Technological innovation and engineering practice of damage reduction mining and ecosystem restoration in open-pit coal mine

Non-technical summary To address the issues of declining groundwater levels and the degradation of soil ecological functions caused by open-pit coal mining in China. Based on theoretical analysis, laboratory experiments, on-site monitoring, mathematical modeling, and other means, the concept of coal ecological protection mining of 'damage reduction mining, three-dimensional protection, systematic restoration' is proposed. The mining concept has achieved remarkable ecological restoration effects, leading the scientific and technological progress of safe, efficient and green mining in open-pit coal mines. Technical summary The mechanism of damage propagation among 'rock-soil-water' ecological elements in open-pit coal mining was revealed. Adopting comprehensive damage-reducing mining technology throughout the entire stripping process, mining and drainage, shengli open-pit coal mine has doubled its production capacity, and reduced the land excavation and damage by 60 mu/year, reduced the mining area by 1,128 mu, and raised the groundwater level by 2.6-6 m, and the ecological restoration of the drainage field was advanced by more than 1 year. Adopting the three-dimensional water storage technology involves underground reservoirs, aquifer reconstruction, and near-surface distributed water storage units, baorixile open-pit mine has built the world's first open-pit underground water reservoir, with a water storage capacity of 1.22 million m(3), and the speed of groundwater level restoration has been increased by more than 70%. By adopting the systematic restoration technology of geomorphology-soil-vegetation in the discharge site, the soil water content in the demonstration area has been increased by 52%, the survival rate of plants has been increased by 34%, and the vegetation coverage has been increased by more than 40%. Social media summary Damage-reducing mining and systematic ecological restoration in open-pit coal mining are essential for the safe, efficient and green development of coal.