Rare earth element associations in the Kentucky State University stoker ash


Journal Article

© 2018 Elsevier B.V. The Kentucky State University heating plant stoker ash, with over 1000 μg/g Rare earth elements + yttrium (REY), was previously shown to be more resistant to acid-extraction than pulverized-coal fly ashes of similar bulk composition. In this study, the petrology and mineralogy of this stoker ash was examined in greater detail as a means to better understand why the REY were relatively inert towards acid extraction. The results showed that this stoker ash is dominated by mullite and quartz/cristobalite with lesser amounts of hematite and magnetite compared to the glass-dominated assemblages of pulverized-coal-combustion fly ashes with similar chemical compositions. On the nanometer to micron scale, La-Ce-Nd-bearing monazite and Ce phosphates (monazite – CePO4 and CeP3O9) are seen to be part of the mineral assemblage. Overall, the results demonstrate that despite the presence of discrete REY-bearing minerals in the sample, their encapsulation within other phases may explain their low extractability.

Full Text

Duke Authors

Cited Authors

  • Hower, JC; Qian, D; Briot, NJ; Henke, KR; Hood, MM; Taggart, RK; Hsu-Kim, H

Published Date

  • March 15, 2018

Published In

Volume / Issue

  • 189 /

Start / End Page

  • 75 - 82

International Standard Serial Number (ISSN)

  • 0166-5162

Digital Object Identifier (DOI)

  • 10.1016/j.coal.2018.02.022

Citation Source

  • Scopus