When performing Stripping operations, it is not rational to spend energy on regrinding waste rock. in this case, it is sufficient to achieve a total value of the pre-destruction intensity coefficient equal to one. The explosion must be performed separately in each well with large decelerations. The study of the effect of the borehole grid showed that with an increase in the distance between the axes of wells from 4 to 8 m, the mass of the charge increases twice, and the number of wells on a block of 1000 m2 decreases by 3.75 times. Due to the greater intensity of reducing the number of wells, the cost of charging explosives for the entire block with a large grid is reduced by 1.9 times, the cost of drilling operations is reduced, and the productivity of drilling and blasting operations is increased. In the case of mining a mineral, for example, iron ore, which is subsequently crushed during processing, it is rational to use the energy of the explosion for grinding, since the mechanical methods of crushing the ore by crushers and especially by mills are incomparably more energy-intensive. By increasing the power of the explosion (the radius of the zone of destruction of wells), you can significantly increase the pre-destruction of rocks, achieving a uniform set of grinding.

The task of the article is to determine the influence of the blasting charge power on the intensity of preliminary destruction of the blasting block mass at long delays. Increase of the destruction radius r from the blasthole charges action at diagonal pattern of hole-by-hole blasting, caused by change of explosive charge energy or rock properties, decreases the number of stress waves passing in the vicinity of specific blast holes. They cause the rock disturbance in the pre-destruction area due to increasing of explosion energy absorption in the area of blasthole charges destruction. However, at the same time, the value of the predestruction factor increases. The calculation shows that 3.5 times increase of the blasthole charge destruction radius, reduces in 1.36 times the number of stress waves passing through the vicinity of specific blasthole charges, but the factor of pre-destruction intensity increases tenfold and the total impact of these factors – by a factor of 8.