Effect of Dialkylsulfosuccinate-Based Ionic Liquids on the Extraction of Lanthanides(III), Uranium(VI), and Thorium(IV) with Diphenyl(dibutylcarbamoylmethyl)phosphine Oxide from Nitric Acid Solutions

The extraction of lanthanides(III), uranium(VI), and thorium(IV) ions from nitric acid solutions with diphenyl(dibutylcarbamoylmethyl)phosphine oxide solutions significantly increases in the presence of ionic liquids, 1-butyl-3-methylimidazolium dialkylsulfosuccinates, in the organic phase. The dependence of the ionic liquid distribution between the organic and aqueous phases on the concentrations of the ionic liquid and nitric acid was studied. The stoichiometry of the extracted complexes of lanthanides(III), uranium(VI), and thorium(IV) was determined by the equilibrium shift method. The influence of the length of alkyl radicals in the ionic liquid anionic part and the HNO 3 concentration in the aqueous phase on the efficiency of metal ions extraction into the organic phase containing the ionic liquid was considered.