화학공학소재연구정보센터
Separation Science and Technology, Vol.51, No.3, 474-484, 2016
Comparison in the extraction behavior of uranium(VI) from nitric acid medium using CHON based extractants, monoamide, malonamide, and diglycolamide, dissolved in piperidinium ionic liquid
Liquid-liquid extraction of U(VI) from nitric acid medium was carried out using three different class of CHON based molecular extractants namely monoamide, malonamide, and diglycolamide present in 1-butyl-1-methylpiperidinium bis(trifluoromethanesulfonyl)imide ([C(4)mpip][NTf2]) ionic liquid. The extractants investigated were di-n-hexyloctanamide (DHOA), N,N-dimethyl-N,N-di-octyl-2-(2-hexyloxylethyl)malonamide (DMDOHEMA) and N,N,N',N'-tetra(ethylhexyl)diglycolamides (T2EHDGA). The extraction behavior of uranium(VI) in ionic liquid medium was investigated as a function of various parameters, such as the duration and temperature of equilibration, aqueous phase concentrations of feed acid, extractant, NaNO3, and ionic liquid cation, etc. The extraction of U(VI) observed in these systems were compared with each other and the distribution ratios of U(VI) decreased in the order T2EHDGA > DMDOHEMA > DHOA. The slope analysis of the extraction data was carried out to understand the mechanistic aspects of extraction. The extraction of U(VI) observed in [C(4)mpip][NTf2] ionic liquid was also compared with pyrrolidinium ([C(4)mpyr][NTf2]) and imidazolium ([C(4)mim][NTf2]) based ionic liquids under identical experimental condition.