Summary of water disaster characteristics and water prevention and control technology in open-pit coal mines in China

Opencast mining is one of the two ways of coal mining in China. Similar to the underground coal mine, the open-pit coal mine also faces the problem of water prevention and control in the process of mining. Due to the relatively single type of water disaster in open-pit coal mines in China, domestic scholars have conducted in-depth study on the characteristics of water disaster and water control technology. Based on the distribution of open-pit coal mines in China, this paper analyzes the characteristics of water hazards in open-pit coal mines from three aspects of water filling source, water filling channel and water filling intensity. It is concluded that atmospheric precipitation, surface water and shallow groundwater are the main water filling sources; direct channel formed by human excavation, strong permeable aquifer or permeable layer, vertical guide water drilling, surface cracks formed by landslide are the main water filling channels; obvious seasonal change, long drainage time and large quantative are the main characteristics of open-pit coal mine drainage. This paper sums up seven kinds of water control technologies commonly used in open-pit coal mines in China and puts forward a three-dimensional water control technology system from far to near, from top to bottom and from surface to point. From the perspective of groundwater resource and ecological environmental protection, in order to realize the green mining and sustainable development of open-pit coal mine, the curtain closure technology aimed at cutting off the supply channel and reducing the drainage of the mine is the main method in the future.