METHOD FOR PRODUCING HIGH-PURITY NICKEL SULFATE

摘要

PROBLEM TO BE SOLVED: To provide a method for producing nickel sulfate that obtains nickel sulfate with high purity using an impurity element removing method of selectively removing Mg from a solution containing Ni.SOLUTION: A method for producing high-purity nickel sulfate is characterized by processing an acid solution containing Ni in the order of steps (1) to (3). (1) In a carbonation step, a carbonating agent is added to the solution containing Ni, the Ni contained in the solution containing Ni is precipitated in the form of nickel carbonate or a mixture comprising nickel carbonate and nickel hydroxide to produce slurry after carbonation comprising the precipitate and a liquid after carbonation. (2) In a solid-liquid separation step, the slurry after carbonation produced in the carbonation step (1) is separated into the precipitate and the liquid after carbonation. (3) In a neutralization step, a neutralizing agent is added to the liquid after carbonation having been separated through the solid-liquid separation step (2) to recover the Ni contained in the liquid after carbonation as a precipitate of the Ni.