Abstract:
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 coalformation. 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 coupledplasma mass spectrometry (ICPMS), Xray fluorescence spectrometry (XRF), coldvapor atomic absorption spectrometry (CVAAS), atomic fluorescence spectrometry (AFS), ionselective spectrometry (ISF), scanning electron microscope equipped with dispersive Xray energy (SEMEDX), and sequential chemical extraction technology (SCET). The results show that minerals in the No.2 coal are mainly pyrite of lowtemperature hydrothermal origin and clay minerals of detrital terrigenous origin. The pyrite in the No.2 coal mainly occurs as fracturefillings 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 lowtemperature 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.