DEZINCIFICATION PLANT, METHOD FOR OPERATING DEZINCIFICATION PLANT, AND HYDROMETALLURGICAL METHOD FOR NICKEL OXIDE ORE

摘要

PROBLEM TO BE SOLVED: To provide a hydrometallurgical method for nickel oxide ore, in which the plant can be smoothly started after completion of a periodic inspection because zinc sulfide separation imposes no load on a filter cloth and it is possible to reduce the amount of zinc remaining in a mother liquor (dezinced liquid) for nickel recovery to 1 mg/L or less.SOLUTION: After completion of a periodic inspection, the plant is started up in the following manner. In the beginning of the start-up, the neutralized liquid is not sulfided, and a switching valve 39 in feed piping 34 is switched so that the neutralized liquid may be circulated to a dezincification tank 31 through circulatory piping 38. When the flow rate and/or temperature of the neutralized liquid being circulating has reached a given value or higher, the neutralized liquid is sulfided in the dezincification tank to yield a mother liquor for nickel recovery that contains zinc sulfide. The switching valve 39 is switched to transfer the zinc sulfide-containing mother liquor for nickel recovery to a filter device 33 through transfer piping 37.