Rare Earth Element Distribution in Fly Ash Derived from the Fire Clay Coal, Kentucky

Authors

Madison M. Hood, University of Kentucky, Center for Applied Energy Research, 2540 Research Park Drive, Lexington, KY 40511, USA
Ross K. Taggart, Duke University, Department of Civil and Environmental Engineering, Durham, NC 27708, USA
Ryan C. Smith, Duke University, Department of Civil and Environmental Engineering, Durham, NC 27708, USA
Heileen Hsu-Kim, Duke University, Department of Civil and Environmental Engineering, Durham, NC 27708, USA
Kevin R. Henke, University of Kentucky, Center for Applied Energy Research, 2540 Research Park Drive, Lexington, KY 40511, USA
Uschi Graham, University of Kentucky, Center for Applied Energy Research, 2540 Research Park Drive, Lexington, KY 40511, USA; Topasol LLC, 1525 Bull Lea Road No. 5, Lexington, KY 40511, USA
John G. Groppo, University of Kentucky, Center for Applied Energy Research, 2540 Research Park Drive, Lexington, KY 40511, USA
Jason M. Unrine, University of Kentucky, Department of Plant and Soil Sciences, Lexington, KY 40506, USA
James C. Hower, University of Kentucky, Center for Applied Energy Research, 2540 Research Park Drive, Lexington, KY 40511, USA

Document Type

Article

Abstract

Fly ash was collected from individual mechanical and electrostatic precipitator (ESP) hoppers at a 130-MW pulverized-coal utility unit burning a southeastern Kentucky moderate- to high-S Pennsylvanian Fire Clay coal. The fly ash particle size is generally similar within each row of the mechanical and ESP hoppers, with the mean particle diameter decreasing from >36 μmin the mechanical hoppers to 6 μm in the last ESP row. Rare earth element (REE)–bearing phases occur within fine minerals and, possibly, as part of the fly ash glass phase. Transmission electron microscopy was used to identify Y-Ce-Nd-La–bearing regions within a glassy matrix. Y- and U-bearing zircons were also found in the fly ash. Total REE plus yttrium (REY) occupies a narrow range from 719 to 775 ppm, showing an overall lack of partitioning of the REY elements with respect to particle size and temperature in ash collection systems. The heavy REE increase and the light REE/heavy REE ratio decreases from the mechanical hoppers through ESP rows.

First Page

22

Last Page

33

DOI

https://doi.org/10.4177/CCGP-D-17-00002.1

Volume

9

Publication Date

1-1-2017

Recommended Citation

Hood, Madison M., Taggart, Ross K., Smith, Ryan C., Hsu-Kim, Heileen, Henke, Kevin R., Graham, Uschi, Groppo, John G., Unrine, Jason M., Hower, James C., 2017, Rare Earth Element Distribution in Fly Ash Derived from the Fire Clay Coal, Kentucky. Coal Combustion and Gasification Products 9, 22-33, doi: 10.4177/CCGP-D-17-00002.1