碳酸盐岩抑制煤中有害元素释放和迁移能力的研究

为了揭示碳酸盐岩地质背景下碳酸盐岩对煤中有害元素的抑制作用,以煤和碳酸盐岩为实验材料设计了3个不同组合的淋溶柱,采用淋溶实验方法,探讨了碳酸盐岩对煤中Fe、Mn、Cu、As等元素释放和迁移的抑制能力.结果表明:碳酸盐岩能有效中和煤中黄铁矿等硫化矿物氧化产生的酸,淋溶液pH值显著升高;碳酸盐岩对煤中硫的释放和迁移能力的抑制作用不明显,对煤中Fe、Cu和As元素的释放和迁移的抑制能力较强,但对煤中Mn、Pb和Cd元素的释放和迁移的抑制能力相对较弱.碳酸盐岩能有效抑制酸性矿山废水的形成和演化,可作为碳酸盐岩地区酸性矿山废水防治的理想材料.

Effect of carbonate on release and transport of toxic elements from coal

To provide the basis for prevention and treatment of acid mine drainage (AMD) for the karst region, we explored the mechanism of carbonate rock control of toxic elements (Fe, Mn, Cu, As etc.) in karst geological sites. Three different leaching columns composed of coal and carbonate were employed to determine how carbonate affects release and transport of toxic elements in coal. The results show that carbonate can effectively neutralize the acidity caused by the oxidation of pyrite and increase the pH value of the leachate. The total amounts of SO2-4 in the leachate from the three leaching columns were almost equivalent, suggesting that the ability of carbonate to immobilize S in coal is poor. Carbonate can effectively immobilize Fe, Cu and As, but its effect on Mn, Pb and Cd was relatively poor. It is concluded that carbonate can effectively control the formation and evolution of AMD, and it is an ideal reaction medium to prevent and treat AMD in carbonate rock areas.