US Patent 7964165 Separation method for zinc sulfide

The separation method for zinc sulfide, in the hydrometallurgical process by a High Pressure Acid Leach for nickel oxide ore comprising leaching and solid/liquid separation step, neutralization step, zinc removal step, and nickel recovery step, which can inhibit clogging of a filter cloth and reduce a frequency of washing operation and replacement operation of a filter cloth by improving filtration performance of zinc sulfide, and inhibit decrease of nickel recovery ratio, in the zinc removal step in which zinc sulfide is formed by adding a sulfurizing agent to the neutralization final liquid containing zinc as well as nickel and cobalt and zinc sulfide is separated to obtain a mother liquid for nickel recovery containing nickel and cobalt.