Martynyuk M. Development of borehole charge design for bench rock blasting at iron ore deposits

Object of research - Actual state of drilling and blasting operations at Open-Pit mines has been studied. Influence of mining and geological conditions as well as of new kinds of explosives at the mechanism of rock breaking has been defined. To reduce original top effect of detonation products on the walls of a borehole saving earlier achieved quality of rock massif breakage, the design of explosive borehole charge having radial clearance at the upper part of the charge has been improved which allows to decrease considerably explosive consumption by 15-18 %. Technology of borehole charges placing having radial interval depending on drilling and blasting operations parameters and on physical and mechanical rock properties has been worked out. Blasting patterns using explosive borehole charge with radial clearance have been developed. Implementation of explosive borehole charge with radial clearance into production has allowed to obtain an economical benefits of 0,36 UAH/м3 of blasted rock mass. Branch - mine-metallurgical.