大屯矿区煤和煤系岩石淋出微量元素行为比较

A comparison of trace element leaching behavior from coal and coal measure strata rock in the Xuzhou-Datun coal mine district

对徐州大屯矿区矿井水中主要微量元素的含量以及淋出行为进行了分析,发现矿井水呈弱碱性,高矿化度的特点,Hg、Se等元素含量较高。为研究微量元素淋出的行为,在不同淋滤条件下(p H值为2,5.6和12)对煤及煤系岩层进行了淋滤实验,结果显示:金属微量元素Pb和Cd在酸性条件下溶出量较大,As,Hg和Se在碱性条件下淋出量较大;Cr在酸性条件下淋出量略高于碱性条件下的淋出量。与煤中微量元素淋出行为相比较,煤系岩层的的淋出量更大。Pb、Cd、As的岩石淋出比例明显高于煤的淋出率,Hg和Se的淋出比例在两种介质中差别较小,与微量元素的赋存状态有关。矿区地表水中As、Hg等含量降低,Pb、Zn、Cu等元素的含量升高,说明矿井水与地表水混合的过程中,微量元素的形态发生了显著的变化。

The trace elements in the coal mine water in the Xuzhou-Datun coal mine district were analyzed,finding that Hg and Se were relatively high,with high polluting potential comparing with the national standard. Leaching experiments of the coal and coal measure strata rock in varies p H conditions（ p H = 2,5,6,12）.The metal elements,Pb and Cd,tend to leach more in the acid environment,meanwhile,As,Hg,and Se tend to leach more in the alkaline environment. The chromium tends to relatively balance,but a little high in the acid environment. Comparing the leaching behavior of coal and rock,the rock was found to release higher trace element concentrations. Considering the content in solid bulk,the Pb,Cd and As were leached higher from rock than coal. Up to present,the trace element researches in coal mine water focus more on the coal leaching,but not the rock leaching behavior. The result suggests that the behavior and mechanism of leaching from coal and coal measure strata rock need deeper insight.