Accurate detonators in trials boost production, reduce shock

Highly precise, electric detonators, when used to provide millisecond (MS) delays in sequential blasting in surface mines, have proved able to increase fragmentation of overburden significantly and reduce adverse shock and vibration effects. These electric delay detonators-also called MS delays caps by the trade-replaced the conventional delay detonators. This was the conclusion from tests with the new more-accurate detonators, performed under the guidance of Atlas Powder Co. researchers over a three-year period. During the tests, researchers from Atlas worked with research teams from a number of other organizations, including Vibra-Tech Engineers, U.S. Bureau of Mines, Sandia National Laboratories, Los Alamos National Laboratory and Martin Marietta Laboratories. The test involved 26 production blasts that were monitored by high-speed cameras, seismographs and other sophisticated instrumentation. During all these tests, the sequence and pattern of the blasts, as well as the firing time of delays between holes, were kept identical between those blasts with conventional electric detonators and those using the newer, more accurate detonators. Since the conventional detonators produced more scatter in the exact time that the blasts go off, the tests actually pinpointed the effects of scatter on the efficiency of the shots.