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Production of Critical Minerals from Coal Ash
David Gamliel, Dorin Preda, Prakash B. Joshi, Bryan Sharkey, Eric Hernandez, and Nick Skovran
Physical Sciences Inc.
James C. Hower and John G. Groppo
University of Kentucky, Center for Applied Energy Research,
Todd Beers, Mike Schrock, and Brad Perrine
Winner Water Services
Nortey Yeboah, Riley Flowers, and Shane Powell
Southern Company
Jeff Hogan
Neo Performance Materials
ABSTRACT: Coal byproducts are a potential source of rare earth elements (REEs). New technologies to recover
REEs from these feedstocks will enable utilization of coal combustion waste in environmentally benign ways to
produce strategically important materials. Our goal was to develop and demonstrate a pilot plant that recovers
REEs from coal ash via economical and environmentally-friendly processes. The team collected, processed, and
concentrated REEs from coal ash deposits located across the Southeastern U.S. We constructed and operated a
sub-scale (0.5 kg/day) micropilot facility to demonstrate the key physical and chemical processing operations,
predict yields, and troubleshoot process bottlenecks. The project team designed, constructed and operated
two decoupled pilot plant operations: (1) an operational pilot plant for physical separation processes with a
capacity of 0.4 metric tons per day (tpd) where we optimized processes to generate selected ash fractions as the
feedstock for chemical processing as well as byproducts such as cenospheres, magnetic ash and secondary fuel
carbon, and (2) an operational pilot plant for chemical ash processing with a capacity of 0.5 tpd that developed
optimized processes for the production of REEs and beneficiated ash as valuable byproduct suitable for cement
applications. The team achieved REE purities in excess of 90 wt.% (oxide basis) and generated 100 g of REE
concentrate material. This work reports on a potential new domestic resource for REEs.
INTRODUCTION
Rare Earth Elements (REE) are important materials used
in many modern applications, including high field mag-
nets, lighting phosphors, industrial catalysts, high strength
alloys, and NiMH batteries. REE have been traditionally
obtained from mining ores or from clays. China dominates
the production of REE (80%) and the only US source,
the reopened Mountain Pass mine, sends the majority
of its concentrate product to China for processing and
refinement. As a result, new domestic sources of REE are
Production of Critical Minerals from Coal Ash
David Gamliel, Dorin Preda, Prakash B. Joshi, Bryan Sharkey, Eric Hernandez, and Nick Skovran
Physical Sciences Inc.
James C. Hower and John G. Groppo
University of Kentucky, Center for Applied Energy Research,
Todd Beers, Mike Schrock, and Brad Perrine
Winner Water Services
Nortey Yeboah, Riley Flowers, and Shane Powell
Southern Company
Jeff Hogan
Neo Performance Materials
ABSTRACT: Coal byproducts are a potential source of rare earth elements (REEs). New technologies to recover
REEs from these feedstocks will enable utilization of coal combustion waste in environmentally benign ways to
produce strategically important materials. Our goal was to develop and demonstrate a pilot plant that recovers
REEs from coal ash via economical and environmentally-friendly processes. The team collected, processed, and
concentrated REEs from coal ash deposits located across the Southeastern U.S. We constructed and operated a
sub-scale (0.5 kg/day) micropilot facility to demonstrate the key physical and chemical processing operations,
predict yields, and troubleshoot process bottlenecks. The project team designed, constructed and operated
two decoupled pilot plant operations: (1) an operational pilot plant for physical separation processes with a
capacity of 0.4 metric tons per day (tpd) where we optimized processes to generate selected ash fractions as the
feedstock for chemical processing as well as byproducts such as cenospheres, magnetic ash and secondary fuel
carbon, and (2) an operational pilot plant for chemical ash processing with a capacity of 0.5 tpd that developed
optimized processes for the production of REEs and beneficiated ash as valuable byproduct suitable for cement
applications. The team achieved REE purities in excess of 90 wt.% (oxide basis) and generated 100 g of REE
concentrate material. This work reports on a potential new domestic resource for REEs.
INTRODUCTION
Rare Earth Elements (REE) are important materials used
in many modern applications, including high field mag-
nets, lighting phosphors, industrial catalysts, high strength
alloys, and NiMH batteries. REE have been traditionally
obtained from mining ores or from clays. China dominates
the production of REE (80%) and the only US source,
the reopened Mountain Pass mine, sends the majority
of its concentrate product to China for processing and
refinement. As a result, new domestic sources of REE are