In the practice of rock excavation by borehole and borehole charges, oversized lumps of rock mass are formed, the yield of which is caused by: the physical and mechanical properties of rocks, the blockiness of rock masses, the parameters of drilling and blasting operations and other factors. The presence of oversized lumps of rocks on working platforms of open pits complicates technological processes of excavation and transport, reduces the efficiency of loading and transporting equipment. In underground mining the crushing of oversized lumps of rock mass is carried out on scraper tracks, in ducts and ore stacks, during the works in which the most difficult are the cases of jamming and vaulting.
