EXTRACTION OF ACTINIDES WITH TROPOLONE .1. SYNERGISTIC EXTRACTION OF URANIUM(VI) WITH TROPOLONE AND SOME NEUTRAL DONORS

The partition coefficient of tropolone in xylene, dichloroethane and c hloroform was determined from 0.05M HCI medium.The values obtained wer e 5.6,25.5 and 43, respectively. In the extraction of UO22+ using trop olone (HT) in xylene from an aqueous medium of ionic strength 0.05, th e species UO2T2 . HT was established. The species extracted in presenc e of a neutral donor was found to be UO2T2 . S [S + dioctyl sulfide(DO S), dibutylhexanamide (DBHA), tri-n-butyl phosphate (TBP), dioctyl sul foxide (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 UO2T 2 . DOSO were also calculated by the temperature coefficient method. T he 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 .