Extraction of Am(III) and lanthanides(III) with organo dithiophosphinic acids

Extraction of Am(III) and Ln(III) from NaClO(4) medium has been investigated with di(2-ethylhexyl) dithiophosphoric acid, di(2-ethylhexyl) monothiophosphoric acid, di(2-ethylhexyl) monothiophosphinic acid, octylphenyl dithiophosphinic acid and I I kinds of dialkyl dithiophosphinic acids (alkyl = hexyl, heptyl, octyl, nonyl, 2-ethylhexyl, 1-methylheptyl, phenyl, chlorophenyl, methylphenyl, 2,5-dimethylphenyl, and 3,5-dichloro-4-methylphenyl) in xylene. The effect of chemical structures of those extractants on separation capability has been studied. The relationship between the slope value of the IgD-pH and extraction conditions call be described as: Ig S = a 1g(C(HA)/C(M)(S/4)) + b. In the presence of macro amounts of Eu(CIO(4))(3), the formula Ig SF(Am/Eu) = B - 2 lg (C(HL) - D(Eu)/ (D(Eu) + 1)C(Eu)), call well describe file relationship between separation factor and the extraction condition. A high separation factor (SF(Am/Eu) = 2500) is obtained by solvent extraction from 1 mnol/L NaNO(3), solution with 0.5 mol/L di(2-ethylhexyl) dithiophosphinic acid in toluene.