AQUEOUS COBALT CHLORIDE SOLUTION PURIFICATION METHOD

摘要

[Problem] To provide an aqueous cobalt chloride solution purification method capable of efficiently removing impurities from a cobalt salt solution. [Solution] A method for bringing metallic nickel into contact with an aqueous cobalt chloride-containing solution to remove impurities by a substitution reaction, wherein the pH of the aqueous cobalt chloride-containing solution is adjusted to 1.5 to 2.5. Since the pH of the aqueous cobalt chloride-containing solution is adjusted to 1.5 to 2.5, it is possible to effectively remove the passive film on the surface of the metallic nickel. When the passive film is removed and the metallic nickel is brought into contact with the aqueous cobalt chloride-containing solution, impurities that are more electropositive than metallic nickel can be precipitated by a substitution reaction. Moreover, since the metallic nickel need only be brought into contact with the aqueous cobalt chloride-containing solution, it is possible to remove impurities from the aqueous cobalt chloride-containing solution easily.