METALLURGICAL COAL RESOURCES IN THE EASTERN KENTUCKY COAL FIELD, CENTRAL APPALACHIAN BASIN

Eight major mineable coal beds in the eastern Kentucky coal field were assessed for their metallurgical coal potential. Collectively, the eight beds contained original resources of 11.4 billion tons of coal greater than 28 inches in thickness. However, the eastern Kentucky coal field is a mature mining region, and remaining resources are only 5.5 billion tons, or 48 percent of the original resources. Furthermore, most of these remaining resources (83 %) occur in coal 28 and 42 inches thick; only 17 percent of remaining coal is greater than 42 inches in thickness. As such, more recent development is in thinner coal (28 to 42 inches), which requires the extraction of additional rock (roof and/or floor) along with the coal, resulting in higher mining and processing costs. Run-of-mine samples, collected during the course of the study, commonly contained 20 to 50 % ash, showing the extent of this historical development.

Beneficiated (washed) coal samples from these eight beds were consistently low in ash yield (avg. 6.6 %, dry basis). Sulfur contents were generally low (avg. 1.1 %, dry basis), though sulfur variability was found to be quite high. Much of the sulfur occurs as very small (<10 microns), highly-disseminated, pyrite grains that are not easily removed by coal preparation techniques. The average volatile matter and total carbon contents of the eastern Kentucky coal samples were 40.0 % and 80.5 % (dry, ash free basis), respectively. The average maximum reflectance of coal samples was 0.89 %, with an observed range between 0.77 and 0.98 %. Reactive/Inert component ratios in the coals averaged 4:1. Predicted coke strength after reaction (CSR) values averaged 40.3, and ranged from 18 to 51.

Although many parameters for the analyzed coals fall outside limitations proposed for coking coal consideration, no single parameter qualifies, or disqualifies, an individual coal from metallurgical consideration. Results indicate that many eastern Kentucky coals can be used as metallurgical feedstock, though primarily through blending with other (mainly low volatile bituminous) coals. Furthermore, low ash, low sulfur eastern Kentucky coal appears to be of prime consideration as pulverized coal injection (PCI) coal, as many samples analyzed during the course of this study had calorific values in excess of 14,000 BTU/lb (dry basis).