CCTEG Xi’an Research Institute
China Coal Research Institute

The border area between Mongolia and Shaanxi is the core area for China’s energy security. However, a largenumber of mine water produced in the process of coal mining contains a variety of pollution components. Only by findingout the sources and characteristics of pollution components can we deal with and utilize mine water resources more scientificallyand reasonably, which is also in line with the requirements of high-quality de-velopment of the Yellow River region. Based on the investigation of the geological, hydrogeological and coal mining disturbance conditions in the borderarea between Mongolia and Shaanxi, the hydrogeochemical charac-teristics of coal seam roof aquifer and the characteristicsof typical pollution components in mine water were studied, and the sources of these typical pollution componentswere analyzed. The results showed that the border area between Mongolia and Shaanxi was located in the Yishan slope.According to the coal seam buried depth conditions, it could be divided into shallow buried area, medium deep buried areaand deep buried area. The mine water in the shallow buried area came from all aquifer water of the coal seam roof, and themine water in the medium deep buried area came from aquifer water of the Yan’an formation and the Zhiluo Formation(divided into complete bedrock section and weathered bedrock section) of the coal seam roof. The concentration of TDS inthe Quaternary and Jurassic groundwater in the shallow buried area and the medium deep buried area was lower than 1 000mg/L. The mine water in the deep buried area came from the aquifer water of the Jurassic Yan’an Formation and ZhiluoFormation in the roof of the coal seam. The Jurassic aquifer was relatively closed and stagnant. The long-term water rockinteraction led to the concentration of TDS in groundwater upper than 1 000 mg/L, and the main exceeding standard componentswere Na+, Ca2+ and . The pollution components in mine water included two categories: one was from the roofaquifer water, and the long-term water rock interaction led to the entry of ion components into mine water. The other camefrom the underground production activities of coal mines. The release of coal cuttings, dust and oil led to the dissolution ofsuspended solids, nitrogen, organic matter and other pollution into mine water. The concentration of TDS in mine water inthe shallow and medium deep buried areas was lower than 1 000 mg/L, which is mainly weakly alkaline HCO3-Ca water,and the main cation and anion (including Na+, Ca2+, Cl−, ) basically did not exceed the standard. The TDS concentrationin the mine water in the deep buried area (including the Xiaojihan coal mine) was 1 824.00−3 684.00 mg/l, which wasslightly higher than that in the roof water. The increase of Na+ and ion concentration accounted for the largest proportion,which was mainly due to the further water rock interaction in the goaf. The concentration of COD in mine waterof most coal mines exceeded the standard, but the TOC concentration and UV254 value were low, it showed that the organicmatter in the mine water was mainly suspended. The 3DEEM spectrum detection results showed that the dissolved organicmatter was mainly natural amino acids and humus, the fluorescence intensity of all kinds of organic matter was low,and there were few organic pollutants in mine water.

国家自然科学基金项目(42007179)；陕西省重点研发计划资助项目(2022SF−046)

杨建，王皓，王强民，等. 蒙陕接壤区矿井水中典型污染组分特征及来源[J]. 煤炭学报，2023，48(4)：1687−1696

YANG Jian，WANG Hao，WANG Qiangmin，et al. Characteristics and sources of typical pollution components in mine water in the border area of Inner Mongolia and Shaanxi[J]. Journal of China Coal Society，2023，48(4)：1687−1696