Research of high efficient crushing methods for coal rock

In view of the increasing proportion of hard-to-mine coal and rock in China and the low efficiency of traditional coal rock mining methods, a comprehensive review of high-efficiency coal rock crushing methods for hard-to-mine coal and rock has been carried out. First of all, according to the working principle, the existing high-efficiency coal rock crushinng technologies were divided into coal rock breaking by pure jet, coal rock breaking by jet assisted mechanic, coal rock breaking by impact pick-assisted mechanic, coal rock breaking by disc cutter, coal rock breaking by laser, coal rock breaking by drilling and cracking agent. The working principle of each coal rock breaking technology was expounded, and the advantages of each rock breaking technology were preliminarily summarized. Secondly, the research status of various coal and rock crushing methods was summarized, the current research foundation in China was outlined. According to the existing research, the limitations of each technology were analyzed, and the limitations of different coal and rock crushing technologies were evaluated through the established limitation indicators. Among them, the limitation of jetting coal and rock method was the lowest, and that of the laser method was the highest. Pick-assisted coal and rock breaking, disc cutter breaking coal and rock and drilling expansion and cracking agent breaking coal and rock shared the same limitations as jet breaking of coal and rock on the basis of ignoring the theoretical limit indicators, and they have the same engineering application value and theoretical research value. Finally, the future development trend of China’s hard-to-mine coal and rock crushing technology was analyzed. Taking into account the development trend of deep mining and hard-to-mine coal and rock mining, the two development concepts of the "overcoming or utilization of high in-situ stress" and "viscosity prevention or viscosity failure of cohesive coal" were put forward, and considering the development of China’s Internet of Things and the continuous improvement of intelligent mining, and the future development trend of China's hard-to-mine coal crushing technology and the development of traditional technologies are proposed. Their processes are different. Multiple coal and rock crushing technologies were coexisted and combined with each other so as to realize the combined work of various coal and rock crushing technologies under complex conditions such as thin coal seams, hard coal seams, and high gas coal seams.