INFLUENCE OF THE NATURE OF ORGANIC DILUENTS ON THE EXTRACTION OF URANIUM(VI) BY BIS(2-ETHYLHEXYL) SULFOXIDE FROM NITRIC-ACID SOLUTIONS

The extraction of uranium(VI) from nitric acid solutions by bis(2-ethy lhexyl) sulfoxide (BESO) has been examined using sixteen inert organic diluents in order to establish the correlation between its distributi on coefficient and some physico-chemical properties of the diluents. T he extracted solvated species is shown to be UO2(NO3)(2) . 2BESO, irre spective of their nature, The extraction rate is lower in halogen subs tituted hydrocarbons as compared to the other diluents used. Among ben zene derivatives, extraction is found to decrease with number of subst ituted methyl groups, Extraction efficiency decreases as the organic s olvent is varied in the order: benzene > nitromethane > toluene > > ni trobenzene > cyclohexane > p-xylene > monochlorobenzene > dodecane > o -dichlorobenzene > > hexane > decalin > 1,2-dichloroethane > 1,1,1-tri chloroethane > carbontetrachloride > > tetrachloroethane > chloroform, Among the properties showing good correlations with distribution coef ficient are Hansen's three-dimensional solubility parameters and Dimro th's empirical solvent polarity parameters [E(T(30))]. Polarizability indices are most satisfactorily applicable to a wide variety of solven ts.