A method for separating copper and arsenic in a high-nickel copper-arsenic solution

Abstract

The application discloses a method for separating copper and arsenic in a high-nickel copper-arsenic solution and relates to the technical field of non-ferrous metal hydrometallurgy purification separation and impurity removal, solves the problems of incomplete separation of copper and arsenic in the high-nickel copper-arsenic solution and low valuable metal recovery rate, adopts hydrogen sulfide gas as a single sulfuration agent, realizes effective separation of copper and arsenic through a first-stage sulfuration copper removal, a second-stage sulfuration copper removal and a sulfuration arsenic removal procedure, processes second-stage sulfuration copper residue through a copper residue arsenic removal procedure, processes sulfuration arsenic residue through an arsenic residue nickel removal procedure, and sets up a material circulation system in which copper residue arsenic removal post-liquid enters the second-stage sulfuration copper removal procedure and arsenic residue nickel removal post-liquid enters the sulfuration arsenic removal procedure, so that the method has the advantages of simple technological process, good separation effect, high recovery rate, low operation cost and the like.

Description

Technical Field

[0001] This invention belongs to the field of purification, separation and impurity removal technology in non-ferrous metal hydrometallurgical processes, specifically relating to a method for separating copper and arsenic from a high-nickel copper-arsenic solution. Background Technology

[0002] In the hydrometallurgical process of non-ferrous metals, the high-nickel copper-arsenic solution has a complex composition, containing valuable metals such as nickel and copper with recycling value, as well as highly hazardous arsenic. How to separate copper from arsenic and simultaneously recover nickel and copper resources and safely dispose of arsenic is a technical challenge in this field.

[0003] Currently, traditional industrial methods each have significant drawbacks. Chemical precipitation is simple to operate, but the introduction of the precipitant introduces new impurities, affecting the purity of the metal product. Electrodeposition can preferentially extract copper, but it releases highly toxic arsine gas at the cathode, posing a serious safety hazard. Solvent extraction has good separation results, but it is costly and prone to organic phase contamination. Ion exchange is suitable for purifying trace impurities, but its processing capacity is limited and it is difficult to meet the industrial needs of high-concentration solutions. Crystallization separation requires multiple recrystallizations due to insufficient product purity, resulting in a lengthy process and low recovery rate.

[0004] In summary, existing technologies generally suffer from drawbacks such as incomplete separation, low recovery rate, complex process flow, high operating cost, or significant safety risks. Therefore, there is an urgent need to develop a treatment process that is simple in process flow, has significant separation effect, low cost, and is environmentally friendly and harmless. Summary of the Invention

[0005] This invention provides a method for separating copper and arsenic in a high-nickel copper-arsenic solution to solve the problems mentioned above.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A method for separating copper and arsenic in a high-nickel copper-arsenic solution, wherein the copper concentration in the high-nickel copper-arsenic solution is 10–40 g / L, the nickel concentration is 10–40 g / L, and the arsenic concentration is 20–60 g / L, characterized in that the method includes the following steps:

[0008] Step 1, First-stage copper removal by sulfidation: Hydrogen sulfide gas is introduced into a high-nickel copper-arsenic solution at a flow rate of 5–50 L / h to carry out a first-stage copper removal by sulfidation reaction. The reaction time is controlled at 30–60 min and the reaction temperature at 60–70 °C. The reaction is stopped when the redox potential of the solution reaches 340–360 mV, and solid-liquid separation is performed to obtain a first-stage copper removal liquid and a first-stage copper sulfide slag. The copper content of the first-stage copper sulfide slag is 30–45 wt%, the arsenic content is ≤2 wt%, and the nickel content is ≤0.5 wt%. The first-stage copper sulfide slag is then subjected to pyrometallurgical smelting to recover copper.

[0009] Step 2, Two-stage copper removal by sulfidation: Hydrogen sulfide gas is continuously introduced into the copper removal solution obtained in Step 1 for a two-stage copper removal by sulfidation. The hydrogen sulfide gas flow rate is controlled at 10–80 L / h, the reaction time at 30–60 min, and the reaction temperature at 60–70 °C. The reaction is stopped when the redox potential of the solution reaches 230–250 mV, and solid-liquid separation is performed to obtain the copper removal solution after two-stage copper removal and the copper slag after two-stage copper removal. The copper concentration in the copper removal solution after two-stage copper removal is ≤0.2 g / L.

[0010] Step 3, arsenic removal by sulfidation: The two-stage copper removal solution obtained in Step 2 is further perfused with hydrogen sulfide gas to carry out the arsenic removal by sulfidation reaction. The hydrogen sulfide gas flow rate is controlled at 18–100 L / h, the reaction time is 1–2 h, and the reaction temperature is 60–70 °C. The reaction is stopped when the redox potential of the solution reaches ≤30 mV, and solid-liquid separation is performed to obtain the arsenic removal solution by sulfidation and arsenic sulfide slag. The arsenic concentration in the arsenic removal solution is ≤0.5 g / L, and the copper concentration is ≤0.05 g / L.

[0011] Step 4, copper slag dearsenic removal: The second-stage sulfide copper slag obtained in Step 2 is mixed with an additional high-nickel copper-arsenic solution at a liquid-to-solid ratio of L:S = (8-10):1 to carry out the copper slag dearsenic removal reaction. The reaction temperature is controlled at 60-80℃, and after 4-6 hours of reaction, the solid and liquid are separated to obtain displacement sulfide copper slag and copper slag dearsenic removal liquid. The displacement sulfide copper slag has a copper content of 40-60wt%, an arsenic content of ≤2wt%, and a nickel content of ≤0.5wt%. The displacement sulfide copper slag is then subjected to pyrometallurgical smelting to recover copper. The copper slag dearsenic removal liquid is then mixed with the first-stage sulfide copper removal liquid in Step 2 to carry out a second-stage sulfide copper removal reaction.

[0012] Step 5, arsenic slag nickel removal: The arsenic sulfide slag obtained in Step 3 is mixed with the two-stage sulfide copper removal liquid obtained in Step 2 at a liquid-to-solid ratio of L:S = (5-7):1, and the arsenic slag nickel removal reaction is carried out. The reaction temperature is controlled at 60-80℃, and the solid and liquid are separated after 3-5 hours to obtain displacement arsenic sulfide slag and arsenic slag nickel removal liquid. The arsenic content in the displacement arsenic sulfide slag is 30-80wt%, and the nickel content is ≤0.5wt%. The displacement arsenic sulfide slag is subjected to safe disposal of arsenic-containing slag. The arsenic slag nickel removal liquid is mixed with the two-stage sulfide copper removal liquid in Step 3 to carry out sulfide arsenic removal reaction.

[0013] Furthermore, the volume ratio of the copper slag dearsenic removal liquid in step 4 to the copper decoupling liquid in step 2 is 1:(8-19).

[0014] Furthermore, the volume ratio of the arsenic slag denicking liquid in step 5 to the copper decoupling liquid in step 3 is 1:(10-14).

[0015] The beneficial effects of this invention are:

[0016] 1. This invention achieves the separation and purification of copper and arsenic through a stepped sulfidation process consisting of a first-stage sulfidation copper removal, a second-stage sulfidation copper removal, sulfidation arsenic removal, copper slag arsenic removal, and arsenic slag nickel removal. It solves the problem of metal ion inclusions in copper slag and arsenic slag, and realizes effective arsenic removal from sulfidated copper slag and effective nickel removal from sulfidated arsenic slag. It has the advantages of simple process, high recovery rate and low cost.

[0017] 2. The process system realizes the recycling of materials. The copper sulfide slag from the first stage and the replacement copper sulfide slag obtained after the copper slag dearsenic removal reaction can be directly smelted by pyrometallurgy to recover copper. The copper slag dearsenic removal liquid is returned to the second stage copper sulfide removal process, and the arsenic slag denickel removal liquid is returned to the arsenic sulfide removal process. This reduces waste liquid discharge, makes full use of the effective components in the solution, and improves resource utilization.

[0018] 3. Only hydrogen sulfide gas is used as the sulfiding agent throughout the entire process, avoiding the introduction of other impurities. The entire production process is carried out in a closed environment, which has good safety and environmental protection. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the process of the present invention.

[0020] Figure 2 This is the XRD analysis spectrum of a section of copper sulfide slag in Example 4 of the present invention.

[0021] Figure 3 This is an XRF analysis chart of arsenic sulfide slag from Example 4 of the present invention.

[0022] Figure 4 XRF analysis chart of copper sulfide slag in Example 4 of this invention.

[0023] Figure 5 XRF analysis chart of the arsenic sulfide slag in Example 4 of this invention. Detailed Implementation

[0024] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. The described embodiments are only some embodiments of the present invention, and not all embodiments. The specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0025] Example 1

[0026] like Figure 1 As shown, the present invention provides a method for separating copper and arsenic in a high-nickel copper-arsenic solution, comprising the following steps:

[0027] Step 1, First-stage copper removal by sulfidation: Take 1L of solution containing 30.65g / L Ni, 32.85g / L Cu, 40.79g / L As, and H... + A high-nickel copper-arsenic solution with a concentration of 6.5 g / L and an oxidation-reduction potential (ORP) of 470 mV was heated to 60 °C. Hydrogen sulfide gas was then introduced into the solution at a flow rate of 10 L / h to carry out a first-stage copper sulfide removal reaction. After 30 min of reaction, when the reaction endpoint potential reached 360 mV, the hydrogen sulfide gas was stopped, and solid-liquid separation was performed to obtain 1 L of first-stage copper sulfide removal liquid and 31.80 g of first-stage copper sulfide slag.

[0028] The contents of copper (Cu), nickel (Ni), and arsenic (As) in a section of copper sulfide slag are shown in Table 1.

[0029] Table 1. Cu, Ni, and As content in a first-stage copper sulfide slag.

[0030]

[0031] The copper-nickel ratio (Cu:Ni) in a first-stage copper sulfide slag is ≥30, so no secondary treatment is required, and copper can be directly recovered by pyrometallurgical smelting.

[0032] Step 2, two-stage copper removal by sulfidation: The temperature of the copper removal liquid obtained in Step 1 after the first-stage copper removal by sulfidation is maintained at 60℃, and hydrogen sulfide gas is continuously introduced to carry out the second-stage copper removal by sulfidation. The flow rate of hydrogen sulfide gas is controlled at 25L / h. After the reaction is carried out for 30 minutes, the hydrogen sulfide gas is stopped when the reaction endpoint potential reaches 250mV, and solid-liquid separation is performed to obtain 1L of copper removal liquid after the second-stage copper removal by sulfidation and 113.71g of copper sulfide slag after the second-stage copper removal by sulfidation.

[0033] The concentrations of copper (Cu), nickel (Ni), and arsenic (As) in the solution after the second-stage sulfidation copper removal are shown in Table 2.

[0034] Table 2. Concentrations of Cu, Ni, and As in the solution after copper removal via the second-stage sulfidation process.

[0035]

[0036] The contents of copper (Cu), nickel (Ni), and arsenic (As) in the two-stage copper sulfide slag are shown in Table 3.

[0037] Table 3. Cu, Ni, and As content in the second-stage copper sulfide slag

[0038]

[0039] Step 3, sulfide removal of arsenic: The temperature of the liquid obtained after the two-stage copper removal by sulfide in Step 2 is maintained at 60℃, and hydrogen sulfide gas is continuously introduced to carry out the sulfide removal of arsenic reaction. The flow rate of hydrogen sulfide gas is controlled at 28L / h. After 1 hour of reaction, when the reaction endpoint potential reaches 30mV, the introduction of hydrogen sulfide gas is stopped, and solid-liquid separation is carried out to obtain 1L of sulfide removal of arsenic liquid and 122.48g of arsenic sulfide slag.

[0040] The concentrations of copper (Cu), nickel (Ni), and arsenic (As) in the sulfide-treated solution are shown in Table 4.

[0041] Table 4. Concentrations of Cu, Ni, and As in the solution after arsenic removal by sulfidation

[0042]

[0043] The contents of copper (Cu), nickel (Ni), and arsenic (As) in arsenic sulfide slag are shown in Table 5.

[0044] Table 5. Cu, Ni, and As content in arsenic sulfide slag

[0045]

[0046] After sulfidation and arsenic removal, the copper concentration in the liquid was reduced to 0.03 g / L and the arsenic concentration was reduced to 0.08 g / L, achieving efficient removal of copper and arsenic. This sulfidation and arsenic removal liquid can be used for subsequent nickel recovery.

[0047] Step 4, copper slag dearsenic removal: 110g of the second-stage sulfide copper slag obtained in Step 2 is mixed with 0.88L of additional original high-nickel copper-arsenic solution. The reaction temperature is controlled at 60℃ for copper slag dearsenic removal reaction. After 4 hours of reaction, solid-liquid separation is performed to obtain 116.80g of replaced sulfide copper slag and 0.89L of copper slag dearsenic removal liquid. This copper slag dearsenic removal liquid is then mixed with 7.12L of the first-stage sulfide copper removal liquid in Step 2 for a second-stage sulfide copper removal reaction.

[0048] The contents of copper (Cu), nickel (Ni), and arsenic (As) in the replacement copper sulfide slag are shown in Table 6.

[0049] Table 6. Cu, Ni, and As content in copper sulfide slag

[0050]

[0051] The concentrations of copper (Cu), nickel (Ni), and arsenic (As) in the slag dearsenic solution are shown in Table 7.

[0052] Table 7. Concentrations of Cu, Ni, and As in the liquid after arsenic removal from copper slag

[0053]

[0054] The Cu content of the replacement copper sulfide slag is enriched, while the nickel and arsenic content is significantly reduced. The resulting replacement copper sulfide slag can be directly smelted by pyrometallurgy to recover copper.

[0055] Step 5, arsenic slag nickel removal: 120g of the arsenic sulfide slag obtained in Step 3 is mixed with 0.60L of the second-stage sulfide copper removal liquid obtained in Step 2. The reaction temperature is controlled at 80℃ for the arsenic slag nickel removal reaction. After reacting for 3 hours, solid-liquid separation is performed to obtain 102.46g of replaced arsenic sulfide slag and 0.62L of arsenic slag nickel removal liquid. This arsenic slag nickel removal liquid is then mixed with 6.20L of the second-stage sulfide copper removal liquid in Step 3 for the sulfide arsenic removal process.

[0056] The contents of copper (Cu), nickel (Ni), and arsenic (As) in the replacement arsenic sulfide slag are shown in Table 8.

[0057] Table 8. Cu, Ni, and As content in arsenic sulfide slag

[0058]

[0059] The concentrations of copper (Cu), nickel (Ni), and arsenic (As) in the slag denicking solution are shown in Table 9.

[0060] Table 9. Concentrations of Cu, Ni, and As in the solution after nickel removal from arsenic slag

[0061]

[0062] After undergoing a nickel removal reaction, the arsenic content of the replaced arsenic sulfide slag increases significantly while the nickel content decreases markedly, achieving the goal of deep nickel removal from the arsenic slag. This allows for the safe disposal of arsenic-containing arsenic slag.

[0063] Example 2

[0064] like Figure 1 As shown, a method for separating copper and arsenic in a high-nickel copper-arsenic solution includes the following steps:

[0065] Step 1, First-stage copper removal by sulfidation: Take 1L of solution containing 30.65g / L Ni, 32.85g / L Cu, 40.79g / L As, and H... + A high-nickel copper-arsenic solution with a concentration of 6.5 g / L and an oxidation-reduction potential (ORP) of 470 mV was heated to 65 °C. Hydrogen sulfide gas was then introduced into the solution at a flow rate of 8 L / h to carry out a first-stage copper sulfide removal reaction. After 45 min of reaction, when the reaction endpoint potential reached 350 mV, the hydrogen sulfide gas was stopped, and solid-liquid separation was performed to obtain 1 L of first-stage copper sulfide removal liquid and 34.80 g of first-stage copper sulfide slag.

[0066] The contents of copper (Cu), nickel (Ni), and arsenic (As) in a section of copper sulfide slag are shown in Table 10.

[0067] Table 10. Cu, Ni, and As content in a first-stage copper sulfide slag

[0068]

[0069] No secondary treatment is required for copper sulfide slag; it can be directly smelted and recycled for copper.

[0070] Step 2, Second-stage copper removal by sulfidation: The temperature of the copper removal liquid obtained in Step 1 after the first-stage copper removal by sulfidation is maintained at 65℃, and hydrogen sulfide gas is continuously introduced to carry out the second-stage copper removal by sulfidation. The flow rate of hydrogen sulfide gas is controlled at 16L / h. After the reaction is carried out for 45min, the hydrogen sulfide gas is stopped when the reaction endpoint potential reaches 240mV, and solid-liquid separation is performed to obtain 1L of copper removal liquid after the second-stage copper removal by sulfidation and 82.44g of copper sulfide slag after the second-stage copper removal by sulfidation.

[0071] The concentrations of copper (Cu), nickel (Ni), and arsenic (As) in the solution after the second-stage sulfidation copper removal are shown in Table 11.

[0072] Table 11 Concentrations of Cu, Ni, and As in the solution after copper removal via the second-stage sulfidation process.

[0073]

[0074] The contents of copper (Cu), nickel (Ni), and arsenic (As) in the second-stage copper sulfide slag are shown in Table 12.

[0075] Table 12. Cu, Ni, and As contents in the second-stage copper sulfide slag.

[0076]

[0077] Step 3, sulfide removal of arsenic: The temperature of the liquid obtained after the two-stage sulfide removal of copper in Step 2 is maintained at 65℃, and hydrogen sulfide gas is continuously introduced to carry out the sulfide removal of arsenic reaction. The flow rate of hydrogen sulfide gas is controlled at 20L / h. After the reaction is carried out for 1.5h, the hydrogen sulfide gas is stopped when the reaction endpoint potential reaches 20mV, and solid-liquid separation is carried out to obtain 1L of sulfide removal of arsenic liquid and 104.85g of sulfide arsenic slag.

[0078] The concentrations of copper (Cu), nickel (Ni), and arsenic (As) in the sulfide-treated solution are shown in Table 13.

[0079] Table 13 Concentrations of Cu, Ni, and As in the solution after arsenic removal by sulfidation

[0080]

[0081] The contents of copper (Cu), nickel (Ni), and arsenic (As) in arsenic sulfide slag are shown in Table 14.

[0082] Table 14. Cu, Ni, and As content in arsenic sulfide slag

[0083]

[0084] After sulfidation and arsenic removal, the copper concentration in the liquid was reduced to 0.02 g / L and the arsenic concentration was reduced to 0.08 g / L, achieving efficient removal of copper and arsenic. This sulfidation and arsenic removal liquid can be used for subsequent nickel recovery.

[0085] Step 4, copper slag dearsenic removal: Take 80g of the second-stage sulfide copper slag obtained in Step 2 and mix it with 0.72L of additional original high-nickel copper-arsenic solution. Control the reaction temperature at 70℃ to carry out the copper slag dearsenic removal reaction. After reacting for 5 hours, perform solid-liquid separation to obtain 91.88g of replaced sulfide copper slag and 0.74L of copper slag dearsenic removal liquid. This copper slag dearsenic removal liquid is then mixed with 10.36L of the first-stage sulfide copper removal liquid in Step 2 for a second-stage sulfide copper removal reaction.

[0086] The contents of copper (Cu), nickel (Ni), and arsenic (As) in the replacement copper sulfide slag are shown in Table 15.

[0087] Table 15. Cu, Ni, and As contents in copper sulfide slag.

[0088]

[0089] The concentrations of copper (Cu), nickel (Ni), and arsenic (As) in the slag dearsenic solution are shown in Table 16.

[0090] Table 16 Concentrations of Cu, Ni, and As in the liquid after arsenic removal from copper slag

[0091]

[0092] The resulting copper sulfide slag is directly subjected to pyrometallurgical smelting to recover copper.

[0093] Step 5, arsenic slag nickel removal: Take 100g of the arsenic sulfide slag obtained in Step 3 and mix it with 0.6L of the two-stage sulfide copper removal liquid obtained in Step 2. Control the reaction temperature at 70℃ to carry out the arsenic slag nickel removal reaction. After reacting for 4 hours, perform solid-liquid separation to obtain 88.68g of replaced arsenic sulfide slag and 0.63L of arsenic slag nickel removal liquid. This arsenic slag nickel removal liquid is then mixed with 8.19L of the two-stage sulfide copper removal liquid in Step 3 for the sulfide arsenic removal process.

[0094] The contents of copper (Cu), nickel (Ni), and arsenic (As) in the replacement arsenic sulfide slag are shown in Table 17.

[0095] Table 17 Cu, Ni, and As content in arsenic sulfide slag

[0096]

[0097] The concentrations of copper (Cu), nickel (Ni), and arsenic (As) in the slag denicking solution are shown in Table 18.

[0098] Table 18 Concentrations of Cu, Ni, and As in the nickel removal solution from arsenic slag

[0099]

[0100] The arsenic content of the replaced arsenic sulfide slag increases significantly, and it can be safely disposed of directly as arsenic-containing slag.

[0101] This embodiment further verifies the adaptability and stability of the method of the present invention under different process parameters.

[0102] Example 3

[0103] like Figure 1 As shown, a method for separating copper and arsenic in a high-nickel copper-arsenic solution includes the following steps:

[0104] Step 1, First-stage copper removal by sulfidation: Take 1L of solution containing 30.65g / L Ni, 32.85g / L Cu, 40.79g / L As, and H... + A high-nickel copper-arsenic solution with a concentration of 6.5 g / L and an oxidation-reduction potential (ORP) of 470 mV was heated to 70 °C. Hydrogen sulfide gas was then introduced into the solution at a flow rate of 7 L / h to carry out a first-stage copper sulfide removal reaction. After 60 min of reaction, the hydrogen sulfide gas was stopped when the reaction endpoint potential reached 340 mV, and solid-liquid separation was performed to obtain 1 L of first-stage copper sulfide removal liquid and 35.40 g of first-stage copper sulfide slag. The first-stage copper sulfide slag was then used for pyrometallurgical recovery of copper.

[0105] The contents of copper (Cu), nickel (Ni), and arsenic (As) in a section of copper sulfide slag are shown in Table 19.

[0106] Table 19. Cu, Ni, and As content in a first-stage copper sulfide slag

[0107]

[0108] Step 2, two-stage copper removal by sulfidation: The temperature of the copper removal liquid obtained in Step 1 after the first-stage copper removal by sulfidation is maintained at 70℃, and hydrogen sulfide gas is continuously introduced to carry out the second-stage copper removal by sulfidation. The flow rate of hydrogen sulfide gas is controlled at 13L / h. After the reaction is carried out for 60min, when the reaction endpoint potential reaches 230mV, the hydrogen sulfide gas is stopped, and solid-liquid separation is performed to obtain 1L of copper removal liquid after the second-stage copper removal by sulfidation and 63.80g of copper slag after the second-stage copper removal by sulfidation.

[0109] The concentrations of copper (Cu), nickel (Ni), and arsenic (As) in the solution after the second-stage sulfidation copper removal are shown in Table 20.

[0110] Table 20 Concentrations of Cu, Ni, and As in the solution after copper removal via the second-stage sulfidation process.

[0111]

[0112] The contents of copper (Cu), nickel (Ni), and arsenic (As) in the second-stage copper sulfide slag are shown in Table 21.

[0113] Table 21. Cu, Ni, and As contents in the second-stage copper sulfide slag.

[0114]

[0115] Step 3, sulfide removal of arsenic: The temperature of the liquid obtained after the two-stage sulfide removal of copper in Step 2 is maintained at 70℃, and hydrogen sulfide gas is continuously introduced to carry out the sulfide removal of arsenic reaction. The flow rate of hydrogen sulfide gas is controlled at 18.5L / h. After 2 hours of reaction, when the reaction endpoint potential reaches 10mV, the introduction of hydrogen sulfide gas is stopped, and solid-liquid separation is carried out to obtain 1L of sulfide removal of arsenic liquid and 105.80g of sulfide arsenic slag.

[0116] The concentrations of copper (Cu), nickel (Ni), and arsenic (As) in the sulfide-treated solution are shown in Table 22.

[0117] Table 22 Concentrations of Cu, Ni, and As in the sulfide-treated arsenic removal solution

[0118]

[0119] The contents of copper (Cu), nickel (Ni), and arsenic (As) in arsenic sulfide slag are shown in Table 23.

[0120] Table 23 Cu, Ni, and As content in arsenic sulfide slag

[0121]

[0122] After sulfidation and arsenic removal, the copper concentration in the liquid was reduced to 0.02 g / L and the arsenic concentration was reduced to 0.07 g / L, achieving efficient removal of copper and arsenic. This sulfidation and arsenic removal liquid can be used for subsequent nickel recovery.

[0123] Step 4, copper slag dearsenic removal: Take 60g of the second-stage sulfide copper slag obtained in Step 2 and mix it with 0.60L of additional original high-nickel copper-arsenic solution. Control the reaction temperature at 80℃ to carry out the copper slag dearsenic removal reaction. After reacting for 6 hours, perform solid-liquid separation to obtain 75.63g of replaced sulfide copper slag and 0.64L of copper slag dearsenic removal liquid. This copper slag dearsenic removal liquid is then mixed with 12.16L of the first-stage sulfide copper removal liquid in Step 2 for the second-stage sulfide copper removal reaction.

[0124] The contents of copper (Cu), nickel (Ni), and arsenic (As) in the replacement copper sulfide slag are shown in Table 24.

[0125] Table 24 Cu, Ni, and As content in copper sulfide slag

[0126]

[0127] The concentrations of copper (Cu), nickel (Ni), and arsenic (As) in the slag dearsenic solution are shown in Table 25.

[0128] Table 25 Concentrations of Cu, Ni, and As in the liquid after arsenic removal from copper slag

[0129]

[0130] The resulting copper sulfide slag is directly subjected to pyrometallurgical smelting to recover copper.

[0131] Step 5, arsenic slag nickel removal: Take 100g of the arsenic sulfide slag obtained in Step 3 and mix it with 0.70L of the second-stage sulfide copper removal liquid obtained in Step 2. Control the reaction temperature at 80℃ to carry out the arsenic slag nickel removal reaction. After reacting for 5 hours, perform solid-liquid separation to obtain 94.60g of replaced arsenic sulfide slag and 0.73L of arsenic slag nickel removal liquid. This arsenic slag nickel removal liquid is then mixed with 10.22L of the second-stage sulfide copper removal liquid in Step 3 for the sulfide arsenic removal process.

[0132] The contents of copper (Cu), nickel (Ni), and arsenic (As) in the replacement arsenic sulfide slag are shown in Table 26.

[0133] Table 26. Cu, Ni, and As content in arsenic sulfide slag

[0134]

[0135] The concentrations of copper (Cu), nickel (Ni), and arsenic (As) in the slag denicking solution are shown in Table 27.

[0136] Table 27 Concentrations of Cu, Ni, and As in the nickel removal solution from arsenic slag

[0137]

[0138] The arsenic content of the replaced arsenic sulfide slag increases significantly, and it can be safely disposed of directly as arsenic-containing slag.

[0139] Example 4

[0140] like Figure 1 As shown, a method for separating copper and arsenic in a high-nickel copper-arsenic solution includes the following steps:

[0141] Step 1, First-stage copper removal by sulfidation: Take 1L of solution containing 30.65g / L Ni, 32.85g / L Cu, 40.79g / L As, and H... +A high-nickel copper-arsenic solution with a concentration of 6.5 g / L and an oxidation-reduction potential (ORP) of 470 mV was heated to 70 °C. Hydrogen sulfide gas was then introduced into the solution at a flow rate of 40 L / h to carry out a first-stage copper sulfide removal reaction. After 60 min of reaction, the hydrogen sulfide gas was stopped when the reaction endpoint potential reached 340 mV, and solid-liquid separation was performed to obtain 1 L of first-stage copper sulfide removal liquid and 31.34 g of first-stage copper sulfide slag. The first-stage copper sulfide slag was then used for pyrometallurgical recovery of copper.

[0142] XRD analysis spectrum of a section of copper sulfide slag is as follows Figure 2 As shown.

[0143] The contents of copper (Cu), nickel (Ni), and arsenic (As) in a section of copper sulfide slag are shown in Table 28.

[0144] Table 28. Cu, Ni, and As content in a first-stage copper sulfide slag.

[0145]

[0146] Step 2, two-stage copper removal by sulfidation: The temperature of the copper removal liquid obtained in Step 1 after the first-stage copper removal by sulfidation is maintained at 70℃, and hydrogen sulfide gas is continuously introduced to carry out the second-stage copper removal by sulfidation. The flow rate of hydrogen sulfide gas is controlled at 50L / h. After the reaction is carried out for 60min, when the reaction endpoint potential reaches 230mV, the hydrogen sulfide gas is stopped, and solid-liquid separation is performed to obtain 1L of copper removal liquid after the second-stage copper removal by sulfidation and 71.86g of copper slag after the second-stage copper removal by sulfidation.

[0147] The concentrations of copper (Cu), nickel (Ni), and arsenic (As) in the solution after the second-stage sulfidation copper removal are shown in Table 29.

[0148] Table 29 Concentrations of Cu, Ni, and As in the solution after copper removal via the second-stage sulfidation process.

[0149]

[0150] The contents of copper (Cu), nickel (Ni), and arsenic (As) in the two-stage copper sulfide slag are shown in Table 30.

[0151] Table 30. Cu, Ni, and As content in the second-stage copper sulfide slag

[0152]

[0153] Step 3, sulfide removal of arsenic: The temperature of the liquid obtained after the two-stage copper removal by sulfide in Step 2 is maintained at 70℃, and hydrogen sulfide gas is continuously introduced to carry out the sulfide removal of arsenic reaction. The flow rate of hydrogen sulfide gas is controlled at 50L / h. After 2 hours of reaction, when the reaction endpoint potential reaches 10mV, the introduction of hydrogen sulfide gas is stopped, and solid-liquid separation is carried out to obtain 1L of sulfide removal liquid and 70.00g of arsenic sulfide slag.

[0154] The concentrations of copper (Cu), nickel (Ni), and arsenic (As) in the sulfide-treated solution are shown in Table 31.

[0155] Table 31 Concentrations of Cu, Ni, and As in the sulfide-treated arsenic removal solution

[0156]

[0157] XRF analysis charts of arsenic sulfide slag are shown below Figure 3 As shown.

[0158] The contents of copper (Cu), nickel (Ni), and arsenic (As) in arsenic sulfide slag are shown in Table 32.

[0159] Table 32 Cu, Ni, and As content in arsenic sulfide slag

[0160]

[0161] After sulfidation and arsenic removal, the copper concentration in the liquid was reduced to 0.01 g / L and the arsenic concentration was reduced to 0.07 g / L, achieving efficient removal of copper and arsenic. This sulfidation and arsenic removal liquid can be used for subsequent nickel recovery.

[0162] Step 4, copper slag dearsenic removal: Take 60g of the second-stage sulfide copper slag obtained in Step 2 and mix it with 0.60L of additional original high-nickel copper-arsenic solution. Control the reaction temperature at 80℃ to carry out the copper slag dearsenic removal reaction. After reacting for 5 hours, perform solid-liquid separation to obtain 81.3g of replaced sulfide copper slag and 0.62L of copper slag dearsenic removal liquid. This copper slag dearsenic removal liquid is then mixed with 10.00L of the first-stage sulfide copper removal liquid in Step 2 for the second-stage sulfide copper removal reaction.

[0163] XRF analysis charts of displacement sulfide copper slag are shown below Figure 4 As shown.

[0164] The contents of copper (Cu), nickel (Ni), and arsenic (As) in the replacement copper sulfide slag are shown in Table 33.

[0165] Table 33 Cu, Ni, and As content in copper sulfide slag

[0166]

[0167] The resulting copper sulfide slag is directly subjected to pyrometallurgical smelting to recover copper.

[0168] Step 5, arsenic slag nickel removal: Take 100g of the arsenic sulfide slag obtained in Step 3 and mix it with 0.70L of the second-stage sulfide copper removal liquid obtained in Step 2. Control the reaction temperature at 80℃ to carry out the arsenic slag nickel removal reaction. After reacting for 4 hours, perform solid-liquid separation to obtain 95.6g of replaced arsenic sulfide slag and 0.70L of arsenic slag nickel removal liquid. This arsenic slag nickel removal liquid is then mixed with 8.00L of the second-stage sulfide copper removal liquid in Step 3 for the sulfide arsenic removal process.

[0169] XRF analysis charts of displacement arsenic sulfide slag are shown below Figure 5 As shown.

[0170] The contents of copper (Cu), nickel (Ni), and arsenic (As) in the replacement arsenic sulfide slag are shown in Table 34.

[0171] Table 34. Cu, Ni, and As contents in arsenic sulfide slag

[0172]

[0173] The concentrations of copper (Cu), nickel (Ni), and arsenic (As) in the slag denicking solution are shown in Table 35.

[0174] Table 35 Concentrations of Cu, Ni, and As in the nickel removal solution from arsenic slag

[0175]

[0176] The arsenic content of the replaced arsenic sulfide slag increases significantly, and it can be safely disposed of directly as arsenic-containing slag.

[0177] This invention uses hydrogen sulfide gas as a single sulfiding agent. A first-stage sulfidation copper removal reaction is performed on a nickel-copper-arsenic solution to obtain a first-stage sulfidation copper removal liquid and a first-stage sulfidation copper slag. The first-stage sulfidation copper slag contains 30-45% copper, <2% arsenic, and <0.5% nickel, and can be directly used for pyrometallurgical copper recovery. Based on this, a second-stage sulfidation copper removal reaction is performed on the first-stage sulfidation copper removal liquid to obtain a second-stage sulfidation copper removal liquid and a second-stage sulfidation copper slag. The second-stage sulfidation copper removal liquid has a copper concentration of <0.2 g / L, achieving effective separation of copper and arsenic in the nickel-copper-arsenic solution. The second-stage sulfidation copper slag contains 10-35% copper, 10-25% arsenic, and 1-5% nickel. The replacement sulfidation copper slag obtained after the copper slag arsenic removal reaction contains 40-60% copper, <2% arsenic, and <0.5% nickel, and can be directly used for pyrometallurgical copper recovery. The copper-free solution from the second stage of sulfidation was further subjected to arsenic-free sulfidation to obtain arsenic-free sulfidation solution and arsenic-free sulfidation slag. The arsenic concentration in the arsenic-free sulfidation solution was <0.5 g / L, and the copper concentration was <0.05 g / L, achieving effective removal of copper and arsenic from the nickel-copper-arsenic solution, allowing for subsequent nickel recovery. The arsenic content in the arsenic-free slag was 15–45%, and the nickel content was 1–5%. The arsenic-replaced slag obtained after the nickel removal reaction of the arsenic slag had an arsenic content of 30–80% and a nickel content of <0.5%, allowing for safe disposal of the arsenic.

Claims

1. A method for separating copper and arsenic in a high-nickel copper-arsenic solution, wherein the copper concentration in the high-nickel copper-arsenic solution is 10–40 g / L, the nickel concentration is 10–40 g / L, and the arsenic concentration is 20–60 g / L, characterized in that, The method includes the following steps: Step 1, First-stage copper removal by sulfidation: Hydrogen sulfide gas is introduced into a high-nickel copper-arsenic solution to carry out a first-stage copper removal by sulfidation reaction. The reaction time is controlled at 30-60 min and the reaction temperature at 60-70℃. The reaction is stopped when the redox potential of the solution reaches 340-360 mV, and solid-liquid separation is performed to obtain a first-stage copper removal liquid and a first-stage copper sulfide slag. The copper content of the first-stage copper sulfide slag is 30-45 wt%, the arsenic content is ≤2 wt%, and the nickel content is ≤0.5 wt%. The first-stage copper sulfide slag is then subjected to pyrometallurgical smelting to recover copper. Step 2, Two-stage copper removal by sulfidation: Hydrogen sulfide gas is continuously introduced into the copper removal solution obtained in Step 1 for a two-stage copper removal by sulfidation. The reaction time is controlled at 30–60 min, and the reaction temperature at 60–70 °C. The reaction is stopped when the redox potential of the solution reaches 230–250 mV, and solid-liquid separation is performed to obtain the copper removal solution after two-stage copper removal by sulfidation and the copper slag after two-stage copper removal by sulfidation. The copper concentration in the copper removal solution after two-stage copper removal by sulfidation is ≤0.2 g / L. Step 3, arsenic removal by sulfidation: Hydrogen sulfide gas is continuously introduced into the two-stage copper removal solution obtained in Step 2 to carry out the arsenic removal by sulfidation reaction. The reaction time is controlled at 1–2 hours, and the reaction temperature is controlled at 60–70°C. The reaction is stopped when the redox potential of the solution reaches ≤30mV, and solid-liquid separation is performed to obtain the arsenic removal solution by sulfidation and arsenic sulfide slag. The arsenic concentration in the arsenic removal solution is ≤0.5g / L, and the copper concentration is ≤0.05g / L. Step 4, copper slag dearsenic removal: The second-stage sulfide copper slag obtained in Step 2 is mixed with an additional high-nickel copper-arsenic solution at a liquid-to-solid ratio of L:S = (8-10):1 to carry out the copper slag dearsenic removal reaction. The reaction temperature is controlled at 60-80℃, and after 4-6 hours of reaction, the solid and liquid are separated to obtain displacement sulfide copper slag and copper slag dearsenic removal liquid. The displacement sulfide copper slag has a copper content of 40-60wt%, an arsenic content of ≤2wt%, and a nickel content of ≤0.5wt%. The displacement sulfide copper slag is then subjected to pyrometallurgical smelting to recover copper. The copper slag dearsenic removal liquid is then mixed with the first-stage sulfide copper removal liquid in Step 2 to carry out a second-stage sulfide copper removal reaction. Step 5, arsenic slag nickel removal: The arsenic sulfide slag obtained in Step 3 is mixed with the two-stage sulfide copper removal liquid obtained in Step 2 at a liquid-to-solid ratio of L:S = (5-7):1, and the arsenic slag nickel removal reaction is carried out. The reaction temperature is controlled at 60-80℃, and the solid and liquid are separated after 3-5 hours to obtain displacement arsenic sulfide slag and arsenic slag nickel removal liquid. The arsenic content in the displacement arsenic sulfide slag is 30-80wt%, and the nickel content is ≤0.5wt%. The displacement arsenic sulfide slag is subjected to safe disposal of arsenic-containing slag. The arsenic slag nickel removal liquid is mixed with the two-stage sulfide copper removal liquid in Step 3 to carry out sulfide arsenic removal reaction.

2. The method for separating copper and arsenic in a high-nickel copper-arsenic solution according to claim 1, characterized in that: The volume ratio of the copper slag dearsenic removal liquid in step 4 to the copper decoupling liquid in step 2 is 1:(8-19).

3. The method for separating copper and arsenic in a high-nickel copper-arsenic solution according to claim 1, characterized in that: The volume ratio of the arsenic slag denicking liquid in step 5 to the copper decoupling liquid in step 3 is 1:(10-14).

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