Study On Trace Elements Of No.6 Coal Seam In Haerwusu Mine

The study on characteristics of trace elements in the coal, is help to discuss the origin and the formation of coal and may have important significance for the development of new energy in coal and the impact on humans and environment in coal-fired process. The research object is the trace elements and coal forming environment from No.6 coal seam in Haerwusu mine, Junger coalfield, Inner Mongolia.Content level, occurrence state, enrichment mechanism, coal petrology and organic matter characteristics of the No.6 coal seam from Haerwusu have been researched, using the knowledge of coal petrology, mineralogy, organic geochemistry, sedimentology, coal geology. Coal facies, sediment source and coal forming environment have been inferred by the characteristics of trace elements. The methods respectively are microscope observation, inductively coupled plasma mass spectrometry (ICP-MS) testing, scanning electron microscopy analysis, organic extraction experiment and gas chromatography, etc.The results indicate that Li, Ga, Pb, Bi and U are obviously riched in No.6 coal mine, and the enrichment coefficients of Li, Pb and Bi are greater than 1. However, compared with the average value of China, the PZ2 and America, the content of latent toxic trace elements Cd, Pb, U, V are higher in the samples, with enrichment coefficient large than 0.6, we should be to prevent pollution. In the vertical distribution, the content of mass trace elements are higher in coal seam near roof.Vitrinite and inertinite are the dominant microscopic macerals, and less liptinite in No.6 coal seam. The mineral include clay minerals, pyrite, calcite, quartz, etc. The trace element in microscopic component is less likely to occur, and close to the minerals.Soluble organic matter has high in aromatic hydrocarbons, and concluded that coal-forming plant most are higher plant, but also have lower plants and aquatic organisms.The No.6 coal bed was formed in delta plain which has brackish water-fresh water environment. The groundwater condition is relative weak, from bottom to top, the water covered degree undergoes the strong-weak-strong evolution, and change in excess oxygen and poor oxygen. Coal facies can be divided into 3 types, namely arid forest peat swamp (including two subfacies) and reed peat swamp. The coal-forming process is completed in the regressive background, and divided into 11 secondary sequences.Distribution of trace elements in different types of peat is also different, Li, Ga, Pb, Bi and U all have different enrichment levels in three typs. Li has highest level in lowland bog, but the sulfophile elements Pb, Bi and U have highest level in shallow overlying water forest swamp.