A COUNTER CURRENT EXPERIMENT FOR THE SEPARATION OF TRIVALENT ACTINIDES AND LANTHANIDES BY THE SETFICS PROCESS

The SETFICS process, a variation of TRUEX process, was developed for t he recovery of Am and Cm from acidic waste solution and the separation of actinides(III) and light lanthanides. The process uses the general TRUEX solvent as the extracting reagent and a DTPA-sodium nitrate sol ution for selective stripping of actinides(III). The basic flow sheet is composed of four steps: extraction-scrubbing; acid stripping; actin ide(III) stripping; and lanthanide stripping. To demonstrate the usefu lness of the SETFICS process, a counter current experiment was conduct ed using a real TRUEX product solution. Americium and curium were succ essfully recovered with a solution of 0.05 M DTPA-4 M NaNO3 (pH 2.0). Although the actinide(III) product solution contained Sm and Eu, the d econtamination factor of Ce-144/Am-241 was 72, and most of the light l anthanides, specifically La, Ce, Pr, Nd, were removed. At least 80 % o f the lanthanides were separated from the Am and Cm end products. In o rder to minimize the acidity in the actinide(III) stripping step, the nitric acid which extracted with the trivalent metals was previously r emoved with a solution of 0.5 M NaNO3 (pH 2.0) in the ''acid stripping '' step.