Influence of Ionic Liquid on the Extraction of Actinides and Lanthanides(III) with Phosphorylureas from Nitric Acid Solutions

The effect of the ionic liquid 1-butyl-3-methylimidazolium bis[(trifluoromethyl)sulfonyl]imide on the extraction of U(VI), Th(IV) and lanthanides(III) from nitric acid solutions with phosphorylureas RR'P(O)NHC(O)NHC8H17 n differing in the nature of the substituents at the phosphorus atom was studied. A significant synergistic effect was discovered during the extraction of metal ions in the presence of an ionic liquid in the organic phase. The stoichiometry of the extracted complexes was determined. The influence of the structure of the extractant, the nature of the organic diluent, and the concentration of HNO3 in the aqueous phase on the efficiency of the extraction of metal ions into the organic phase is considered.