考虑采动效应的闭坑矿井水硫酸盐污染规律  

Sulphate contamination in an abandoned coal mine in light of mining effects

作　　者：齐跃明[1] 周沛 周来[2] 蒋丹 杨雨晴 刘延卓 QI Yueming;ZHOU Pei;ZHOU Lai;JIANG Dan;YANG Yuqing;LIU Yanzhuo(School of Resources and Geosciences,China University of Mining and Technology,Xuzhou 221116,China;School of Environment and Spatial Informatics,China University of Mining and 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]中国矿业大学环境与测绘学院,江苏徐州221116

出　　处：《煤田地质与勘探》2024年第4期89-100,共12页Coal Geology & Exploration

基　　金：国家重点研发计划课题(2022YFC3702203);国家自然科学基金项目(52274243);江苏省研究生科研与实践创新计划项目(KYCX23_2765);中国矿业大学研究生创新计划项目(2023WLJCRCZL004)。

摘　　要：高硫煤矿闭坑后成为埋藏在地表以下深部的产酸污染场,对相邻含水层和周边环境造成了潜在危害,且因采动效应影响和矿井空间分布复杂导致相邻含水层的污染过程与污染程度评价困难。以某闭坑矿区为研究对象,选取SO_(4)^(2-)作为特征污染物,考虑多煤层采动裂隙对含水层结构的破坏影响,运用数值模拟技术对闭坑矿区酸性矿井水中SO_(4)^(2-)污染迁移特征进行研究,并分析流体扩散系数对含水层污染物运移的影响。结果表明:SO_(4)^(2-)在二叠系童子岩组砂岩含水层中水平迁移面积随时间增大而增大,增大速率逐渐减小,垂向渗透系数扩大10倍,空间变异性增强;闭坑5、10、15a后,最大水平迁移距离分别为215、414、612m,最大垂向迁移距离分别达到50、65、70m;而扩散系数越大,产酸时间越长,SO_(4)^(2-)迁移距离和污染范围将随之增大,相较于水平方向,垂向上SO_(4)^(2-)浓度变化对扩散系数的敏感度更高。基于模拟结果,结合闭坑矿区实际条件,针对性提出了“源头减量-过程阻断-末端治理”的综合防控与治理方案。研究结果将为该闭坑煤矿酸性矿井水污染治理与防控提供理论基础,也为其他同类矿井提供科学借鉴。Abandoned high-sulfur coal mines will become deeply buried acid-producing contamination sites,posing hazards to adjacent aquifers and surrounding environments.Furthermore,mining effects and the complex spatial distribution of abandoned mines complicate the assessment of the contamination processes and degrees in adjacent aquifers.Focusing on a certain abandoned coal mine,this study examined the migration characteristics of SO_(4)^(2-)pollution in acid mine drainage using numerical simulations by taking sulfate(SO_(4)^(2-))as the characteristic contaminant and considering the effects of the fractures formed by the mining of multiple coal seams on the aquifer structure.Furthermore,it analyzed the influence of the fluid diffusion coefficient on the transport of contaminants in the aquifers.The results show that the area covered by the SO_(4)^(2-)horizontal migration in the sandstone aquifers of the Tongziyan Formation increased with time,with increasing rate gradually decreasing.Concurrently,the vertical permeability coefficient of the sandstone aquifers increased by 10 times,suggesting elevated spatial variability.The simulation results show that 5,10,and 15 years after the coal mine was abandoned,the maximum horizontal migration distances were 215 m,414 m,and 612 m,and the maximum vertical migration distances were 50 m,65 m,and 70 m,respectively.The SO_(4)^(2-)migration distance and contamination range increased with the diffusion coefficient and the acid-producing time.Compared to the horizontal direction,the variations in the SO_(4)^(2-)concentration were more sensitive to the diffusion coefficient in the vertical direction.Based on the simulation results,as well as the actual conditions of the abandoned coal mine,this study proposed the comprehensive prevention,control,and management strategy of“reducing recharge to mines,blocking contamination process,and treating contamination in the end”.The results of this study will provide a theoretical basis for the treatment,prevention,and control of contamination c

关 键 词：闭坑煤矿 酸性矿井水 硫酸盐 导水裂隙带 采动效应 综合防控 

分 类 号：P641[天文地球—地质矿产勘探] TD741[天文地球—地质学]