Room temperature ionic liquid system for the mutual separation of Pu(IV) from other actinides using 2-hydroxy acetamide extractant

N,N-dioctyl-2-hydroxyacetamide (DOHyA) in 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)amide ([C4mim][NTf2]) was employed for the extraction of actinides from nitric acid medium. The extraction of Pu(IV) was studied as a function of various parameters such as concentration of nitric acid, extractant concentration, temperature, alkyl chain length attached to amidic nitrogen of the extractant etc. The distribution ratio of plutonium(IV) (DPu(IV)) obtained in DOHyA/[C4mim][NTf2] was compared with that obtained in DOHyA/n-dodecane (n-DD). Extraordinary extraction of Pu(IV) was achieved when ionic liquid was employed as a diluent. DPu(IV) in DOHyA/[C4mim][NTf2] decreased marginally with increase in nitric acid concentration up to 3 M nitric acid, and there after the DPu(IV) remained constant. A significant separation was achieved for Pu(IV) over U(VI) and Am(III) from the employed mixture of actinides at various nitric acid concentrations using DOHyA/[C4mim][NTf2]. Stripping of metal ion (Pu(IV)) from the loaded ionic liquid phase was carried out using aqueous soluble complexing agents such as oxalic acid and acetohydroxamic acid.