BLAST-HOLE STEMMING Russian patent published in 2000 - IPC

FIELD: drilling and blasting operations, particularly, locking of gaseous explosion products in charging cavity (blast-hole), applicable in pyrite mines in operations associated with the danger of explosion of sulfide dust. SUBSTANCE: composition of stemming material is selected in the following relation: high-pressure polyethylene- high-density filler-salt=3:3:4. The profile of the inner cavity of stemming has the shape of two conjugated truncated cones; the taper of the inlet section makes up 1:6, and that of the outlet section - 1:14. The external surface of stemming is cylinder-shaped with a spacer ring on the side of the outlet. EFFECT: simplified procedure of charging at a low cost of stemming, burnt-out small explosive fractions of sulfide dust, formed at the instant of explosion of the main charge of explosive, reduced concentration of toxic sulfur oxides at an increase of the effective action of explosion. 1 dwg