皖北煤矿区主要含水层岩石浸泡溶解释放规律研究

Study on the Dissolution and Release Pattern of Rock Immersion in the Major Aquifers in the Coal Mining Area of North Anhui Province, China

摘要: 为研究皖北矿区地下水水岩相互作用过程，本研究采取典型煤矿主要含水层砂岩、灰岩、松散层等岩石进行浸泡实验，通过测试浸泡后水溶液离子含量、微量元素含量，探究不同岩石溶解释放规律。结果表明，研究区不同含水层岩石浸泡液中阳离子浓度最大的均为Na⁺，分别为68.82 mg/L，20.86 mg/L，32.18 mg/L，8.72 mg/L；阴离子浓度最大的均为HCO3−，分别为202.14 mg/L，111.13 mg/L，101.27 mg/L，28.96 mg/L，且Na⁺和HCO3−浓度随浸泡时间变化具有相似的增长趋势。除了松散层浸泡液中Fe浓度，其他浸泡液元素浓度值均低于生活饮用水标准。灰岩、砂岩、松散层岩石浸泡液中Cr、Ni、Cu、Zn元素溶解比率大小为灰岩 < 砂岩 < 松散层。此研究对矿区地下水水质评价、重金属来源分析，甚至地下水演化探讨及矿井水害防治均具有重要意义。

Abstract: In order to study the process of groundwater-water-rock interaction in the mining area of northern Anhui Province, this study takes sandstone, tuff, loose layer and other rocks of the main water-bearing layers of a typical coal mine to carry out immersion experiments and explores the dissolution and release laws of different rocks by testing the ion content of the aqueous solution and the content of trace elements after immersion. The results showed that the largest cation concentration in the soaking solution of rocks from different aquifers in the study area was Na⁺, which was 68.82 mg/L, 20.86 mg/L, 32.18 mg/L, and 8.72 mg/L, respectively; the largest anion concentration wasHCO3−, which was 202.14 mg/L, 111.13 mg/L, 101.27 mg/L, and 28.96 mg/L, respectively. The Na⁺ andHCO3−concentrations had similar increasing trends with soaking time. Except for the Fe concentration in the loose layer leachate, the elemental concentration values of other leachates were lower than the standard for domestic drinking water. The dissolution ratios of Cr, Ni, Cu, and Zn in the leaching solution of gray rock, sandstone, and loose layer rocks were gray rock < sandstone < loose layer. This study is of great significance to the evaluation of groundwater quality in the mining area, the analysis of heavy metal sources, and even the exploration of groundwater evolution and the prevention and control of mine water hazards.