| abstract |
Aq. soln. of nickel chloride are purified by addn. of CaCl2 so that a concn. of 4-5.5 moles CaCl2/l of the soln. is obtd. and the soln. is then treated, without prior oxidn., by liq. -liq. extn. using an organic phase contg. a neutral organic solvent chosen from tri-n-butyl phosphate, phosphonic- or phosphinic- esters, tri-octyl-phosphine-oxide, hexone, octylol, or di-isobutyl-acetone. The organic solvent is pref. diluted with an organic diluent of low polarity and is esp. pure tri-n-butyl phosphate (TBP) or TBP diluted with xylene or kerosine and contg. min. 40% TBP. The liq. -liq. extn. pref. occurs in several stages. Method is esp. for removal of ferrous iron Fe++ from the soln. but also Fe+++, Co, Cu, zn, Mn, Cr, Sn, Bi, Sb and may be used to obtain nickel with e.g. 0.1% impurities. |