Method for preparing nickel/manganese/lithium/cobalt sulfate and tricobalt tetraoxide from battery wastes

1. A method for preparing, nickel sulfate, manganese sulfate, lithium sulfate, cobalt sulfate and tricobalt tetraoxide from battery wastes, comprising the following steps: dissolving battery waste with acid, removing iron and aluminum, removing calcium, magnesium and copper, carrying extraction separation, and carrying out, evaporative crystallization to prepare nickel sulfate, manganese sulfate, lithium sulfate, cobalt sulfate and tricobalt tetraoxide; wherein,

the evaporative crystallization adopts the following steps:

recovering manganese sulfate by extracting pre-extraction solution with a di-2-ethylhexyl phosphoric acid extractant at first so that manganese in the solution is extracted to an organic phase, adding sulfuric acid solution into the organic phase for washing to obtain 150-200 g/L manganese-containing manganese sulfate solution, and carrying out evaporative crystallization and centrifugation on the solution to obtain a manganese sulfate product;

recovering cobalt sulfate by extracting di-2-ethylhexyl phosphoric acid extraction raffinate obtained after extraction of manganese in the previous process with mono(2-ethylhexyl) 2-ethylhexyl phosphonate so that cobalt in the solution is extracted to an organic phase, adding sulfuric acid solution into the organic phase for washing to obtain 80-130 g/L cobalt-containing cobalt sulfate solution, and carrying out evaporative crystallization and centrifugation on the solution to obtain a cobalt sulfate product;

recovering nickel sulfate by extracting mono(2-ethylhexyl) 2-ethylhexyl phosphonate extraction raffinate obtained after extraction of cobalt in the previous process with di-2-ethylhexyl phosphoric acid again so that nickel in the solution is extracted to an organic phase, adding sulfuric acid solution into the organic phase for washing to obtain 70-130 g/L nickel-containing nickel sulfate solution, and carrying out evaporative crystallization and centrifugation on the solution to obtain a nickel sulfate product;

recovering sodium sulfate by evaporating di-2-ethylhexyl phosphoric acid extraction raffinate obtained after extraction of nickel in the previous process with an MRV(mechanical vapor recompression) evaporative crystallization system to form sodium sulfate crystals, and carrying out centrifugal filtration to obtain an anhydrous sodium sulfate byproduct; and

recovering lithium carbonate by adding saturated sodium carbonate solution into centrifugation mother liquor obtained after recovery of sodium sulfate to obtain a lithium carbonate precipitate, wherein, a reaction temperature is controlled to 60-100° C., and react lasts, for 0.5-4 h. carrying out centrifugal filtration on the precipitate, washing and drying to obtain a lithium carbonate product.

2. The method for preparing nickel sulfate, manganese sulfate, lithium sulfate, cobalt sulfate and tricobalt tetraoxide from battery wastes according to claim 1 , wherein, the dissolving battery wasters with acid is realized by adding acid in the battery wastes with a solid/liquid mass ratio of 1:(2-6), reacting and then filtering to obtain acid dissolved filtrate.

3. The method for preparing nickel sulfate, manganese sulfate, lithium sulfate, cobalt sulfate and tricobalt tetraoxide from battery wastes according to claim 1 , wherein, the removing iron and aluminum is realized by adding calcium carbonate and sodium chloride in acid dissolved solution, stirring and then adding sodium carbonate solution, and filtering to obtain iron-removing and aluminum-removing filtrate.

4. The method for preparing nickel sulfate, manganese sulfate, lithium sulfate, cobalt sulfate and tricobalt tetraoxide from battery wastes according to claim 1 , wherein, the removing calcium, magnesium and copper is realized by adding sodium fluoride into the iron-removing and aluminum-removing filtrate, stirring and then adding sodium carbonate, and filtering to obtain pre-extraction solution.

5. The method for preparing nickel sulfate, manganese sulfate, lithium sulfate, cobalt sulfate and tricobalt tetraoxide from battery wastes according to claim 1 , wherein, the extraction separation comprises the following steps:

a. separating a manganese element by extracting and stripping the pre-extraction solution to obtain high-purity and high-concentration anti-manganese liquid;

b. separating a cobalt element by allowing extraction raffinate obtained after extraction of manganese to enter an extraction process for separating cobalt, extracting and stripping to obtain high-purity high-concentration anti-cobalt liquid; and

c. separating a nickel element by allowing extraction raffinate obtained after extraction of cobalt to enter an extraction process for separating nickel, extracting and stripping to obtain high-purity high-concentration anti-nickel liquid.

6. The method for preparing nickel sulfate, manganese sulfate, lithium sulfate, cobalt sulfate and tricobalt tetraoxide from battery wastes according to claim 5 , wherein, a stripping liquid uses 0.5-4N sulfuric acid.

7. The method for preparing nickel sulfate, manganese sulfate, lithium sulfate, cobalt sulfate and tricobalt tetraoxide from battery wastes according to claim 1 , wherein, in the step of recovering cobalt sulfate, after 80-130 g/L cobalt-containing cobalt sulfate solution is obtained, hydroxy cobalt is synthesized with sodium hydroxide solution, centrifugal filtration is carried out, and firing is carried out at 700-950° C. to prepare tricobalt tetraoxide.

8. The method for preparing nickel sulfate, manganese sulfate, lithium sulfate, cobalt sulfate and tricobalt tetraoxide from battery wastes according to claim 1 , wherein, in the step of recovering manganese sulfate, the organic phase is regenerated via acid washing, saponification is carried out with caustic soda solution to restore activity to be recycled, and centrifugation mother liquor is added into the next-batch manganese sulfate solution for evaporative crystallization.

9. The method for preparing nickel sulfate, manganese sulfate, lithium sulfate, cobalt sulfate and tricobalt tetraoxide from battery wastes according to claim 1 , wherein, in the step of recovering cobalt sulfate, the organic phase is regenerated via acid washing, saponification is carried out with caustic soda solution to restore activity to be recycled, and centrifugation mother liquor is added into the next-batch cobalt sulfate solution for evaporative crystallization.

10. The method for preparing nickel sulfate, manganese sulfate, lithium sulfate, cobalt sulfate and tricobalt tetraoxide from battery wastes according to claim 1 , wherein, in the step of recovering nickel sulfate, the organic phase is regenerated via acid washing, saponification is carried out with caustic soda solution to restore activity to be recycled, and centrifugation mother liquor is added into the next nickel sulfate solution for evaporative crystallization.

11. The method for preparing nickel sulfate, manganese sulfate, lithium sulfate, cobalt sulfate and tricobalt tetraoxide from battery wastes according to claim 1 , wherein, in the step of recovering lithium carbonate, the reaction temperature is controlled to 65-95° C., and the reaction time is 1.0-3.5 h.

12. The method for preparing nickel sulfate, manganese sulfate, lithium sulfate, cobalt sulfate and tricobalt tetraoxide from battery wastes according to claim 1 , wherein, in the step of recovering lithium carbonate tailwater and washing liquid are returned back to the MVR evaporative crystallization system.

13. The method for preparing nickel sulfate, manganese sulfate, lithium sulfate, cobalt sulfate and tricobalt tetraoxide from battery wastes according to claim 1 , wherein, the battery wastes comprise all waste batteries whose shells are stripped, wastes from battery manufacture factories and clearing wastes.