Method for manufacturing nickel and cobalt-containing solution from hydroxide containing nickel and cobalt

Abstract

A method of manufacturing a cobalt-nickel-containing solution including: preparing a crude nickel hydroxide and/or a crude cobalt hydroxide as a starting material, the crude nickel or cobalt hydroxide containing cobalt and nickel and elements except the cobalt and nickel as impurities, the crude nickel hydroxide containing the nickel more than the cobalt, and the crude cobalt hydroxide containing the cobalt more than the nickel; a water-washing process for obtaining a post-water-washing crude hydroxide from the starting material; a leaching process for obtaining a post-leaching solution from the post-water-washing crude hydroxide; a neutralization process of subjecting the post-leaching solution to neutralization and solid-liquid-separation to remove the impurities as a post-neutralization residue containing one or more of iron, silicon, aluminum, and chromium, thereby obtaining a post-neutralization solution; and an extraction process of subjecting the post-neutralization solution to solvent extraction to obtain a post-extraction solution containing cobalt and nickel with the impurities reduced.