Garry D. Wild

Petrographic variation in the Springfield (No. 9) coal in Western Kentucky

Abstract The Springfield (Western Kentucky No. 9) coal of the Carbondale Formation (Middle Pennsylvanian) in the Western Kentucky Coal Field of the Illinois Basin was sampled in eleven mines from one to three channels of three equal benches. The rank of the coal is high-volatile C bituminous in the Moorman Syncline and in the Henderson Basin and high-volatile B bituminous in the Webster Syncline. The percentage of total vitrinite macerals and of total vitrinite plus liptinite was found to decrease significantly from the bottom bench through to the top bench. In a comparison of the sources of variation within the set of maceral data it was found that the only significant variation in the vitrinite and vitrinite plus liptinite percentages was between the benches. Both the rank of the coal and the maceral percentages are varying in a predictable manner.

Coal microlithotype response to froth flotation in selected Western Kentucky coals

Abstract Seven coals representing four western Kentucky coal seams and the coal rank range from high volatile C to high volatile A bituminous were selected for bench-scale froth flotation processing. Each coal was represented by two splits of the run-of-mine coal: a 12.7 mm × 0 fraction (crushed to 28 mesh × 0) and a 28 mesh × 0 fraction. The original 28 mesh × 0 split was found to be higher in the inertinite macerals fusinite and semifusinite than the coarser fraction. The separation of the inertinite macerals, expressed as the microlithotype inertite, from the vitrinite-rich vitrite and clarite microlithotypes proved to be markedly rank dependent. In the higher rank coals vitrite and clarite were concentrated in the clean coal while inertite was concentrated in the clean product in the high volatile C coals. Whereas in gravity-based coal cleaning only the finest pyrite usually remains in the clean coal, in this study no consistent trend in pyrite-size or pyrite-quantity partitioning was noted.

Petrography of the Herrin (No. 11) coal in western Kentucky

Abstract The Herrin (No. 11) coal in western Kentucky is in the upper part of the Pennsylvanian (Des Moinesian) Carbondale Formation. Samples were obtained from 13 mines in Kentucky and one mine in Illinois in three equal benches from two to three channels for a total of 93 samples. The rank of the coal (as vitrinite reflectance) is high volatile C bituminous in the Moorman Syncline and high volatile A bituminous in the Webster Syncline. Reflectance does not vary between mines in in the Moorman Syncline. The percentage of total vitrinite macerals for each mine is over 85% and the percentage of togal vitrinite plus liptinite maceralsis over 89% (average over 90%) (both on dry, mineral-free basis). The variation of the two maceral percentages is only significant at the betweenbench level, the middle bench generally having the lowest vitrinite and vitrinite plus liptinite percentages.

Coal metamorphism in the upper portion of the Pennsylvanian Sturgis Formation in western Kentucky

Coals from the Pennsylvanian upper Sturgis Formation (Missourian and Virgilian) were sampled from a borehole in Union County, western Kentucky. The coals exhibited two discrete levels of metamorphism. The lower-rank coals with vitrinite reflectances indicative of high volatile C bituminous were assumed to represent the normal level of metamorphism. A second set of coals with vitrinite reflectances indicative of high volatile A bituminous was found to be associated with sphalerite, chlorite, and twinned calcite. The latter mineral assemblages indicate that hydrothermal metamorphism was responsible for the anomalous high rank. Consideration of the sphalerite fluid-inclusion temperatures from nearby ores and coals and the time-temperature aspects of the coal metamorphism suggests that the hydrothermal metamorphic event was in the 150 to 200 °C range for a brief time (10 5 –10 6 yr), as opposed to the longer term (25–50 m.y.) 60 to 75 °C ambient metamorphism.

Coal resources, production, and quality in the Eastern kentucky coal field: Perspectives on the future of steam coal production

The Eastern Kentucky coal field, along with adjacent portions of Virginia and southern West Virginia, is part of the greatest production concentration of high-heating-value, low-sulfur coal in the United States, accounting for over 27% of the 1993 U.S. production of coal of all ranks. Eastern Kentuckys production is spread among many coal beds but is particularly concentrated in a limited number of highquality coals, notably the Pond Creek coal bed and its correlatives, and the Fire Clay coal bed and its correlatives. Both coals are relatively low ash and low sulfur through the areas of the heaviest concentration of mining activity. We discuss production trends, resources, and the quality of in-place and clean coal for those and other major coals in the region.

Lithologic succession in the Path Fork coal bed (Breathitt Formation, Middle Pennsylvanian), southeastern Kentucky

Abstract The Path Fork coal bed (Breathitt Formation, Middle Pennsylvanian/Westphalian B) on the Pine Mountain thrust sheet in southeastern Kentucky and adjacent portions of Virginia exhibits a lithologic succession which is traceable for about 25 km. Lateral continuity of lithotypes within the bed can be demonstrated using organic petrography, palynology, and ash geochemistry. The lithologic continuity is a consequence of the initial levelling of the pre-peat topography and the interaction of the peat with growing anticlines and synclines.

Petrography of the Paradise (No. 12), Baker (No. 13), and Coiltown (No. 14) coals of the lower portion of the Sturgis Formation (Pennsylvanian) in western Kentucky

Coal rank (based on vitrinite reflectance) and maceral composition were determined for 50 channel and borehole samples of the Paradise (No. 12), Baker (No. 13), and Coiltown (No. 14) coals in the Western Kentucky Coal Field. The three coal beds are in the lower part of the Pennsylvanian Sturgis Formation (Desmoinesian). Coal rank trends for the three coals vary across structural provinces in a similar and predictable manner. Coals in the Moorman syncline in the southeast are predominantly of high volatile C bituminous rank but approach high volatile B bituminous rank within the Pennyrile and Central fault systems that border the Moorman syncline. Westward, across the Central faults, rank of coals is high volatile B bituminous in the Webster syncline but increases to high volatile A bituminous northward, within the Rough Creek fault system. Coal rank in the Henderson basin north of the Rough Creek faults decreases to high volatile C bituminous. The Paradise, Baker, and Coiltown coals have consistently high percentages of total vitrinite (vitrinite and pseudovitrinite) (88% for the Paradise coal; 87% for the Baker coal; 85% for the Coiltown coal) and concomitant uniform low percentages of inertinites (less than 10% for each coal) (dry, mineral-matter-free basis). Total reactives (total vitrinite and liptinites) constitute 91% of the Paradise and Baker coals, and 90% of the Coiltown coal. Comparison of the three coals with stratigraphically lower coals in the Pennsylvanian of western Kentucky indicates that rank trends and maceral composition continue to be predictable, not only across the Western Kentucky Coal Field, but also within a large portion of the Pennsylvanian stratigraphic section.

Influence of regional structure on the development and quality of the Upper Elkhorn No. 2 coal bed, eastern Kentucky

Abstract The Upper Elkhorn No. 2 coal bed (Middle Pennsylvanian Breathitt Formation) in eastern Kentucky exhibits thickness and coal quality trends which suggest that peat deposition was contemporaneous with tectonism. The coal thickens and has high vitrinite and low ash and sulfur content the Belfry anticline in Pike Country. T in the vicinity of the Floyd Country channel, a basement trough. In both cases other Pennsylvanian coals exhibit similar trends, suggesting that the penecontemporaneous tectonism persisted at least through a portion of the Carboniferous.

Maceral Partitioning through Beneficiation of Illinois Basin Coals

Coals from 28 Illinois Basin preparation plants, primarily in western Kentucky, were studied for maceral partitioning around several unit operations. Consideration was also given to two sets of plants with similar designs; in one case cleaning the same seam and in the other case cleaning three different seams. More consistent maceral partitioning was exhibited in the finer fractions than in the coarse coal with the fine clean coal being enriched in vitrinite and the fine refuse being enriched in fusinite plus semifusinite. Comparison of coals prepared through similar operations indicated that a significant difference existed in the maceral partitioning both between different coals cleaned in one plant and between the same coal seam (different mines) beneficiated through similar design plants. The petrographic characteristics of each coal appear to be site specific and include inherent factors, such as maceral-mineral associations, as well as factors imposed during mining.

Maceral and pyrite partitioning through high-gradient magnetic separation of selected western kentucky coals

Abstract The −0.5 inch (−1.27 cm) and −28 mesh (−600 μm) fractions of the run-of-mine coals from seven western Kentucky preparation plants were crushed to 90 percent passing 200 mesh (75 μm) and processed through high-gradient magnetic separation (HGMS). Petrographic analysis of the clean and refuse fractions indicated that the refuse contained nearly the same amount of vitrinite as the associated clean coal. This contrasts with the findings for other fine coals from the same plants where fine refuse had consistently less vitrinite and more fusinite and semifusinite than fine clean coals. Pyrite remaining in HGMS clean coals was significantly finer than pyrite in the refuse. Most of the pyrite in the clean was less than 5 μm in diameter, and, in all but one case, greater than 98 percent of the “clean” pyrite was less than 10 μm.