The purpose of developing advanced in-pit crushing and conveying technology for deep open pits

The development of open pits, both in terms of their mining intensity and a significant increase in the current and design depth, requires improvement of transport systems that form the bulk of the production cost. One of the most proven types of combined transport that provides high productivity is the truck-and-conveyor system. Therefore, this paper focuses on its adaptation to the future mining conditions (high dynamics of open pit mining development with creation of deep quarries, the need to reach open pit depths of up to 800–1200 m). The field of application of different types of transport is not static and changes along with the technical development of transport means, their introduction into mass production, and a change in the target group of mining and operating conditions. The article provides a systematization of open-pit transport applicable in modern conditions and shows the experience gained by the Institute of Mining of Ural branch of RAS in the in-pit crushing and conveying technology, mobile (semi-stationary) crushing and reloading plants and self-propelled crushing units. The results of calculations and technical and economic parameters of open-pit truck haulage and conveyor transport in a wide range of mining conditions are described. It is shown that an urgent research and engineering challenge is the development of technologies for the phased introduction of high-performance equipment for in-pit crushing and conveying transport to a great depth with a minimal additional extension of the open pit walls. At the same time, it is possible to use both steeply inclined and traditional belt conveyors, depending on the specific operating conditions. Conveyor transport is preferable for use at the main stage of the life cycle of deep quarries in terms of its efficiency and throughput, but its use is constrained by a number of factors considered in the paper.