ARAÚJO, G. J. L.; ARAÚJO, Gildácio José de Lima.
Résumé:
Rock blasting using high technology explosives and accessories has progressed,
despite its complexity and the small faction of the energy effectively used in fragmentation
and the environmental impacts and risks of accidents. New techniques for monitoring are
tools that may help to improve fragmentation, rock throw, muck pile shape, and slopes
stability, and control undesirable impacts.
Tuning of initiation timing and sequencing represents parameters of great
relevance in rock blasting process. Presently there are several types of initiators, both
instantaneous and with delay elements. Among the initiators types one may cite the
following: pyrotechnic, electric, electromagnetic, non-electric and electronic.
The electronic initiation system, despite being in its second generation, has
been employed in Brazil only after 2002. That system allows greater flexibility in the
adjustment of timing (1 to 15,000 milliseconds) and a smaller dispersion, as compared with
other types of initiators. Those features allows for a better control of blasting operations.
The sequence of detonation and the timing for initiation of explosives charges
have an effective participation in the particle velocities and in the fragmentation the results
form blasting. The control of those two parameters may turn viable blasting in areas
previously interdicted, or even allowing continuity of blasting works in other areas, by
attending environmental norms in economically viable ways.
The use of electronic detonators has proved that the control f the above
mentioned parameters presents positive results in controlling vibrations and fragmentation
in rock blasting with explosives. That fact will enhance the horizon for the mining industry.
