Liquid-liquid extraction process for isolating cobalt product, which is highly pure with respect to nickel, from aqueous solutions containing cobalt and nickel

摘要

A process for the separation of cobalt from magnesium and nickel by extraction is disclosed in which a magnesium-bearing aqueous solution which contains cobalt and nickel is contacted with an organic solution which contains di-(alkyl)-phosphoric acid, alkylphosphonic acid monoalkyl ester or alkylphosphinic acid monoalkyl ester under conditions in which the distribution coefficient of cobalt is at minimum 1.5 times higher than the distribution coefficient of magnesium and at the same time at minimum 30 times higher than the distribution coefficient of nickel, in which case the cobalt/magnesium ratio, prior to the extraction or during the extraction in the aqueous solution is adjusted to between 0.2 and 2.