Impact of Coal Quality Considerations on Availability of Low-Sulfur Coal in Appalachian Region of Kentucky

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

A major role of the states in coal research is to build data bases to assist producers in exploration, development, and marketing, as well as help consumers locate coals needed for particular applications. For any coal, a full complement of analyses is necessary to determine those factors that influence its end use.

Commonly, statements about the availability of low-sulfur coal concern only the amount of sulfur dioxide generated per million Btu of coal consumed. However, other characteristics are very important for particular purposes. Some factors are ash slagging and fouling indices, ash fusion temperatures, heat content, chlorine content, and grindability. Examples using data from the Kentucky Energy Cabinet's Kentucky Coal Marketing Information System (KCMIS), which includes the Kentucky Energy Cabinet Laboratory's data base on coal quality, and the Kentucky Geological Survey's Kentucky Coal Resource Information System (KCRIS) demonstrate the need to include other parameters in any assessment of low-sulfur coal resources.

Two of the most important coal beds in eastern Kentucky are the Pond Creek and Upper Elkhorn 3. In 1985, 85 mines in the Pond Creek (also known as the lower Elkhorn), in Pike and Martin Counties, produced over 13.1 million tons of coal. That same year 155 mines in the upper Elkhorn 3 in seven counties produced over 5.7 million tons of coal. Total estimated resources of these two seams and their equivalents are about 12 billion tons.

In south-central Pike County, the sulfur content of the Pond Creek is generally below 1% and the chlorine content is about 0.1%. Northward, the sulfur content is more variable, ranging from 0.6 to 1.8% (sometimes within 100 m) with some chlorine contents exceeding 0.3%. Compliance specifications range from 0.69 to 2.52 lb SO₂ per million Btu. Vitrinite reflectance decreases from about 1.0% R_max in the south to about 0.8% R_max in the north, with hardgrove grindability following a similar decrease. A 600°F range of fusion temperatures has been observed in the Pond Creek at sites only 1.6 km apart. This difference likely would be decreased by cleaning.

The compliance specifications for the upper Elkhorn 3 exhibit a wider range than for the Pond Creek coal bed, from 0.79 to 4.76 lb SO₂ per million Btu. Vitrinite reflectance ranges from 0.7 to 1.1 R_max. Limited data suggest a lower range in ash fusion temperatures than for the Pond Creek, but the chlorine range is similar.

AAPG Search and Discovery Article #91031©1988 AAPG Eastern Section, Charleston, West Virginia, 13-16 September 1988.