Abstract:LIX84 is used to separate Ni, Co and Cu from the cuprous ammonia leach solution of ocean polymetallic nodules. Cu and Ni are co-extracted via 5 stages of count-current extraction, while cobalt remains in the raffinate. The organic phase loaded with Ni and Cu is scrubbed to remove the entrained ammonia. The spent nickel electrolyte is used to strip selectively nickel via 7 stages of stripping, so Ni and Cu can separated primarily. The organic phase is further stripped to produce a pure copper sulphate solution. The little copper containing in the nickel stripper liquor, which is removed by LIX84 again for a complete Ni-Cu separation. The separation of Ni, Co and Cu from the ammonia solution has been achieved with a single solvent reagent. Thus the results indicate that a good separation with a high metal recovery can be obtained via this process. 99.0% Ni, 99.7% Co, and 99.9% Cu can be recovered.