Raw material is blasted from a stratum, e.g. for open-cast mining of limestone, by placing compressible material at the blasting hole bottom to attenuate wave propagation transverse to the blasting direction

摘要

Raw material blasting from a stratum, using a compressible material at the blasting hole bottom to attenuate detonation and pressure wave propagation transverse to the blasting direction, is new. Raw material is mined from a stratum by drilling a blasting hole from the stratum surface, filling the hole with an explosive and an additional filling and detonating the explosive to release a pressure wave which propagates in a blasting direction to effect separation and comminution of the raw material. The additional filling comprises a compressible material placed at the deepest point in the blasting hole for attenuating propagation of detonation and pressure waves transverse to the blasting direction.