A Field Survey of Rare Earth Element Concentrations in Process Streams Produced by Coal Preparation Plants in the Eastern USA

Journal Article · Mon Aug 19 00:00:00 EDT 2019 · Mining, Metallurgy & Exploration

DOI:https://doi.org/10.1007/s42461-019-00124-5· OSTI ID:1908175

Luttrell, Gerald H. ^[1]; Kiser, Michael J. ^[2]; Yoon, Roe-Hoan ^[3]; Noble, Aaron ^[3]; Rezaee, Mohammad ^[4]; Bhagavatula, Abhijit ^[5]; Honaker, Rick Q. ^[5]

---

1. Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States); Virginia Tech
2. Marshall Miller & Associates, Inc., Blacksburg, VA (United States)
3. Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States)
4. Pennsylvania State Univ., University Park, PA (United States)
5. Univ. of Kentucky, Lexington, KY (United States)

I this work, a field study was undertaken to experimentally measure the concentrations of rare earth elements (REEs) contained in the process streams generated by a group of 20 coal preparation plants located in the eastern USA. For each site, representative samples of clean coal product, coarse refuse, and fine refuse were collected. Each sample was then partitioned into preselected size and density classes by wet screening/sieving and float-sink testing. The resultant products were dried and subjected to laboratory analyses to determine ash contents and rare earth element concentrations including Yttrium and Scandium. A detailed analysis of the database generated by this exercise showed that coal-based products from these preparation plants contained significant quantities of rare earth elements. In particular, the coarse refuse streams currently discarded by the 20 plants examined were found to contain a sufficient tonnage of REEs to satisfy the current domestic demand for these important elements. The data also showed a strong positive correlation between ash content and REE concentration, which suggested that the primary association of REEs in eastern USA bituminous coal sources is likely within fractions containing inorganic impurities. This association was well described using a simple power equation relating ash content and REE concentration. The ratio of heavy-to-light rare earth elements was discovered to be significantly higher in organically rich fractions of clean coal, suggesting that mineral impurities intimately associated with carbonaceous matter have elevated concentrations of heavy rare earth elements. A similar trend was observed for a grouping of rare earth elements (Y, Nd, Eu, Tb, and Dy) that are likely subject to near-term supply shortages. Finally, the database showed that a linear correlation existed between La for many REEs of interest, although there were several notable exceptions for some high-value REEs (Lu, Pr, and Tb).

• Research Organization: Univ. of Kentucky, Lexington, KY (United States); Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States)
• Sponsoring Organization: USDOE Office of Fossil Energy (FE)
• Grant/Contract Number: FE0027035
• OSTI ID: 1908175
• Alternate ID(s): OSTI ID: 1799865
• Journal Information: Mining, Metallurgy & Exploration, Journal Name: Mining, Metallurgy & Exploration Journal Issue: 5 Vol. 36; ISSN 2524-3462
• Publisher: Springer
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
Coal characterization
Coal preparation
Critical elements
Rare earth elements