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 r ank 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 dif ferent coal seams without a clear distribution pattern. The presence of oth er minerals. such as rutile, anatase, tourmaline, zircon, and phosphates. w as also noted. The total sulphur content of Liupanshui coals is higher in the marine-influ enced coal seams (up to 7.5% dry), and lower in the nonmarine-influenced co als las low as 0.3%). In the Luizhi coal field, the coal is characterised b y a high sulphur and iron content, whereas in the Shuichene coal field, con tents varied from low to high, depending on the coal seams. An inverse geoc hemical distribution was detected for the mean contents of Ca-Mn-Ge, with l ower contents in the Luizhi coal field. The Liupanshui coals ale characteri sed by relatively high contents of Mn, V, Cu, Li, Zr, Nb, Hf, Ta, Tl, Tn, a nd U, when comparing with the usual concentration ranges in bituminous coal s, Trace elements in coals from Liupanshui showed narrow variations in thei r concentrations among coal seams and coal. Three major trace element affin ities (aluminium-silicates, sulphides, and carbonates) accounted for the oc currence and distribution of most of the elements studied were determined. (C) 2000 Elsevier Science B.V. All rights reserved.