A method for removing heavy metal ions from a manganese sulfate solution

Abstract

The present application relates to electrolytic manganese technology field, specifically to a kind of method for removing heavy metal ions in manganese sulfate solution.The method for removing heavy metal ions in manganese sulfate solution provided by the present application includes the following steps: adding oxidizing agent to pretreated manganese sulfate solution, mixing and stirring, then adjusting the pH value of solution to 5.5-6.0, filtering, to obtain the first purified manganese sulfate solution;Add sulfidation agent to the first purified manganese sulfate solution, filter, to obtain the second purified manganese sulfate solution;Add porous resin polymer to the second purified manganese sulfate solution, add the mixed solution into a sealed container, introduce nitrogen, make the pressure in the sealed container reach 1.1-1.5MPa and maintain for 2-10min, then open the air valve and release pressure instantaneously, stand, filter, fine filter, to obtain the purified manganese sulfate solution.The method provided by the present application can not only effectively remove heavy metal ions in solution, but also effectively reduce the COD value of the purified solution, reduce the loss of manganese content in solution.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electrolytic manganese, in particular to a method for removing heavy metal ions in manganese sulfate solution. BACKGROUND

[0002] Electrolytic manganese has a wide range of applications, which can be used to increase alloy hardness and is widely used in steel smelting, non-ferrous metallurgy, battery materials, semiconductor materials and other fields. Electrolytic manganese is generally obtained by leaching manganese ore with acid to obtain manganese salt, and then electrolyzing the manganese salt to obtain elemental metal. In the production process of electrolytic manganese, in order to improve the electrolytic current efficiency of manganese and ensure the quality of electrolytic manganese and manganese salt products, it is necessary to purify the electrolytic manganese sulfate solution to remove heavy metals and impurities in the solution.

[0003] At present, most domestic electrolytic manganese production plants generally use sulfuric acid to directly leach manganese ore powder. The leaching solution obtained contains low-valence iron, heavy metal ions and organic impurities. Before being used for electrolytic manganese solution, the related impurities need to be purified. Generally, an oxidizing agent or air blowing is added to the mixed solution to remove iron, and then a sulfidizing agent is added after the iron removal is completed. The heavy metal ions (cobalt, nickel, etc.) are converted into insoluble sulfides, thereby achieving the purposes of impurity removal and solution purification. However, although the existing process has good iron and heavy metal removal effect, it is difficult to achieve good removal of organic impurities in the solution. For the removal of organic impurities in the solution, the existing process generally uses porous resin or activated carbon for adsorption. However, the existing porous resin will partially adsorb manganese ions in the solution while adsorbing organic impurities, resulting in a decrease in the manganese content of the solution. SUMMARY

[0004] In order to overcome the defects of the existing manganese sulfate solution purification process that the removal effect of organic impurities in the solution is limited and the manganese content of the solution is easily reduced, a new method for removing heavy metal ions in manganese sulfate solution is provided. The method can effectively remove heavy metal ions in the solution while effectively reducing the COD value of the purified solution and reducing the loss of manganese content in the solution.

[0005] To achieve the above purpose, the technical scheme adopted by the present application is as follows:

[0006] A method for removing heavy metal ions in manganese sulfate solution, comprising the following steps:

[0007] 1) adding an oxidizing agent to the pretreated manganese sulfate solution and mixing and stirring, then adjusting the pH value of the solution to 5.5-6.0, filtering, and obtaining a first purified manganese sulfate solution;

[0008] 2) adding a sulfidizing agent to the first purified manganese sulfate solution, filtering, and obtaining a second purified manganese sulfate solution;

[0009] 3) adding the porous resin polymer into the secondly purified manganese sulfate solution, adding the mixture into a closed container, passing nitrogen into the closed container, making the pressure in the closed container reach 1.1-1.5 MPa and maintaining for 2-10 min, then opening the air valve to instantaneously release the pressure, standing, filtering, fine filtering, and obtaining the purified manganese sulfate solution.

[0010] Preferably, the preparation method of the porous resin polymer comprises the following steps:

[0011] a) mixing the aqueous manganese sulfate solution and the terephthalic acid methanol solution, then heating the mixture to react, after the reaction is completed, concentrating, washing, and drying the reaction solution to obtain the manganese metal organic framework;

[0012] b) mixing the ethyl methacrylate, the polyvinyl alcohol, the manganese metal organic framework, the divinylbenzene, the foaming agent, the initiator, and the solvent, heating the mixture to react, after the reaction is completed, cooling, filtering, washing, and drying to obtain the porous resin polymer.

[0013] Preferably, the concentration of the aqueous manganese sulfate solution is 1-3 mol / L, and the concentration of the terephthalic acid methanol solution is 1-3 mol / L.

[0014] In step a), the molar ratio of the manganese sulfate to the terephthalic acid in the mixture is 1:(2-2.2).

[0015] Preferably, in step a), the heating reaction temperature is 85-95 ℃, and the reaction time is 3-6 h.

[0016] In step a), water and methanol are used for the washing step.

[0017] Preferably, in step b), the mass ratio of the ethyl methacrylate, the polyvinyl alcohol, the manganese metal organic framework, the divinylbenzene, the foaming agent, the initiator, and the solvent is (38-42):(15-25):(6-7):(4-5):(2-5):(1-3):(150-250).

[0018] Preferably, in step b), the solvent is water and toluene, and the mass ratio of the water to the toluene is (2-4):1.

[0019] The foaming agent is selected from one of ethyl acetate, n-pentane, and n-butane.

[0020] The initiator is selected from azobisisobutyronitrile.

[0021] Preferably, in step b), the heating reaction temperature is 75-85 ℃, and the reaction time is 5-10 h.

[0022] In step b), methanol and hot water at 60-70 ℃ are used for the washing step.

[0023] Preferably, the oxidant in step 1) is selected from a hydrogen peroxide solution, and the concentration of the hydrogen peroxide solution is 30-40%.

[0024] The ratio of the amount of substance of hydrogen peroxide added in the hydrogen peroxide solution to the amount of substance of iron in the pretreated manganese sulfate solution is (1-1.2):1.

[0025] The stirring time in step 1) is 1-3h.

[0026] In step 1), sodium hydroxide is used to adjust the pH value of the solution to 5.5-6.0.

[0027] Preferably,

[0028] The sulfidizing agent in step 2) is selected from at least one of sodium sulfide, ammonium sulfide, barium sulfide, and thiram.

[0029] In step 2), the content of Co, Ni, and Pb in the solution is reduced to Co≤3ppm, Ni≤3ppm, and Pb≤3ppm, respectively, by adding the sulfidizing agent.

[0030] Preferably,

[0031] The amount of the porous resin polymer added in step 3) is 1-8% of the mass of the pretreated manganese sulfate solution.

[0032] The standing time in step 3) is 1-3h.

[0033] The fine filtration step is performed using a GOR fine filter.

[0034] The pretreated manganese sulfate solution in the present application can be a leaching solution formed by mixing manganese ore and sulfuric acid. Alternatively, the element content in the pretreated manganese sulfate solution includes Mn: 20-30g / L, Ni: 6-7g / L, Co: 5-6g / L, Pb: 3-4g / L, Fe: 3-4g / L, and CODcr: 1-3g / L.

[0035] Alternatively, selenium dioxide can be added to the purified manganese sulfate solution. Alternatively, the filter residue bottom stream obtained after fine filtration can be returned to step 2) for use as a crystal seed.

[0036] The beneficial effects of the present application are:

[0037] The method for removing heavy metal ions from manganese sulfate solution provided by this invention involves adding an oxidizing agent and a sulfiding agent to remove iron and heavy metals from the solution, followed by adding a porous resin polymer obtained through a specific preparation method to the pre-purified solution. Then, mixing and adsorption are carried out through a pressurized-instantaneous depressurization gas explosion method, which effectively reduces the CODcr content of the purified manganese sulfate solution. Furthermore, during the preparation of the porous resin polymer, metallic manganese is introduced into the porous resin constructed from ethyl methacrylate, polyvinyl alcohol, and divinylbenzene via terephthalic acid linkage, which effectively weakens the adsorption of manganese ions in the solution. Simultaneously, a network structure is formed in the porous resin, further enhancing the adsorption effect on CODcr. The method provided by this invention not only effectively removes heavy metal ions from the solution but also effectively reduces the COD value of the purified solution and minimizes the loss of manganese content. Detailed Implementation

[0038] The following embodiments are provided to better understand the present invention and are not limited to the preferred embodiments described. They do not constitute a limitation on the content and scope of protection of the present invention. Any product that is the same as or similar to the present invention, derived by any person under the guidance of the present invention or by combining the features of the present invention with other prior art, falls within the protection scope of the present invention.

[0039] For experiments not specifically described in the examples, the procedures or conditions should be followed according to the conventional experimental procedures described in the literature in this field. Reagents or instruments whose manufacturers are not specified are all commercially available conventional reagent products.

[0040] The polyvinyl alcohol used in the following examples and comparative examples of this invention is model 1788, purchased from Shanghai Kee Chemical Technology Co., Ltd.

[0041] The elemental contents of the pretreated manganese sulfate solutions used in the following examples and comparative examples include: Mn: 25.6 g / L, Ni: 6.7 g / L, Co: 5.2 g / L, Pb: 3.1 g / L, Fe: 3.4 g / L, CODcr: 1.9 g / L.

[0042] Example 1

[0043] This embodiment provides a method for removing heavy metal ions from manganese sulfate solution, including the following steps:

[0044] 1) Add 30% hydrogen peroxide solution to 1 kg of pretreated manganese sulfate solution and stir for 1 h. The ratio of the amount of hydrogen peroxide added to the amount of iron in the pretreated manganese sulfate solution is 1:1. Then add sodium hydroxide to adjust the pH of the solution to 5.8. Filter to obtain the first purified manganese sulfate solution (Fe≤1mg / L) and filter residue.

[0045] 2) To the first purified manganese sulfate solution, sodium sulfide is added to make the contents of Co, Ni, Pb to be: Co≤3ppm, Ni≤3ppm, Pb≤3ppm, and then filtered to obtain a second purified manganese sulfate solution and a sulfidation residue;

[0046] 3) To the second purified manganese sulfate solution, a porous resin polymer is added (the amount of the porous resin polymer added is 5% of the mass of the pretreated manganese sulfate solution), the mixture is introduced into a steam explosion cylinder, nitrogen is introduced to make the pressure in the steam explosion cylinder reach 1.2 MPa and maintain for 5 min, then the vent valve is opened for instantaneous pressure relief, and then the mixture is filtered, the filtrate is refined by a Gao filter to obtain a purified manganese sulfate solution (Mn 2+ concentration 37.2 g / L, CODcr content 3.2 mg / L).

[0047] The preparation method of the porous resin polymer comprises the following steps:

[0048] a) 100 mL of 1 mol / L manganese sulfate aqueous solution and 200 mL of 1 mol / L terephthalic acid methanol solution are mixed, and then the mixture is heated to 90°C for 5 h, after the reaction is completed, the reaction solution is concentrated, washed with water and methanol respectively, and dried to obtain a manganese metal organic framework;

[0049] b) 40 g of ethyl methacrylate, 20 g of polyvinyl alcohol, 6.5 g of manganese metal organic framework, 4.5 g of divinylbenzene, 3.0 g of ethyl acetate, 2.0 g of azobisisobutyronitrile, 150 g of water and 50 g of toluene are mixed, the mixture is heated to 78°C for 8 h, after the reaction is completed, the mixture is cooled to room temperature, filtered, the filter cake is washed with methanol and 60°C hot water in sequence, dried and then broken to obtain the porous resin polymer.

[0050] Example 2

[0051] The embodiment provides a method for removing heavy metal ions in a manganese sulfate solution, comprising the following steps:

[0052] 1) To 1 kg of pretreated manganese sulfate solution, a hydrogen peroxide solution with a concentration of 40% is added and mixed and stirred for 1.5 h, the ratio of the amount of substance of hydrogen peroxide in the hydrogen peroxide solution to the amount of substance of iron in the pretreated manganese sulfate solution is 1:1, then sodium hydroxide is added to adjust the pH value of the solution to 5.8, and then filtered to obtain a first purified manganese sulfate solution (Fe≤1 mg / L) and a filter residue;

[0053] 2) To the first purified manganese sulfate solution, sodium sulfide is added to make the contents of Co, Ni, Pb to be: Co≤3ppm, Ni≤3ppm, Pb≤3ppm, and then filtered to obtain a second purified manganese sulfate solution and a sulfidation residue;

[0054] 3) adding porous resin polymer into the secondly purified manganese sulfate solution (the adding amount of the porous resin polymer is 6% of the mass of the pretreated manganese sulfate solution), passing the mixed solution into a steam explosion cylinder, passing nitrogen, making the pressure in the steam explosion cylinder reach 1.2 MPa and maintaining for 8 min, then opening the air valve to instantaneously release the pressure, standing for 1.5 h, then filtering the mixed solution, using a Gao filter to fine filter the filtrate, to obtain the purified manganese sulfate solution (Mn 2+ concentration 37.1 g / L, CODcr content 3.0 mg / L).

[0055] The preparation method of the porous resin polymer comprises the following steps:

[0056] a) mixing 100 mL of 1 mol / L manganese sulfate aqueous solution and 200 mL of 1 mol / L terephthalic acid methanol solution, then heating the mixed solution to 95℃ for 5 h, after the reaction, concentrating the reaction solution, washing with water and methanol respectively, and drying to obtain a manganese metal organic framework;

[0057] b) mixing 40 g of ethyl methacrylate, 22 g of polyvinyl alcohol, 6.8 g of manganese metal organic framework, 4.5 g of divinylbenzene, 3.0 g of ethyl acetate, 2.2 g of azobisisobutyronitrile, 150 g of water and 50 g of toluene, heating the mixed solution to 78℃ for 9 h, after the reaction, cooling to room temperature, filtering, washing the filter cake with methanol and 60℃ hot water in sequence, drying and crushing to obtain the porous resin polymer.

[0058] Example 3

[0059] The embodiment provides a method for removing heavy metal ions in a manganese sulfate solution, comprising the following steps:

[0060] 1) adding a hydrogen peroxide solution with a concentration of 30% into 1 kg of pretreated manganese sulfate solution, mixing and stirring for 1.2 h, the ratio of the amount of substance of hydrogen peroxide in the hydrogen peroxide solution to the amount of substance of iron in the pretreated manganese sulfate solution is 1:1, then adding sodium hydroxide to adjust the pH value of the solution to 5.9, and filtering to obtain a firstly purified manganese sulfate solution (Fe≤1 mg / L) and filter residue;

[0061] 2) adding sodium sulfide into the firstly purified manganese sulfate solution, so that the contents of Co, Ni and Pb are respectively Co≤3 ppm, Ni≤3 ppm and Pb≤3 ppm, then filtering to obtain a secondly purified manganese sulfate solution and sulfidation residue;

[0062] 3) Add porous resin polymer (7% of the mass of the pretreated manganese sulfate solution) to the second purified manganese sulfate solution. Pass the mixture into a vapor explosion cylinder, introduce nitrogen gas, and maintain the pressure inside the cylinder at 1.2 MPa for 7 minutes. Then, open the vent valve to release the pressure momentarily. Let it stand for 1.0 h, then filter the mixture. Use a Gore filter to further filter the filtrate to obtain the purified manganese sulfate solution (Mn). 2+ The concentration was 36.9 g / L, and the CODcr content was 2.9 mg / L.

[0063] The preparation method of the porous resin polymer includes the following steps:

[0064] a) Mix 100 mL of 1 mol / L manganese sulfate aqueous solution and 200 mL of 1 mol / L terephthalic acid methanol solution, then heat the mixture to 95 °C and react for 6 h. After the reaction is completed, concentrate the reaction solution, wash with water and methanol respectively, and dry to obtain manganese metal-organic framework.

[0065] b) Mix 42g ethyl methacrylate, 25g polyvinyl alcohol, 7.0g manganese metal-organic framework, 4.8g divinylbenzene, 3.0g ethyl acetate, 2.2g azobisisobutyronitrile, 150g water and 50g toluene. Heat the mixture to 78°C and react for 8 hours. After the reaction is complete, cool to room temperature, filter, and wash the filter cake successively with methanol and hot water at 60°C. After drying, crush to obtain the porous resin polymer.

[0066] Example 4

[0067] This embodiment provides a method for removing heavy metal ions from manganese sulfate solution, including the following steps:

[0068] 1) Add 30% hydrogen peroxide solution to 1 kg of pretreated manganese sulfate solution and stir for 1.2 h. The ratio of the amount of hydrogen peroxide added to the amount of iron in the pretreated manganese sulfate solution is 1:1. Then add sodium hydroxide to adjust the pH of the solution to 5.6. Filter to obtain the first purified manganese sulfate solution (Fe≤1mg / L) and filter residue.

[0069] 2) Add sodium sulfide to the first purified manganese sulfate solution to make the contents of Co, Ni and Pb reach: Co≤3ppm, Ni≤3ppm, Pb≤3ppm respectively. Then filter to obtain the second purified manganese sulfate solution and sulfide residue.

[0070] 3) Add porous resin polymer (4% of the mass of the pretreated manganese sulfate solution) to the second purified manganese sulfate solution. Pass the mixture into a vapor explosion cylinder, introduce nitrogen gas, and maintain the pressure in the cylinder at 1.2 MPa for 7 minutes. Then, open the vent valve to release the pressure momentarily. Let it stand for 1.0 h, then filter the mixture. Use a Gore filter to further filter the filtrate to obtain the purified manganese sulfate solution (Mn). 2+ The concentration was 37.5 g / L, and the CODcr content was 3.3 mg / L.

[0071] The preparation method of the porous resin polymer includes the following steps:

[0072] a) Mix 100 mL of 1 mol / L manganese sulfate aqueous solution and 200 mL of 1 mol / L terephthalic acid methanol solution, then heat the mixture to 95 °C and react for 6 h. After the reaction is completed, concentrate the reaction solution, wash with water and methanol respectively, and dry to obtain manganese metal-organic framework.

[0073] b) Mix 40g ethyl methacrylate, 22g polyvinyl alcohol, 6.4g manganese metal-organic framework, 4.5g divinylbenzene, 2.5g ethyl acetate, 2.2g azobisisobutyronitrile, 150g water and 50g toluene. Heat the mixture to 78°C and react for 8 hours. After the reaction is complete, cool to room temperature, filter, and wash the filter cake successively with methanol and hot water at 60°C. After drying, crush to obtain the porous resin polymer.

[0074] Comparative Example 1

[0075] This comparative example provides a method for removing heavy metal ions from a manganese sulfate solution. The difference from Example 1 is that in step 3), a porous resin polymer is added to the second-purified manganese sulfate solution (the amount of porous resin polymer added is 5% of the mass of the pretreated manganese sulfate solution). The mixture is stirred at 800 rpm for 1 hour, filtered, and the filtrate is further filtered using a Gore filter to obtain a purified manganese sulfate solution (Mn). 2+ The concentration was 32.1 g / L, and the CODcr content was 18.9 mg / L.

[0076] Comparative Example 2

[0077] This comparative example provides a method for removing heavy metal ions from manganese sulfate solution. The difference between this method and Example 1 lies in the preparation method of the porous resin polymer, which includes the following steps: 40g of ethyl methacrylate, 20g of polyvinyl alcohol, 4.5g of divinylbenzene, 3.0g of ethyl acetate, 2.0g of azobisisobutyronitrile, 150g of water, and 50g of toluene are mixed. The mixture is heated to 78°C and reacted for 8 hours. After the reaction, it is cooled to room temperature, filtered, and the filter cake is washed successively with methanol and hot water at 60°C. After drying, it is crushed to obtain the porous resin polymer. The final purified manganese sulfate solution contains Mn... 2+ The concentration was 34.4 g / L, and the CODcr content was 8.1 mg / L.

[0078] Comparative Example 3

[0079] This comparative example provides a method for removing heavy metal ions from manganese sulfate solution. The difference between this method and Example 1 lies in the preparation method of the porous resin polymer, which includes the following steps: 40g ethyl methacrylate, 20g polyvinyl alcohol, 6.5g manganese sulfate, 4.5g divinylbenzene, 3.0g ethyl acetate, 2.0g azobisisobutyronitrile, 150g water, and 50g toluene are mixed. The mixture is heated to 78°C and reacted for 8 hours. After the reaction, it is cooled to room temperature, filtered, and the filter cake is washed successively with methanol and hot water at 60°C. After drying, it is crushed to obtain the porous resin polymer. The final purified manganese sulfate solution contains Mn... 2+ The concentration was 34.9 g / L, and the CODcr content was 6.4 mg / L.

[0080] In summary, the porous resin polymer obtained by the present invention, after being mixed with a manganese sulfate solution using a specific preparation method, is subjected to a gas explosion-like mixing and adsorption process involving pressurization and instantaneous depressurization. This effectively reduces the CODcr content of the purified manganese sulfate solution. The test results of Example 1 and Comparative Example 1 clearly show that, compared to stirring, the specific mixing method of the present invention significantly reduces the CODcr content of the manganese sulfate solution. The inventors speculate that the reduction in manganese ion concentration is due to the smaller water loss in the solution compared to gas explosion mixing.

[0081] Furthermore, a comparison between Example 1 and Comparative Example 2 shows that when no metallic manganese is introduced into the porous resin, the Mn content in the purified manganese sulfate solution is lower. 2+The concentration decreased significantly because the presence of manganese in the porous resin greatly weakens its adsorption of manganese ions in the solution. When no metallic manganese is introduced, its adsorption of manganese ions in the solution becomes stronger, resulting in a significant decrease in the manganese ion content in the purified solution of Comparative Example 2. Furthermore, because metallic manganese is linked to the network of the porous resin via terephthalic acid, it weakens the adsorption of manganese ions while forming a specific network structure with the porous resin, thereby enhancing its adsorption effect on CODcr. When metallic manganese is introduced without terephthalic acid (e.g., in Comparative Example 3), the CODcr content of the purified manganese sulfate solution is significantly higher than that of the embodiments of the present invention, and its manganese ion content also shows a significant decrease.

[0082] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A method for removing heavy metal ions from a manganese sulfate solution, characterized in that, The method comprises the following steps: 1) adding an oxidizing agent to a pretreated manganese sulfate solution, mixing and stirring, then adjusting the pH value of the solution to 5.5-6.0, filtering to obtain a first purified manganese sulfate solution; 2) adding a sulfuration agent to the first purified manganese sulfate solution, filtering to obtain a second purified manganese sulfate solution; 3) adding a porous resin polymer to the second purified manganese sulfate solution, adding the mixed solution into a sealed container, introducing nitrogen, making the pressure in the sealed container reach 1.1-1.5 MPa and maintaining for 2-10 min, then opening the air valve to instantaneously release the pressure, standing, filtering, fine filtering to obtain a purified manganese sulfate solution; The preparation method of the porous resin polymer comprises the following steps: a) mixing a manganese sulfate aqueous solution and a terephthalic acid methanol solution, then heating the mixed solution to react, after the reaction is completed, concentrating, washing and drying the reaction solution to obtain a manganese metal organic framework; b) mixing ethyl methacrylate, polyvinyl alcohol, the manganese metal organic framework, divinylbenzene, a foaming agent, an initiator and a solvent, heating the mixed solution to react, after the reaction is completed, cooling, filtering, washing and drying to obtain the porous resin polymer; In step 3), the adding amount of the porous resin polymer is 1-8% of the mass of the pretreated manganese sulfate solution; and the standing time in step 3) is 1-3 h. The fine filtering step adopts a Gao filter for fine filtering.

2. The method of removing heavy metal ions from a manganese sulfate solution according to claim 1, characterized in that, The concentration of the manganese sulfate aqueous solution is 1-3 mol / L, and the concentration of the terephthalic acid methanol solution is 1-3 mol / L; In step a), the molar ratio of manganese sulfate to terephthalic acid in the mixed solution is 1: (2-2.2).

3. The method of removing heavy metal ions from a manganese sulfate solution of claim 1, wherein, In step a), the heating reaction temperature is 85-95 ℃, and the reaction time is 3-6 h; In step a), the washing step adopts water and methanol.

4. The method of removing heavy metal ions from a manganese sulfate solution of claim 1, wherein, In step b), the mass ratio of ethyl methacrylate, polyvinyl alcohol, the manganese metal organic framework, divinylbenzene, the foaming agent, the initiator and the solvent is (38-42):(15-25):(6-7):(4-5):(2-5):(1-3):(150-250).

5. The method of removing heavy metal ions from a manganese sulfate solution of claim 1, wherein, In step b), the solvent adopts water and toluene, and the mass ratio of water to toluene is (2-4):1; The foaming agent is selected from one of ethyl acetate, n-pentane and n-butane; The initiator is selected from azobisisobutyronitrile.

6. The method of removing heavy metal ions from a manganese sulfate solution of claim 1, wherein, In step b), the heating reaction temperature is 75-85 ℃, and the reaction time is 5-10 h; In step b), the washing step adopts methanol and hot water at 60-70 ℃ for washing.

7. The method of removing heavy metal ions from a manganese sulfate solution of claim 1, wherein, In step 1), the oxidizing agent is selected from a hydrogen peroxide solution, and the concentration of the hydrogen peroxide solution is 30-40%; The ratio of the amount of substance of hydrogen peroxide added in the hydrogen peroxide solution to the amount of substance of iron in the pretreated manganese sulfate solution is (1-1.2):1; In step 1), the stirring time is 1-3 h; In step 1), sodium hydroxide is used to adjust the pH value of the solution to 5.5-6.

0.

8. The method of removing heavy metal ions from a manganese sulfate solution of claim 1, wherein, The sulfuration agent in step 2) is at least one selected from sodium sulfide, ammonium sulfide, barium sulfide, and thiram; and the content of Co, Ni, and Pb in the solution is reduced to Co≤3ppm, Ni≤3ppm, and Pb≤3ppm, respectively, by adding the sulfuration agent in step 2). The sulfuration agent in step 2) is at least one selected from sodium sulfide, ammonium sulfide, barium sulfide, and thiram; and the content of Co, Ni, and Pb in the solution is reduced to Co≤3ppm, Ni≤3ppm, and Pb≤3ppm, respectively, by adding the sulfuration agent in step 2). The sulfuration agent in step 2) is at least