Extraction of uranium from acidic media with a novel synergistic mixture of di-nonyl phenyl phosphoric acid and tri-<i style="">n</i>-octyl phosphine oxide

708-712The extraction of uranium from aqueous acidic solutions of nitrate, perchlorate, sulphate, chloride and phosphate with a novel synergistic mixture of di-nonyl phenyl phosphoric acid (DNPPA) and tri-n-octyl phosphine oxide (TOPO) in an aliphatic hydrocarbon diluent has been studied at varying concentrations of aqueous acids, extractant and uranium. The mole ratio [DNPPA]:[TOPO] has been found to have a significant effect on extraction of uranium. Maximum extraction was found at 2:1 mole ratio and no antagonistic effect was observed at higher concentration of TOPO. The extracted species has been found to be UO2 (HR2)2.TOPO. The extraction order of uranium in aqueous media follows the sequence: perchlorate > nitrate > chloride > sulphate > phosphate. The selectivity of uranium with respect to other metals including Zn, Cu, Ni, Ca, and Fe has been investigated as a function of concentrations of sulphuric acid and extractant. Based on these findings, extraction of uranium has been carried out from leach liquor generated at an industrial plant, using 0.03 M DNPPA + 0.015 M TOPO with high recovery (>99%), selectivity and having added advantage of low inventory cost on extractants