伊南煤田伊犁一矿侏罗纪煤系地下水化学特征与水循环演化  

Chemistry and water cycle of the groundwater in the Jurassic confined fissured aquifers at Ili No.1 Coal Mine,South Ili Coalfield,China

作　　者：王长申[1] 黄炳香[2] 赵兴龙[2] 任冬冬[3] 李奎水[3] 赵国宏 刘家丞 李丽华 WANG Changshen;HUANG Bingxiang;ZHAO Xinglong;REN Dongdong;LI Kuishui;ZHAO Guohong;LIU Jiacheng;LI Lihua(School of Resources and Geosciences,China University of Mining and Technology,Xuzhou,Jiangsu 221116,China;State Key Laboratory for Fine Exploration and Intelligent Development of Coal Resources,China University of Mining and Technology,Xuzhou,Jiangsu 221116,China;No.1 Coal Mine,Xinwen Mining Group(Ili)Energy Development Co Ltd,Ili,Xinjiang 835000,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]中国矿业大学煤炭精细勘探与智能开发全国重点实验室,江苏徐州221116 [3]新汶矿业集团(伊犁)能源开发有限责任公司一矿,新疆伊犁835000

出　　处：《采矿与安全工程学报》2024年第1期160-170,共11页Journal of Mining & Safety Engineering

基　　金：国家重点研发计划项目(2021YFC2902104)。

摘　　要：伊犁盆地伊南煤田是我国较早发现的重要含砂岩铀矿煤田,侏罗纪煤系裂隙-孔隙承压水是伊犁一矿和周边铀矿共同扰动和影响的主要地下水系统,煤铀协调开采的重点问题是如何协调煤矿和铀矿对侏罗纪煤系含水层的影响。及时研究和预测煤矿对侏罗纪煤系含水层已有影响对于煤铀协调开采重要且必要。伊犁一矿是目前投产的伊南煤田唯一的大型煤炭生产矿井。在伊犁一矿自上而下取煤系第四系水、3煤顶板水、5煤顶板水、5煤底板水和矿井混合水水样,做水质全分析、D/^(18)O、T和^(14)C测年,运用水文地球化学分析方法研究伊犁一矿现状条件下煤系地下水质特征和水循环演化状态。结果表明:矿井地下水为近中性、低矿化的HCO_(3)·SO_(4)型或HCO_(3)·SO_(4)型淡水;δD和δ^(18)O分别为-91‰~-118‰和-12.7‰~-16.0‰;除5煤底板水(铀含量11.1μg/L)外,煤系水铀含量仅约0.8μg/L;煤系地下水平均年龄为5000~6000 a,而3煤顶板水和5煤顶板水年龄为1.25万~2.5万a。伊犁一矿侏罗纪煤系地下水具有显著的“三低、一老、一少”即低矿化、低氘、低铀、较老和少污染特征。由于煤矿疏放5煤底板水,围绕伊犁一矿已形成侏罗纪煤系深层裂隙-孔隙水的疏干式局部水文循环,5煤底板含水子系统水位漏斗已顺层扩展和水循环已顺层局部加速;3煤顶板和5煤顶板含水子系统仍相对独立和封闭,疏干后难以恢复。3煤顶板水和5煤顶板水属于理想的低氘和水质优良地下水。South Ili Jurassic Coalfield in Ili Basin is an important coalfield in China for having been early discovered sandstone⁃hosted U deposits.The active Ili No.1 Coal Mine and the neighbor uranium mines are all simultaneously influencing or destroying the groundwater systems of the Jurassic fissured confined aquifers.To coordinate mining the two types of syngenetic minerals with distinctly different attributes,the key issue is how to manage the impact of the coal mines and the uranium mines on the Jurassic groundwater systems.It is of necessary and imperative to investigate and predict the existing impacts of coal mines on the Jurassic coal aquifer.Ili No.1 Coal Mine now is the only and the largest active coal mine in South Ili Coalfield.The water samples were collected from the quaternary unconso⁃lidated aquifer,the roof sandstone confined aquifers of the No.3 coal seam and the No.5 coal seam,the floor sandstone confined aquifer of the No.5 coal seam,and the overall mixed mine water at the underground site of Ili No.1 Coal Mine respectively.By testing the water chemistry,stable isotopes of D and 18O,and T&^(14)C dating,and adopting geochemistry analysis,we investigated how the mining and dewatering activities of Ili No.1 Coal Mine affect the water chemistry and water cycle of the Juras⁃sic fissured confined aquifers.It indicates that the groundwater is near⁃neutral,low mineralized HCO_(3)⁃SO_(4)or HCO_(3)⁃SO_(4)freshwater;δD andδ^(18)O are-91‰--118‰and-12.7‰--16.0‰respectively.Except for the floor sandstone aquifer of the No.5 coal seam(U concentration of 11.1μg/L),the ura⁃nium concentration in the Jurassic aquifers is only about 0.8μg/L.The average age of the groundwater is 5000-6000 a,among which the age of groundwater in the roof aquifers of the No.3 coal seam and the No.5 coal seam is up to 12500-25000 a.The Jurassic groundwater at Ili No.1 Coal Mine has the remarkable characteristics of“three Lows,one Old,and one Less”,i.e.,Low salinity,Low deute⁃rium,Low uranium,Older age,and Le

关 键 词：伊南煤田 侏罗纪煤系含水层 稳定水文同位素 地下水年龄 水文循环 

分 类 号：P618[天文地球—矿床学]