NON IDEAL DETONATION OF EMULSION EXPLOSIVES MIXED WITH METAL PARTICLES

The detonation of ammonium nitrate based compositions like emulsion explosives mixed with metal particles was experimentally investigated. Aluminum powder with a mean particle size of 6 mu m was used, and the mass concentration of aluminum on the explosive charge ranged from 0 to 30% wt. The values of the detonation velocity, the pressure attenuation - P(x) - of the shock front amplitude in a standard PMMA monitor and manganin gauges pressure-time histories are shown as a function of the explosive charge porosity and specific mass. All these parameters except the pressure-times histories have been evaluated using the multi-fiber optical probe (MFOP) method which is based on the use of an optical fiber strip, with 64 independent optical fibers. The MFOP allows a quasi-continuous evaluation of the detonation wave run propagation and the assessment of spatial resolved measurements of the shock wave induced in the PMMA barrier. Results of that characterization process are presented and discussed for aluminized and non-aluminized emulsion explosives. The experimental results have shown that the detonation velocity decreases monotonically with the increase of aluminum content. Nevertheless the peak of detonation pressure profiles presents a non-monotonic behavior increasing its value up to an Al content of 20% wt, after which it starts to decrease.