神东矿区顶板垮落岩体在不同水化学条件下的离子迁移特征  

Migration characteristics of metal ions from caving rock in ShendongMinging Area under different chemical conditions

作　　者：苏琛 吴敏 唐佳伟 包一翔 刘兆峰 薛蕊 张海琴 蒋斌斌 SU Chen;WU Min;TANG Jiawei;BAO Yixiang;LIU Zhaofeng;XUE Rui;ZHANG Haiqin;JIANG Binbin(State Key Laboratory of Water Resource Protection and Utilization in Coal Mining,China Energy Investment Corporation Limited,Beijing 102209,China;School of Water Resources and Environment,China University of Geosciences(Beijing),Beijing 100083,China)

机构地区：[1]国家能源集团煤炭开采水资源保护与利用国家重点实验室,北京102209 [2]中国地质大学(北京)水资源与环境学院,北京100083

出　　处：《煤炭学报》2023年第3期1353-1364,共12页Journal of China Coal Society

基　　金：煤炭开采水资源保护与利用国家重点实验室自主研发资助项目(GJNY-18-88,SHGF-16-22)。

摘　　要：采空区内含有大量的顶板垮落岩体,矿井水在地下水库内储存过程中,与采空区内顶板垮落岩体存在离子交换/吸附、溶滤等水岩相互作用,在一定程度上影响矿井水水质。采集了内蒙古哈拉沟矿区采空区顶板垮落岩体,对其阳离子交换容量(CEC)进行测定,并开展了不同水化学条件下(Na^(+)、Mg^(2+)、K^(+)、Ca^(2+)质量浓度各250 mg/L)的水岩耦合静态吸附-溶出实验。实验结果表明:采空区顶板垮落岩体的CEC与粒径大小成反比,当粒径小于120目(0.125 mm)时CEC达134 mmol^(+)/kg,采空区顶板垮落岩体中交换性盐基离子总量排序为交换性钙交换性镁>交换性钠>交换性钾;静态吸附-溶出实验48 h后各体系中离子质量浓度趋于平衡,Na^(+)体系溶液中阳离子质量浓度均有所升高,其他3种体系中,原有离子质量浓度均有所下降,且K^(+)质量浓度下降幅度最大。采空区顶板垮落岩体交换至水溶液中的离子质量浓度由高到低的顺序为:Ca^(2+)>Na^(+)>Mg^(2+)>K^(+),Ca^(2+)质量浓度在试验结束后依然有上升趋势。反应后采空区顶板垮落岩体的CEC均有所增加,Ca^(2+)体系下CEC最大达183.7 mmol^(+)/kg。基于XRD等表征结果进一步揭示了微斜长石、钠长石、硫铁矿等非黏土矿物的溶滤作用可以导致溶液中Ca^(2+)、Na^(+)的质量浓度增加,而伊利石、高岭石等黏土矿物则通过配位作用等对溶液中的阳离子进行吸附/交换。对于阳离子而言,若溶滤作用>离子交换作用(初始质量浓度较低)则质量浓度有所上升;反之则有所下降。因此当矿井水Ca^(2+)、Mg^(2+)质量浓度较高时,煤矿地下水库可通过水岩相互作用在一定程度上降低矿井水的硬度。There is a large amount of rock in the underground reservoir.During the process of storage in the underground reservoir,there are water-rock interactions such as ion exchange,adsorption and leaching between mine water and rock in the underground reservoir,which affect the quality of mine water.The rock in the Halagou was collected,its cation exchange capacity(CEC)was measured,and the static adsorption-dissolution experiments under different chemical conditions(250 mg/L for Na^(+),Mg^(2+),K^(+),Ca^(2+))were carried out.The experimental results show that the CEC of rock is inversely proportional to the particle size.When the particle size is less than 120 mesh,the CEC reaches 134 mmol^(+)/kg.The order of exchangeable base ions in rock is Exchangeable Calcium Exchangeable Magnesium>Exchangeable Sodium>exchangeable Potassium.After 48 hours of experiment,the ion concentration in each system tended to balance.The cation concentration in the Na^(+)system solution all increased,but in the other three systems,the original ions all decreased,and the K^(+)decreased the most.The order of the ion concentration exchanged from the caving roof rock to the aqueous solution from high to low is:Ca^(2+)>Na^(+)>Mg^(2+)>K^(+),and the Ca^(2+)concentration still had an upward trend after the end of the test.After the reaction,the CEC of the rock increased to a certain extent,and the maximum CEC value under the Ca^(2+)system was up to 183.7 mmol^(+)/kg.Based on XRD and other characterization results,it is further revealed that the leaching of non-clay minerals such as microcline,albite and pyrite can increase the concentration of Ca^(2+)and Na^(+)in the solution,while clay minerals such as illite and kaolinite adsorb/exchange cations in the solution through coordination.For cations,if leaching>ion exchange(the initial concentration is low),the concentration increases.On the contrary,it decreased.Therefore,when the content of Ca^(2+)and Mg^(2+)in mine water is high,the hardness of mine water can be reduced to a certain extent through wate

关 键 词：煤矿地下水库 水岩作用 离子交换容量 吸附 溶滤作用 

分 类 号：TD353[矿业工程—矿井建设]