METHOD OF REFINING NICKEL SULFATE AQUEOUS SOLUTION CONTAINING COBALT AND CALCIUM

摘要

PROBLEM TO BE SOLVED: To provide a high efficient refining method for obtaining a refined nickel sulfate aqueous solution having low concentration of cobalt and calcium by improving cobalt extraction efficiency in the exchange reaction to increase the quantity of cobalt to be treated in a method for refining the nickel sulfate aqueous solution by a solvent extraction method using the exchange reaction.

SOLUTION: The refining method of the nickel sulfate aqueous solution containing cobalt and calcium is performed by using a multistage countercurrent reaction vessel, supplying the nickel sulfate aqueous solution to a final stage as a water phase, supplying a mixed organic solvent prepared by diluting 2-ethyl hexyl phosphonic mono-2 ethyl hexyl ester extracting agent holding nickel with hydrocarbon so that the concentration becomes 20-30 vol.% to a 1st stage as an organic phase and controlling the water phase in the final stage to pH 4.5-5.5, the calcium concentration in the organic phase in the final stage to≤0.4 g/L and the total concentration of cobalt and calcium to≤25 g/L.

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