Environmental Geochemistry Of Heavy Metal Elements In Coal Mines Of The Western-South Of Shandong Province

The heavy metal contamination in coal mining industry and its environmental geochemistry are becoming research hotspots nowadays. Coal-mining area located at southwest of Shangdong Province is one of the13largest coal-production bases in China. Long-term mining exploitation and utilization caused mining subsidence, soil-water-air contamination, ecological disruption and other environmental problems. Heavy metal in coal, gangue and ash generated during burning led to serious pollution on soil, water, plants and air. Yanzhou, Jining, Tengzhou and Ningwen in southwest coal fields of Shandong Province were chosen as research areas. This study is based on coal-mining geology, geochemistry, environmental geology, environmental impact assessment and data statistics, to discuss the environmental geochemistry of heavy metal in coal and other solid wastes in the southwest of Shandong Province by using ICP-MS, X-ray diffraction, energy spectrum analysis, leaching toxicity test and other analytic-experimental methods. The conclusions are as follows:(1) The mean values of trace heavy metals (Pb, Cu, and Zn) in coal mining area in southwest of Shandong Province are higher than in China and North China, which was indicating the higher accumulation in southwest of Shandong Province.(2) Existence state of heavy metals (As, Pb, Cu, and Zn) in the coal was discussed (i.e., Tangkou coal mining). It indicated that Zn was consisted in inorganic sulphide in layer3and17, and in organic sulphide in layer16. Pb was consisted in sulphide in layers3,16, and17. In addition, Pb was captured by organic sulfur. As was consisted in sulfur and other related minerals.(3)As, Pb, Cu, Zn, and Cd distribution in gangue from four coal fields and three layers of mining (layer3, layer12, and layer16) were studied seperatively. It was determined that concentrations of Hg, Cd, As, Pb, and Zn were the highest in the coal gangue in the southwest of Shandong Province. Bio-available fractions of these metals in the coal gangue were low according to form analysis. Majority of metals were in tailings.(4) Toxicity of leaking from coal gangue under different pH was monitored. The risk of metals accumulation toxicities were evaluated. Concentrations of metals decreased with the distance from the coal gangue based on study of Yanzhou and Beisu coal mining area, and decreased in vertical direction with the increased depth. Coal mining soil was according to base value of the Shandong soil. The contamination level were between delight to high contamination.(5) Distribution of trace metals including As, Pb, Cu, Zn, and F were determined. Results showed the agreement of metals distribution of the three ashes in the electric power plants with the mine run coal. Majority of heavy metals deposited in ash, and accumulated. Distribution and transportation of trace metals (i.e., As, Pb, Cu, Zn, and F) were studied. All these results were the fundamental for the heavy metal transportation and releasing mechanism in the mining process.