Method for recovering metals

Abstract

A method for recovering metals from a metal-containing solution containing nickel ions, lithium ions, and anions of an inorganic acid, the method including: a nickel extraction step including extraction that mixes the metal-containing solution with a solvent while adjusting an equilibrium pH using a pH adjusting agent containing lithium ions, transfers the nickel ions in the metal-containing solution to the solvent, and separates the solvent containing the nickel ions from an extracted solution, wherein in the nickel extraction step, the extraction is carried out under conditions where the total of a lithium ion concentration of the metal-containing solution and a lithium ion concentration of the pH adjusting agent is less than or equal to a lithium ion concentration of a saturated solution of a lithium salt made of the anions of the inorganic acid and the lithium ions contained in the metal-containing solution.

Dependencies are inferred from the claim text.