The characterization of coal quality from the Jining coalfield

The Jining coalfield in the west Shandong Province contains coal of Permian and Carboniferous age. The 31 and 32 seams of the Permian Shanxi Formation and seams 6, 10, 15, 16 and 17 of the Carboniferous Taiyuan Formation were analyzed for coal petrogrophy, mineralogy and geochemical parameters. The coal rank parameters indicate that the coal grade is a high volatile bituminous rank. The coal of the Taiyuan Formation is characterized by high vitrinite, low to medium inertinite and liptinite contents, lower ash yield and higher sulfur content than the Shanxi Formation. These properties may be related to the coal forming environment from more reducing conditions in a marine influenced lower delta plain environment for the early Taiyuan coals to more oxidizing paleoenvironmental conditions in an upper delta plain for the upper Shanxi coal seams. The major mineral phases present in the coal are quartz, kaolinite, pyrite and calcite. Sulfur is one of hazardous elements in coal. The major form of sulfur in coal is pyritic sulfur. The sulfur content of the Taiyuan coal seams is considerably higher than that of the Shanxi coals. The sulfur content is positively correlated with pyritic sulfur.