| 摘要 |
PROBLEM TO BE SOLVED: To provide a purification method of a nickel chloride solution which removes impurities efficiently.SOLUTION: A purification method of a nickel chloride solution containing at least cobalt as an impurity includes a solvent extraction step of separating cobalt contained in a nickel chloride solution by solvent extraction and an oxidation neutralization step of removing impurities contained in the nickel chloride solution after the solvent extraction step by oxidation neutralization method. In the oxidation neutralization step, the pH of the nickel chloride solution is adjusted to 4.9-5.5, and the oxidation-reduction potential, based on the silver/silver chloride reference, is adjusted to 900-1,100 mV. Even a nickel chloride solution of a low cobalt concentration can improve chlorine efficiency in the oxidation neutralization step, allowing efficient removal of impurities. |
