Geochemical Characteristics Of Jurassic Coal From Tatuo Mine In Qinghai Province

A total of 25 coal samples are analyzed by polarization microscope, ICP-MS,XRD, XRF, SEM-EDS techniques. The figures and data, derived from tests, are analysed by SPSS, Excel, CAD, CorelDRAW, MDI Jade and other software. This paper research the characteristics of maceral, mineral and associated elements based on the theory of coal petrology, mineralogy, geochemistry and sedimentology.The results shows that Tatuo coal are riched with fracture and easily broken.From the nature of the fracture, the paper speculate that Tatuo coal were affected by tectonic stress in the coal forming and the late stage. By coal industry analysis, there are medium-volatile, medium-ash, low-sulfur coal in the study area. Measured by polarization microscope, vitrinite reflectance is 0.84%, which prove that Tatuo coal belong to medium hard coal. The main maceral is vitrinite, the inertinite content is less than that of vitrinite, and the exinite content is smallest. The mineral mainly are clay mineral and halite, also contain quartz, pyrite, calcite, illite, siderite, gypsum,barite, potash feldspar and rutile.In Tatuo coal, the content of Na2 O is 6.9 times higher than that of China. And a great deal of the fractures in the coal show that high levels of sodium mainly state as NaCl crystal adsorpting in the surface of coal particles and pore fracture. Trace elements are more lithophile elements in the coal, which explains that the trace elements in the coal probably derived from terrigenous detrital minerals. Enrichment of trace element Pb larger probability occurrence in potash feldspar. There are enrichment of LM-REY in the coal. The enrichment of REY is mainly affected by the qualitative of mother provenance lithology. Across the distribution patterns of REY,the process of deposition has a relatively stable terrigenous supply, and coal rocks is magmatic rocks or shale.From comprehensive analysis, coal formed in higher salinity, relatively dry continental peat swamp environment. Coal seam fromed in acid reductive environment, and the sedimentary center is close to the provenance in the study area.