PETROLOGY OF APPALACHIAN COKING COALS

The availability of the Bethlehem Steel Corporation database of petrographic analyses of Appalachian coking coals provides a unique opportunity to characterize these coals. The database contains about 8000 petrographic and chemical analyses from major coking coal seams in western and central Pennsylvania, West Virginia, and eastern Kentucky. The petrographic analyses include the macerals vitrinite, pseudovitrinite, exinite, resinite, fusinite and semifisinite, semimscrinite, massive and granular micrinite, and mineral matter. Reflectance data include mean maximum reflectance on both vitrinite and pseudovitrinite as well as the reflectance distributions. The ranks of the coals range through high volatile A, medium volatile and low volatile Bituminous. Both types of data were run under slightly modified ASTM standards. The chemical data includes ASTM dry volatile matter, dry, ash, and dry sulfur. Initial analysis indicates that the vitrinite content ranges from 50-65% and the peudovitrinite content ranges from 25 -35 % with the total vitrinite maceral group ranging from 70-90%. The reflectance data show that the pseudovitrinite always has a higher mean maximum reflectance than the vitrinite in the same coal with the differences ranging from 0.04-1.25% Ro with the lower values occurring in the higher rank coals. The data also show that in these coals the semifusinite is on average twice as abundant as the fusinite macerals and that total vitrinite macerals vary inversely with the total inertinite content.