Liquid-Liquid Extraction of Cerium(III) from Thiocyanate Media with Mixtures of Organophosphorus Extractants

Abstract

The extraction of Ce(III) from thiocyanate solutions with mixtures of 2-ethylbexylphosphonic acid mono-2-ethylhexyl ester (EHPNA) and di(2-ethylhexyl)-phosphoric acid (DEHPA) or tri-n-butyl phosphate (TBP) in benzene has been studied systematically over a wide range of conditions. A relatively small synergistic enhancement has been observed with mixtures of acidic organophosphorus extractants (EHPNA + DEHPA) and also with mixtures of acidic and neutral organophosphorus extractants (EHPNA + TBP). These extraction data have been analysed theoretically, taking into account complexation of the metal in the aqueous phase by inorganic ligands and plausible complexation in the organic phase.