Influence of Coal Quality Parameters on Utilization of High-Sulfur Coals: Examples from Springfield (Western Kentucky No. 9) Coal Bed

Thomas B. Griswold, James C. Hower, James C. Cobb

The Springfield (Western Kentucky No. 9) coal bed is the most important energy resource in the Western Kentucky coalfield (Eastern Interior coalfield), accounting for over 30 million tons of annual production from remaining resources of over 9 billion tons. For many coal quality parameters, the quality of the coal bed is relatively consistent throughout the region. For example, the Springfield has about 80-85% vitrinite, 10% ash, and 3.5-4.5% total sulfur at most sites in the coalfield. However, coal quality variation is more than just the changes in ash and sulfur. As demonstrated by the Springfield coal bed, it is a complex interaction of related and unrelated variables many of which directly affect utilization of the coal.

Significant, though generally predictable, changes are observed in other parameters. Comparison of data from the Millport (Muhlenberg and Hopkins Counties), Providence (Hopkins and Webster Counties), and Waverly (Union County) 7½^Prime Quadrangles illustrated such variations. The highest vitrinite reflectances are found in Webster and Southern Union Counties, the Springfield in the Providence Quadrangle averaging 0.75% R_max compared to 0.57% R_max and 0.52% R_max for the Millport and Waverly Quadrangles, respectively. Other parameters directly and indirectly related to rank also change similarly. For example, free swelling index is near 6 in Providence compared to nearly 3 in Waverly. Chlorine content also increases to the west, ranging from 0.05% ( s-determined) in Millport to 0.11% in Waverly to 0.26% in Providence (and to 0.30% in the Bordley Quadrangle north of Providence). Trace element concentrations in the coal bed in the eastern half of the coalfield are relatively small and vary little between benches of the coal bed. In contrast, concentrations of V, Cr, Ni, Zn, and Ba exhibit significant increases to the top of the Springfield in Webster and Union Counties. Other coals in the region exhibit similar variations, particularly in the rank-related parameters, but also in the geochemical parameters.

AAPG Search and Discovery Article #91023©1989 AAPG Eastern Section, Sept. 10-13, 1989, Bloomington, Indiana.