METHOD OF OPEN-PIT MINING Russian patent published in 1997 - IPC

FIELD: mining industry; may be used in mineral open-pit mining. SUBSTANCE: method includes stage mining of open-pit field with layer extraction of rocks and formation of benches with their sloping by means of smooth blasting, construction of horizontal safety berms and inclined haulage berms, increasing the resulting angle of pit flank with progress of work and formation of platforms of smooth angle of inclination of route. Working of overlaying stage is started by construction of horizontal safety berm with vertical angle of slope of bench overlying above haulage berm and lower brow of neighboring overlying bench. Then inclined haulage berm is constructed by spiral successive access ramps of route. Mining is continued by formation under access ramp on pit flank of benches with vertical slope angle and horizontal berms to form a group of concentric benches as open pit is deepened over open pit perimeter. Platforms for smooth rough angle of inclination are made horizontal. Berm of bench on the section adjacent to the platform is made with constant width and formed between adjacent turns of spiral route over open pit perimeter, beginning from the platform, is additional concentric horizontal safety berm. In so doing, as rock is extracted in final contour of open pit formed on one of flank parts is loop system of narrow access ramps with end horizontal platforms. EFFECT: higher efficiency. 2 cl