Study on fluoride leaching regularity of natural minerals in Shendong Mining Area
ZHANG Haiqin1,2, BAO Yixiang1,2, TANG Jiawei1,2, CAO Zhiguo1,2, JIANG Binbin1,2, LI Jie1,3, LI Jingfeng1, LIU Zhaofeng1,2
随着神东矿区煤炭开采向深部转移,矿井水中氟化物超标问题凸显,因此研究氟化物的主要来源对控制矿井水中的氟化物浓度具有重要的意义。为证明天然含氟矿物是矿井水中的氟的主要来源,深入了解天然含氟矿物在矿井水中的浸出过程,以神东矿区为对象,分析了不同深度矿井水中的水质变化规律,研究了不同深度矿物中的氟化物变化,并讨论了天然含氟矿物在矿井水中的氟化物浸出规律。研究结果表明,当煤炭开采深度大于120 m 时,矿井水中氟化物浓度超过地表III 类氟化物标准值,并且含氟矿物在天然矿物中的比例增大。通过对矿井水中阴阳离子成分分析,认为矿井水中氟化物主要来源于煤炭开采深部含氟矿物的浸出。研究不同水岩作用条件下含氟矿物浸出规律发现,提高水岩作用强度,可以加速含氟矿物中氟化物的浸出;当岩水比例增大(大于1∶50)时,部分含氟矿物的氟浸出浓度大于1.0 mg/L;特别在酸性或碱性条件下,由于离子交换作用和溶解平衡机制,含氟矿物中难溶性氟化物发生浸出。综上所述,在一定的水岩作用环境中,天然含氟矿物中的氟化物浸出,可导致矿井水中氟化物浓度超标(大于1.0 mg/L),这一结论为在复杂地质条件下精确管控天然矿物的氟化物浸出提供了重要指导。
As coal mining is shifted to the deep in Shendong mining area and fluorine concentration in mine water is increasing, it is of great significance to study the main sources of fluoride for the control of fluoride pollution in mine water. In order to further prove that natural fluorine-containing minerals are the main source of fluorine in mine water, it is necessary to deeply understand the leaching process of natural fluorine-containing minerals in mine water.Take the Shendong mining Area as an example, the water quality change law of mine water at different depths was analyzed, the fluoride content change of rock mining areas at different depths was studied, and the fluoride leaching regularity of natural fluorine-containing minerals in mine water was discussed. The results show that the fluoride concentration in the mine water exceeds the standard value of class III fluoride on the surface, and the proportion of fluorine-containing minerals in natural minerals increases,when the coal mining depth is more than 120 m. Through analyzing the anion and cation components of the mine water, it is believed that the fluoride in the mine water mainly comes from the leaching of fluorine-containing minerals in deep coal mining. Further study on the leaching law of fluorine-containing minerals under different water rock interaction conditions shows that the leaching of fluoride in fluorine-containing minerals can be accelerated by increasing the strength of water rock interaction; When the rock water ratio was increased (more than 1∶50), the fluoride leaching concentration of some fluorine-containing minerals was greater than 1.0 mg/L; Especially under acidic or alkaline conditions, the insoluble fluorides in fluorine-containing minerals were dissolved due to ion exchange and leaching equilibrium mechanism.To sum up, the high fluoride (more than 1.0 mg/L) in mine water was caused by fluoride leaching, because fluoride in natural fluorine-containing minerals is dissolved out under certain water rock interaction conditions. It is an important guidance to accurately control the fluoride leaching of natural minerals under complex geological conditions.
mine water; natural fluorine-containing minerals; fluorine source; fluorine leaching; mine water pollution
主办单位:煤炭科学研究总院有限公司 中国煤炭学会学术期刊工作委员会