Mine water drainage pollution in China's coal mining areas and the construction of prevention and control technical system

Mining activities are bound to produce enormous mine water drainage. Mine water in China shows relatively poor water quality and high cost of water treatment and other problems. Firstly, the main characteristics of mine water quality in China's typical mine areas are clarified in this paper: conventional ions are the main chemical components causing poor mine water quality; mine water has a small proportion of toxic and harmful substances, which is generally better than the quality standard of class Ⅲ groundwater. Secondly, some scientific issues on the formation and evolution of mine water quality are discussed in detail, including the leading role of physical-chemical effects under different hydrogeological structures, the influence of time effect on water quality evolution, the relationship between microbial community structure characteristics and environmental factors, the multi-field coupling of hydrodynamic field, chemical field, microbial field and temperature field. Then, this paper mainly introduces the prevention and control techniques of mine water pollution where on the premise of reducing the amount of water inrush and the protection of water resources, with the goal of realizing the coordinated mining of coal and water resources and the green mining, and the main ideas of "block, reduction and protection" for prevention and control of mine water, scientific issues such as mine water blocking technology, pollution substances reduction technology and pollution area restoration and treatment are analyzed. The cost of coal mine water treatment can be minimized through various existing technologies, methods and processes, such as underground pretreatment, surface in-depth treatment, super deep recharge and storage, ecological resources utilization. Finally, the paper puts forward the development of blocking materials, adsorption materials, grouting equipment, monitoring equipment, feeding equipment, in-situ sampling and detection equipment for groundwater and pollutants in coal mine areas, forming the technical system of mine water pollution prevention and control in coal mine areas. The construction of this technical system provides theoretical and technical support for green mining, the prevention and control of deep groundwater pollution in coal mine areas, the prevention and control of water pollution in closed mines, the protection and utilization of groundwater resources and ecological environment in mine areas.