KINETICS OF LANTHANIDE/ACTINIDE CO-EXTRACTION WITH N,N′-DIMETHYL-N,N′-DIBUTYLTETRADECYLMALONIC DIAMIDE (DMDBTDMA)

Abstract

Studies were made on the kinetics of lanthanide(III)/actinide(III) co-extraction with N,N′-dimethyl-N,N′-dibutyltetradecylmalonic diamide (DMDBTDMA), which is an extraction system for partitioning of high level liquid nuclear waste (HLLW). Extraction rates were measured in a stirred cell. A linear relationship between stirring rate and fluxes was found for both lanthanides and americium. This indicates that mass transfer is controlled by diffusion. Two sets of extraction rates were observed within the lanthanide series. The extraction rates for La(III), Ce(III) and Pr(III) are about 50% higher than for the heavier lanthanides investigated (Nd(III), Sm(III), Eu(III)). The Am(III) extraction rate was found near those of the lighter lanthanides.