Review and thirty years prospect of research on water-preserved coal mining

Coal is the most important energy source in China’s industrialization process and has been playing important roles in China’s economic development. But one of the main problems facing all industrialized countries is the subject that has been generally termed as environmental degradation and the short-term economic benefits are obtained at the expense of huge environmental losses.Water-preserved coal mining is a scientific mining idea and method for the environmental problems that occurred during the development of the Jurassic coalfield in northern Shaanxi. It has made great progress in the past 20 years. This paper reviews the discovery of Shenfu coalfield and analyzes its resource characteristics and highlights the prominent environmental problems that occurred during the exploration of coal，such as land desertification and water supply and demand conflicts. The paper puts forward the proposal and development process of water-preserved coal mining，and explains the concept and scientific connotation of water-preserved coal mining. Based on the results of CNKI literature search，the research projects, published papers, thesis and academic conferences around the problem of water-preserved coal mining were reviewed in detail, and the main key scientific issues in this field were pointed out. The main achievements of the study on the eco-logical water level and threshold research of the mining area, the control of shallow buried coal seams, the development height of the water-conducting fracture zone, the division of water-retaining conditions, the water-preserved coal mining technology and the construction of the groundwater monitoring network are introduced in detail. Water-preserved coal mining is an important mean to maintain and improve the function of the mine ecosystem and the quality of the environment. It must be sustained and implemented continuously. In the future, the implementation of water-preserved coal mining technology project needs to thoroughly implement the important concept of “the mountains，rivers，forests，lakes and grass are a life community”，and promote the successful experience and practice mode of the pilot project, in order to comprehensively promote the ecological protection and restoration of the national soil space.