Features of using equipment for in-pit crushing and conveying technology on the open pit walls with complex structure

Abstract

Purpose is to substantiate the use of an in-pit crushing and conveying technology at the open pits with complex structure of the working zone, which technological complex includes inclined and steeply inclined conveyors for improved economic efficiency of mineral mining at deep levels. Methods. The study applies a complex method including: technical-economical analysis of the practice of mining enterprises, experience of using conveying units at concentration plants and open pits; mining-geometrical analysis in terms of open pit sections – to identify the structure of the working zone of a deep open pit wall and its features along the depth; structural developments – to improve the design of a steeply-inclined conveyor; simulation modelling of the technological processes – to select optimal technical solutions. Findings. Basing on the performed studies, it has been identified that transfer to a new trend of the in-pit crushing and conveying technology, considering the structural features of the working zone of a deep open pit, is rather prospective. In this context, it is expedient to use inclined conveyors or deep-trough conveyors on the sites of an open pit wall with the inclination angle of 10-18°; in case of sites with the inclination angle of 30-36°, it is recommended to use steeply inclined conveyors. Originality. For the first time, a relation between the working zone of a deep open pit and formation of the structure of technological complexes has been identified. Dependences of the boundary inclination angle αn of a pipe conveyor on the angle of non-filling θ of its belt with the cargo at different coefficients of cargo-belt friction have been defined. Practical implications. The obtained results make it possible to widen the application sphere and increase the efficiency of mineral mining with the use of in-pit crushing and conveying technology.