神华神东矿区许多矿井水中氟化物(F- )质量浓度超标(>1 mg/ L)，给矿井水的利用和排 放带来巨大挑战。 为了调查矿井水中氟化物的潜在来源以及研究高氟矿井水的形成机制，从神东 矿区 8 个煤矿采集了矿井水、萨拉乌苏组松散层潜水以及地表水样品共 81 个，进行了氢氧同位素 和主要离子质量浓度测定。 测试结果显示:神东矿区矿井水中 F- 质量浓度介于 0.05 ~ 11.65 mg / L， 平均为 1.96 mg / L，其中 51%的矿井水为高氟矿井水。 氢氧同位素分析表明绝大多数的高氟矿井 水具有偏轻的 δD 和 δ18 O，且随着 F- 质量浓度的增高，δD 和 δ18 O 降低。 分析认为，δD 和 δ18 O 偏轻 的矿井水相对古老，滞留时间长，其与松散层潜水以及地表水的水力联系较差，处于相对封闭的地 下水环境，径流滞缓，水-岩反应充分，当含水层的矿物学和地球化学条件适宜条件下，含氟矿物中 氟释放，导致水中 F- 的富集。 矿井水水化学类型与 F- 质量浓度的关联性分析显示，Na-HCO3 型水 具有最高的 F- 质量浓度;所有的高氟矿井水均为 Na 型水，Na 型矿井水中 F- 的质量浓度明显高于 Ca 型矿井水，随着 Na+ 质量浓度的增高和 Ca2+ 质量浓度的降低，F- 质量浓度升高，反映出 F- 的富集 主要与矿井水中Na+增高以及Ca2+消耗的水-岩作用有关。 综合分析认为，神东矿区高氟矿井水的 形成主要与矿井水中 Ca2+ 与岩石表面吸附的 Na+ 的阳离子交换吸附作用有关，同时，较高的碱性水 环境下 OH- -F- 阴离子交换以及 Ca( OH) 2 矿物沉淀也有助于矿井水中 F- 的富集;此外，氢氧同位 素分析表明少部分高氟矿井水的形成与蒸发作用有关。

The fluoride(F-) mass concentrations in many mine water samples in the Shendong mining area of Shenhua exceed the national standard(> 1 mg/L)，which brings some great challenges to the storage，reuse and discharge of the mine water. In order to investigate the potential sources of fluoride in the mine water and study the forma⁃ tion mechanism of high⁃fluoride mine water，81 water samples including mine water，phreatic water of unconsolidated formation of Salawusu Formation，and surface water were collected from 8 coal mines in the Shendong mining area. Their hydrogen and oxygen isotopes and main ion mass concentrations were determined.The test results show that the F- mass concentration of mine water in the Shendong mining area ranges from 0.05 to 11.65 mg / L，with an average of 1.96 mg/L.51% of mine water is high⁃fluoride mine water.The analysis of hydrogen and oxygen isotopes shows that most of the high⁃fluoride mine water samples have relatively lighter δD and δ18 O values，moreover，the δD and δ18O values decrease with the increase of the F- mass concentrations in mine water samples. The analyses suggest that the mine water samples with lighter δD and δ18O values are relatively old and have a long residence time in the formation.They have poor hydraulic connections with the phreatic water of unconsolidated formation and surface water and are within a relatively closed groundwater environment，leading to a stagnant runoff condition and sufficient water⁃rock reactions.Once the mineralogy and geochemical conditions of the aquifer are appropriate，the F of the fluor⁃ ide⁃bearing minerals releases， resulting in the enrichment of F- in the water. The correlation analysis between the hydrochemical types of mine water and the F- mass concentration shows that the Na - HCO3 type water has the highest F- mass concentration.The F- mass concentrations in the Na⁃type mine water are obviously higher than that in the Ca⁃type mine water.With the increase of the Na+ mass concentration and the decrease of the Ca2+ mass concen⁃ tration，the mass concentration of F- increases，reflecting that the enrichment of F- is mainly related to the water⁃rock reactions of increasing the Na+ mass concentration and consuming the Ca2+ in the mine water.The comprehensive anal⁃ ysis shows that the formation of high⁃fluoride mine water in the Shendong mining area is mainly related to the cation exchange adsorption of Ca2+ in the mine water for Na+ absorbed on the minerals.Meanwhile，under higher alkaline water environment，the OH- -F- anion exchange and the Ca(OH)2 mineral precipitation also contribute to the enrich⁃ ment of F- in the mine water.In addition，the hydrogen and oxygen isotope analysis indicates that the formation of a small part of high⁃fluoride mine water is related to evaporation.