Separation of plutonium(IV) from uranium(VI) using phosphonate-based task-specific ionic liquid

Abstract

ABSTRACT The extraction behavior of plutonium(IV) and uranium(VI) from nitric acid medium by a solution of diethyl-2-(3-methylimidazolium)ethylphosphonate bis(trifl uoromethanesulfonyl)imide (ImPNTf2) ionic liquid in the room temperature ionic liquid (RTIL), 1-alkyl-3-methylimidazolium bis(trifl uoromethanesulfonyl)imide (alkyl = butyl, hexyl or octyl) was studied. The distribution ratio of Pu(IV) in ImPNTf2/amimNTf2 increased with increase in the concentration of nitric acid reached a maximum at 0.5 M in nitric acid followed by decrease. The DPu(IV) values, then, reached a minimum at 4–5 M and thereafter increase. The distribution ratio of U(VI) was insignificant as compared to the distribution ratio of Pu(IV) that led to the unusual separation of plutonium (IV) from uranium(VI).