EXTRACTION OF URANYL IONS BY SYNERGISTIC MIXTURES OF THENOYLTRIFLUOROACETONE AND MACROCYCLIC DONORS

ABSTRACT

A linear polyether, 1, 13-bis[8-qulnoly]-l,4,7,10,13-pentaoxa-trldecane (K-5) and an aza-crown ether, 4,13-didodecyl-1,7,10,16-tetraoxadiazacyclooctadecane (K22DD) when combined with thenoyltrlfluoroacetone (HTTA) have been shown to exhibit a synergistic effect on the extraction of uranyl ion. The effects of the addition to the organic phase of K-5, K22DD, and tert-butylcyclohexyl-15-crown-5 (15-C-5) on the extraction of UO₂ ⁺² by HTTA in chloroform from 0.5 M NaNO₃ at 25°C have been measured. The results indicate the extraction is enhanced by the formation of an adduct, UO₂(TTA)₂S for K-5 and K22DD. No enhancement of the extraction was seen with the crown ether. The organic phase stability constants for both K-5 and K22DD were evaluated and found to be similar in magnitude. These results suggest that the major factor in the formation of the synergistic adduct is the presence of the nitrogen atom in the synergist.