The Concept of Explosives Malfunctioning in Rock Blasting

The problem of cross-hole explosive malfunctioning in rock blasting (including sympathetic detonation, desensitization and cut-offs) is a function of delay and spacing in a blast which should be designed to avoid such occurrences. On a delay-spacing chart, the phenomenon of explosive malfunctioning is explained by dividing the chart into different regions, while the shape and size of each region could vary from one explosive to the other. Over seventy blasts have been carried out at the CANMET Experimental Mine to identify the malfunctioning characteristics of specific emulsion, water-gel and dynamite explosives. In each experiment, two parallel blastholes, 32 mm in diameter and 1.7 m deep, were drilled downwards in an underground drift.