METHOD FOR MINING OF MINERAL DEPOSITS Russian patent published in 1997 - IPC

FIELD: mining industry. SUBSTANCE: rooms and pillars are formed by pairs so that their total width amounts to 0.8-0.9 of that of rock caving step. Pillar width equals to 0.4-0.5 of the required one according to strength conditions and after breaking of pillar, to room space, ore is drawn through chamber draw openings under protection of rock cantilever up to formation of ore slope. Then concurrent breakage of rock block above broken pillar is accomplished, rock self-caving is initiated and induced caving of rocks above room at a height equals to value of thickness of ore body. Then ore is drawn under sinking rock block. In insecure rocks, room-pillar pairs are worked in staggered manner. To increase efficiency, cutoff holes are located over hyperbolic surface. EFFECT: higher efficiency. 3 cl, 8 dwg