Kinetics of lanthanide/actinide co-extraction with N,N '-dimethyl-N,N '-dibutyltetradecylmalonic diamide (DMDBTDMA)

Studies were made on the kinetics of lanthanide(III)/actinide(III) co-extra ction 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 r elationship between stirring rate and fluxes was found for both lanthanides and americium. This indicates that mass transfer is controlled by diffusio n. 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 lanthanide s.