Geochemical Characteristics Of High Aluminacoal In Qinshui Coalfield

The study of mineralogical characteristics and associated elements in High-Alumina coal is of great significance to the development and utilization of coal resources.They can not only provide data support for the analysis of coal seam sedimentation process,but also provide theoretical basis for the extraction of valuable elements and the removal of harmful elements in coal.This paper uses the disciplines of coalfield geology,coal petrology,mineralogy and geochemistry as the theoretical guidance,the geochemical characteristics of No.15 coal in Pingshang Coalfield and Shouyangshan Coal Mine of Qinshui Coalfield were studied preliminarily by using the polarization microscope,XRD,XRF,ICP-MS,SEM-EDS techniques and other experimental instruments.Pingshang Coal Mine and Shouyangshan Coal Mine No.15 are mainly bright coal,with a small amount of dark coal,and are generally glass luster.The main macerals were vitrinite?69.28%and 79.24%?,followed by inertinite?19.35%and 11.54%?,and no crustal macerals were found,indicating that the maturity of coal seams in the two mines is relatively high.The minerals in the two coal seams are mainly clay minerals,quartz,calcite and pyrite,followed by a small amount of pyrite,chalcopyrite,rutile,ilmenite,iron dolomite,boehmite and apatite.Among the macroelements,except for the content of Al₂O₃ and P₂O₅ in No.15 coal of Pingshang Mine,which is slightly higher than the background value of elemental content in Chinese coal,the content of other major elements in the two mines is lower than the Chinese value.Among the trace elements,the contents of trace elements in No.15 coal seam of Pingshang and Changzhi Shouyangshan are almost the same,showing a deficit state on the whole,and the distribution trend is roughly the same,indicating that the two coal seams may have the same source and geological background.Through R-type clustering analysis,it can be seen that in the process of coal seam deposition,due to the influence of land supply,environmental changes,geological structure and other factors,the clustering trend of elements in the two coal mines is quite different.Rare earth elements in No.15 coal of Pingshang Coal Mine may exist in the form of organic adsorption.Coal No.15 of Shouyangshan Coal Mine in Changzhi may coexist in the form of organic adsorption and inorganic state,and is mainly distributed in inorganic minerals.The enrichment types of rare earth elements in both mines are L-type type and HREY elements are seriously depleted.The parent rocks of both coal seams are continental sources,but the sedimentary process is constantly affected by seawater erosion.The coal-forming environment is an interfacies of sea and land dominated by acid-reduction environment.