Detonation behavior of emulsion explosives (I) - detonation velocity and reactivity of the emulsion explosives sensitized with relatively large voids

The effects of size and volume fraction of voids in the ammonium nitrate-based emulsion explosive were examined. Resin balloons sizes ranging from 0.05 mm to 2.42 mm in average diameter were used as void material. The detonation velocity (Dv) at infinite charge diameter, Di, was estimated from the linear relationship between the Dv and the inverse charge diameter and it was compared with the ideal Dv calculated with KHT code. Di coincides well with that calculated provided the void fraction of the explosive is larger than 0.2 and the diameter of the void is smaller than 0.5 mm. The greater the void size is the bigger the discrepancy between the Di extrapolated and the Di calculated. It was considered that the major reason is the decrease in the fraction of ammonium nitrate reacted in the reaction zone due to the rarefaction wave from the voids themselves. It was shown that the reaction zone length is strongly affected by the void size and void volume fraction. The material of void such as glass or resin will not affect the detonation behavior such as Dv or reaction zone length.