THE SEPARATION OF TRIVALENT ACTINIDES FROM LANTHANIDES BY DITHIOPHOSPHINIC ACIDS FROM HNO3 ACID-MEDIUM

The extraction of Am(III) and Eu(III) has been investigated using mixt ures of synthesized aromatic dithiophosphinic acids (R2PSSH) and tribu tylphosphate (TBP), trioctylphosphine oxide (TOPO) or tributylphosphin e oxide (TBPO) in toluene from nitric acid (0.01-1.5 mol l-(1)). There was no detectable extraction when R(2)PSSHs were used alone as extrac tants for either Am(III) or Eu(III) (D-Am,D-Eu <10(-4)) under the expe rimental conditions used in this study, High separation factors (D-Am/ D-Eu>20) with D-Am>1 were achieved in the nitric acid range 0.1-1 mol l(-1) by means of a synergistic mixture of bischlorodithiophosphinic a cid with TBP, TOPO or TBPO. (C) 1998 Elsevier Science S.A.