Mineralogy and geochemistry of coal from the Liupanshui mining district, Guizhou, south China

This study focuses on the geochemistry and mineralogy of 23 coal seams from the Shuicheng and Luizhi coal fields from the Late Permian Liupanshui coal mining district, in the west of Guizhou province in southern China. Coal rank ranges widely from high volatile bituminous to low volatile bituminous and anthracite. Major mineral phases present in the Liupanshui coal are kaolinite, quartz, pyrite, and calcite. Traces of other primary minerals are marcasite. gypsum, and dolomite, The Shuicheng coal usually has higher kaolinite and quartz contents than the Luizhi coal, Marcasite occurs indiscriminately in the different coal seams without a clear distribution pattern. The presence of other minerals. such as rutile, anatase, tourmaline, zircon, and phosphates. was also noted. The total sulphur content of Liupanshui coals is higher in the marine-influenced coal seams (up to 7.5% dry), and lower in the nonmarine-influenced coals las low as 0.3%). In the Luizhi coal field, the coal is characterised by a high sulphur and iron content, whereas in the Shuichene coal field, contents varied from low to high, depending on the coal seams. An inverse geochemical distribution was detected for the mean contents of Ca-Mn-Ge, with lower contents in the Luizhi coal field. The Liupanshui coals ale characterised by relatively high contents of Mn, V, Cu, Li, Zr, Nb, Hf, Ta, Tl, Tn, and U, when comparing with the usual concentration ranges in bituminous coals, Trace elements in coals from Liupanshui showed narrow variations in their concentrations among coal seams and coal. Three major trace element affinities (aluminium-silicates, sulphides, and carbonates) accounted for the occurrence and distribution of most of the elements studied were determined. (C) 2000 Elsevier Science B.V. All rights reserved.