COMBINED STEMMING Russian patent published in 2007 - IPC F42D1/08 

FIELD: mining; coal-mining industry; other industries; production of the combined spreading stemmings used in the drilling-and-blasting operations.

SUBSTANCE: the invention is pertaining to the field of drilling-and-blasting operations in the strong rocks and may be used in the various branches of industry applying the drilling-and-blasting operations in the mountain ranges of the rocks. The combined stemming consists of the upper and lower parts connected among themselves by the bonding forces of the solidifying materials. The upper part represents the monolithic plug made out of the quick-hardening binding materials. The lower part represents the hollow metallic cylinder with the bottom buried by 1/4 from its upper edge the walls of which have at least three slits located along the generatrix. At that the lower part of the monolithic plug made out of the quick- hardening binding materials enters inside the plastic cylinder up to its bottom. The length of the monolithic plug made out of the quick-hardening binding materials makes from 0.6 up to 0.8 m. The length of the hollow plastic cylinder makes no less than 5-7 the borehole diameters. As the quick-hardening binding materials they use the quick-hardening concrete mixture based on the expanding cement, or the mixture of the alabaster with the filler. The invention allows closing the explosion products in the charging hollowness up to the rocks crushing and so to increase efficiency of usage the explosion energy applied to the rock crushing.

EFFECT: the invention allows locking the explosion products in the charging hollowness up to the rocks crushing to increase efficiency of usage the explosion energy applied to the rock crushing.

4 cl, 1 dwg