Impurity removal and recovery method for electrodeposited nickel anolyte

Abstract

The invention provides an impurity removal and recovery method of electrodeposited nickel anolyte, which comprises the following steps: (1) mixing the electrodeposited nickel anolyte with liquid caustic soda, carrying out solid-liquid separation to obtain nickel hydroxide and filtrate, and evaporating the filtrate to obtain sodium sulfate; mixing the electrodeposited nickel anolyte with a nickel source to obtain a mixed solution; (2) mixing the mixed solution with barium salt, and carrying out lead removal treatment; (3) adjusting the pH value of a material obtained after lead removal treatment by using nickel hydroxide to obtain a solution to be subjected to arsenic removal, and mixing the solution to be subjected to arsenic removal with polyferric sulfate for arsenic removal treatment; and (4) a material obtained after arsenic removal treatment is mixed with an oxidizing agent, a solution to be subjected to iron removal is obtained, solid-liquid separation treatment is conducted on the solution to be subjected to iron removal, catholyte with lead, arsenic and iron removed and iron-containing slag are obtained, sodium sulfate is supplemented into the catholyte with lead, arsenic and iron removed, and the catholyte is reused in the nickel electrodeposition process. According to the method, lead, arsenic and iron in the electrodeposited nickel anolyte can be efficiently and rapidly removed and recycled.

Description

Technical Field

[0001] The invention belongs to the technical field of nickel hydrometallurgy and relates to a method for removing impurities and recovering an electrodeposited nickel anode liquid. Background Art

[0002] Electrolytic nickel products are widely used in electroplating, batteries, high-temperature alloys and other fields. In order to make electrolytic nickel products better used in these special fields, the impurity content must be strictly controlled. Impurities are usually brought in by new electrolytic solution and anode plates. Replacing the anode plates with precious metal titanium coatings can effectively prevent the impurity problem caused by the anode plates. However, the precious metal titanium coating plates are expensive and have a short service life, which limits their industrial application.

[0003] At present, electrolytic nickel mainly uses multi-element alloy anode plates. The electrolytic process may introduce impurities such as lead, arsenic, and iron. Therefore, it is inevitable to mix the electrolytic raw solution and the anode effluent, remove impurities, and return them to electrolytic processing to obtain high-purity electrolytic nickel products.

[0004] CN117107341A discloses a method for regenerating and circulating an electrodeposited nickel anolyte, wherein the electrodeposited nickel anolyte is used in the stripping section of a nickel sulfate extraction and enrichment line to strip the nickel-loaded P507 extractant, specifically comprising: (1) a first stripping section: using the electrodeposited nickel anolyte to strip the nickel-loaded P507 extractant to obtain a first stripping phase and a first P507 organic phase; (2) a second stripping section: using an acid to strip the first P507 organic phase to obtain a second stripping phase and a second P507 organic phase; (3) electrolysis: detecting the impurity content in the first stripping phase, and when the impurity content meets the control standard, returning the second stripping phase to the first stripping section, mixing it with the electrodeposited nickel anolyte and using it together as the stripping agent for the first stripping section, and using the first stripping phase as the cathode liquid for the electrodeposited nickel to electrolyze nickel to obtain nickel and the electrodeposited nickel anolyte.

[0005] CN119194538A discloses a method for removing lead and replenishing nickel from an electrolytic nickel anode liquid, which comprises the following steps: adding the electrolytic anode liquid to a refined nickel sulfate deoiled liquid and a nickel carbonate slurry, introducing air, controlling the temperature, and entering an acid-soluble lead removal tank for acid dissolution. The acid-soluble liquid is then filtered through an acid-soluble filter press, the obtained primary filtrate is pumped into a precision filter, the obtained secondary filtrate enters a secondary filtrate storage tank, the secondary filtrate is pumped into a cathode liquid tank through a secondary filtrate delivery pump, and the obtained cathode liquid enters the electrolytic process as the cathode liquid of the electrolytic cell.

[0006] The above scheme takes a long time to remove impurities, requires high impurity removal efficiency and is a complicated process, which results in the returned electrolytic solution not being able to keep up with the electrolytic consumption, resulting in a decrease in production capacity and additional economic losses. Summary of the invention

[0007] The object of the present invention is to provide a method for removing impurities and recovering nickel electrodeposition anode liquid. The method of the present invention can efficiently and quickly remove lead, arsenic and iron in the nickel electrodeposition anode liquid, ensure the timely supply of the electrodeposition liquid, ensure the smooth progress of the electrodeposition reaction, and avoid the reduction of production capacity due to the impurity removal process.

[0008] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0009] In a first aspect, the present invention provides a method for removing impurities from an electrolytic nickel anolyte, the method comprising the following steps:

[0010] (1) mixing a first nickel electrolytic anolyte with liquid alkali, subjecting the mixture to a first solid-liquid separation treatment to obtain nickel hydroxide and a filtrate, and evaporating the filtrate to obtain sodium sulfate; mixing a second nickel electrolytic anolyte with a nickel source to obtain a mixed solution;

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

[0012] (3) using the nickel hydroxide obtained in step (1) to adjust the pH of the material obtained after the lead removal treatment in step (2) to obtain a solution to be de-arsenicized, and mixing the solution to be de-arsenicized with polyferric sulfate to perform de-arsenicization treatment;

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

[0014] The first solid-liquid separation treatment and the second solid-liquid separation treatment of the present invention are independently carried out by means of filter pressing, suction filtration or filtration, preferably filter pressing.

[0015] The electrolytic nickel anode liquid of the present invention is the anode liquid produced by the anode during the electrolytic nickel process. The first electrolytic nickel anode liquid and the second electrolytic nickel anode liquid of the present invention can be selected from the same electrolytic nickel anode liquid or different electrolytic nickel anode liquids, and there is no limitation on the amount or ratio of the two. The nickel hydroxide and sodium sulfate produced by the first electrolytic nickel anode liquid, if excessive, can be used in the impurity removal and recovery process of the electrolytic nickel anode liquid in the next process.

[0016] The impurity removal and recovery method of the electrolytic nickel anolyte of the present invention is reasonable in allocating each step, and the lead, arsenic and iron impurities in the electrolytic nickel anolyte are sequentially precipitated. The lead, arsenic and iron impurities in the electrolytic nickel anolyte can be removed in a timely and efficient manner, which greatly shortens the impurity removal time, ensures the timely supply of the electrolytic solution, ensures the smooth progress of the electrolytic reaction, and avoids the reduction of production capacity due to the impurity removal process. The impurity removal and recovery method of the present invention realizes cyclic production and achieves the purpose of removing impurities. During the period, no auxiliary materials required for electrolytic deposition such as sodium sulfate are lost, which is conducive to reducing production costs.

[0017] Preferably, in step (1), the mass concentration of nickel ions in the first and second nickel electrolytic anode liquids are 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., not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0018] Preferably, the mass concentration of sodium sulfate in the first and second nickel electrolytic anode liquids in step (1) 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., not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

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

[0020] Preferably, the mass concentration of the liquid caustic soda in step (1) is 30% to 42%, for example, 30%, 32%, 35%, 40% or 42%, etc., not limited to the listed values, and other values ​​not listed within the numerical 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 nickel electrolytic anode liquid is (2-2.2):1, for example: 2:1, 2.05:1, 2.1:1, 2.15:1 or 2.2:1, etc., not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0022] Preferably, the nickel source in step (1) comprises 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., not limited to the listed values, and other unlisted values ​​within the numerical 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., and is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0025] Preferably, the mass concentration of nickel ions in the mixed solution of 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., not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0026] Preferably, the mass concentration of sodium sulfate in the mixed solution of 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., not limited to the listed values, and other values ​​not listed within the numerical 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., and is not limited to the listed values. Other values ​​not listed within the range are also applicable.

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

[0029] Preferably, the mass 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., not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0030] Preferably, a first stirring is performed during the lead removal treatment 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, and other values ​​not listed within the numerical range are also applicable.

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

[0035] Preferably, the mass volume ratio of the polyferric sulfate in step (3) to the arsenic removal solution 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., not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0036] Preferably, a second stirring is performed during the arsenic removal treatment 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., and is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

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

[0039] Preferably, the oxidant in step (4) comprises 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 the numerical range are also applicable.

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

[0042] Preferably, the mass volume ratio of the sodium sulfate to the cathode liquid for removing lead, arsenic and iron in step (4) is 80g / L to 100g / L, for example: 80g / L, 85g / L, 90g / L, 95g / L or 100g / L, etc., not limited to the listed values, and other unlisted values ​​within the numerical 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 of the present invention can achieve rapid impurity removal during the nickel electrolytic deposition process, allowing the electrolytic solution to flow more quickly, reducing concentration polarization and ensuring a stable and high liquid level difference between the cathode and the anode, effectively preventing hydrogen ions from migrating to the cathode and thus increasing the holes in the nickel plate. At the same time, the rapid flow of the electrolytic solution can effectively avoid the accumulation of impurities in the electrolytic deposition tank, thereby reducing the precipitation of impurities at the cathode and improving the product quality of the electrolytic nickel.

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

[0046] (3) The impurity removal and recovery method of the electrolytic nickel anode liquid of the present invention can obtain a lead mass concentration in the cathode liquid of less than 1.9 mg / L, while the arsenic mass concentration can be less than 0.2 mg / L and the iron mass concentration can be less than 1.9 mg / L. By adjusting the amount of material added during the recovery process, the lead mass concentration in the cathode liquid can be less than 1.3 mg / L, while the arsenic mass concentration can be less than 0.1 mg / L and the iron mass concentration can be less than 1.2 mg / L. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 The present invention is a schematic diagram of the process flow of the method for removing impurities and recovering the electrolytic nickel anode liquid provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0048] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

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

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

[0051] Example 1

[0052] This embodiment provides a method for removing impurities and recovering nickel anode liquid. The process flow chart of the method is as follows: Figure 1 As shown, the impurity removal and recovery method comprises the following steps:

[0053] (1) Take the nickel electrodeposition anolyte and mix it with 35% liquid caustic soda (OH - The molar ratio of Ni in the nickel electrodeposition anolyte is 2:1), and nickel hydroxide and a filtrate are obtained by filter pressing, and the filtrate is evaporated to obtain sodium sulfate, and the nickel electrodeposition anolyte is 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) mixing barium carbonate with the mixed solution at 60° C. to obtain a barium carbonate mass concentration of 0.1 g / L in the solution, and stirring to remove lead for 30 minutes;

[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, the mass concentration of the polyferric sulfate was 0.3 g / L, and the arsenic was removed by stirring for 30 minutes;

[0056] (4) At 60° C., a hydrogen peroxide solution with a mass concentration of 30% is added to the material obtained after the arsenic removal treatment to obtain a solution to be iron-removed, the volume ratio of the hydrogen peroxide solution to the material obtained after the arsenic removal treatment is 10 mL / L, and after stirring for 30 minutes, the solution is subjected to filter press treatment to obtain a cathode liquid for removing lead, arsenic and iron and an iron-containing slag, and the sodium sulfate obtained in step (1) is added to the cathode liquid for removing lead, arsenic and iron, the concentration of the sodium sulfate is 90 g / L, and the solution is reused in the nickel electrowinning process.

[0057] Example 2

[0058] This embodiment provides a method for removing impurities and recovering nickel anode liquid. The process flow chart of the method is as follows: Figure 1 As shown, the impurity removal and recovery method comprises the following steps:

[0059] (1) Take the nickel electrodeposition anolyte and mix it with 35% liquid caustic soda (OH -The molar ratio of Ni in the nickel electrodeposition anolyte is 2.2:1), and nickel hydroxide and a filtrate are obtained by filter pressing, and the filtrate is evaporated to obtain sodium sulfate, and the nickel electrodeposition anolyte is 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) mixing barium carbonate with the mixed solution at 70° C. to obtain a mass concentration of barium carbonate in the solution of 0.4 g / L, and stirring to remove lead for 40 minutes;

[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, the mass concentration of the polyferric sulfate was 0.6 g / L, and the arsenic was removed by stirring for 30 minutes;

[0062] (4) At 70° C., a hydrogen peroxide solution with a mass concentration of 35% is added to the material obtained after the arsenic removal treatment to obtain a solution to be deironized, wherein the volume ratio of the hydrogen peroxide solution to the material obtained after the arsenic removal treatment is 20 mL / L. After stirring for 30 minutes, the solution is subjected to filter press treatment to obtain a cathode liquid for removing lead, arsenic and iron and an iron-containing slag. The sodium sulfate obtained in step (1) is added to the cathode liquid for removing lead, arsenic and iron, and the sodium sulfate concentration is 100 g / L, which is then reused in the nickel electrowinning process.

[0063] Example 3

[0064] This embodiment provides a method for removing impurities and recovering nickel anode liquid. The process flow chart of the method is as follows: Figure 1 As shown, the impurity removal and recovery method comprises the following steps:

[0065] (1) Take the nickel electrodeposition anolyte and mix it with a liquid caustic soda with a mass concentration of 42% (OH - The molar ratio of Ni in the nickel electrodeposition anolyte is 2.1:1), and nickel hydroxide and a filtrate are obtained by filter pressing, and the filtrate is evaporated to obtain sodium sulfate, and the nickel electrodeposition anolyte is 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) mixing barium carbonate with the mixed solution at 50° C. to obtain a mass concentration of barium carbonate in the solution of 0.3 g / L, and stirring to remove lead for 40 minutes;

[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, the mass concentration of the polyferric sulfate was 0.6 g / L, and the arsenic was removed by stirring for 30 minutes;

[0068] (4) At 50° C., a hydrogen peroxide solution with a mass concentration of 42% is added to the material obtained after the arsenic removal treatment to obtain a solution to be deironized, wherein the volume ratio of the hydrogen peroxide solution to the material obtained after the arsenic removal treatment is 20 mL / L. After stirring for 30 minutes, the solution is subjected to filter press treatment to obtain a cathode liquid for removing lead, arsenic and iron and an iron-containing slag. The sodium sulfate obtained in step (1) is added to the cathode liquid for removing lead, arsenic and iron, and the sodium sulfate concentration is 80 g / L, which is then reused in the nickel electrowinning process.

[0069] Example 4

[0070] This embodiment provides a method for removing impurities and recovering nickel anode liquid. The process flow chart of the method is as follows: Figure 1 As shown, the impurity removal and recovery method comprises the following steps:

[0071] (1) Take the nickel electrodeposition anolyte and mix it with 35% liquid caustic soda (OH - The molar ratio of Ni in the nickel electrodeposition anolyte is 2:1), and nickel hydroxide and a filtrate are obtained by filter pressing, and the filtrate is evaporated to obtain sodium sulfate, and the nickel electrodeposition anolyte is 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) mixing barium carbonate with the mixed solution at 60° C. to obtain a mass concentration of barium carbonate in the solution of 0.4 g / L, and stirring to remove lead for 30 minutes;

[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, the mass concentration of the polyferric sulfate was 0.6 g / L, and the arsenic was removed by stirring for 30 minutes;

[0074] (4) At 60° C., a hydrogen peroxide solution with a mass concentration of 32% is added to the material obtained after the arsenic removal treatment to obtain a solution to be deironized, wherein the volume ratio of the hydrogen peroxide solution to the material obtained after the arsenic removal treatment is 20 mL / L. After stirring for 30 minutes, the solution is subjected to filter press treatment to obtain a cathode liquid for removing lead, arsenic and iron and an iron-containing slag. The sodium sulfate obtained in step (1) is added to the cathode liquid for removing lead, arsenic and iron, and the sodium sulfate concentration is 90 g / L, which is then recycled to the nickel electrowinning process.

[0075] Example 5

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

[0077] Example 6

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

[0079] Example 7

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

[0081] Example 8

[0082] The only difference between this embodiment and embodiment 1 is that the mass concentration of polyferric sulfate is 0.7 g / L, and other conditions and parameters are exactly the same as those in embodiment 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 deironed is 5 mL / L, and the other conditions and parameters are exactly the same as those 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 deironed is 30 mL / L, and the other conditions and parameters are exactly the same as those in embodiment 1.

[0087] Comparative Example 1

[0088] The only difference between this comparative example and Example 1 is that polyferric sulfate is added first to remove arsenic and then barium carbonate is added to remove lead. Other conditions and parameters are exactly the same as those in Example 1.

[0089] Comparative Example 2

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

[0091] Comparative Example 3

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

[0093] Performance Testing:

[0094] The mass concentrations of lead, arsenic and iron in the cathode liquid for lead, arsenic and iron removal were tested. The test 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 can be seen from Table 1, from Examples 1-10, the impurity removal and recovery method for the electrolytic nickel anode liquid of the present invention can obtain a lead mass concentration in the cathode liquid of less than 1.9 mg / L, while the arsenic mass concentration can reach less than 0.2 mg / L, and the iron mass concentration can reach less than 1.9 mg / L. By adjusting the amount of material added during the recovery process, the lead mass concentration in the cathode liquid can reach less than 1.3 mg / L, while the arsenic mass concentration can reach less than 0.1 mg / L, and the iron mass concentration can reach less than 1.2 mg / L.

[0098] By comparing Example 1 with Examples 5-6, it can be seen that in the impurity removal and recovery process of the electrolytic nickel anode liquid of the present invention, the addition amount of the barium salt will affect the impurity removal and recovery effect. When the addition amount of the barium salt is controlled at 0.1g / L to 0.4g / L, the lead impurity removal effect is better. If the addition amount of the barium salt is too large, the gain is not obvious compared with the lead removal effect of 0.4g / L. If the addition amount of the barium salt is too small, the lead removal effect is not significant.

[0099] By comparing Example 1 with Examples 7-8, it can be seen that in the impurity removal and recovery process of the electrolytic nickel anode liquid of the present invention, the addition amount of polyferric sulfate will affect the impurity removal and recovery effect. When the addition amount of polyferric sulfate is controlled at 0.3g / L to 0.6g / L, the impurity removal effect of arsenic is better. If the addition amount of polyferric sulfate is too large, the gain compared with the arsenic removal effect of 0.6g / L is not obvious. If the addition amount of polyferric sulfate is too small, the arsenic removal effect is not significant.

[0100] By comparing Example 1 with Examples 9-10, it can be seen that in the impurity removal and recovery process of the electrolytic nickel anode liquid of the present invention, the amount of the oxidant (hydrogen peroxide) added will affect the impurity removal and recovery effect. When the amount of the oxidant added is controlled at 10mL / L to 20mL / L, the iron impurity removal effect is better. If the amount of the oxidant added is too large, the gain compared to the iron removal effect of 20ml / L is not obvious. If the amount of the oxidant added is too small, the iron removal effect is not significant.

[0101] By comparing Example 1 with Comparative Examples 1-3, it can be seen that in the impurity removal and recovery method of the present invention, barium carbonate can achieve better results in lead removal within a relatively low pH range, so it is added before adjusting the pH; and polyferric sulfate has a better arsenic removal effect under more neutral conditions, so it is added after adjusting the pH; and finally, hydrogen peroxide is added to remove iron in order to give sufficient reaction time for arsenic removal 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 removal and iron removal effects. The impurity removal and recovery method of the electrolytic nickel anolyte of the present invention is reasonably allocated through each step, and the electrolytic nickel anolyte is sequentially precipitated with lead, arsenic and iron, and the lead, arsenic and iron impurities in the electrolytic nickel anolyte can be removed in a timely and efficient manner, which greatly shortens the impurity removal time, ensures the timely supply of the electrolytic solution, ensures the smooth progress of the electrolytic reaction, and avoids the reduction of production capacity due to the impurity removal process.

[0102] The applicant declares that the above is only a specific implementation mode 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 thought of by those skilled in the art within the technical scope disclosed by the present invention shall fall within the protection scope and disclosure scope of the present invention.

Claims

1. A method for removing impurities and recovering nickel electrodeposition anolyte, characterized in that: The impurity removal and recovery method comprises the following steps: (1) mixing a first nickel electrolytic anolyte with liquid alkali, subjecting the mixture to a first solid-liquid separation treatment to obtain nickel hydroxide and a filtrate, and evaporating the filtrate to obtain sodium sulfate; mixing a second nickel electrolytic anolyte with a nickel source to obtain a mixed solution; (2) mixing the mixed solution obtained in step (1) with a barium salt to perform lead removal treatment; (3) using the nickel hydroxide obtained in step (1) to adjust the pH of the material obtained after the lead removal treatment in step (2) to obtain a solution to be de-arsenicized, and mixing the solution to be de-arsenicized with polyferric sulfate to perform de-arsenicization treatment; (4) The material obtained after the arsenic removal treatment in step (3) is mixed with an oxidant to obtain a solution to be de-ironized, and the solution to be de-ironized is subjected to a second solid-liquid separation treatment to obtain a cathode liquid for removing lead, arsenic and iron and iron-containing slag, and the sodium sulfate obtained in step (1) is added to the cathode liquid for removing lead, arsenic and iron, and the solution is reused in the nickel electrowinning process.

2. The impurity removal and recovery method according to claim 1, characterized in that: Step (1) the mass concentration of nickel ions in the first and second nickel electrolytic anode solutions is independently 75 g / L to 85 g / L; Preferably, in step (1), the mass concentration of sodium sulfate in the first nickel electrodeposition anolyte and the second nickel electrodeposition anolyte is independently 80 g / L to 100 g / L; Preferably, in step (1), the pH of the first and second nickel electrolytic anode solutions are independently between 0 and 1.

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3. The impurity removal and recovery method according to claim 1 or 2, characterized in that: The mass concentration of the liquid caustic soda in step (1) is 30% to 42%; Preferably, the molar ratio of sodium hydroxide in the liquid alkali in step (1) to nickel ions in the first nickel electrolytic anode liquid is (2-2.2):

1.

4. The impurity removal and recovery method according to any one of claims 1 to 3, characterized in that: The nickel source in step (1) comprises nickel sulfate crystals and / or nickel sulfate solution; Preferably, the mass concentration of nickel ions in the nickel sulfate solution in step (1) is 100 g / L to 105 g / L; Preferably, the pH of the nickel sulfate solution in step (1) is 3.5 to 4.5; Preferably, the mass concentration of nickel ions in the mixed solution of step (1) is 80 g / L to 90 g / L; Preferably, the mass concentration of sodium sulfate in the mixed solution of step (1) is 60 g / L to 85 g / L; Preferably, the pH of the mixed solution in step (1) is 0-2.

5. The impurity removal and recovery method according to any one of claims 1 to 4, characterized in that: The barium salt in step (2) comprises barium carbonate; Preferably, the mass volume ratio of the barium salt to the mixed solution is 0.1 g / L to 0.4 g / L.

6. The impurity removal and recovery method according to any one of claims 1 to 5, characterized in that: During the lead removal process in step (2), a first stirring is performed; Preferably, the first stirring time is 20 min to 40 min; Preferably, the temperature of the lead removal treatment in step (2) is 50°C to 70°C.

7. The impurity removal and recovery method according to any one of claims 1 to 6, characterized in that: The pH of step (3) is 3.5 to 4.5; Preferably, the mass concentration of nickel ions in the arsenic removal solution in step (3) is 100 g / L to 105 g / L; Preferably, the mass volume ratio of the polyferric sulfate in step (3) to the solution to be arsenic removed is 0.3 g / L to 0.6 g / L.

8. The impurity removal and recovery method according to any one of claims 1 to 7, characterized in that: During the arsenic removal treatment in step (3), a second stirring is performed; Preferably, the second stirring time is 20 min to 40 min; Preferably, the temperature of the arsenic removal treatment in step (3) is 50°C to 70°C.

9. The impurity removal and recovery method according to any one of claims 1 to 8, characterized in that: The oxidant in step (4) comprises a hydrogen peroxide solution; 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; Preferably, the mass concentration of the hydrogen peroxide solution is 30% to 42%.

10. The impurity removal and recovery method according to any one of claims 1 to 8, characterized in that: The mass volume ratio of the sodium sulfate to the cathode liquid for removing lead, arsenic and iron in step (4) is 80g / L to 100g / L.

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