Process for refining battery-grade nickel sulfate from crude nickel sulfate

Abstract

The invention provides a process for refining battery-grade nickel sulfate from crude nickel sulfate. The process comprises the following steps: dissolving crude nickel sulfate with high-temperature water according to a certain ratio, carrying out solid-liquid separation to remove a part of calcium and magnesium impurities in crude nickel sulfate in a precipitation form, adjusting the pH value ofa solution obtained after water dissolution to a proper value by using calcium hydroxide, allowing iron to form an iron hydroxide precipitate and allowing calcium to form a calcium sulfate precipitate; according to different precipitation coefficients of sulfides of arsenic, copper, zinc and nickel, adding a certain amount of sodium hydrosulfide to enable copper sulfide, arsenic sulfide and zinc sulfide precipitates to be formed in the solution so as to remove impurity elements including copper, arsenic and zinc; adding sodium fluoride with a certain excess coefficient into a sulfurized solution to form calcium fluoride and magnesium fluoride precipitates and a fluorinated solution; adding sodium carbonate into the fluorinated solution to adjust a pH value, thereby forming a nickel carbonate precipitate and wastewater; adding dilute sulfuric acid with a certain concentration into nickel carbonate to partially dissolve the nickel carbonate so as to form a pure nickel sulfate solution and undissolved nickel carbonate, wherein the nickel sulfate solution is neutral, the undissolved nickel carbonate returns to a dissolving procedure, and subjecting the nickel sulfate solution to high-temperature evaporation crystallization to obtain battery-grade nickel sulfate meeting national standards in China.

Description

technical field [0001] The invention relates to the recovery of crude nickel sulfate, in particular to a process for refining battery-grade nickel sulfate from crude nickel sulfate, which belongs to the field of hydrometallurgy. Background technique [0002] Nickel sulfate is widely used in metal coloring, electroplating, catalyst preparation and ceramic industry. With the continuous advancement of science and technology, the clean and efficient nickel-metal hydride battery has developed rapidly, and the demand for its main raw material, nickel sulfate, has increased, resulting in a long-term nickel sulfate market. Tighten. [0003] Copper concentrate contains a small amount of nickel, which enters the copper anode plate after copper pyro-smelting, and enters the copper electrolyte after copper electrolytic refining, which leads to the increase of impurity elements in the copper electrolyte, which is not conducive to copper electrolytic refining. The copper electrolyte is p...

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Problems solved by technology

[0003] Copper concentrate contains a small amount of nickel, which enters the copper anode plate after copper pyro-smelting, and enters the copper electrolyte after copper electrolytic refining, which leads to the increase of impurity elements in the copper electrolyte, which is not conducive to the electrolytic refining of copper

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