Liq.-liq. extn. of cobalt from nickel contg. soln.

摘要

Cobalt is removed using an organic liq. comprising 65-98 vol.% of a conc. alpha-hydroxy oxime extractant (I), 2-35 vol.% of a cpd. (R1O)2P(O) OH (II) and 0-33 vol.% of an inert, water-immiscible organic diluent. The pH is held at 1-6 (pref. 2.5-4.5) and the organic liq. pref. contains 2-20 vol % of trichloroethylene, R1 is alkyl, aryl or aralkyl. - Esp. for extn. of Co from solns. of its sulphate, and also for its chloride, etc. The process is comparatively cheap and selective. - (II) is pref. di(2-ethoxyhexyl/phosphoric acid and an emulsion inhibitor is optional. The Co and Ni are finally re-extracted with aq. solns. of HCl and H2SO4 respectively. Very pure NiSO4 crystals were obtd. in this way.