New solvents for more efficient rare earth mining
European industries depend heavily on imported rare earth elements, with the largest volume of supplies coming from China. Import demand for critical raw materials such as lanthanides needs to be reduced as Europe has enough deposits to be self-sufficient. This monopoly in China has led to a surge of studies on recycling processes that make use of volatile and flammable organic solvents. In the EU-funded project INNOVILLN (Ionic liquids as innovative organic phase for solvent extraction and separation of lanthanoids: A comparative study of conventional and synergistic systems), scientists aimed to further explore ionic liquids for use as solvents that are non-volatile and non-flammable. Ionic liquids, which are salts that are liquid at room temperatures, can be used as solvents to extract and separate the rare earth elements from a mixture of them. The project team used two widely used organic solvents and four ionic liquids to test their synergistic effect on the extraction efficiency of lanthanides. In all cases, scientists reported that ionic liquids more efficiently extracted the rare earth elements, except for one case where separation efficiency was poor. Project results are promoting more efficient extraction processes compared to the state of the art, and that are also more economical and have little environmental impact.