Aqueous cobalt chloride solution purification method

Abstract

The present invention provides an aqueous cobalt chloride solution purification method, in which impurities can be efficiently removed from a cobalt salt solution. Provided is a method for bringing metallic nickel into contact with an aqueous solution containing cobalt chloride to remove an impurity by a substitution reaction, in which the pH of the aqueous solution containing cobalt chloride is adjusted to not less than 1.5 and not more than 2.5. Since the pH of the aqueous solution containing cobalt chloride is adjusted to not less than 1.5 and not more than 2.5, a passive film on a surface of the metallic nickel can be effectively removed. When the passive film is removed, the metallic nickel comes in contact with the aqueous solution containing cobalt chloride, so that an impurity more noble than the metallic nickel can be precipitated by the substitution reaction. In addition, since the metallic nickel is only brought into contact with the aqueous solution containing cobalt chloride, the impurity can be easily removed from the aqueous solution containing cobalt chloride.

Dependencies are inferred from the claim text.