Extraction of actinides with tropolone

Abstract

The partition coefficient of tropolone in xylene, dichloroethane and chloroform was determined from 0.05M HCl medium. The values obtained were 5.6, 25.5 and 43, respectively. In the extraction of UO 2 2+ using tropolone (HT) in xylene from an aqueous medium of ionic strength 0.05, the species UO2T2·HT was established. The species extracted in presence of a neutral donor was found to be UO2T2·S[S+dioctyl sulfide (DOS), dibutylhexanamide (DBHA), tri-n-butyl phosphate (TBP), dioctyl sulfoxide (DOSO), and tri-n-octylphosphine oxide (TOPO)]. The equilibrium constant of complex formation between the self-adduct and the neutral donor was calculated and was found to follow the basicity order (DOS«DBHA<TBP<DOSO»TOPO). The thermodynamic parameters of the adduct UO2T2·DOSO were also calculated by the temperature coefficient method. The values of free energy, enthalpy and entropy changes obtained were −1.26 kJ·mol−1, −1.98 kJ/mol and −2.5 J·mol−1·deg−1, respectively.