METHOD FOR MINING OF ORE BODIES BY ROOM SYSTEMS WITH YIELDING PILLARS Russian patent published in 1997 - IPC

FIELD: mining industry; may be used in underground mining of ore bodies by level-room systems. SUBSTANCE: method consists in that in mining of ore bodies by room systems with yielding pillars, slot in the next (adjacent) room is made before formation of yield of interblock pillar. Yield of interblock pillar is ensured by breakage on hanging wall in interblock pillar of trihedral prism by alternate short-delay-blasting of preceding block onto worked-out space by blasthole rings with reduction of width of each subsequent borehole ring, and the lost borehole in angle of prism is spaced from boundary of yielding interblock pillar, on the side of adjacent rooms, at a distance equals to radius of breakage of charge blast in this hole. With rock pressure close to limit one for the given rock mass, slot is driven in adjacent block spaced from yielding interblock pillar at a distance equals to thickness of layer broken for one mass blast together with breakage of trihedral prism in yielding interblock pillar. EFFECT: higher efficiency. 2 cl, 5 dwg