METHOD OF BLASTING OF CRUMBLING ROCKS ONTO OPEN SURFACE Russian patent published in 1999 - IPC

FIELD: blasting of crumbling rocks of any type. SUBSTANCE: the method consists in drilling of rows of holes in a strictly definite order: the rows are drilled at an angle of 30 deg to the axis of the broken block; the first row at distance W, the rest, 2W, beginning from the toe of the bench of the broken block; the distance between holes in rows shall not exceed R_r, the depth of drilling of each hole does not exceed L_hi, and the amount of charge in it does not exceed L_chi; quantities W, R_r, L_hi,L_chi are determined depending on mining-geological and mining- engineering conditions of mining operations. EFFECT: enhanced efficiency of operations due to optimum dispersion of holes in area and depth of the rock mass to be broken, as well as differentiated distribution of explosive within the block to be broken. 2 dwg