Extraction of americium(III) from nitric acid medium by CMPO-TBP extractants in ionic liquid diluent

Abstract

Extraction of americium(III) from nitric acid medium by a solution of tri-n-butylphosphate (TBP) and n-oc-tyl(phenyl)-N,N-diisobutylcarbamoylmethylphosphine oxide (CMPO) in room temperature ionic liquid, 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide (bmimNTf 2 ), was studied and the results were compared with that obtained with CMPO-TBP in n-doddecane (n-DD). The distribution ratio of 241 Am(III) in TBP-CMPO/bmimNTf 2 was measured as a function of various parameters such as concentrations of nitric acid, CMPO, bmimNO 3 , NaN0 3 and TBP and temperature. Remarkably large distribution ratios were observed for the extraction of americium(III) when bmimNTf 2 acted as diluent and the extraction was insignificant in the absence of CMPO. The stoichiometry of metal―solvate in organic phase was determined by the slope analysis of extraction data and it indicated the formation of 1: 3 (Am: CMPO) complex in organic phase. Viscosity of TBP-CMPO/bmimNTf 2 at various temperatures and enthalpy change accompanied by the extraction of americium(III) were determined and reported in this paper.