Dissolution of UO2 can be successfully achieved in imidazolium-based Fe-containing ILs with the help of DMSO without additional oxidants.
Compared with the total amount of uranium and the rare-earth elements, even if 15.2 wt% of the rare-earth elements of Sm, Eu, and Gd exist in the IL, only uranium-containing crystals would be selectively formed and separated from the system.
The separation of the rare-earth elements from uranium has also been achieved via a combination of crystallization and solvent extraction.