马兰煤矿矿井水水质变化特征及成因

Variation characteristics and cause of mine water quality in Malan coal mine

通过对山西省马兰煤矿2号煤层采掘面在开采和封闭时期的矿井水和沉积物的研究,揭示采掘面封闭前后对矿井水水质和沉积物的影响机理。研究结果表明:马兰煤矿矿井水均为SO4—Ca型水质,矿井水均富含SO24-和Fe离子;随着上部煤层的不断开采,3处矿井水呈现相同的变化规律,矿井水的pH值升高,Eh值降低,SO24-、Fe、Mn和Zn离子浓度随之下降,其中北一暗斜井处的矿井水水质变化最显著;矿井水水质指标和流速变化能够控制其沉积物的矿物组成和结晶程度,北一暗斜井处的沉积物在两次采样中由斯沃特曼铁矿变为针铁矿,而其他两处的矿井水沉积物矿物组分没有发生变化,主要由针铁矿组成。研究结果能够提高对老空区积水水质的预测精度,并对煤矿突水水源判识具有重要意义。

Quality characteristics of mine water and mineral compositions of sediments at different time from the Malan coal mines,Shanxi Province,China were investigated.The results show that water quality types of all mine water samples were SO4—Ca,and mine water samples had high concentrations of sulfate and iron.With mining of the upper coal seam,pH increased and Eh value,SO24-,Fe,Mn and Zn ions concentrations of mine water samples decreased.Mine water samples in three sampling sites showed the same change patterns and the most significant changes of mine water quality happened in No.1 northern inclined shaft.Mineral composition and crystalline degree of sediments are controlled by water quality index and velocity of mine water.The minerals of sediment in No.1 northern inclined shaft have changed form schwertmannite to goethite in twice sampling.There were no changes of mineral constituents in other two sediment sampling sites,which were composed of goethite.