原位微区分析华北典型富锂煤中关键金属赋存规律OA北大核心CSTPCD

Coal,a significant organic sedimentary rock,possesses the potential to serve as a source of various critical metals. Lithium mineralization in the coals of North China has been extensively documented. This study employed a suite of in-situ analytical techniques,including LA-ICP-MS,SEM-EDX,Micro-Raman,and Micro-FTIR,to investigate the host phases of Li and other enriched critical metals in high-Li coals from North China. This study offers a new perspective on the understanding of the enrichment mechanisms and exploration potential of critical metals within coal deposits. The results indicate that lithium is predominately hosted within kaolinite,exhibiting three distinct assemblages:Li-Ga,Li-Zr-Nb-Hf-Ta,and Li-Y-Sr. Kaolinite with Li-Ga and Li-Zr-Nb-Hf-Ta enrichments originated from detrital input and ash supply during peat formation. The Li-Y-Sr enrichments in kaolinite are a result of epigentic fluid activity in the coal. Telinite presents enrichment with zirconium (Zr),hafnium (Hf),and thorium (Th). Additionally,sodium-bearing clay veins display elevated concentrations of gallium (Ga),barium (Ba),and thallium (Tl),while apatite veins exhibit enrichments in Ba,strontium (Sr),and yttrium (Y). These critical metal enrichments in mineral veins are attributed to fluid activity during coalification.