The University of Kentucky Center for Applied Energy Research (UK CAER) continues to be at the leading edge in the hunt to recover rare earth elements (REE) from coal and coal byproducts. Two of the four U.S. Department of Energy (DOE) projects recently selected to receive funding for novel REE research were born out of UK innovation and collaboration.

DOE selected four projects to move on to a second phase of research in their efforts to advance recovery of rare earth elements. DOE will invest $17.4 million to develop and test REE recovery systems originally selected and designed under phase 1 of a prior funding opportunity announcement through DOE’s Office of Fossil Energy (FE).

UK researchers are involved in two of these projects totaling $12 million of the $17.4 million in total funding.  

The projects, expected to be completed by 2020, fall under two areas of interest: (1) bench-scale technology to economically separate, extract, and concentrate mixed REEs from coal and coal byproducts, including aqueous effluents; and (2) pilot-scale technology to economically separate, extract, and concentrate mixed REEs from coal and coal byproduct solids.

Both of the UK projects received $6 million and were selected under DOE interest 2 (pilot-scale technology development).

UK CAER will work on the project awarded to Physical Sciences, Inc. of Andover, Mass. The project will use coal fly ash physically processed near Trapp, Ky. as their feedstock. The fly ash is a byproduct of combusting Central Appalachian bituminous coal in a power plant boiler. The select portion will be shipped to a Pennsylvania location for subsequent processing to produce the final rare earth product. In addition, researchers will evaluate recovery of other useful materials from the fly ash.  Jim Hower, a principal research scientist at UK CAER and a research professor in UK’s Earth & Environmental Sciences Department, and Jack Groppo, a principal research engineer at CAER and faculty member in UK Mining Engineering, will serve as co-PIs on this grant.  

UK’s Department of Mining Engineering will oversee the second project. The research will use two sources of coal preparation (coal washing) byproducts as feedstock for recovery of REEs. The team will also recover dry, fine coal from the feedstock material. The first location for installation and testing of the pilot plant will be at a coal preparation plant in Perry County, Ky. that processes Central Appalachian bituminous coal. The second location for testing of the pilot plant will be at a coal preparation plant that processes Illinois Basin bituminous coal near Nebo, Ky.  UK CAER’s Dr. Groppo will also provide expertise in physical separation processing and plant design on that project.

“The research advances made in rare earths over the last several years has been remarkable,” said Dr. Hower, who first discovered rare earth concentrations in Kentucky coal seams in the late 1990s. “We hope this research funding will accelerate research and development in this promising area that could have a profound impact on Kentucky’s energy economy.” 


REEs are a series of 17 chemical elements found in the Earth’s crust. Due to their unique chemical properties, REEs are essential components of technologies spanning a range of applications, including electronics, computer and communication systems, transportation, health care and national defense. The demand for REEs has grown significantly in recent years, stimulating an interest in economically feasible approaches for domestic REE recovery.