矿井水铁超标将腐蚀配水管道、工业设备，损害人体肝脏，威胁人类健康。煤系铁的含量、赋存形态及其在水–煤/岩作用过程中的溶解释放决定了矿井水中铁的富集或贫化。通过采集东部草原某矿区煤及岩石样品18组，利用等离子电感耦合质谱仪、X射线衍射、带能谱的扫描电镜、逐级化学提取，分析煤系铁的含量、赋存形态、赋存载体，开展室内水−煤/岩模拟试验，研究煤/岩中铁的释放机制。结果表明：煤与顶板砂岩中的铁含量均较高，18组煤/岩样中铁的富集因子均大于1；煤与砂岩中铁的赋存形态主要以残渣态为主，有机结合态次之，碳酸盐结合态与可交换态最少。煤中残渣态、碳酸盐结合态、可交换态铁的赋存载体分别为高岭石、菱铁矿、伊利石；砂岩中残渣态、碳酸盐结合态、可交换态铁的赋存载体分别为绿泥石、菱铁矿、伊利石。水–煤/岩相互作用过程中，煤与砂岩中铁的最大释放量分别为1.26、2.75 mg/L，显然砂岩中铁的释放量大于煤中。对比水−煤/岩作用前后煤/岩中铁的赋存形态变化可知，残渣态、有机结合态及铁锰氧化物结合态的铁含量基本不变，可交换态及碳酸盐结合态的铁含量均减小，这2种形态的铁稳定性差，迁移性强，易于释放进入水中，是导致矿井水中铁富集的主要原因，将为高铁矿井水的处理与利用提供基础。

The mine water with iron out of limit corrodes the water distribution pipeline and the industrial equipment, thereby damaging the liver of human body, and further threatening the human health. The enrichment or dilution of iron in mine water is determined by the iron content and its occurrence in coal measures, as well as its release mechanism during water-coal and water-rock interactions. Herein, 18 groups of coal and rock samples were collected from a mine in the eastern grassland, and had the iron content, occurrence and carrier in the coal measure analyzed with an inductively coupled plasma mass spectrometry (ICP-MS), an X-ray diffractometer, a scanning electron microscope with energy spectrum (SEM-EDS) and a sequential chemical extraction experiment (SCEE). Meanwhile, laboratory water-coal and water-rock simulation tests were carried out to study the release mechanism of iron from coal and rock. The results show that: (1) The iron content is high in coal and roof sandstone, and the enrichment factors of iron in the 18 coal and rock samples are all greater than 1. (2) The iron in coal and sandstone is mainly presented in the residue, followed by the organics, carbonate and the exchangeable form in descending order. (3) The occurrence carriers of iron in residual, carbonate and exchangeable form in coal are kaolinite, siderite and illite respectively, while those in sandstone are chlorite, siderite and illite respectively. The maximum release amount of iron from coal and sandstone during the water-coal and water-rock interactions is 1.26 mg/L and 2.75 mg/L, respectively. Thus, it is indicated that the release amount of iron from sandstone is significantly greater than that from coal. As shown by the comparison of changes in the occurrence of iron in coal and rocks before and after the water-coal and water-rock interactions, the iron content in the residue, organics and iron-manganese oxide is basically unchanged, while the iron content in the exchangeable form and carbonate is reduced. This is because the iron is prone to being released in water due to the poor stability and strong mobility of iron in these two forms, which is also the main reason for iron enrichment in mine water. The results will provide a basis for the treatment and utilization of high iron mine water.