Hydrochemical evolution of mine water injection in Hojirt Mining Area

Recent years, the mining scale in Ordos Basin has been expanding gradually. And mine water has always been a crucial problem in coal mines. It’s a threaten for coal mine production. But at the same time, mine water is also precious water resource. So the dual utilization of coal and water is necessary for environmental protection. The hydrochemical evolution of mine water injection is the main factor of groundwater quality. So, the study of hydrochemical is the key to ensure groundwater quality, and also the premise of injection feasibility. In this paper, the hydrochemical evolution was analyzed by experiments and simulation. The results show that: ① The high temperature makes more precipitation.② It will generate calcium sulfate and magnesium sulfate, mainly calcium sulfate. Gypsum and anhydrite will increase in aquifer. ③ The precipitation of calcium sulfate would be flushed to the downstream of the flow network. It will adversely affect the injection process. ④ The farther away from the injection well, the less precipitation will stay. The above analysis provided a basis for the mechanism of hydrochemical evolution in mine water injection. And it provided significant reference for the application of mine water injection.