METHOD OF FORMATION OF SHORT COMBINED STEMMING OF BLAST HOLES AND DEVICE FOR ITS IMPLEMENTATION Russian patent published in 2015 - IPC F42D1/08 

FIELD: mining.

SUBSTANCE: method of formation of short combined stemming includes the formation of the lower fill part from inert fine materials with the height of 1.5-2 diameters above air interval and formation on the lower fill part of the top part from stone material elements to the height of 0.5-1.5 well diameters. On the lower part the transport container installed in the soft bag with stone material elements of 0.2-0.6 of well diameter is lowered, it is unloaded and removed from the well. After that again the inert fine material is filled to the height 1-1.5 of well diameter on which again the stone material is unloaded from the transport container. The process is repeated until full formation of the combined stemming with the height no more than 10 well diameters. In the method the transport container is used which is made in the form of metal or plastic cylinder. The top ring of the container with the size 0.8-0.9 well diameter, where the bars are evenly fixed with the step excluding loss of small pieces of stone material, is fitted with the bearing cord. The transport container is inserted into the soft bag 20-30% larger then the well diameter, fitted with ears for fastening of the bearing cord.

EFFECT: improvement of efficiency of locking of detonation products in a charging cavity by the short combined stemming and decrease of costs for its formation.

2 cl, 4 dwg