METHOD OF FORMATION OF PLANE EXPLOSIVE CHARGE Russian patent published in 1998 - IPC

FIELD: mining industry, in particular, methods of blasting of mineral resources, applicable at mining enterprises for underground mining of hard rock deposits of mineral resources by stepped caving systems. SUBSTANCE: method consists in drilling of a group of conjugate holes of parallel - exposed surface of block, filling of holes with explosive after installation of plug, placement of initiators in explosive charge and blasting of the charge, a cavity is formed in the block by drilling of parallel groups consisting of two or more conjugate holes; part of the holes in the first group are arranged and loaded with explosive in conjugation with and perpendicularly to the remaining unloaded holes, and the last group of holes is loaded at a distance of 0.5 of the cavity charge line of least resistance from the undercutting roof before installation of plug; blasting from the second group of holes loaded with explosive is accomplished with retardation required for clearing of the cutting cavity from massif after blasting of the first group of holes. EFFECT: enhanced efficiency of formation of plane explosive charge, reduced scope of holes drilling. 4 dwg