Abstract:

The coal mining areas spanning the Inner Mongolia-Shaanxi border represent both a quintessential ecologically vulnerable zone and a critically important coal production base in China. However, large-scale, high-intensity coal mining has generated vast amounts of mine water. Currently, investigating the hydrogeochemical genesis of mine water and advancing its resource utilization have become critical issues for the green transition of coal industry. This study systematically collected mine water samples from multiple active large-scale coal mines in the region. The hydrogeochemical characteristics and formation mechanisms of the mine water were revealed through laboratory testing and data analysis, and technical pathways for the classified utilization of mine water were proposed based on water quality characteristics. The results indicate that the mine water in the study area is generally weakly alkaline, with an average TDS value of 2 053.57 mg/L. The dominant cations are Na⁺ and Ca²⁺, while the dominant anions are SO₄²⁻ and HCO₃⁻. The hydrochemical types are primarily SO₄-Na, HCO₃-Na and HCO₃-Ca. The chemical composition of the mine water is jointly controlled by silicate weathering and dissolution, evaporative concentration, and cation exchange. The main exceeding indicators in the mine water include TDS, Na⁺, SO₄²⁻, total hardness (TH), Cl⁻,and F⁻. Among these, TDS and Na⁺ have the highest exceeding rates(65%), followed by SO₄²⁻(45%). Furthermore, the integrated weighted water quality index was employed to evaluate mine water quality: Class Ⅰ and Class Ⅱ water each accounted for 25%, Class Ⅲ for 10%, and Class Ⅳ and Class Ⅴ accounted for 5% and 35%, respectively. Class Ⅰ mine water meets the quality requirements for ecological and agricultural irrigation use, whereas water of other classes is unsuitable for direct utilization and requires targeted treatment measures based on its specific hydrochemical characteristics to prevent soil salinization and vegetation degradation.

Key words: arid, semi-arid, coal mining areas, mine water, water quality, resource utilization

摘要：

蒙陕接壤煤矿区是我国典型的生态脆弱区和重要的煤炭生产基地，但大规模高强度的煤炭开发产生了大量的矿井水，当前矿井水的水文地球化学成因及资源化利用是煤炭行业绿色转型的关键问题。系统采集了区内多个大型煤矿的矿井水样品，通过实验室测试与数据分析，揭示了矿井水的水文地球化学特征及成因，并基于矿井水质特征，提出了矿井水分质利用的技术途径。研究结果表明：研究区矿井水整体呈弱碱性，总溶解性固体（TDS）平均值为2 053.57 mg/L；矿井水中优势阳离子为Na⁺与Ca²⁺，优势阴离子为SO₄ ^2-与HCO₃ ^-，水化学类型以SO₄-Na型、HCO₃-Na型和HCO₃-Ca型为主；矿井水水化学组分受硅酸盐岩风化溶滤作用、蒸发浓缩作用与阳离子交换作用等因素共同控制。矿井水中主要超标指标有TDS、Na⁺、SO₄ ^2-、总硬度（TH）、Cl^-、F^-，其中TDS和Na⁺超标率最高（65%），SO₄ ^2-次之（45%）；在此基础上，采用综合权重水质指数（IWQI）对矿井水质量进行评价，水质Ⅰ类和Ⅱ类占比都为25%，Ⅲ类占比为10%，Ⅳ类和Ⅴ类占比分别为5%和35%，Ⅰ类矿井水可满足生态与农业灌溉用水水质需求，其他水质等级矿井水不适宜直接利用，需根据水质特征采取相对应的水处理措施，防止土壤积盐与植被退化。

关键词: 干旱, 半干旱, 煤矿区, 矿井水, 水质, 资源化利用

CLC Number: 

• X703.1