CONTOUR DEEP-HOLE CHARGE Russian patent published in 2007 - IPC F42D1/02 F42D3/04 

FIELD: blasting operations for production of preset mining extraction contours without a considerable dislocation of the rock mass continuity beyond the rated profile, applicable in mining industry and construction.

SUBSTANCE: the contour deep-hole charge includes formation of a string of elements 1 of explosive 2 and initiation. The string is formed from the deep-hole bottom in single polymeric branch 3 in the form of cylindrical elements 1 of explosives 2 of a similar height and diameter formed by pinch 4 of branch 3 and being spaced at distance l_d=l_e(ρ_ed_ech ²/ρ_echd_dh ²-l) cm, where l_e - the length of the cylindrical element of the string of the contour explosive charge, cm; d_ech - the diameter of the cylindrical element of the string of the contour explosive charge, cm; d_dh - the deep-hole diameter, cm; ρ_e - the explosive density, g/cu. cm; ρ_ech - the density of deep-hole loading by explosive, q/cu. cm. Initiation is effected by detonating cord 8 fastened with one end on the lower end face of last cylindrical element 1 in the bottom section of the explosive passing along the charge column in the form of alternating linear sections 9 between explosive cylindrical elements 1 and binder assemblies 10 of each explosive cylindrical element 1 in diameter.

EFFECT: enhanced efficiency of contour blasting due to simplified method for formation of the contour charge, expanded assortment of the explosive, reduced cost.

7 cl, 1 dwg