Solvent extraction separation of Th(IV) and U(VI) with PC-88A

Liquid-liquid extraction of Th(IV) and U(VI) has been investigated by comme rcial extractant PC-88A in toluene. The optimum conditions for extraction o f these metals have been established by studying the various parameters lik e acid concentration/pH, reagent concentration, diluents and shaking lime. The extraction of Th(IV) was found to be quantitative with 0.1-1.0M HNO3 ac id and in the pH range 1.0-4.0 while U(VI) was completely extracted in the pH range 1.0-3.5 with 2.5.10(-2)M and 2.10(-2)M PC-88A in toluene, respecti vely. The probable extracted species have been ascertained by log D-log C p lot as ThR4.4HR and UO2R2.2HR, respectively. The method permits separation of Th(IV) and U(VI) from associated metals with a recovery of greater than or equal to 99.0%.