Method for removing impurities and recovering from nickel electrowinning anode solution

Abstract

This invention provides a method for removing impurities and recovering nickel anolyte from electrolytic nickel. The method includes the following steps: (1) mixing the electrolytic nickel anolyte with liquid alkali, separating the solid and liquid components to obtain nickel hydroxide and filtrate, evaporating the filtrate to obtain sodium sulfate; mixing the electrolytic nickel anolyte with a nickel source to obtain a mixed solution; (2) mixing the mixed solution with barium salt for lead removal; (3) adjusting the pH of the material obtained after lead removal with nickel hydroxide to obtain an arsenic removal solution, mixing the arsenic removal solution with polyferric sulfate for arsenic removal; (4) mixing the material obtained after arsenic removal with an oxidant to obtain an iron removal solution, performing solid-liquid separation on the iron removal solution to obtain lead-, arsenic-, and iron-removed cathode liquid and iron-containing slag, adding sodium sulfate to the lead-, arsenic-, and iron-removed cathode liquid, and reusing it in the electrolytic nickel process. The method of this invention can efficiently and quickly remove lead, arsenic, and iron from electrolytic nickel anolyte and reuse it.

Description

Technical Field

[0001] This invention belongs to the field of nickel hydrometallurgical technology and relates to a method for removing impurities and recovering electrolytic nickel anolyte. Background Technology

[0002] Electrolytic nickel products are widely used in electroplating, batteries, and high-temperature alloys. To ensure optimal application in these specialized fields, the impurity content of electrolytic nickel products must be strictly controlled. Impurities are typically introduced through the new electrolytic solution and the anode plate. Replacing the anode plate with a precious metal titanium coating can effectively prevent impurity problems caused by the anode plate; however, precious metal titanium-coated anode plates are expensive and have a short service life, limiting their industrial application.

[0003] Currently, electrowinning nickel mainly uses multi-element alloy anode plates. The electrowinning process may introduce impurities such as lead, arsenic, and iron. Therefore, it is inevitable to mix the electrowinning solution and the anode solution and then perform impurity removal treatment before returning them to the electrowinning process to obtain high-purity electrowinning nickel products.

[0004] CN117107341A discloses a method for regenerating and recycling electrolytic nickel anolyte, which uses electrolytic nickel anolyte in the back-extraction section of a nickel sulfate extraction enrichment line for back-extraction of nickel-loaded p507 extractant. Specifically, it includes: (1) First-stage back-extraction: using electrolytic nickel anolyte to back-extract nickel-loaded p507 extractant to obtain a first-stage back-extraction phase and a first-stage p507 organic phase; (2) Second-stage back-extraction: using acid to back-extract the first-stage p507 organic phase to obtain a second-stage back-extraction phase and a second-stage p507 organic phase; (3) Electrolytic deposition: detecting the impurity content in the first-stage back-extraction phase, and when the impurity content meets the control standard, returning the second-stage back-extraction phase to the first-stage back-extraction, mixing it with the electrolytic nickel anolyte to be used as the back-extraction agent for the first-stage back-extraction, and using the first-stage back-extraction phase as the cathode liquid for electrolytic nickel deposition to obtain nickel and electrolytic nickel anolyte.

[0005] CN119194538A discloses a method for removing lead and replenishing nickel in electrolytic nickel anolyte. The method involves mixing the electrolytic anolyte with refined nickel sulfate degreasing solution and nickel carbonate slurry, introducing air, controlling the temperature, and then entering an acid dissolution tank for lead removal. The acid-dissolved solution is then filtered through an acid dissolution filter press. The resulting primary filtrate is pumped into a precision filter, and the resulting secondary filtrate enters a secondary filtrate storage tank. The secondary filtrate is then pumped into a cathode liquid tank via a secondary filtrate transfer pump. The resulting cathode liquid is then used as the cathode liquid in the electrolytic electrodeposition process.

[0006] The above-mentioned method has a long impurity removal time, requires high impurity removal efficiency, and is relatively complicated. As a result, the returned electrowinning solution cannot keep up with the electrowinning consumption, leading to a decrease in production capacity and additional economic losses. Summary of the Invention

[0007] The purpose of this invention is to provide a method for removing impurities and recovering nickel anolyte by electrowinning. The method described in this invention can efficiently and quickly remove lead, arsenic and iron from nickel anolyte by electrowinning, ensuring timely supply of electrowinning solution, guaranteeing the smooth progress of electrowinning reaction, and avoiding production capacity reduction due to impurity removal process.

[0008] To achieve this objective, the present invention adopts the following technical solution:

[0009] In a first aspect, the present invention provides a method for removing impurities and recovering nickel anolyte by electrowinning, the method comprising the following steps:

[0010] (1) Take the first electrolytic nickel anolyte and mix it with liquid alkali, and obtain nickel hydroxide and filtrate through the first solid-liquid separation treatment. Evaporate the filtrate to obtain sodium sulfate; take the second electrolytic nickel anolyte and mix it with nickel source to obtain a mixed solution;

[0011] (2) Mix the mixed solution obtained in step (1) with barium salt and perform lead removal treatment;

[0012] (3) After adjusting the pH of the material obtained after lead removal treatment in step (2) with nickel hydroxide obtained in step (1), the arsenic removal solution is obtained. The arsenic removal solution is then mixed with polyferric sulfate for arsenic removal treatment.

[0013] (4) The material obtained after the arsenic removal treatment in step (3) is mixed with an oxidant to obtain an iron removal solution. The iron removal solution is subjected to a second solid-liquid separation treatment to obtain a catholyte containing lead, arsenic and iron and iron-containing slag. Sodium sulfate obtained in step (1) is added to the catholyte containing lead, arsenic and iron and reused in the nickel electrowinning process.

[0014] The first solid-liquid separation process and the second solid-liquid separation process of the present invention are independently carried out by pressure filtration, vacuum filtration or filtration, preferably pressure filtration.

[0015] The nickel anolyte described in this invention is the anolyte produced by the anode during the nickel electrolysis process. The first and second nickel anolytes of this invention can be selected from the same or different nickel anolytes, and the amount or ratio of the two is not limited. If the nickel hydroxide and sodium sulfate produced by the first nickel anolyte are in excess, they can be used in the impurity removal and recovery process of the nickel anolyte in the next process.

[0016] The impurity removal and recovery method for electrowinning nickel anolyte described in this invention, through the rational allocation of each step, sequentially performs lead, arsenic, and iron precipitation on the electrowinning nickel anolyte. This allows for timely and efficient removal of lead, arsenic, and iron impurities from the electrowinning nickel anolyte, significantly shortening the impurity removal time. This ensures a timely supply of the electrowinning solution, guarantees the smooth progress of the electrowinning reaction, and avoids capacity reduction due to the impurity removal process. The impurity removal and recovery method of this invention achieves cyclical production, achieving the purpose of impurity removal without losing any auxiliary materials required for electrowinning, such as sodium sulfate, thus helping to reduce production costs.

[0017] Preferably, in step (1), the mass concentration of nickel ions in the first and second electrolytic nickel anolytes is independently 75 g / L to 85 g / L, for example: 75 g / L, 78 g / L, 80 g / L, 82 g / L or 85 g / L, etc., and is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0018] Preferably, in step (1), the mass concentration of sodium sulfate in the first and second electrolytic nickel anolytes is independently 80 g / L to 100 g / L, for example: 80 g / L, 85 g / L, 90 g / L, 95 g / L or 100 g / L, etc., and is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0019] Preferably, in step (1), the pH of the first electrolytic nickel anolyte and the second electrolytic nickel anolyte are independently 0 to 1.5, for example: 0, 0.1, 0.5, 0.8, 1 or 1.5, etc., not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0020] Preferably, the mass concentration of the liquid alkali in step (1) is 30% to 42%, for example: 30%, 32%, 35%, 40% or 42%, etc., and is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0021] Preferably, the molar ratio of sodium hydroxide in the liquid alkali in step (1) to nickel ions in the first electrolytic nickel anolyte is (2-2.2):1, for example: 2:1, 2.05:1, 2.1:1, 2.15:1 or 2.2:1, etc., and is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0022] Preferably, the nickel source in step (1) includes nickel sulfate crystals and / or nickel sulfate solution.

[0023] Preferably, the mass concentration of nickel ions in the nickel sulfate solution in step (1) is 100 g / L to 105 g / L, for example: 100 g / L, 101 g / L, 102 g / L, 103 g / L, 104 g / L or 105 g / L, etc., and is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0024] Preferably, the pH of the nickel sulfate solution in step (1) is 3.5 to 4.5, for example: 3.5, 3.8, 4, 4.2 or 4.5, etc., not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0025] Preferably, the mass concentration of nickel ions in the mixed solution in step (1) is 80 g / L to 90 g / L, for example: 80 g / L, 82 g / L, 85 g / L, 88 g / L or 90 g / L, etc., and is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0026] Preferably, the mass concentration of sodium sulfate in the mixed solution in step (1) is 60 g / L to 85 g / L, for example: 60 g / L, 65 g / L, 70 g / L, 80 g / L or 85 g / L, etc., and is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0027] Preferably, the pH of the mixed solution in step (1) is 0 to 2, for example: 0, 0.5, 1, 1.5 or 2, etc., not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0028] Preferably, the barium salt in step (2) includes barium carbonate.

[0029] Preferably, the mass-to-volume ratio of the barium salt to the mixed solution is 0.1 g / L to 0.4 g / L, for example: 0.1 g / L, 0.15 g / L, 0.2 g / L, 0.3 g / L or 0.4 g / L, etc., and is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0030] Preferably, the first stirring is performed during the lead removal process described in step (2).

[0031] Preferably, the first stirring time is 20 min to 40 min, for example: 20 min, 25 min, 30 min, 35 min or 40 min, etc., and is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0032] Preferably, the temperature of the lead removal process in step (2) is 50℃~70℃, for example: 50℃, 55℃, 60℃, 65℃ or 70℃, etc., not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0033] Preferably, the pH in step (3) is 3.5 to 4.5, for example: 3.5, 3.8, 4, 4.2 or 4.5, etc., and is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0034] Preferably, the mass concentration of nickel ions in the arsenic removal solution in step (3) is 100 g / L to 105 g / L, for example: 100 g / L, 101 g / L, 102 g / L, 103 g / L, 104 g / L or 105 g / L, etc., and is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0035] Preferably, the mass-to-volume ratio of polyferric sulfate to the arsenic removal solution in step (3) is 0.3 g / L to 0.6 g / L, for example: 0.3 g / L, 0.35 g / L, 0.4 g / L, 0.5 g / L or 0.6 g / L, etc., and is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0036] Preferably, a second stirring is performed during the arsenic removal process described in step (3).

[0037] Preferably, the second stirring time is 20 min to 40 min, for example: 20 min, 25 min, 30 min, 35 min or 40 min, etc., not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0038] Preferably, the temperature of the arsenic removal treatment in step (3) is 50℃~70℃, for example: 50℃, 55℃, 60℃, 65℃ or 70℃, etc., not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0039] Preferably, the oxidant in step (4) includes a hydrogen peroxide solution.

[0040] Preferably, the volume ratio of the oxidant in step (4) to the material obtained after arsenic removal treatment is 10 mL / L to 20 mL / L, for example: 10 mL / L, 12 mL / L, 15 mL / L, 18 mL / L or 20 mL / L, etc., not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0041] Preferably, the mass concentration of the hydrogen peroxide solution is 30-42%, for example, 30%-42%, such as 30%, 32%, 35%, 40% or 42%, etc., and is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0042] Preferably, the mass-to-volume ratio of sodium sulfate to catholyte for removing lead, arsenic and iron in step (4) is 80 g / L to 100 g / L, for example: 80 g / L, 85 g / L, 90 g / L, 95 g / L or 100 g / L, etc., and is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0043] Compared with the prior art, the present invention has the following beneficial effects:

[0044] (1) The impurity removal and recovery method described in this invention can achieve rapid impurity removal during the nickel electrowinning process, allowing the electrowinning solution to flow more quickly, reducing concentration polarization and ensuring a stable and high liquid level difference between the cathode and anode, effectively preventing hydrogen ions from migrating to the cathode and thus increasing the porosity of the nickel plate. At the same time, the rapid flow of the electrowinning solution can effectively avoid the accumulation of impurities in the electrowinning cell, thereby reducing the precipitation of impurities at the cathode and improving the product quality of the electrowinning nickel.

[0045] (2) The method for removing impurities from the electrolytic nickel anode liquid described in this invention can effectively remove lead, arsenic and iron impurities in the same reaction vessel without the need for complicated operation procedures and liquid transfer, thereby reducing labor intensity and improving work efficiency.

[0046] (3) The method for removing impurities and recovering nickel anolyte described in this invention can achieve a lead concentration of less than 1.9 mg / L, an arsenic concentration of less than 0.2 mg / L, and an iron concentration of less than 1.9 mg / L in the cathode solution. By adjusting the amount of material added during the recovery process, the lead concentration in the cathode solution can be reduced to less than 1.3 mg / L, the arsenic concentration to less than 0.1 mg / L, and the iron concentration to less than 1.2 mg / L. Attached Figure Description

[0047] Figure 1 This is a schematic diagram of the process flow for the method of removing impurities and recovering electrolytic nickel anolyte provided in an embodiment of the present invention. Detailed Implementation

[0048] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0049] The specific composition of the electrowinning nickel anolyte used in the embodiments and comparative examples of this invention is as follows:

[0050] Ni: 82 g / L, Sodium sulfate: 93.5 g / L, Pb: 3.5 mg / L, As: 0.4 mg / L, Fe: 2.8 mg / L, pH: 0.85.

[0051] Example 1

[0052] This embodiment provides a method for removing impurities and recovering impurities from electrolytic nickel anolyte. The process flow diagram of the method is shown below. Figure 1 As shown, the impurity removal and recovery method includes the following steps:

[0053] (1) Mix the electrolytic nickel anolyte with a 35% (w / w) liquid alkali solution (the liquid alkali contains OH-). - The nickel anolyte contains nickel hydroxide in a molar ratio of 2:1 (Ni in the electrolytic nickel anolyte is 2:1). After pressure filtration, nickel hydroxide and filtrate are obtained. The filtrate is evaporated to obtain sodium sulfate. The electrolytic nickel anolyte is then mixed with a nickel sulfate solution with a mass concentration of 102 g / L and a pH of 4 to obtain a mixed solution with a nickel mass concentration of 86 g / L, a sodium sulfate mass concentration of 72 g / L, and a pH of 1.2.

[0054] (2) At 60℃, barium carbonate was mixed with the mixed solution to obtain a barium carbonate mass concentration of 0.1 g / L in the solution, and the solution was stirred for 30 min to remove lead.

[0055] (3) At 60°C, the pH of the material obtained after lead removal treatment was adjusted to 4 using the nickel hydroxide obtained in step (1), and polyferric sulfate (PFS) was added with a mass concentration of 0.3 g / L. The mixture was stirred for 30 min to remove arsenic.

[0056] (4) At 60°C, a 30% hydrogen peroxide solution was added to the material obtained after arsenic removal treatment to obtain an iron removal solution. The volume ratio of the hydrogen peroxide solution to the material obtained after arsenic removal treatment was 10 mL / L. After stirring for 30 min, the solution was filtered to obtain a catholyte with lead, arsenic and iron removed and iron-containing slag. The sodium sulfate obtained in step (1) was added to the catholyte with lead, arsenic and iron removed. The sodium sulfate concentration was 90 g / L and it was reused in the nickel electrowinning process.

[0057] Example 2

[0058] This embodiment provides a method for removing impurities and recovering impurities from electrolytic nickel anolyte. The process flow diagram of the method is shown below. Figure 1 As shown, the impurity removal and recovery method includes the following steps:

[0059] (1) Mix the electrolytic nickel anolyte with a 35% (w / w) liquid alkali solution (the liquid alkali contains OH-). -The nickel anolyte (with a molar ratio of Ni to Ni in the electrolytic nickel anolyte of 2.2:1) was filtered under pressure to obtain nickel hydroxide and filtrate. The filtrate was then evaporated to obtain sodium sulfate. The electrolytic nickel anolyte was then mixed with a nickel sulfate solution with a mass concentration of 105 g / L and a pH of 3.5 to obtain a mixed solution with a nickel mass concentration of 80 g / L, a sodium sulfate mass concentration of 60 g / L, and a pH of 2.

[0060] (2) At 70℃, barium carbonate was mixed with the mixed solution to obtain a barium carbonate mass concentration of 0.4 g / L in the solution, and the solution was stirred to remove lead for 40 min.

[0061] (3) At 70°C, the pH of the material obtained after lead removal treatment was adjusted to 3.5 using the nickel hydroxide obtained in step (1), and polyferric sulfate (PFS) was added with a mass concentration of 0.6 g / L. The mixture was stirred for 30 min to remove arsenic.

[0062] (4) At 70°C, a 35% hydrogen peroxide solution is added to the material obtained after arsenic removal treatment to obtain an iron removal solution. The volume ratio of the hydrogen peroxide solution to the material obtained after arsenic removal treatment is 20 mL / L. After stirring for 30 min, the solution is filtered to obtain a catholyte with lead, arsenic and iron removed and iron-containing slag. The sodium sulfate obtained in step (1) is added to the catholyte with lead, arsenic and iron removed. The sodium sulfate concentration is 100 g / L and it is reused in the nickel electrowinning process.

[0063] Example 3

[0064] This embodiment provides a method for removing impurities and recovering impurities from electrolytic nickel anolyte. The process flow diagram of the method is shown below. Figure 1 As shown, the impurity removal and recovery method includes the following steps:

[0065] (1) Mix the electrolytic nickel anolyte with a 42% (w / w) liquid alkali solution (the liquid alkali contains OH-). - The nickel anolyte contains nickel hydroxide in a molar ratio of 2.1:1 (Ni in the electrolytic nickel anolyte is 2.1:1). After pressure filtration, nickel hydroxide and filtrate are obtained. The filtrate is then evaporated to obtain sodium sulfate. The electrolytic nickel anolyte is then mixed with a nickel sulfate solution with a mass concentration of 100 g / L and a pH of 4.5 to obtain a mixed solution with a nickel mass concentration of 90 g / L, a sodium sulfate mass concentration of 80 g / L, and a pH of 0.8.

[0066] (2) At 50℃, barium carbonate was mixed with the mixed solution to obtain a barium carbonate mass concentration of 0.3 g / L in the solution, and the solution was stirred to remove lead for 40 min.

[0067] (3) At 50°C, the pH of the material obtained after lead removal treatment was adjusted to 4.5 using the nickel hydroxide obtained in step (1), and polyferric sulfate (PFS) was added with a mass concentration of 0.6 g / L. The mixture was stirred for 30 min to remove arsenic.

[0068] (4) At 50°C, a hydrogen peroxide solution with a mass concentration of 42% was added to the material obtained after arsenic removal treatment to obtain an iron removal solution. The volume ratio of the hydrogen peroxide solution to the material obtained after arsenic removal treatment was 20 mL / L. After stirring for 30 min, the solution was filtered to obtain a catholyte with lead, arsenic and iron removed and iron-containing slag. The sodium sulfate obtained in step (1) was added to the catholyte with lead, arsenic and iron removed. The sodium sulfate concentration was 80 g / L and it was reused in the nickel electrowinning process.

[0069] Example 4

[0070] This embodiment provides a method for removing impurities and recovering impurities from electrolytic nickel anolyte. The process flow diagram of the method is shown below. Figure 1 As shown, the impurity removal and recovery method includes the following steps:

[0071] (1) Mix the electrolytic nickel anolyte with a 35% (w / w) liquid alkali solution (the liquid alkali contains OH-). - The nickel anolyte contains nickel hydroxide in a molar ratio of 2:1 (Ni in the electrolytic nickel anolyte is 2:1). After pressure filtration, nickel hydroxide and filtrate are obtained. The filtrate is evaporated to obtain sodium sulfate. The electrolytic nickel anolyte is then mixed with a nickel sulfate solution with a mass concentration of 102 g / L and a pH of 4 to obtain a mixed solution with a nickel mass concentration of 86 g / L, a sodium sulfate mass concentration of 72 g / L, and a pH of 1.2.

[0072] (2) At 60℃, barium carbonate was mixed with the mixed solution to obtain a barium carbonate mass concentration of 0.4 g / L in the solution, and the solution was stirred to remove lead for 30 min.

[0073] (3) At 60°C, the pH of the material obtained after lead removal treatment was adjusted to 4 using the nickel hydroxide obtained in step (1), and polyferric sulfate was added with a mass concentration of 0.6 g / L. The mixture was stirred for 30 min to remove arsenic.

[0074] (4) At 60°C, a hydrogen peroxide solution with a mass concentration of 32% was added to the material obtained after arsenic removal treatment to obtain an iron removal solution. The volume ratio of the hydrogen peroxide solution to the material obtained after arsenic removal treatment was 20 mL / L. After stirring for 30 min, the solution was filtered to obtain a catholyte with lead, arsenic and iron removed and iron-containing slag. The sodium sulfate obtained in step (1) was added to the catholyte with lead, arsenic and iron removed. The sodium sulfate concentration was 90 g / L and it was reused in the nickel electrowinning process.

[0075] Example 5

[0076] The only difference between this embodiment and Example 1 is that the mass concentration of barium carbonate is 0.05 g / L; all other conditions and parameters are exactly the same as in Example 1.

[0077] Example 6

[0078] The only difference between this embodiment and Example 1 is that the mass concentration of barium carbonate is 0.5 g / L; all other conditions and parameters are exactly the same as in Example 1.

[0079] Example 7

[0080] The only difference between this embodiment and Example 1 is that the mass concentration of polyferric sulfate is 0.2 g / L, while the other conditions and parameters are exactly the same as in Example 1.

[0081] Example 8

[0082] The only difference between this embodiment and Example 1 is that the mass concentration of polyferric sulfate is 0.7 g / L, while the other conditions and parameters are exactly the same as in Example 1.

[0083] Example 9

[0084] The only difference between this embodiment and Embodiment 1 is that the volume concentration of hydrogen peroxide in the solution to be iron removed is 5 mL / L; all other conditions and parameters are exactly the same as in Embodiment 1.

[0085] Example 10

[0086] The only difference between this embodiment and Embodiment 1 is that the volume concentration of hydrogen peroxide in the solution to be iron removed is 30 mL / L. All other conditions and parameters are exactly the same as in Embodiment 1.

[0087] Comparative Example 1

[0088] The only difference between this comparative example and Example 1 is that polyferric sulfate was added first to remove arsenic, followed by barium carbonate to remove lead. All other conditions and parameters are exactly the same as in Example 1.

[0089] Comparative Example 2

[0090] The only difference between this comparative example and Example 1 is that hydrogen peroxide was added first to remove iron, followed by polyferric sulfate to remove arsenic. All other conditions and parameters are exactly the same as in Example 1.

[0091] Comparative Example 3

[0092] The only difference between this comparative example and Example 1 is that hydrogen peroxide was added first to remove iron, followed by barium carbonate to remove lead and polyferric sulfate to remove arsenic. All other conditions and parameters are exactly the same as in Example 1.

[0093] Performance testing:

[0094] The mass concentrations of lead, arsenic, and iron in the catholyte used for lead, arsenic, and iron removal were tested, and the results are shown in Table 1.

[0095] Table 1

[0096] Pb (mg / L) As (mg / L) Fe (mg / L) Example 1 1.2 0.1 1.1 Example 2 0.9 0.1 1.2 Example 3 1.3 0.1 1.2 Example 4 0.8 0.1 1.1 Example 5 1.9 0.1 1.1 Example 6 1.1 0.1 1.3 Example 7 1.2 0.2 1.2 Example 8 1.0 0.1 1.4 Example 9 1.1 0.1 1.9 Example 10 1.1 0.1 1.2 Comparative Example 1 2.4 0.1 1.0 Comparative Example 2 1.1 0.2 2.3 Comparative Example 3 2.6 0.2 2.7

[0097] As shown in Table 1, and based on Examples 1-10, the method for removing impurities and recovering the electrolytic nickel anolyte described in this invention can achieve a lead concentration of less than 1.9 mg / L, an arsenic concentration of less than 0.2 mg / L, and an iron concentration of less than 1.9 mg / L in the cathode solution. By adjusting the amount of material added during the recovery process, the lead concentration in the cathode solution can be reduced to less than 1.3 mg / L, the arsenic concentration to less than 0.1 mg / L, and the iron concentration to less than 1.2 mg / L.

[0098] A comparison of Examples 1 and 5-6 shows that in the impurity removal and recovery process of the electrolytic nickel anolyte described in this invention, the amount of barium salt added affects the impurity removal and recovery effect. When the amount of barium salt added is controlled between 0.1 g / L and 0.4 g / L, the lead removal effect is better. If the amount of barium salt added is too large, the lead removal effect is not significant compared to 0.4 g / L. If the amount of barium salt added is too small, the lead removal effect is not significant.

[0099] A comparison of Examples 1 and 7-8 shows that the amount of polyferric sulfate added affects the impurity removal and recovery effect during the impurity removal and recovery process of the electrolytic nickel anolyte described in this invention. When the amount of polyferric sulfate added is controlled between 0.3 g / L and 0.6 g / L, the arsenic removal effect is better. If the amount of polyferric sulfate added is too large, the gain compared with the arsenic removal effect of 0.6 g / L is not obvious. If the amount of polyferric sulfate added is too small, the arsenic removal effect is not significant.

[0100] A comparison of Examples 1 and 9-10 shows that in the impurity removal and recovery process of the electrolytic nickel anolyte described in this invention, the amount of oxidant (hydrogen peroxide) added affects the impurity removal and recovery effect. When the amount of oxidant added is controlled at 10 mL / L to 20 mL / L, the iron removal effect is better. If the amount of oxidant added is too large, the gain is not obvious compared with the iron removal effect of 20 mL / L. If the amount of oxidant added is too small, the iron removal effect is not significant.

[0101] Comparing Example 1 and Comparative Examples 1-3, it can be seen that in the impurity removal and recovery method of the present invention, barium carbonate achieves better lead removal effect in a lower pH range, therefore it is added before pH adjustment; while polyferric sulfate has a better arsenic removal effect under more neutral conditions, therefore it is added after pH adjustment; finally, hydrogen peroxide is added to remove iron to provide sufficient reaction time for arsenic and iron removal, because the hydrolysis of polyferric sulfate still requires a certain amount of time, so adding hydrogen peroxide first and then adding polyferric sulfate will result in less than ideal arsenic and iron removal effects. The impurity removal and recovery method of electrowinning nickel anolyte of the present invention, through the reasonable allocation of each step, sequentially performs lead precipitation, arsenic precipitation and iron precipitation on the electrowinning nickel anolyte, so that lead, arsenic and iron impurities in the electrowinning nickel anolyte can be removed in a timely and efficient manner, greatly shortening the impurity removal time, ensuring the timely supply of electrowinning solution, ensuring the smooth progress of the electrowinning reaction, and avoiding the reduction of production capacity due to the impurity removal process.

[0102] The applicant declares that the above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A method for removing impurities and recovering electrolytic nickel anolyte, characterized in that, The impurity removal and recovery method includes the following steps: (1) Take the first electrolytic nickel anolyte and mix it with liquid alkali, and obtain nickel hydroxide and filtrate through the first solid-liquid separation treatment. Evaporate the filtrate to obtain sodium sulfate; take the second electrolytic nickel anolyte and mix it with nickel source to obtain a mixed solution; (2) Mix the mixed solution obtained in step (1) with barium salt and perform lead removal treatment; (3) After adjusting the pH of the material obtained after lead removal treatment in step (2) with nickel hydroxide obtained in step (1), the arsenic removal solution is obtained. The arsenic removal solution is then mixed with polyferric sulfate for arsenic removal treatment. (4) Mix the material obtained after the arsenic removal treatment in step (3) with the oxidant to obtain the iron removal solution. Perform a second solid-liquid separation treatment on the iron removal solution to obtain the lead-arsenic-iron catholyte and iron-containing slag. Add sodium sulfate obtained in step (1) to the lead-arsenic-iron catholyte and reuse it in the nickel electrowinning process.

2. The method for removing impurities and recovering waste as described in claim 1, characterized in that, In step (1), the mass concentration of nickel ions in the first and second electrolytic nickel anolytes is independently 75 g / L to 85 g / L.

3. The method for removing impurities and recovering waste as described in claim 1, characterized in that, In step (1), the mass concentration of sodium sulfate in the first and second electrolytic nickel anolytes is independently 80 g / L to 100 g / L.

4. The method for removing impurities and recovering waste as described in claim 1, characterized in that, Step (1) The pH of the first electrolytic nickel anolyte and the second electrolytic nickel anolyte are independently 0 to 1.

5.

5. The method for removing impurities and recovering waste as described in claim 1, characterized in that, The mass concentration of the liquid alkali in step (1) is 30%~42%.

6. The method for removing impurities and recovering waste as described in claim 1, characterized in that, The molar ratio of sodium hydroxide in the liquid alkali in step (1) to nickel ions in the first electrolytic nickel anolyte is (2~2.2):

1.

7. The method for removing impurities and recovering waste as described in claim 1, characterized in that, The nickel source in step (1) includes nickel sulfate crystals and / or nickel sulfate solution.

8. The method for removing impurities and recovering waste as described in claim 7, characterized in that, The mass concentration of nickel ions in the nickel sulfate solution in step (1) is 100 g / L to 105 g / L.

9. The method for removing impurities and recovering waste as described in claim 7, characterized in that, The pH of the nickel sulfate solution in step (1) is 3.5~4.

5.

10. The method for removing impurities and recovering waste as described in claim 1, characterized in that, The mass concentration of nickel ions in the mixed solution in step (1) is 80 g / L to 90 g / L.

11. The method for removing impurities and recovering waste as described in claim 1, characterized in that, The mass concentration of sodium sulfate in the mixed solution in step (1) is 60 g / L to 85 g / L.

12. The method for removing impurities and recovering waste as described in claim 1, characterized in that, The pH of the mixed solution in step (1) is 0~2.

13. The method for removing impurities and recovering waste as described in claim 1, characterized in that, The barium salt mentioned in step (2) includes barium carbonate.

14. The method for removing impurities and recovering waste as described in claim 1, characterized in that, The mass-to-volume ratio of the barium salt to the mixed solution in step (2) is 0.1 g / L to 0.4 g / L.

15. The method for removing impurities and recovering waste as described in claim 1, characterized in that, The first stirring is carried out during the lead removal process described in step (2).

16. The method for removing impurities and recovering waste as described in claim 15, characterized in that, The first stirring time is 20 min to 40 min.

17. The method for removing impurities and recovering waste as described in claim 1, characterized in that, The temperature for lead removal in step (2) is 50℃~70℃.

18. The method for removing impurities and recovering waste as described in claim 1, characterized in that, The pH value in step (3) is 3.5 to 4.

5.

19. The method for removing impurities and recovering waste as described in claim 1, characterized in that, The mass concentration of nickel ions in the arsenic removal solution in step (3) is 100 g / L to 105 g / L.

20. The method for removing impurities and recovering waste as described in claim 1, characterized in that, The mass-to-volume ratio of the polyferric sulfate to the arsenic removal solution in step (3) is 0.3 g / L to 0.6 g / L.

21. The method for removing impurities and recovering waste as described in claim 1, characterized in that, In step (3), a second stirring is performed during the arsenic removal process.

22. The method for removing impurities and recovering waste as described in claim 21, characterized in that, The second stirring time is 20 min to 40 min.

23. The method for removing impurities and recovering waste as described in claim 1, characterized in that, The temperature for the arsenic removal treatment in step (3) is 50℃~70℃.

24. The method for removing impurities and recovering waste as described in claim 1, characterized in that, The oxidant in step (4) includes a hydrogen peroxide solution.

25. The method for removing impurities and recovering waste as described in claim 1, characterized in that, The volume ratio of the oxidant to the material obtained after arsenic removal treatment in step (4) is 10 mL / L to 20 mL / L.

26. The method for removing impurities and recovering waste as described in claim 24, characterized in that, The mass concentration of the hydrogen peroxide solution is 30%~42%.

27. The method for removing impurities and recovering waste as described in claim 1, characterized in that, The mass-to-volume ratio of sodium sulfate to lead, arsenic and iron-removing cathodic liquid in step (4) is 80 g / L to 100 g / L.

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