1. State Key Laboratory of Water Resource Protection and Utilization in Coal Mining,Beijing　 100011,China; 2. China Energy Investment Corporation,Bei-jing　 100011,China

A large-scale coal-fired power base in the eastern grassland area is located in the eastern part of the north- ern anti-sand belt of “Two-barrier and Three-belt” scheme in China,and the development of regional coal power base has a certain influence on the surrounding ecological environment. The “Ecological Restoration and Integrated Remedi- ation Technology and Demonstration Research of Large-scale Coal Power Bases in the Eastern Prairie Region” re- search project was launched in 2016. In terms of the problems of unclear impact boundary and cumulative effect of the development of coal power base on the regional ecological elements of water,soil and vegetation,the ecological restoration technology and safety control method in mining area are required,therefore,the major technical research and engi- neering demonstration are carried out. According to the national key R&D plan,this paper puts forward the connotation of ecological environment protection of coal-fired power base,and constructs the concept of active ecological derogation based on the active derogation of mining source,covering the whole life cycle including prior to mining,mining in pro- gress,end of mining and pit closure,with the goal of minimizing the ecological damage of coal mining,and realizing water,soil,vegetation indicators reaching or better than the ecological background values prior to mining. From the basic theory,key technologies, integrated demonstration and regional control mode, the project research progress is elaborated. Firstly,in terms of basic theoretical research,a hydro-logical monitoring platform and network,and the full- space time-shift monitoring system of the ecological elements of coal-fired power base are constructed,which is one of the real-time observation system of meteorological and near-surface soil. The boundary and influence degree of coal mining on groundwater,soil physical and chemical properties and vegetation cover are clarified,and the method of landscape and regional ecological evaluation are put forward. Secondly,in the research of key technology aspects,the integrated technology of extraction and discharge based on ecological derogation is proposed. The three-dimensional water storage technology system of open-pit coal mine combining ground and underground is constructed. The type of the water-conducting crack of strata and its water-flow characteristics are obtained. This paper puts forward the ground- water in-situ protection technology,optimizes and designs open-pit mine drainage field surface slope shaping technolo- gy,investigates the surface soil substitute materials,selects the local vegetation species adapted to the eastern grassland area,puts forward the organic biological improvement technology for soil quality improvement,and optimizes the re- gional landscape distribution. Thirdly,the above-mentioned key technologies are integrated and demonstrated in Hulun- buir and Xilinhot coal power bases. Three preliminary demonstration projects are completed in two regions. The ecolog- ical restoration and comprehensive remediation system of coal power base in the eastern grassland area is basically constructed,and the demonstration is applied in the typical mining area,which will provide a technical support for the ecological environment protection in the region.

LI Quansheng. Progress of ecological restoration and comprehensive remediation technology in large-scale coal-fired power base in the eastern grassland area of China[J]. Journal of China Coal Society,2019,44(12):3625-3635.