Abstract
Coal and coal byproducts produced annually contain a sufficient amount of rare earth elements (REEs) to meet current U.S. demand. The REEs exist in the form of minerals, ion-adsorbed elements associated with clays, and chemically bonded elements within the organic coal matrix or host mineral. Researchers at three universities collaborated to evaluate the effectiveness of existing physical and chemical concentration processes for the recovery of the REEs. The efforts found that physical separation processes can increase the total REE content in the thickener underflow material collected from a Central Appalachian coal cleaning facility from around 300 ppm to values greater than 17, 500 ppm on an ash basis. Leaching followed by solvent extraction was found to be the most effective to recover the REEs from coarse middlings materials collected from multiple coal basins, as indicated by recovery values exceeding 80 percent. Based on material characterization data and process evaluations conducted for several potential feed coal sources, economic recovery of the REEs will require byproduct production of both clean coal and REE concentrate using a process flowsheet that is unique for each source.
Original language | English |
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Pages (from-to) | 107-115 |
Number of pages | 9 |
Journal | Minerals and Metallurgical Processing |
Volume | 34 |
Issue number | 3 |
DOIs | |
State | Published - Aug 2017 |
Bibliographical note
Funding Information:This material is based upon work supported by the Department of Energy under Award Number DE-FE0027035. The authors are greatly appreciative of the contributions provided by Dr. James Hower, Dr. Cortland Eble and Mr. Jason Backus. The completion of the experimental work would not have been possible without the efforts of several graduate research associates, including Mr. Wencai Zhang, Ms, Xinbo Yang and Mr. Alind Chandra
Keywords
- Coal
- Flowsheet
- Process evaluation
- Rare earth elements
ASJC Scopus subject areas
- Control and Systems Engineering
- General Chemistry
- Geotechnical Engineering and Engineering Geology
- Mechanical Engineering
- Metals and Alloys
- Materials Chemistry