Probing the Critical Element Chemistry of Coal-Combustion Fly Ash

Authors

• Debora Berti, Baylor UniversityFollow
• John G. Groppo, University of KentuckyFollow
• Prakash Joshi, Physical Sciences Inc.Follow
• Dorin V. Preda, Physical Sciences Inc.Follow
• David P. Gamliel, Physical Sciences Inc.Follow
• Todd Beers, Winner Water ServicesFollow
• Michael Schrock, Winner Water ServicesFollow
• Shelley D. Hopps, University of KentuckyFollow
• Tonya D. Morgan, University of KentuckyFollow
• Bernd Zechmann, Baylor UniversityFollow
• James C. Hower, University of KentuckyFollow

Abstract

Along with the principal rare earth (REE) minerals such as monazite, xenotime, and bastnasite, Y-and REE-bearing zircon and associated minerals survive the combustion process and are found in coal-combustion fly ash. Beneficiated fly ash from a power plant burning an eastern-Kentucky-sourced coal blend was found to have zircon (ZrSiO₄), baddeleyite (ZrO₂), fergusonite (YNbO₄), yttriaite (Y₂O₃), and xenotime (YPO₄). Previous studies of the same fly had also identified monazite with a broad REE suite. Scanning electron microscopy–electron dispersive spectroscopy (EDS) and transmission electron microscopy (TEM)–EDS as well as other TEM-based techniques revealed a variety of zircon associations, including heavy-REE suites with Y, Nb, and Hf. Hafnium is a common accessory element in zircons and the Y and Nb may be present as fergusonite (YNbO₄) intermixed with zircon.

Document Type

Article

Publication Date

5-1-2025

Notes/Citation Information

Publisher Copyright: © 2025 by the authors.

Digital Object Identifier (DOI)

10.3390/min15050461

Archival?

Archival

Repository Citation

Berti, Debora; Groppo, John G.; Joshi, Prakash; Preda, Dorin V.; Gamliel, David P.; Beers, Todd; Schrock, Michael; Hopps, Shelley D.; Morgan, Tonya D.; Zechmann, Bernd; and Hower, James C., "Probing the Critical Element Chemistry of Coal-Combustion Fly Ash" (2025). Earth and Environmental Sciences Faculty Publications. 76.
https://uknowledge.uky.edu/ees_facpub/76