Hard rock fragmentation with pulsed power

Recent work on an electrical method for breaking rock shows that such technology is progressing toward commercial applications. The method, called plasma blasting, is based on the fast delivery of stored electrical energy to fracture the rock. In this paper, an overview of the work done during the last eight years at the Noranda Technology Center is presented. Joint projects between Noranda and Maxwell Laboratories are also introduced, but will be discussecl in more depth in a companion paper. Scaling up of the blast energy from several kilojoules to hundredis of kilojoules is first reviewed. Capacitor storage unit, switching device, cable and blasting electrode used for testing at various (energy levels are described. A discussion of the electrical behavior of the plasma channel created during a blast is then presented, together with computer simulations used for the analysis of test results. An overview of mining equipment based on plasma blasting concludes the discussion.