大海则煤矿2号煤层顶板水化学特征分析

Analysis of roof hydrochemical characteristics of No.2 coal seam in Dahaize Coal Mine

大海则煤矿地处鄂尔多斯盆地陕北侏罗纪煤田榆横矿区北部,2号煤煤层顶板赋存有多层含水层。煤层开采后,顶板受到采掘扰动,一旦波及到强含水体,将受到突水危害,建立地下水水化学数据库能快速准确判断出矿井的出水水源,有效指导煤矿的防治水工作。根据矿区以往水文地质勘探成果,采用水质全分析、同位素测试、腐蚀性评价等多种方法对2号煤煤层顶板各含水层水文地球化学特征进行分析。结果表明,从浅部含水层到深部含水层,水化学类型变化规律为HCO_(3)—Ca→SO_(4)•HCO_(3)—Na•Ca→SO_(4)—Ca•Na→SO_(4)—Na,含水层的矿化度呈递增趋势,氕、氘的百分含量呈递减趋势;水对钢筋混凝土的腐蚀性由弱到强。

The Dahaize Coal Mine is located in the northern part of the Yuheng mining area of the Jurassic coalfield in the northern Shaanxi region of the Ordos Basin.The roof of the No.2 coal seam contains multiple aquifers,after coal seam mining,the roof is disturbed by excavation,and once it reaches a strong aquifer,it will be endangered by water inrush.Establishing a groundwater hydrochemical database can quickly and accurately determine the source of water in the mine,effectively guiding the water prevention and control in the coal mine.Based on the results of hydrogeological exploration in the mining area,the hydrogeological chemical characteristics of each aquifer in the roof of No.2 coal seam are analyzed by means of water quality complete analysis,isotope test,corrosion evaluation,etc.The results show that from shallow aquifer to deep aquifer,the variation law of hydrochemical type is HCO_(3)—Ca→SO_(4)•HCO_(3)—Na•Ca→SO_(4)—Ca•Na→SO_(4)—Na.The mineralization degree of the aquifer shows a decreasing trend,while the percentage content of protium and deuterium shows a decreasing trend;the corrosion of water on reinforced concrete varies from weak to strong.