Safe and green mining of thick coal seam under Neogene aquifer and clean utilization of water resources

Coal mining not only supports the high-quality development of national economy and society,but also has a serious impact on the safety of water bodies,surface buildings(structures)and ecological environment. In order to accelerate the process of green mine construction,based on the concept of green mining and sustainable development,the safety of coal mining under Neogene aquifer was divided into regions,and the combined up-down well drainage technology to convert roof water into mine water was proposed,which solves the threat of water damage in loose aquifer and realizes safe and efficient mining. Based on the green mining,the surface response characteristics of fully mechanized top coal caving mining were analyzed,the law of surface dynamic evolution was clarified,the surface dynamic movement and deformation parameters were obtained. Through the regional division of the damage degree of the subsidence area,and based on the principle of the combination of engineering and ecological reclamation,the land reclamation measures were implemented in the mining subsidence area. Combined with the concept of water protection and comprehensive utilization of clean energy,based on the whole life cycle theory,the whole life cycle cost model of the mine heating method was established,and the reasonable supply method was analyzed. The results show that the dewatering and drainage not only liberates the coal resources under water of 5.99 Mt,but also provides rich mine water waste heat for the comprehensive utilization of overburden water resource. By analyzing the life cycle cost of different heating modes,it is determined that the waste heat utilization of clean energy is the best way to supply the mine heat,which has the characteristics of low operation cost,high efficiency and energy conservation,green environmental protection and so on,and realizes the efficient utilization of clean energy. Meanwhile,using the surface movement parameter to guide the land reclamation in the subsidence area not only improves the land productivity,but also effectively improves the eco-environment of the mining area,speeds up the construction process of green mines.