(658j) High Yield and Economical Production of Rare Earth Elements from Coal Ash

Authors: 
Preda, D. V., Physical Sciences Inc.
Joshi, P. B., Physical Sciences Inc.
Yee, J., Physical Sciences Inc.
Lambert, R., Physical Sciences Inc.
Hower, J. C., University of Kentucky
Groppo, J. G., University of Kentucky
Beers, T., Winner Global
Schrock, M., Winner Water Services
Coal and coal byproducts are a potential source of rare earth elements (REEs), with particularly heavy rare earth (HREE) content. Demonstration of technologies to recover REE, yttrium and scandium (REYSc) from these feedstocks will enable utilization of coal mining/coal combustion waste products in environmentally benign ways to produce strategically important materials for the United States while generating jobs and economic growth. Under sponsorship from the Department of Energy, the team of Physical Sciences Inc., University of Kentucky/Center for Applied Energy Research, and Winner Water Services is developing and demonstrating a pilot scale plant to economically produce salable REYSc-rich concentrates and commercially viable co-products from coal ash feedstock using environmentally safe and high-yield physical and chemical enrichment/recovery processes. A recently commissioned pilot plant operates at the scale of approximately 0.4-1 tons per day (tpd) ash throughput for physical processing and about 0.5 tpd for chemical processing, producing at least 50 - 500 g of dry REYSc nitrates concentrate containing at least 10-20 wt.% REYSc (elemental basis). Various ash feedstocks have been qualified, and all contain between 400-500 ppm of REYSc. The data obtained from the pilot plant operations will be used to enhance and validate a commercial scale techno-economic analysis that was completed for both the physical and chemical processing plants. Pilot plant processing parameters will also be used to design a commercial scale plant (hundreds of tpd throughput) with return on investment in less than seven years. This presentation will describe the approach and the key results with regard to process optimization, scale up and pilot plant implementation. The talk will provide a comprehensive overview of the overall process for economical production of REY concentrates. The production of valuable co-products will also be discussed. Development and demonstration of modular pilot scale physical and chemical plants for REYSc recovery from coal ash, including enhancement and validation of a techno-economic model using pilot plant operations data, will enable the design of a commercial scale (hundreds of tpd) REYSc plant.

Acknowledgement: This material is based upon work supported by the U.S. Department of Energy under Award DE-FE0027167.

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