METHOD FOR BLASTING OVERBURDEN HARD ROCKS AND MINERALS, VERSIONS Russian patent published in 1995 - IPC

FIELD: equipment for drilling and blasting. SUBSTANCE: method for blasting overburden hard rocks and minerals includes operations for hole drilling, hole charging with explosives having preliminarily introduced coal powder. Additionally introduced into explosive are liquid oil products in volume of 1-4%, and coal powder of 2-20% with fractions sizing from 3·10^-5 to 1·10^-3 m and content of vitrinite of 75 to 99 mas.%. In the other version, introduced additionally into explosive mixture is coal powder in volume of 30% with fractions sizing from 1·10^-3 to 3·10^-3 m. Besides, explosive may be used in form of ammonium nitrate. EFFECT: higher efficiency. 4 cl, 7 tbl