DIAMEX Counter-Current Extraction Process for Recovery of Trivalent Actinides from Simulated High Active Concentrate

The partitioning of trivalent actinides was demonstrated with a new version of the French DIAMEX (DIAMide EXtraction) process. A continuous counter-current experiment using a 16-stage centrifugal extractor battery was tested using 1 mol/L N,N0-dimethyl-N,N0-dioctyl-hexylethoxy-malonamide (DMDOHEMA) in TPH as the extractant. A high active concentrate (HAC), obtained after concentration and denitration of a high active raffinate (HAR) with a concentration factor of 10, was used as a feed. Based on results from cold and hot batch extraction experiments and computer code calculations, a flowsheet was developed and a full test was carried out using a simulated HAC solution spiked with radionuclides (241Am, 244Cm, 152Eu, and 134Cs). In the DIAMEX process, five extraction stages were sufficient to obtain Am and Cm (feed/raffinate) greater than 5000 and for the coextracted lanthanides decontamination factors between 1100 and 4500. Co-extraction of zirconium, molybdenum, and palladium was prevented by using oxalic acid and HEDTA. The back extraction comprising 4 stages was also efficient and the recoveries of actinides were greater

MODOLO G.;  VIJGEN H.;  SERRANO PURROY Daniel;  CHRISTIANSEN Birgit;  MALMBECK Rikard;  SOREL C.;  BARON P.; 

2007-10-29

TAYLOR & FRANCIS INC

JRC41098

0149-6395,   

https://publications.jrc.ec.europa.eu/repository/handle/JRC41098,   

10.1080/01496390601120763,