Present situation and prospect of green filling mining in mines

Based on the requirements of the national green industry and the development of circular economy,starting from the scientific connotation and technical system of green mining in the coal industry,it is clarified that the gob formed after coal mining is the source of ecological and environmental problems such as surface subsidence,soil erosion,gangue dumping and land occupation in mining areas that cause rock formations to move and deform and it is pointed out that the gob filling is the fundamental way to effectively protect the mining area's ecological environment.The main development history of mine filling and the main types of green filling mining in China’s coal mines are reviewed,and the principles of four types of filling mining techologies are introduced,including paste filling,gangue solid filling,ultra-high water filling and overlying strata separation zone isolation grouting filling.The filling process and technical characteristics and the corresponding research status and application results are respectively introduced,focusing on 9 aspects including filling equipment characteristics,filling process characteristics,material sources,paste delivery characteristics and stability,precise control and standardization construction.It also clarified the the main problems and challenges currently faced by coal mine green filling mining,and it is pointed out that the realization of coal mine green filling and mining requires key scientific and technological research and innovative development of new types from five aspects:theoretical research on high-cutting height filling rock formation,filling technology in ecologically fragile areas,intelligent filling technology,precise transportation of filling materials and filling policy guarantees.Key breakthroughs have been made in 5 aspects including the research and development of filling materials,key filling equipment,the construction of new intelligent filling technology,the construction of standardization systems and policy support,and the research and development of efficient waste filling treatment technology,and also prospects for the development and application of coal mine green filling mining technology.