Document Type

Article

Abstract

Kentucky produced over 8 Mt of coal combustion products (CCPs) in 2006, with 30% of the CCPs being utilized, a significant increase from our 1996 and 2001 surveys. As much of the increase is related to increased utilization of flue-gas desulfurization (FGD) gypsum, the increased production of FGD gypsum coincident with the commissioning of new FGD units and the saturation of the (currently) weak market for new construction, the percentage of utilization may decrease by the time of the next planned survey (2011). The concentration of volatile trace elements in the feed coal and in the pulverizer reject, while associated with pyritic sulfur, are somewhat independent of the pyritic sulfur content owing to provincial variations in the trace element content of coal minerals. Consequently, high-pyrite/high-S coals do not necessarily produce the highest-As,-Se, and–Hg (among other elements) fly ashes. Among the power plants in Kentucky, plants with intermediate sulfur contents have some of the highest concentrations of volatile trace elements in their fly ashes. In general, volatile trace elements in fly ash increase in concentration from the first through to the last row of the pollution control system owing to the decrease in flue gas temperature and decrease in particle size (and increase in surface area) in that direction. Mercury is dependent upon the carbon content in addition to the flue gas temperature. Selenium is more problematical, showing no consistent trend within the ash collection systems.

First Page

50

Last Page

62

DOI

https://doi.org/10.4177/CCGP-D-09-00013.1

Volume

1

Publication Date

1-1-2010

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