Bureau of Economic Geology

Carbon Ore, Rare Earth and Critical Minerals

Assessment of Rare Earth Elements and Critical Minerals in Coal and Coal Ash in the U.S. Gulf Coast

Critical minerals and rare earth elements have recently become a security issue for the U.S. with supply chains largely dependent on China. As the U.S. and the globe transition to more renewable energy sources, including solar panels and wind turbines, metal and mineral demand is expected to increase rapidly. Concerns over maintaining secure supply chains for the coming decades have prompted federal and state agencies to investigate and catalogue domestic inventories of these commodities. The Texas Bureau of Economic Geology recently received funding from the Department of Energy via the Carbon Ore, Rare Earth and Critical Minerals (CORE-CM) Initiative for U.S. Basins (DE-FOA-0002364) to conduct a two-year research program to study critical mineral and rare earth potential of Gulf Coast coals and coal-byproducts.

Coal and Coal Byproducts in the Gulf Coast

The Gulf Coast region includes 10 active mines and 26 active power plants that use coal. The dominant coal source is lignite but includes sub-bituminous coal in the southwest. The most recent coal resource assessment was published by Warwick and others (2011). The study will focus on shallow coals (≤ 300 ft deep) and will include any additional data from mines and permits since the previous assessment. There is particular interest in coals that are linked to volcanic deposits as critical minerals (CMs) and rare earth elements (REEs) are likely concentrated in these zones. In addition to the active mines, we have archived coal samples for many of the closed mines at USGS in Reston that can be analyzed for CM and REEs.

The other major source of CM and REEs that will be evaluated in the Gulf Coast is ash from power plants. Many of the power plants source their coal from the Powder River Basin in Wyoming so the ash from these power plants will reflect this source.


Project Partners

The Gulf Coast project extends from Texas to Alabama and as far north as Arkansas. The core team includes the Univ. of Texas Bureau of Economic Geology, Jackson School of Geosciences, Geological Survey of Alabama, University of North Dakota, University of Wyoming, University of Kentucky, and the U.S. Geological Survey. The Gulf Coast Basin has many surface lignite mines that have been highly under-sampled for REEs and CMs.

The core team will interact with various groups to advance linkages between the CM and REE assessments and industries involved in processing these materials and using CM/REEs and non- fuel CBPs. The project will also involve planning for a Technology Innovation Center to develop bench scale projects to assess different approaches for extracting CM/REEs from coal and coal byproducts.

Advisory Board

An Advisory Board has been established to coordinate activities and to enhance communication with the research team and industry and regulators.

The current Advisory Board includes the following:

  • Arkansas Energy and Environment
  • Microbeam Technologies Inc.
  • Louisiana Research Development & Economics
  • Blue Line Corporation
  • San Miguel Electric Cooperative
  • Luminant
  • MS State Geol Surv.
  • Semplastics
  • Southern Company
  • Eagle Pass
  • Texas Mineral Resource Corp / Round Top
  • Dennis James Consulting
  • Texas Mineral Resources Corporation
  • USA Rare Earth
  • Geological Survey of Alabama

Research Objectives

The objectives of this study are to:

  1. Quantify coal (from mines) and coal ash (from power plants) resources, and refuse as feedstocks for rare earth elements (REEs) and critical minerals (CMs) within the U.S. Gulf Coast Basin.
  2. Quantify REEs in water co-produced with oil in reservoirs adjacent to coal resources.
  3. Link CM and REEs to manufacturing of high-value products, including nonfuel carbon-based products (CBPs);
  4. Plan the development of a Technology Innovation Center, and stakeholder outreach and education to achieve the overall goal of enhancing economic growth and job creation to support economic development in the Gulf Coast.

The methods involve development of coal and ash resource assessments by leveraging previous coal assessments and using power plant ash data. The geological assessment involves mapping the resources, considering depositional environments and structural data, resulting in a detailed geomodel of the Gulf Coast coals.

This project will leverage DOE programs at the University of North Dakota (Nolan Theaker) characterizing CM/REEs in lignite in this region and processing REEs from lignites. Preliminary results from lignite in North Dakota are very promising. Charles Nye is also on our team from the Univ. of Wyoming and is characterizing CM/REEs in Power River coal, the primary source of coal in power plants in the Gulf Coast.

Analysis of REEs and CMs in ~ 200 samples of coal and ash are designed to substantially expand the existing database and deepen our understanding of the potential for these resources; however, The study will benefit from rapidly expanding REE and CM processing in the Gulf Coast providing feedback on quality needs and resource value. The intensive industrialization in the Gulf Coast region represents a large market for REE and CM products. The comprehensive assessment of REEs and CMs is designed to evaluate the volumes of these feedstocks and link upstream and midstream supply chains with downstream processing and manufacturing to enhance U.S. national and economic security.



Lignite Geochemistry, April 7, 2022 [link]

Jim Hower Lecture on Coal Petrology, March 14, 2022 [link]

Warwick, Peter Coal Geology and Resources of the U.S. Gulf of Mexico Coastal Plain, Oct 22, 2021 [link]

Theaker, Nolan: North Dakota Lignite Rare Earth Element (REE) Exploration and Extraction Review, July 1, 2021 [link]

Rose, Kelly: Improving prediction of subsurface reservoir properties using the power of geoscience, big data, and AI/ML methods, Jan 22, 2021 [link]

Nye, Charles: Rare Earth Element Concentrations in Produced Water: finding patterns at the part-per-trillion level and deciding what those patterns mean; Sep 18, 2020 [link]

Childress, Tristan: Critical Minerals Texas Potential: Lignites and Rhyolites, Nov 9, 2021 [link]


ADEM, Standards for the Disposal of Coal Combustion Residuals in Landfills and Surface Impoundments: Alabama Department of Environmental Management (ADEM), Solid Waste Branch, Fact Sheet, accessed Nov. 22, 2020. [link]

Ayers Jr., W. B.; Lewis, A. H., The Wilcox Group and Carrizo Sand (Paleogene) in east-central Texas; Depositional systems and deep-basin lignite: University of Texas at Austin, Bureau of Economic Geology Geologic Folio GF0001, 19 p., 30 plates. 1985. [link]

Bagdonas, D. A., A. J. Enriquez, K. A. Coddington, D. C. Finnoff, J. F. McLaughlin, M. D. Bazilian, E. H. Phillips, and T. L. McLing (2022), Rare earth element resource evaluation of coal byproducts: A case study from the Powder River Basin, Wyoming, Renewable and Sustainable Energy Reviews, 158, 112148 [link]

Bragg, L. J.; Oman, J. K.; Tewalt, S. J.; Oman, C. L.; Rega, N. H.; Washington, P. M.; Finkelman, R. B., U.S. Geological Survey coal quality (COALQUAL) database; version 2.0: U.S. Geological Survey Open-File Report 97-134, various pagination, 1997. [link]

Dai, S., R. B. Finkelman, D. French, J. C. Hower, I. T. Graham, and F. Zhao (2021), Modes of occurrence of elements in coal: A critical evaluation, Earth-Science Reviews, 222, 103815 [link]

Dai, S. F.; Finkelman, R. B., Coal as a promising source of critical elements: Progress and future prospects. International Journal of Coal Geology 2018, 186, 155-164 [link]

EPA, Hazardous and Solid Waste Management System: Disposal of Coal Combustion Residuals from Electric Utilities Rulemakings, A Holistic Approach to Closure Part A: Deadline to Initiate Closure,  EPA Rule on 8/28/2020. [link]

Finkelman, R. B., The Origin, Occurrence, and Distribution of the Inorganic Constituents in Low rank Coals. Proceedings of the Basic Coal Science Workshop. H.H. Schobert, compiler. Grand Forks Energy Tech., Center, Grand Forks, N.D., p. 70-90. 1981.

Fisher, W. L., and J. H. McGowen (1967), Depositional systems of the Wilcox Group of Texas and their Relationship to Occurrence of Oil and Gas: Gulf Coast Association of Geological Societies Transactions, 17, p. 105-125.

Finkelman, R. B.; Dai, S. F.; French, D., The importance of minerals in coal as the hosts of chemical elements: A review. International Journal of Coal Geology 2019, 212 [link]

Fu, B., Hower, J.C., Zhang, W., Hu, H., Luo, G., Yao, H., 2022. A review of rare earth elements and yttrium in coal ash: content, modes of occurrences, combustion behavior, and extraction methods. Progress in Energy & Combustion Science 88, 100954 [link]

Hower, J.C., Groppo, J.G., Hsu-Kim, H., Taggart, R.K., 2021. Signatures of Rare Earth Element distributions in fly ash derived from the combustion of Central Appalachian, Illinois, and Powder River basin coals. Fuel 301, 121048 [link]

Kaiser, W. R., W. B. J. Ayers, and L. W. LaBrie (1980), Lignite Resources in Texas, Report of Investigations No. 104, Bureau of Economic Geology and Texas Energy and Natural Resources Advisory Council (1980), p. 5. [link]

Laudal, D. A., S. A. Benson, D. Palo, and R. S. Addleman (2018), Rare Earth Elements in North Dakota Lignite Coal and Lignite-Related Materials, Journal of Energy Resources Technology, 140(6) [link]

TCEQ, Coal Combustion Residuals (CCR) Landfill, Texas Commission on Environmental Quality, Draft Technical Guideline, No. 30, 22 p. 2020. [link]

TCEQ, Coal Combustion Residuals (CCR) Surface Impoundments. Texas Commission on Environmental Quality, Draft Technical Guideline No. 31, 16 p. 2020. [link]

Valentine, B. J., and K. O. Dennen (2011), Shallow Coal Exploration Drill-Hole Data—Alabama, Georgia, Kentucky, Louisiana, Mississippi, Missouri, North Carolina, South Carolina, Tennessee, and Texas, U.S. Geol. Surv. Open File Rept. 2011-1261, variably paginated. [link]

Warwick, P. D., R. W. Hook, and J. R. SanFilipo (2011), Introduction - coal geology, mining history, and assessment methodology and results for the Gulf of Mexico coastal plain region, in Geologic assessment of coal in the Gulf of Mexico coastal plain, U.S.A.: AAPG Discovery Series No. 14/AAPG Studies in Geology, No. 62, p. 9 –  27., edited by P. D. Warwick, A. K. Karlsen, M. Merrill and B. J. Valentine.

Warwick, P. D., A. K. Karlsen, M. Merrill, and B. J. Valentine (2011), Geologic Assessment of Coal in the Gulf of Mexico Coastal Plain, U.S.A., AAPG Discovery Series No. 14, AAPT Studies in Geology NO. 62.

Warwick, P. D., S. S. Crowley, L. F. Ruppert, and J. Pontolillo (1997), Petrography and geochemistry of selected lignite beds in the Gibbons Creek mine (Manning Formation, Jackson Group, Paleocene) of east-central Texas, International Journal of Coal Geology, 34(3-4), 307-326 [link]

Warwick, P. D., S. S. Crowley, L. F. Ruppert, and J. Pontolillo (1996), Petrography and geochemistry of the San Miguel lignite, Jackson Group (Eocene), south Texas, Organic Geochemistry, 24(2), 197-217 [link]

Zielinski, R. A.; Finkelman, R. B., Radioactive Elements in Coal and Fly Ash: Abundance, Forms, and Environmental Significance U.S. Geol. Surv. Fact Sheet FS-163-97. 1997. [link]

Researchers and Assets

Bridget Scanlon, (UT-BEG) – Principle Investigator

Robert Reedy, (UT-BEG)

Jean-Philippe Nicot, (UT-BEG)

Tristan Childress, (UT-BEG)

Kristine Uhlman (UT-BEG)

Richard Kyle, (UT-JSG)

Sheldon Landsberger, (UT-JSG)

Peter Warwick, (USGS)

Leslie Ruppert, (USGS)

James Hower, PhD (University of Kentucky)

Sandy Ebersole, (Geological Survey of Alabama)

Berry H. (Nick) Tew, (Geological Survey of Alabama)

Charles Nye, (University of Wyoming)

Noland Theaker, (University of North Dakota)



University of Texas at Austin

University of Texas

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