Development of Ligand-Associated Solid-Liquid Extraction Media System for Separation of High Purity Individual Rare Earth Elements from Coal-based Resources

The U.S. Department of Energy – National Energy Technology Laboratory is currently sponsoring the development of several pilot plants that are expected to produce 1-3 tons per day of 75 wt% mixed rare earth oxide (MREO) powder in the near future sourced from coal and coal by-products. A significant remaining challenge is to process the MREO into individually separated, high purity (ISHP) REO powders (>99% purity). This is the next generation of goal of the DOE-NETL. GlycoSurf and its project partners Wayne State University and UCLA will continue to build on its Phase I successes using ligand-associated separation media to develop a new class of sorption media, and a process to separate individual rare earth elements resulting in individual high purity rare earth oxide (REO) powders. Phase I results showed that our media is capable of separating REEs from each other in a concentrated mixture of rare earths extracted from coal combustion residuals, or synthetic solutions that represent an acidified rare earth concentrate. During our Phase I project, we have validated our sequential separation approach and shown that our technology and techniques can produce high purity Sc in one pass through a packed-bed column, while producing significant separation among the remaining 15 naturally occurring REEs. We have preliminary data that establishes the capability to achieve similar results with other REEs using additional columns, which will be a major focus of our proposed Phase II project. During the first year of Phase II, GlycoSurf and its partners will (1) continue building on the proof-of- concept results from Phase I, to recover Sc first; then (2) develop a process to combine the bench-scale steps together to test the system components to advance the technology; and (3) work with our commercial partners to testg our ligand-bound sorbent media to produce individually separated rare earths. During the second year of the Phase II, our team will: (1) select a partner to collaboratively develop a mobile pilot- scale separation system using real world solutions, and (2) build, test, and begin operation of a fully- operational prototype capable of producing small quantities of individually separated high purity REOs. GlycoSurf anticipates that Phase II will result in produced materials with an REO purity >90% in less than 10 steps (as opposed to 100’s to 1000’s of steps for current liquid-liquid separations). Overall, our technology will demonstrate a potential cost savings of >20% compared to conventional commercial technologies.