Signatures of rare earth element distributions in fly ash derived from the combustion of Central Appalachian, Illinois, and Powder River basin coals

• Published in: Fuel (Guildford) 2021-05, Vol.301 (C)
• Main Authors: Hower, James C., Groppo, John G., Hsu-Kim, Heileen, Taggart, Ross K.
• Format: Article
• Language: English
• Subjects: 01 COAL, LIGNITE, AND PEAT; fly ash beneficiation; heavy rare earth elements; lanthanides; rare earth processing
• ISSN: 0016-2361; 1873-7153

We report the distribution of Rare Earth elements (REE) in coal-derived fly ashes can have distinctive patterns when fly ashes are produced from different coals within or between basins, such as the Pennsylvanian Class F fly ashes from the Illinois and Central Appalachian basins. Both the Fire Clay coal and a blend of a number of eastern Kentucky coals show strong Gd peaks and an H-type distribution in the Upper Continental Crust-corrected plots. The Fire Clay coal-derived ash has a higher heavy REE concentration than the blended coal-derived ash. The Illinois Basin-derived fly as has an overall lower REE concentration than the latter ashes. Class C fly ash derived from Powder River Basin coals has, with the exception of an Eu peak, a flatter distribution of REE and an overall L-type or indistinct H- versus L-type distribution. The signatures of the REE in fly ashes may be useful in predicting their behavior in the extraction of the REE; simple extrapolations from the basic concentrations and the predicted extraction percentages for ashes from different basins are not necessarily indicative of the actual distribution of the extracted REE.