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An ESCA and SEM Study of Changes in the Surface Composition and Morphology of Low-Calcium Coal Fly Ash as a Function of Aqueous Leaching

Published online by Cambridge University Press:  25 February 2011

Myra M. Soroczak
Affiliation:
College of Engineering, Louisiana State University, Baton Rouge, LA 70803USA
H. C. Eaton*
Affiliation:
College of Engineering, Louisiana State University, Baton Rouge, LA 70803USA
M. E. Tittlebaum
Affiliation:
College of Engineering, Louisiana State University, Baton Rouge, LA 70803USA
*
**Author to whom correspondence should be addressed.
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Abstract

The reactivity of coal fly ash is dependent on the chemical composition of the surface. As reactions occur the ash particle size decreases and new material is available for reaction. This means that the near-surface chemistry can also be important. In the present study the surface chemistries of three ashes are determined by x-ray photoelectron spectroscopy both before and after exposure to a hydrating/leaching environment. Scanning electron microscopy is used to reveal ash morphology. The concentration of sulfur, found at the ash surfaces as a sulfate, and sodium decreased after leaching while the amount of iron and aluminum increased. Other elements, including calcium, increased and decreased with leaching depending on which ash was analyzed. Changes which occurred in the ash morphology after the removal of leachable elements are discussed.

Type
Research Article
Copyright
Copyright © Materials Research Society 1987

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Footnotes

*

Visiting from: Tennessee Valley Authority, National Fertilizer Development Center, Muscle Shoals, AL 35660 USA

References

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