Method for producing aqueous solution containing nickel or cobalt

Abstract

A method for producing an aqueous solution containing nickel or cobalt includes: (A) a leaching step, which includes a first atmospheric pressure heating leaching step and a second atmospheric pressure heating leaching step, in which a raw material is heated and leached under an atmospheric pressure to form a leachate solution containing nickel, cobalt, and impurities; (B) a first extraction step of separating the leachate solution into a first filtrate containing nickel and impurities and a first organic layer containing cobalt and impurities by adding a first solvent extractant to the leachate solution; (C-i) a precipitation removal step of precipitating and removing impurities including magnesium, calcium, or a mixture thereof by adding a precipitating agent to the first filtrate; and (D-i) a target material precipitation step of selectively precipitating a nickel cake containing nickel by adding a neutralizing agent to the first filtrate.

Dependencies are inferred from the claim text.