Investigation of uranyl nitrate extraction from ketone solutions by dimethyl sulfoxide

Abstract

Based on an analysis of low-temperature luminescence spectra (T=77 K) of UO2(NO3)2·6H2O solutions in acetone, the mechanisms of formation of a wide group of uranyl complexes in uranyl extraction from solutions by dimethyl sulfoxide are studied. It is shown that to increase the coefficient of uranyl distribution between the solution and solid phase (in the form of UO2(NO3)2·2DMSO) it is necessary to add sulfoxide in small amounts, of about 0.35–0.5 mole per mole of uranyl. One-time introduction of DMSO in amounts of 1–3 mole per mole of uranyl leads to the formation of a number of uranyl complexes that are well soluble in acetone, and to a corresponding decrease in the distribution coefficient. The role of entropy and enthalpy in improvement of the stability of chelate complexes of uranyl nitrate is evaluated.