黔北晚二叠世6号煤中关键金属元素的富集与来源分析OA

Objectives The Northern Guizhou region in China is endowed with abundant coal resources and is rich in diverse critical elements.In this study,the Late Permian Longtan Formation No.6 coal seam was selected as the research object to explore the enrichment characteristics and sources of critical elements in the coal seam.Methods Industrial analysis,scanning electron microscopy with energy-dispersive X-ray spec-troscopy(SEM-EDX),X-ray fluorescence spectrometry(XRF),and inductively coupled plasma-mass spec-trometry(ICP-MS),were employed to analyze the elemental geochemistry and mineral composition of the samples to investigate the origin of critical elements in the coal.Results The results show that Li,Th,and U in the Late Permian No.6 coal seam of Northern Guizhou are associated with clay minerals,whearas Tl may be hosted in pyrite.Ge and REY(rare earth elements and yttrium)are primarily associated with alumino-silicate minerals.The No.6 coal is enriched in Li,whereas the roof and floor,as well as the partings,are enriched in Nb and Ta.Additionally,the rare earth elements in the coal are of the light rare earth element(LREE)-enriched type.Conclusions It is concluded that the Late Permian No.6 coal seam in Northern Gui-zhou is mainly enriched in Li,with the elements exhibiting a trend of gradual enrichment from west to east,primarily controlled by the terrigenous supply of weathered detritus from the Emeishan high-Ti basalt and the overlying acidic rocks,as well as the input of synsedimentary felsic volcanic ash.