Progress and prospective of the mining key technology for deep metal mines

Mineral resources are essential to human life and social development and play an important role in national security and economic development. China has huge reserves of metal mineral resources, but the per capita possession is low. Especially, it is difficult for iron, copper, aluminum, and other metal mineral resources to be self-sufficient and heavily dependent on foreign countries. Because of the massive exploitation of metal mineral resources, shallow resources are becoming exhausted, and deep mining will become the main force for the supply of metal mineral resources in the future. “Going deep into the earth” corresponds to the current state of national resource strategy development. It is found that there is still a certain gap between China’s deep metal mining technology and mining depth compared with internationally developed mining countries. The mining depth of foreign mining countries is mostly over 3000 m, with three South African mines having a mining depth of over 4000 m, whereas the mining depth of Chinese mines is mostly below 2000 m, and most of the metal mines have not yet broken through the kilometer depth. Furthermore, the level of mining technology in established mining countries abroad is high, and the degree of mechanization and intelligence is high. Deep mining technology in China is insufficient to meet the need for deep mining. China still has a large gap compared with internationally developed countries; therefore, the related rock mass mechanics theory and mining technology are no longer suitable for deep metal mining. In this paper, we summarize the research status of four major theories and technologies for deep mining of metal mines, namely, deep rock mechanics, deep well building and lifting, green mining, and intelligent mining, and proposes future research emphases. Finally, based on the research status and existing problems of the key technologies and theories of deep metal mining at present, the paper puts forward three strategic ideas: deep-part construction of a super-large intelligent autonomous mine, in-situ fluidized mining, and rock mechanics. With the continuous increase of mining depth, it is urgent to study the related theory and technology of deep mining of metal mines so as to ensure the safe, efficient, economical, and environmentally friendly mining of deep metal mineral resources and ensure the resource security of our country.