Abstract

The separation of the trivalent actinides (III) americium and curium from the lanthanide group belongs to the most difficult PARTITIONING processes. The present paper describes a continuous process (ALINA) which uses a mixture of aromatic dithiophosphinic acid and TOPO as an extractant. The ALINA process was tested in a miniature centrifugal extractor battery with the aid of a 24-stage flowsheet consisting of 8 extraction, 8 scrubbing and 8 stripping stages. The An(III)/Ln(III) feed was an Am-241- and Cm-244-tracered synthetic solution whose lanthanide concentration corresponded to a real DIAMEX back-extraction process solution. With the aid of this flowsheet 99.9% of the americium, but only 80% of the curium was extracted and back-extracted. The actinide(III) product stream was only contaminated with approx. 2 mass percent of the lanthanides so that the ambitious aim of < 5% was achieved. Considering the slow extraction kinetics and the efficiency of the extraction stages, the experimental results for americium are in good agreement with theoretical calculations.

This content is only available via PDF.
You do not currently have access to this content.