The Study On The Existing Status, Releasing Laws And Contaminated Forecasting On Environments Of Hazardous Elements In Coal Gangue Of Liuzhi County

As one of the coal mining wastes,coal gangue is the largest amount of emissivity in China mining districts.by the end of 1996,there had existed more than 1,500 gangue hills,whose total stack capacity had amounted to over 30 billion tons and occupied 13,000-hectare land.Moreover,with the development of coal industry,the amount of gangues has increased at 130million tons each year.with the action of leaching by rain and water,the large amount of coal gangue piles on the spot,some hazardous minor element will be dissolved completely or partly into water or soil environment and atmosphere to deteriorate water quality and destroy soil function and influence ecology development and human health,especially in high sulfur coal section in Guizhou.So I select the high sulfur coal section,which is in Liuzhi as the important research in this paper.The paper adopt mostly these esperimental methods,which include Acid neutralizing capacity(ANC) and net acid generation(NAG),polished section identification,X-ray diffraction, sequential extraction and static simulation.All these methods were used to forecast of the connection between gangue's contamination and pyrite,and study of speciation distribution and release disciplinary of some hazardous element in coal mining wastes from some gangue pile in Liuzhi.The main research pointes are as follows:(1) Combining ANG and Nag,observing polished section,X-ray diffraction,we draw a conclusion that the sulfuric content is very high in top slab(5.66%),but the pyrite in top slab exist mainly in micro-crystal aggregation,therefore,in the samples of this experiment,when we dip top slab in H₂O₂,there is no acid to be released.But the bottom slab,the fresh gangue sample and weathering sample all have some potentials to produce acid,and among them,the fresh gangue sample's potential is obviously higher than that of the weathering gangue sample.(2) Gradual Chemical extraction shows:most elements have more than one existing status,and most of the element mostly exist in stable silicate and relatively stable deoxidize status.At the same time,Zn,Ni,Mn,Cr,Fe in the verdure sample,which are greatly high than weathering sample in stable silicate combing status and relatively stable deoxidizing status,but more low in Fe-Mn oxide status.it is likely to the guegus in the weathering process,elements exist in stable silicate combing status and relatively stable deoxidizing status may gradually release.(3) The soaking experiments show:most pollutant's lixiviating concentration decrease with the time's lengthening,the maximum come forth in the beginning,the max soaking value presented the beginning.Only the Cu,Zn and Cr's lixiviating concentration increase with the time's going.but the new gusgue sample lixiviating value is variety,.At the same time,the value of Mn,Fe,Zn in the verdure sample are greatly high than weathering sample,but the Cu in the lixiviating is high than new,and the Pb,Ni' value are basic sameness in the tow samples.