Extraction of REE(III), U(VI), and Th(IV) from Nitric Acid Solutions with Diphenyl(dibutylcarbamoylmethyl)phosphine Oxide in the Presence of Quaternary Ammonium Bis[(trifluoromethyl)sulfonyl]imides

Abstract

The extraction of REE(III), U(VI), and Th(IV) from nitric acid solutions with solutions of diphenyl(dibutylcarbamoylmethyl)phosphine oxide considerably increases in the presence of ionic liquids with the bis[(trifluoromethyl)sulfonyl]imide anion and quaternary ammonium cations. The stoichiometry of the extractable complexes was determined. The influence of the HNO₃ concentration in the aqueous phase, of the cation in the ionic liquid, and of the organic diluent on the efficiency of the extraction of REE(III), U(VI), and Th(IV) ions was examined.