METHOD OF FORMING SHORT COMBINED FILLED STEM OF BLAST HOLES WITH SPACER CONE AND DEVICE FOR ITS IMPLEMENTATION Russian patent published in 2017 - IPC F42D1/08 F42D1/10 B65G65/30 

FIELD: mining.

SUBSTANCE: invention relates to drilling and blasting operations and can be used in various industries using explosive loosening rocky massifs of rocks. Method of forming a short combined filled stem of blast holes with a spacer cone involves formation of the lower filled part from inert fine materials, the middle part of the spacer cone and the upper combined part from a mixture of a fine and a coarse materials. Stem is formed in layers by a stemming machine, herewith first into the well a polypropylene jacket is lowered to a depth providing a specified height of the air gap between the charge of explosive and the stem. By feeding a fine material from the rear hopper into the polypropylene jacket formed is the lower filled part of a specified height. Spacer cone is suspended above it, onto which from the rear hopper the fine material is filled to the middle of the spacer cone. Filled simultaneously from the rear and the front hoppers are the fine material and elements of the coarse material sized 0.2–0.6 of the well diameter til complete formation of the combined stem with a height of up to 10 well diameters. In the stemming machine equipped with a hydraulic grab-manipulator and two hoppers with heating and vibration of walls, onto the bottoms of which there are plate-type feeders discharging the stemming material, the fine and the coarse materials are arranged in different hoppers and are dispensed onto a common rotary chute hinged in the lower part of the hoppers. Spacer cones are arranged on a hinged platform in the rear part of the stemming machine frame and are lowered into the explosive well by the grab-manipulator.

EFFECT: invention provides higher efficiency and reduced labour intensiveness of the works.

2 cl, 7 dwg