METHOD FOR FORMATION OF WATER-PROOF EXPLOSIVE CHARGE IN ENTRY FOR ORE-BREAKING Russian patent published in 2003 - IPC

FIELD: mining art, in particular, methods for formation of explosive charge at underground mining of thick deposits for "mine" ore breaking with block and sublevel caving. SUBSTANCE: the method consists in driving of the entry by the blasthole drilling method, leaving of the broken rock in the mouth part of this opening and use of it as a tamping, charging of the entry cavity by explosive charges from the openings of the higher level, according to the offered design, the entry is driven by the method of successive sectional explosion of dispersed high-explosive charges in a set of holes drilled on the route of the entry, and after the release of the broken rock to the boundary of tamping the mine survey is accomplished of the obtained contour of the entry, and according to the results of this survey, the actually obtained sections of the entry at different heights are determined and with the use of them - the lines of the minimum resistance. Then, with the use of these data the values of the necessary dispersed high-explosive charges are determined in the height of the entry, and a flexible shell inscribed in the section of the covered entry is installed in the cavity of the entry in its entire height, after that the calculated dispersed high-explosive charges are theoretically positioned in the flexible shell, maximum use is made of its section, the elevation marks in the entry of each of these charges are determined according to these theoretical calculations, then each of these high-explosive charges is placed in the flexible shell, with the bullet positioned in it, and the spaces between these high-explosive charges are filled with an inert material and the bullet blasting network is laid through it. As the water-proof high-explosive charge is formed in the flexible shell in the entire height of the entry the space between the outer surface of the flexible shell and the entry contour is filled with an inert material. EFFECT: reduced labor content of formation of the high-explosive charge and enhanced quality of ore crushing due to provision of complete detonation of the explosive charge. 2 cl, 2 dwg