蒙陕接壤浅埋煤层区矿井水水化学特征及资源化利用研究

Study on mine water hydrochemical characteristics and resource utilization in shallow buried coal seams in shaanxi and inner mongolia contiguous area

蒙陕接壤区浅埋煤层下组煤与上组煤开采所产生的大量矿井水在水化学与水质特征方面有着明显差异。为准确掌握下组煤开采前后矿井水水质变化特征,采集了该区域上组煤水样12组、下组煤水样12组,共计24组水样,进行水质全分析,分析了一般水化学特征、离子组分浓度及主要离子占比的变化特征与控制因素,并利用层次-综合污染指数法进行水质评价,根据评价结果对矿井水资源化利用进行讨论。研究结果表明,下组煤产生的矿井水TDS值升高,水化学类型由上组煤矿井水的HCO_(3)·Cl-Na型变化为HCO_(3)·SO_(4)-Na·Ca型,矿井水中阳离子均以K^(+)+Na^(+)为主,阴离子中由以HCO_(3)^(-)与Cl^(-)为主转变为以SO_(4)^(2-)与Cl^(-)为主,水动力条件与溶滤作用强度是引起这一变化的主要因素。水质评价结果显示,上组煤矿井水水质整体优于下组煤矿井水水质,研究区矿井水不适宜作为生活饮用水与灌溉水使用,建议按采区进行水质清污分流,Ⅱ~Ⅲ类较清洁矿井水作为矿区生活清洁用水或工业生产用水。

There are obvious differences in the water chemistry and water quality characteristics of large quantities of mine drainage produced by the mining of the lower and upper coal groups in the shallow coal seam in the Inner Mongolia-Shaanxi connection area.In order to accurately grasp the change characteristics of mine water quality before and after coal mining in the lower group,12 groups of coal water samples in the upper group and 12 groups of coal water samples in the lower group were collected,a total of 24 groups of water samples were collected,and the water quality was completely analyzed.The general water chemical characteristics,the concentration of ion components and the change characteristics and control factors of the main ion proportion were analyzed,and the water quality was evaluated by AHP-comprehensive pollution index method.According to the evaluation results,the utilization of mine water resources is discussed.The results show that the TDS value of mine drainage from the lower coal group increases,and the type of water chemistry changes from HCO_(3)·Cl-Na type to HCO_(3)·SO_(4)-Na·Ca type from HCO_(3)·SO_(4)-Na Ca.The cations in mine drainage are mainly K^(+)+Na^(+),and the anions change from HCO_(3)^(-)and Cl^(-)to SO_(4)^(2-)and Cl^(-)type.The hydrodynamic conditions and the intensity of leaching were the main factors that caused the change.The water quality evaluation results show that the water quality of the coal mine well of the upper group is better than that of the coal mine well of the lower group.The mine water of the study area is not suitable to be used as drinking water and irrigation water.It is suggested to divide the water quality by the mining area,and the cleaner mine water of classⅡ~Ⅲshould be used as the domestic clean water or industrial production water.