SYNERGISTIC EXTRACTION OF U(Ⅵ) AND Th(Ⅳ) FROM NITRIC Acid WITH HBMPPT AND TOPO IN TOLUENE

摘要

The synergistic extraction of U(Ⅵ) and Th(Ⅳ) from nitric acid solution by HBMPPT(4-benzoyl-2,4-dihydro-5-methyl-2-phenyl-3H-pyrazol-3-thione) and tri-n-octylphosphine oxide (TOPO) in toluene was studied. The extraction ability of HBMPPT was not so high as that of its parent (HBMPP), but when a little TOPO was added in, the ability to extract U(Ⅵ) and Th(Ⅳ) was greatly improved. The stoichiometry of the synergistic extracted complexes may be presented as UO_2NO_3.HBMPPT-TOPO and UO_2(HBMPPT)_2-TOPO for U(Ⅵ), and Th(NO_3)_3-HBMPPT-TOPO and Th(NO_3)_2(HBMPPT)_2-TOPO for Th(Ⅳ) respectively.