PROCESS OF DESTRUCTION OF PILLARS Russian patent published in 2001 - IPC

FIELD: mining industry. SUBSTANCE: invention can be used in mining deposits of mineral resources for destruction of various pillars in ore deposits under conditions of enhanced rock pressure. It provides for uniform, qualitative crushing of pillar and for reduced seismic effect of blast. Process of destruction of pillars includes drilling in pillar of row of holes parallel to two crop-out surfaces and oriented from one flank of pillar bordering of rock mass to another, loading of holes with explosive charges and sequential destruction of pillar mass by synchronous blasting of explosive charges into parallel crop-out surfaces. Characteristic feature of process lies in creation of loosening cavities in opposite rows by blast of explosive charges and in their formation with displacement one relative to another through half-distance between them. Loosening cavities are formed to certain depth and central part of pillar has shape of sinusoidal form with amplitude equal to half-width of pillar and half-period equal in plan to distance between symmetry axes of opposite loosening cavities. Breaking part of pillar having sinusoidal form is started by its cutting from rock mass by blast of explosive charges at flanks. Explosive charges placed opposite to vertexes of sinusoidal part of pillar are blasted with advance with reference to the rest of explosive charges in sinusoidal part of pillar. EFFECT: uniform and qualitative crushing of pillar and reduced seismic effect of blast. 1 dwg