Extraction Chromatography for Separation of Rare Earth Elements

Developing efficient and viable processes for separation of critical metals is essential to meet the increasing demand. Rare earth elements (REEs) are identified by the EU as critical resources, and moreover, they are difficult to separate due to their similar properties. Extraction chromatography is a powerful method suitable for difficult, high-purity separations, which could form part of a separation process for recovery of REEs from various sources. In the present work, separation of REEs from synthetic apatite leach solutions is investigated using physically immobilized extractants. By means of reverse-phase columns, reversibly functionalized by acidic organophosphorus compounds, the metals are separated by elution with nitric acid solution.