贵州普安矿区晚二叠世煤中微量元素的质量分数和赋存状态

Understanding the concentrations and origins of trace elements in coal is both practically and theoretically significant in the utilization of potentially valuable trace metals in coal combustion byproducts and revealing origins of coalformation. The contents, occurrence modes, and origin of trace elements in the Late Permian coals from the Puan Coalfield of western Guizhou Province were studied using inductively coupledplasma mass spectrometry (ICPMS), Xray fluorescence spectrometry (XRF), coldvapor atomic absorption spectrometry (CVAAS), atomic fluorescence spectrometry (AFS), ionselective spectrometry (ISF), scanning electron microscope equipped with dispersive Xray energy (SEMEDX), and sequential chemical extraction technology (SCET). The results show that minerals in the No.2 coal are mainly pyrite of lowtemperature hydrothermal origin and clay minerals of detrital terrigenous origin. The pyrite in the No.2 coal mainly occurs as fracturefillings and clay minerals as lenses and fine particles in collodetrinite. The elements including As 〖ＷＴＢＺ〗(36.9×10－6), Cd (10.2×10－6), Cr (167.3×10－6), Cu (365.4×10－6), Hg (2.82×10－6), Mo (92.6×10－6), Ni (82.6×10－6), Pb (184.6×10－6), Se (6.23×10－6), Zn (242.3×10－6), and U (54.6×10－6), 〖ＷＴＢ１〗are significantly enriched in the coal, as compared with those in coals from Guizhou, China, and USA. However, the contents of trace elements in the other 4 coals (No.1, No.3, No.4, and No.5) are close to those in coals from Guizhou, China, and USA. Elements of As, Cd, Hg, Ni, Pb, and Zn in No.2 coal mainly distribute in pyrite, and Cr, Cu and U are mainly in kaolinite, indicating that the lowtemperature hydrothermal fluid and detrital material of terrigenous origin play a critical role in the contents and occurrence modes of trace elements in the No.2 coal.