Research and progress of coal mine green mining in 20 years

The breaking movement of the rock layer caused by coal mining has caused a series of mining damage and environmental problems.From the perspective of broad resources,green mining can reduce the impact of coal mining on the environment from the source by controlling or using the breaking motion of the mining rock layer,and realize the co-mining or protection of coal seams and its associated resources.The concept has been widely recognized by the industry,and the research and application of green mining technology has also achieved important progress.This paper further discussed the connotation of green mining in terms of the concept of resources in a broad sense,based on the principle of rock fracture movement law,source reduction and the concept of full life cycle,etc,and proposed a full life cycle green mining technology framework,including water conservation mining,coal and gas co-mining,waste rock discharge,subsidence reduction mining and environmental restoration.The research history of green mining in coal mine in China in recent 20 years was reviewed.The key strata theory is an important theoretical basis for the study of green mining technology.Its basic academic thought emphasizes the study of overburden as a whole,and unifies the study of mining pressure,water and gas and surface subsidence.Meanwhile,it emphasizes the main contradiction,namely,to find out the key strata that control the overburden movement,and avoid adopting the traditional method of homogenizing the overburden lithology.The theoretical research results on the evolution of rock formations and mining fissures are summarized,including the prediction method of the height of water-conducting fracture zone based on the position of key stratum,the cumulative effect of overburden unloading expansion,and the "three zones" principle of gas pressure relief and drainage.The technical progress,status quo and engineering application effects are discussed for the technologies of water conservation coal mining,co-extraction of coal and gas,and filling and subsidence mining,etc.It puts forward suggestions to further promote the development of green mining technology,including deepening the study on the law of strata movement,determination of green mining technology model suitable for the characteristics of different mining areas,establishing the evaluation index system of green mining in coal mine,carrying out the green mining design of the whole life cycle of coal mines,and development of green mining technologies with high efficiency and low cost.This pointed out the direction for green mining in Chinese coal mines.