nickel, cobalt, zinc, and cadmium in the oxide material during the acid leaching process. Comparing Example 1 and Comparative Example 2, it can be seen that without adding an oxidant in step (2) of the acid leaching process, the Cu content of the acid leaching solution is significantly lower. 2+ When the concentration was reduced from 60 g / L to 45 g / L, the copper content in the acid leaching residue increased from 0.07% to 2.6%, and the copper leaching rate decreased by approximately 25%. In comparison, when the acid leaching process involved adding an oxidant and diluting the conditioning solution, the solution contained Ni... 2+ 1180 mg / L, Co 2+ 1380 mg / L, Fe 2+ 200 mg / L, Zn 2+ 17 g / L, Cd 2+ 2.08 g / L, TAs 1.25 g / L, Cl - 60 mg / L; without oxidant, the solution contains Ni 2+ 920 mg / L, Co 2+ 1170 mg / L, Fe 2+ 170 mg / L, Zn 2+ 14 g / L, Cd 2+ At 1.8 g / L, the leaching rates of nickel, cobalt, zinc, and cadmium decreased by 22%, 15%, 17%, and 10%, respectively. The decrease in leaching rate directly led to a reduction in the overall recovery rate, making it difficult to achieve the goal of comprehensive and efficient recovery.

[0114] Note: Unless otherwise specified, all percentage contents mentioned in this invention are mass percentage contents.

[0115] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made to it in form and detail without departing from the scope defined by the claims of the present invention.

Claims

1. A method for producing electronic-grade copper sulfate from high-chlorine copper slag, characterized in that: Includes the following steps: (1) Pre-oxidation and dechlorination: The high-chlorine copper slag and aqueous solution are mixed at a solid-liquid ratio of 1:2-4 kg:L and then pumped into the reaction tank. Oxidant is continuously added to the reaction tank, and the oxidation temperature is controlled at 30-80 ℃ for 1-3 h to obtain pre-oxidized slurry. Alkali solution is then continuously added to the pre-oxidized slurry for alkaline leaching. After the reaction is completed, the reaction slurry is separated into liquid and solid to obtain chlorine-containing solution and dechlorinated copper slag. (2) Acid leaching: The dechlorinated copper slag produced in step (1) is mixed with acid solution and pumped into a stirred reaction tank. Oxidizing agent is continuously added to the reaction tank. After reacting for 1-3 hours, liquid-solid separation is carried out to obtain acid leaching solution and acid leaching residue. (3) Copper separation and recovery: Copper is recovered from the acid leaching solution in step (2).

2. The method for producing electronic-grade copper sulfate from high-chlorine copper slag according to claim 1, characterized in that: The residual chlorine content of the dechlorinated copper slag produced in step (1) is ≤0.3%. When the residual chlorine content is >0.3%, a water immersion process is added to the dechlorinated copper slag, and the washing water is returned to step (1) for slurry preparation.

3. The method for producing electronic-grade copper sulfate from high-chlorine copper slag according to claim 1, characterized in that: The copper recovery in step (3) specifically involves: 1) dilution and conditioning: adding a low-copper solution to the acid leaching solution produced in step (2) to obtain Cu. 2+ 1) Conditioning solution with a concentration <25 g / L; 2) Extraction: Prepare an organic phase using an extractant, diluent, and modifier, mix it thoroughly with the conditioning solution in the extraction tank, and allow it to stand and separate into layers to obtain raffinate and loaded organic phase I; 3) Washing: Wash the loaded organic phase I with copper sulfate solution to obtain loaded organic phase II and washing solution; 4) Back-extraction: Mix the loaded organic phase II and sulfuric acid solution thoroughly in the extraction tank to obtain regenerated extractant and copper sulfate back-extraction solution; 5) Concentration and crystallization: Concentrate and crystallize the copper sulfate back-extraction solution to obtain electronic grade copper sulfate pentahydrate product.

4. The method for producing electronic-grade copper sulfate from high-chlorine copper slag according to claim 3, characterized in that: The low-copper solution mentioned in step (3) is a mixture of raffinate and washing solution.

5. The method for producing electronic-grade copper sulfate from high-chlorine copper slag according to claim 3, characterized in that: In step (3), the extraction process is a 2-3 stage countercurrent extraction, and the number of extraction stages depends on the residual Cu in the raffinate. 2+ Concentration, controlling the residual Cu in the raffinate 2+ <100 mg / L; the washing process is a 1-2 stage countercurrent washing, the number of washing stages depends on the concentration of impurity ions in the back-extraction solution, and the concentration of Zn in the back-extraction solution is controlled. 2+ <1 mg / L, Cd 2+ <1 mg / L, Ni 2+ <1 mg / L, Co 2+ <1 mg / L, Fe 2+ <1 mg / L.

6. The method for producing electronic-grade copper sulfate from high-chlorine copper slag according to any one of claims 3-5, characterized in that: This also includes the comprehensive recovery of zinc, cadmium, nickel, and cobalt after copper separation and recovery, specifically: 1) Purification and arsenic removal: Neutralizing agent, arsenic precipitant and oxidant are added to the raffinate produced in step (3) to purify and remove arsenic, and arsenic-removed liquid is obtained; 2) Cadmium, nickel and cobalt recovery: A displacement agent is added to the arsenic-removed solution to precipitate cadmium, cobalt and nickel in the solution, resulting in sponge cadmium rich in cobalt and nickel and a pure zinc sulfate solution. 3) Zinc recovery: The zinc in the pure zinc sulfate solution is converted into cathode zinc or zinc sulfate heptahydrate product by electrowinning or concentration crystallization process.

7. The method for producing electronic-grade copper sulfate from high-chlorine copper slag according to claim 6, characterized in that: The residual arsenic concentration in the solution after arsenic removal in step 1) is controlled to be <1 mg / L.

8. The method for producing electronic-grade copper sulfate from high-chlorine copper slag according to claim 1, characterized in that: In step (1), the aqueous solution is industrial production water or water extract produced by the water immersion process.

9. The method for producing electronic-grade copper sulfate from high-chlorine copper slag according to any one of claims 1-8, characterized in that: The high-chlorine copper slag in step (1) contains 10% to 60% copper, 1% to 20% chlorine, 10% to 25% zinc, 2% to 5% cadmium, 1% to 3% cobalt, 1% to 2% nickel, and 0.5% to 10% arsenic.

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