Ionic liquid-based aqueous biphasic systems for rare-earth metal recovery

 Rare-earth elements have high economic importance and are often found in high-tech applications. Solvent extraction is a crucial step and usually a predominant technology for the separation of metal ions, to produce pure compounds or metals from mineral ores or secondary resources (end-of-life products). Ionic liquids (ILs) have been widely studied in solvent extraction system as solvent or extractant for metal separations. However, the high viscosity and high cost of ILs limit their industrial applications. A novel way to deal with these problems is to use IL-based aqueous biphasic systems (IL-based ABS), where two aqueous phases are co-existing with one IL-rich phase and the other salt or polymer-rich phase. The project targets to develop sustainable, environmentally friendly and industrial applicable extraction processes for the extraction of rare-earth metals using the innovative IL-based ABS. This project is divided into three technical parts: (1) development of new IL-based ABS including ILsalt-based ABS and IL-IL-based ABS, (2) investigation of the separation of rare-earth metals using the developed ABS, and (3) research on a real leachate solution using IL-based ABS and finally validation of the obtained results on a mini-pilot scale setup. The newly developed systems will speed up the implementation of ILbased extraction processes on an industrial scale. IL-IL based ABS can be used not only for metal separations but also for recovery of bio-molecules and organics.