METHOD FOR INITIATION OF DEEP-HOLE EXPLOSIVE CHARGES Russian patent published in 2001 - IPC

FIELD: blast breaking of rocks at exploitation of mineral resources. SUBSTANCE: the method consists in the fact that before placement of a detonating cartridge in the deep-hole, loops are formed in the form of a twisted spiral with closed ends into a single continuous line of sections of the detonating cartridge with a length equal to the distance of the straight-line section of the detonating cartridge in the explosive charge between the spirals, determined by formula: L = 2D_CK•V_dc/(V_dc-V_BB), where L - distance between spirals; D_CK-diameter of deep-hole explosive charge; V_dc- detonation speed of the detonating cartridge; V_BB-detonation speed of the explosive charge. The spiral coils are formed by fixation in a bundle, use is made of a spiral with 4 coils. EFFECT: enhanced efficiency of rock breaking. 2 cl, 2 tbl, 2 ex