METHOD OF DETONATION IN OPEN-CAST MININGS OF ROCK MASSES WITH DIFFERENT STRENGTH VALUES Russian patent published in 2015 - IPC F42D1/08 

FIELD: mining.

SUBSTANCE: invention relates to mining industry and construction, namely to methods of detonation on open-pit minings of layered massifs of rocks with the lower less strong layer of rock and the upper stronger layer. The method includes drilling of down wells, their loading by combined borehole explosive charges with placement in the lower part of wells of less heavy explosive. The lower and upper parts of charges are dispersed by a rock inert interval. In the upper part of wells heavier explosive is placed. Then stemming of wells is performed and charges are initiated. During charging the lighter explosive in the lower part of wells is placed to the soil level of stronger layer of rock. The inert interval is made with the height from 1.75 to 2.5 of the well diameter d_well. Charges are initiated with the delay-action blasting of the upper part of charges with reference to their lower part.

EFFECT: increase of efficiency of explosion with decrease of output of boulder, average size of piece of blasted rock mass, specific consumption of explosive and scope of drilling operations.

1 dwg