METHOD FOR PROTECTION OF SAFETY BENCH IN OPEN PIT Russian patent published in 1994 - IPC

FIELD: mineral opencast mining. SUBSTANCE: method consists in drilling peripheral holes for preliminary slot forming in treating nonworking benches, and forming of buffer zone to project upper part of bench from blast seismic effect. Slot depth is taken to fully protect the potential zone of bench breakage at its maximum wearing resulted from debris formation by mathematical relation. Buffer holes corresponding to slot depth are located at angle to bench to provide for maximum crushing of rocks of buffer zone at simultaneous flowing around of this surface by seismic waves. EFFECT: higher efficiency. 2 dwg