Evaluating Efficiency of Coal Combustion Products (CCPs) and Polyacrylamide (PAM) for Mine Hazard Prevention and Revegetation in Coal Mine Area

초록

Since mine wastes were merely dumped in the mine waste dump, they have produced acid mine drainage(AMD). Therefore, main objective of this study was to evaluate the effect of coal combustion products (CCPs)on heavy metal stabilization and detoxification for mine wastes. Total six treatments for incubation test wereconducted depending on mixing method (completely mixing and layered). Also, lysimeter experiment wasconducted to examine efficiency of polyacrylamide (PAM) on reduction of mine wastes erosion. Result ofincubation test showed that concentrations of soluble aluminium (Al) and iron (Fe) in leachate decreasedcompared to control. The lowest soluble Al and Fe in leachate was observed in 50% mixed treatment (14.2 and1.03 mg kg-1 for Al and Fe respectively) compared to control treatment (253.0 for Al and 52.6 mg kg-1 for Fe). The pH of mine wastes (MW) and leachate increased compared to control after mixing with CCPs and orderedas control (MW 6.4, leachate 6.3) < 10% (MW 7.7, leachate 7.1) < 20% (MW 9.0, leachate 7.8) < 30% (MW9.5, leachate 8.3) < 40% (MW 9.9, leachate 8.5) < 50% (MW 10.5, leachate 8.6). Application of PAM, both inliquid and granular type, dramatically decreased the suspended solid (SS) concentration of CCPs treatments. Reduction of SS loss was ordered as MW70CR30L (24.4 mg L-1) > MW70CR30LPL (6.7 mg L-1) > NT (3.1mg L-1) > MW70CR30M (1.6 mg L-1) > MW70CR30MPL (1.1 mg L-1) > MW70CR30PGM (0.7 mg L-1) >MW70CR30LPG (0.5 mg L-1) > MW70CR30MPG (0.4 mg L-1). Overall, application of CCPs can beenvironmental friendly and cost-effective way to remediate coal mine wastes contaminated with heavy metals. In addition, use of PAM could help to prevent the erosion coal mine wastes in mine waste disposal area.

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