Patent attributes
The present invention provides a nickel refining method which uses nickel sulfide produced from nickel oxide ore using a hydrometallurgical process, as the raw material, and in which chlorine leaching is performed using a chloride solution, wherein a cementation reaction is caused between the nickel sulfide and copper ions, using copper ions, preferably included in the leaching solution itself, and a portion of the nickel in the nickel sulfide is leached into the solution, and the remaining nickel and copper are left as a residue, and copper and nickel are chlorine leached from this residue, and wherein the cementation reaction is performed with an oxidation-reduction potential as measured by a silver-silver chloride electrode of below −20 mV, preferably below −100 mV.