Investigation into the effect of blast geometry on rock fragmentation

Abstract

Rock blasting is dependent on explosive, blast geometry and geomechanical parameters. A small-scale study was conducted to evaluate the effect of some blast geometry parameters on fragmentation results (burden, spacing and bench height). Three bench heights of 35 mm, 50 mm and 65 mm were taken with different burdens and spacings. Significant increase in optimum breakage and fragmentation burdens was noticed with increase in bench height. The rate of fall in fragmentation with increase in burden was greater in smaller benches due to the increased stiffness of rock. Spacing to burden ratio of 3.0-4.0 gave better fragmentation results. Considerable improvement in fragmentation was achieved both qualitatively and quantitatively with increase in bench height.