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Science and Technology of Energetic Materials

Vol.71, No.6 (2010)

Letter

A study on mechanical comminution of obsolete HTPB propellants from the rocket motor
Xuanjun Wang, Dayong Jiang, Wenguo Wang, and Shuguang Liu
p.158-162

Abstract

With the replacement of weapons as well as the factor of aging effect, it is urgent to deal with obsolete HTPB propellants effectively which is taken out of the retired rocket motor, and transforming it into civil explosives is regarded as a hopeful direction now. Though obsolete HTPB propellant can meet the basic requirements on the energy characteristics as a component of explosives, its particle size must be decreased and distribute uniformly on the millimeter level at least. Therefore, nothing but comminution can ensure symmetrical mixture with other components so as to achieve the purpose of stable detonation. There are many commonly used mechanical comminution methods which can make granularity of the propellants from the original diameter (10~100mm) to the final (0.5~5mm). But most of them would lead to great loss of AP and Al as the main energetic component inevitably, and the extent of loss has certain relationship with them. Therefore, according to the special characteristics of HTPB, measured by diameter ratio and loss rate of AP and Al before and after the comminution, three kinds of comminution methods (machines) including cage wet grinder, dry cyclone cutter and remote control cutter, are selected comparatively to study which will be fit for HTPB under the premise of security. The result shows that dry cyclone cutter is the most ideal comminution method which can make material diameter size reach about1mm or so, while the loss rates of two active ingredients are 2.6 % and 4.2 % respectively. The following initiation test, in which three kinds of civil explosives prepared by different sizes of samples are detonated by8# detonators, can also verify this conclusion above.

Keywords

military chemistry and pyrotechnics, obsolete HTPB propellants, comminution method, initiation tests.

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