Solvent Extraction of Rare-Earth Elements with Ionic Liquids: Toward a Selective and Sustainable Extraction of These Valuable Elements

In this review, the performance of ionic liquids (ILs) as separating media for selective and sustainable extraction of rare-earth elements (REEs) is analyzed. ILs as solvents have been used as diluents and also as extractants diluted in organic solvents where it has been found that high selectivities were obtained when fractionating heavy REEs from light ones either when ILs are diluents or extractants. However, for adjacent REE separation, there is still a challenge for future research. Finally, an analysis is carried out providing insights for selective and sustainable extraction of REEs with ILs. © 2020 Elsevier B.V.