Asymmetric diglycolamide in BmimNTf2 as an effective solvent system for the uranyl extraction

The extraction behavior of uranyl from the nitric acid medium using an asymmetric diglycolamide, DMDODGA, in BmimNTf2 was studied. The effects of the concentration of HNO3, DMDODGA and temperature on the distribution ratio were discussed. The distribution ratio of uranyl into BmimNTf2 liquid is much higher than that into hydrocarbon diluents. The extraction mechanism was investigated by UV-visible spectroscopic and extraction experiments that all agree the cation-exchange mechanism. Formation of the 1:2 U/DMDODGA complexes was analyzed using the slope analysis method. In addition, uranyl can be effectively separated from perrhenate using DMDODGA-BmimNTf2 system.