METHOD FOR FORMING OF COMBINED CHARGE AND METAL STEMMING FOR ITS REALIZATION Russian patent published in 2007 - IPC F42D1/02 F42D1/08 

FIELD: drilling and blasting operations, applicable in various branches using blasting operations in hard rock masses.

SUBSTANCE: the method consists in forming of a charge of waterproof explosive in the flooded part of the borehole, arrangement of the gap of foamed polystyrene on the surface of water displaced upwards in the borehole, forming of a charge of hydrolabile explosive on it, and installation of the stemming. The charge of waterproof explosive is formed to the depth of the measured water level. After forming of the charge of hydrolabile explosive a metal stemming is installed, and a conductor of initiating pulse from the charge of hydrolabile explosive under the detachable cover with a mechanical lock is placed in it. The metal stemming represents a cylinder with tapered expansions on both ends, at least three longitudinal slots are made on the cylinder ends having tapered expansions, two tapered plugs interconnected by a thick-walled tube with a thread for a nut by a link through which the conductor of initiating pulse runs from the upper charge.

EFFECT: enhanced efficiency of rocks breaking.

5 cl, 6 dwg