Solvent extraction and separation of thorium(IV) and uranium(VI) by an ether-amide type tripodand

摘要

a1,1,1-tris(N,N-diisobutylcarbamoyl-methyleneoxymethyl)propane (L) has been prepared and characterized by using IR, H-1 NMR and positive-ion FAB mass spectra. The extraction of Th4+ and UO22+ with L was studied as a function of concentration of free extractant in an organic phase and of picrate in an aqueous phase from a picrate-nitrate medium at 293 I K. It was found that the extractability of L for Th4+ is larger than that for UO22+. Both extraction % of Th4+ and UO22+ decreased with an increase in the concentration of HNO3. The mechanism of extraction of Th4+ with L was proposed. The composition of extracted species of L with Th4+ in the organic phase is ThL(PiC)(2)(NO3)(2). The results of extraction of trace Th-234(4+) with L from the picrate-nitrate medium containing UO(2)2+ (the initial concentration of UO22+ C-UO2(2+)0 = 1.23 x 10(-4) mol/dm(3) (M)) agreed well with those from the extraction of single component solutions. The tripodand is useful in separation of Th4+ and UO22+ from each other in picrate-nitrate media with a relatively high separation factor.