LEACHING METHOD AND RECOVERING METHOD FOR NICKEL OR COBALT

摘要

In step b (leaching step), sulfuric acid 205 and a reducing agent 220 are added to a slurry ore 204 to reduce a trivalent cobalt oxide while the ore is leached with the sulfuric acid 205 to obtain a sulfuric acid leachate 208 containing nickel and cobalt and a leaching residue 209. The leaching residue 209 contains Natrojarosite generated by a reaction of iron leached from the slurry ore 204 with the sulfuric acid 205 and a sodium salt 206.