Method and apparatus for blasting hard rock

摘要

A method and apparatus for blasting of hard rock using a highly insensitive energetic material ignited with a moderately high energy electrical discharge causing the fracturing and break up of the hard rock is provided. The blasting apparatus comprises a reusable blasting probe including a high voltage electrode and a ground return electrode separated by an insulating tube. The two electrodes of the blasting probe are in electrical contact with a continuous volume of highly insensitive yet combustible material such as a metal powder and oxidizer mixture. The metal particles within the metal powder and oxidizer mixture form a plurality of fusible metal paths between the high voltage electrode and the ground return when subjected to an electric current delivered from a large capacitor bank coupled to the high voltage electrode. The plurality of fused metal paths act much like a fuse in that they provide a sufficiently high electrical resistance to allow coupling of the electrical energy from the capacitor bank to the metal powder and oxidizer mixture causing an increased dissipation of heat which initiates an exothermic reaction of the metal powder and oxidizer mixture generating high pressure gases fracturing the surrounding rock.