煤矿采空区水-岩作用模拟试验研究  

Simulation test on water-rock interaction in coal mine goaf

作　　者：孙亚军[1,2] 赵先鸣 徐智敏 郭娟[1] 张莉 陈歌 陈天赐 朱璐璐[1] 高雅婷 陈炜阳 SUN Yajun;ZHAO Xianming;XU Zhimin;GUO Juan;ZHANG Li;CHEN Ge;CHEN Tianci;ZHU Luu;GAO Yating;CHEN Weiyang(School of Resource and Geoscience,China University of Mining and Technology,Xuzhou 221116,China;National Professional Center Laboratory of Basic Research on Mine Water Disaster Prevention and Control Technology,Xuzhou 221116,China)

机构地区：[1]中国矿业大学资源与地球科学学院,江苏徐州221116 [2]矿山水害防治技术基础研究国家级专业中心实验室,江苏徐州221116

出　　处：《煤田地质与勘探》2023年第1期237-246,共10页Coal Geology & Exploration

基　　金：国家重点研发计划项目(2019YFC1805400);中国矿业大学未来科学家计划项目(2022WLKXJ040);江苏省研究生科研与实践创新计划项目(KYCX22_2607)。

摘　　要：采空区积水在我国煤矿中广泛存在。明确在采空区封闭-半封闭环境条件下的水-岩相互作用机理,对实现煤矿区水污染减量以及地下水资源保护具有重要意义。以内蒙古某煤矿采空区积水为研究对象,设计高度还原采空区环境的箱式模拟试验,采用X射线衍射仪(XRD)和X射线荧光光谱仪(XRF)对模拟采空区填充物(煤、垮落岩体)中矿物成分及元素组成进行分析,借助离子色谱仪(IC)和电感耦合等离子体发射光谱分析仪(ICP-OES)等对水中水化学特征进行表征,探究采空区积水水质形成的水-岩相互作用机制。结果表明:水-岩相互作用主要为煤及垮落岩体中的矿物溶解-沉淀作用、阳离子交换作用、煤中黄铁矿氧化作用以及混合作用。矿物溶解作用占主导地位,采空区积水中的Na+、K+主要来源是钠长石、钾长石等硅酸盐矿物的溶解,而Ca2+和Mg2+主要来自于钙长石、方解石、绿泥石等矿物溶解;离子交换作用主要发生在采空区水-岩作用的初期(0~20 d),而后逐渐减弱;采空区底部残煤中黄铁矿氧化作用是积水SO42-浓度升高、还原性增强、pH和DO(溶解氧)降低的主要原因;混合作用在试验中后期(30~150 d)逐渐凸显,使采空区积水的水化学特征趋向于一致。研究结果为煤矿采空区积水污染预测以及防治提供理论参考。Water accumulation is widely present in the goaf of coal mine in China. It is of great significance to clarify the water-rock interaction mechanism in the closed and semi-closed goaf environment for water pollution reduction and groundwater resource protection in coal mine area. Taking the water accumulation in the goaf of a coal mine in Inner Mongolia as the research object, we designed a box simulation test to highly restore the goaf environment. X-ray diffractometer(XRD) and X-ray fluorescence spectrometer(XRF) were used to analyze the mineral composition and element composition of the simulated filler of goaf(coal and caving rock mass). The hydrochemical characteristics of water were characterized with the aid of ion chromatograph(IC) and the inductively coupled plasma optical emission spectrometry(ICP-OES). The water-rock interaction mechanism of water-quality formation for accumulated water in the goaf was explored. The results show that the water-rock interactions mainly include the mineral dissolution-precipitation and cation exchange in coal and caving rock mass, as well as the pyrite oxidation and mixing in coal. Therein, mineral dissolution is dominant. Na+and K+in water accumulated in goaf are mainly derived from the dissolution of silicate minerals such as albite and potassium feldspar, while Ca2+and Mg2+are mainly from the dissolution of calcium feldspar,calcite and chlorite. Cation exchange mainly occurs in the initial stage(0-20 d) of water-rock interaction in goaf, and then gradually weakens. The oxidation of pyrite in residual coal at the bottom of the goaf is the main reason for the increase of SO42-concentration, the enhancement of reducibility, and the reduction of pH and Dissolved Oxygen(DO). Besides, the mixing effect gradually became prominent in the middle and late period(30-150 d) of the test, which made the hydrochemical characteristics of the groundwater accumulated in goaf tend to be consistent. Generally, the results of the study provide theoretical references for the prediction and

关 键 词：采空区积水 水-岩相互作用 箱式模拟试验 

分 类 号：TD741[矿业工程—矿井通风与安全]