Extraction behavior of several lanthanides from nitric acid with DMDODGA in [C 4 mim][NTf 2 ] ionic liquid

The extraction behavior of several lanthanide ions (La(III), Nd(III), Sm(III), Gd(III), Yb(III)) from the nitric acid medium using ionic liquid [C 4 mim][NTf 2 ] solvent containing N,N’-dimethyl-N,N’-dioctyl-3-oxadiglycolamide (DMDODGA) was studied. The effects of the concentration of HNO 3 , H + and NO 3 − in aqueous phase, as well as the DMDODGA concentration and temperature on the distribution ratio of Ln(III) were analyzed. The distribution ratio of lanthanide ions into [C 4 mim][NTf 2 ] is much higher than that reported for aliphatic hydrocarbon diluents. The extraction mechanism was demonstrated to agree with the cation-exchange mechanism. The stoichiometric ratio of Ln (III)/DMDODGA complex is 1:3 or 1:4.