Impact On Groundwater As A Fluoride Mine Grouting Material In Fly Ash

As important main energy, coal paly an important foundation for the country’s economic lifeline and energy security. Coal as the main energy status in the future for a long period of time will not change. However, due to coal quality reasons, there will be a part of the coal seam spontaneous combustion tendency for the spontaneous combustion of coal seam fire control and extinguishing coal production is an important production safety measures. Fly ash as a byproduct in the process of combustion of pulverized coal fired boiler, is a "misplaced resources, to achieve its resource re-use, some of the coal mine to try fly ash as mine Fire Prevention and grouting materials to use, re-use of the resources at the expense of the current environment for the survival at the expense Therefore, the subject of experiments and specific cases from the perspective of the hydrogeology, hydrogeochemistry, and mathematical models pulverized gray as mine Fire Prevention and grouting materials, the leaching solution would be whether groundwater pollution caused by the analysis made the study reached the following conclusions:(1) Without screening the fly ash sample after leaching by72h leaching test, the leaching of the fluoride ion concentration in the first36h to achieve a maximum of2.113mg/l, more than groundwater quality standards (GB/T14848-93) Grade III on the fluoride content, which standard is1.Omg/L(2) Test, respectively, from the analysis of pH, total hardness, these four factors of the liquid to solid ratio and particle size on the leaching effect of the fluoride ions in fly ash, showed that:alkaline environment, low hardness, low-liquid-solid ratio as well as under conditions of low particle size, help to improve the fluoride concentration in the fly ash leaching solution.(3) Through the combination of specific coal mining coal seam, the actual hydrogeological conditions as well as from the perspective of the spring catchment protection analysis showed that:The coal mining F167normal faults in the northern region and Ida southwest near the collapse column in seam prohibiting the use of fly ash grout, the remaining coal seams in the mining process using fly ash to grouting material to use as a Fire Prevention still do, but in the use of the thorough investigation of the detailed exploration of the water inrush phenomena, once found signs of water inrush found, it should immediately stop using fly ash grout.(4)Through the hydro-geochemical analysis:fly ash leaching solution in the infiltration process due to a variety of complex physical and chemical effects, especially after mechanical filtering effect, the physical and chemical adsorption, and dissolution and precipitation, fluorine content will greatly reduce the fluorine concentration is effectively reduced.(5)Through mathematical model analysis showed that:the leaching of fluoride in the liquid during the migration process, the impact area gradually expanded, but the concentration gradually decreased after a block of solid rock and impermeable layer, and ultimately into groundwater the fluorine content is very low, is not caused to groundwater pollution.(6) Grout material using fly ash as a mine anti-fire, the need to strengthen the protection of groundwater measures:precise survey of the structure of the hydraulic conductivity; adjust the grouting conditions in order to reduce the fluoride in fly ash leaching concentration.