兖州矿区深部奥灰水反向水文地球化学模拟研究

Study on inverse hydrogeochemical modeling of deep Ordovician limestone groundwater in Yanzhou mining area

为了分析深部奥灰水的主要水-岩作用,进而解释水文地球化学演化,基于流场和水化学场综合方法选出反应路径,进而进行兖矿奥灰水水化学模拟,结果表明:方解石、白云石在地下水中具有沉淀趋势;石膏、硬石膏和岩盐在水中处于非饱和状态,沿着水流路径继续溶解;主要水-岩作用为白云石、石膏和岩盐的溶解,方解石沉淀,阳离子交换和二氧化碳气体溶解或逸出等,与定性分析的结果非常一致;奥灰水中含Ca、Mg、Na、SO_4及Cl的矿物相发生溶解,且溶解迁入比率大于沉淀析出比率。

To study water- rock interaction of deep Ordovician limestone groundwater and explain the hydrogeochemical evolution,the hydrogeochemistry simulation of Ordovician limestone groundwater in Yanzhou Coalfield was finished,the reaction paths were chosen by an integrated approach of water flow and geochemical field. The simulation results show that,the calcite and dolomite tends to precipitate; the gypsum,anhydrite and halite are unsaturated and tend to dissolve in groundwater; the major water- rock interactions are the dissolution of dolomite, anhydrite and halite, calcite precipitation,cation exchange,and dissolution or escape of carbon dioxide,and the results are very consistent with the qualitative analysis; the dissolution of the mineral phases containing Ca,Mg,Na,SO4 and Cl in Ordovician limestone groundwater occurres,and the dissolution rate is greater than the precipitation rate.