Environmental Impact of Electric Blasting

Under special circumstances, electrical energy can successfully replace chemical ex­plosives for blasting rock. High pressure plasma can be generated in the confines of a drillhole, by a powerful electrical dis­charge. The energy level can be adjusted to replicate the effect of a high explosive. The main difference is the almost total ab­sence of gas generation with electric blast­ing. Once the rock fractures, the small amount of matter used for generating the plasma rapidly cools off and regains its former volume. High speed film studies clearly show, that the initial speed of blasted rock fragments is the greatest, no further gas propelled acceleration takes place .. Figure 1, shows a typical electric blast of an oversize boulder of quarzite in an open pit mine.