Geochemical Characteristics Of Trace Elements In The Coals Form Xidatan Mining Area

This thesis discusses the content occurrence, enrichment mechanism of trace elements and the maceral in coal of Xidatan Mining Area, which is theoretical guidance for the coal petrology, mineralogy, sedimentology, coal geology and so on, and using the experimental apparatus and methods like polarizing microscope, inductively coupled plasma massspectrometry(ICP-MS), X-ray diffraction(XRD) analyze, scanning electron microscope(SEM) and so on.The results show that:The coal of Xidatan is with low ash yield, high volatile content, low-sulfur content. The main maceral is inertinite, then is vitrinite and the least is exinite. The most mineral is carbonate, and there are clay, sulfide and oxide and so on.The trace elements in the coal of Xidatan Mining Area, whose concentration coefficient(CC) is higher than 5, obviously enriched, are Eu, Tb, Ho, Lu. All of the elements are rare earth element, whose content are higher than those of Chinese, American and the world value. The concentration coefficients of Sr, Tl and Mn are higher than 2, which are slight enrichment. The contents of Co and Rb are loss in the gangue, while the contents of Ga, Cd, U, Cu, Sr, Ba and Mn are normal. Li, Be, Cs and Pb are mild enrichment and Bi is obvious enrichment. The contents of light rare earth element(LREE), they are normal, except Ce is mild enrichment. The contents of mild rare earth elements(MREE) and heavy rare earth elements(HREE) are higher than Chinese value and world value, in which, Eu, Tb and Ho reach obvious enrichment.By analyzing the coal maceral, it is found that Ce is weak positive anomaly, which means that coal-bearing environment is weak oxidation- reduction environment and doesn’t cause heavy loss in Ce. So the sedimentary environment in this area is main of continental peat bog.