Thermal hazard research of smokeless fireworks

The problem of dealing with expired military propellant is paid wide attention throughout the world. Currently, destruction is adopted as the main disposal route; however, the process is cumbersome, dangerous, costly, and even more non-environment-friendly. As a result, it is absolutely necessary to find out an appropriate recycling method. Nowadays a feasible method, by which the expired military powders are used to make smokeless fireworks, has already been proposed. However, the security of expired military propellant is still making all those concerned anxious on account of the stabilizer's volatilization during long-term storage. In this article, waste single base propellant (named powder 128, one of expired military propellants) and waste single base propellant/potassium perchlorate mixed powder are analyzed by differential scanning calorimeter (DSC) and accelerating rate calorimeter (ARC). The mixtures of these two are considered as the ideal raw materials of smokeless fireworks. DSC results show onset temperature, peak temperature, and normalized heat release of thermal decomposition under the condition of linear heating. Based on DSC data, activation energy and pre-exponential factor of the test samples are calculated according to Kissinger method, Ozawa method, and Friedman method. Furthermore, is derived by means of AKTS-Thermokinetics software using DSC data. ARC results reveal onset temperature, adiabatic temperature rise, self-heat rate, time to maximum rate and pressure-temperature profile. , which can be applied for the evaluation of thermal and pressure hazards, can be obtained in two ways from the data measured by ARC. One is calculated directly from the experiment, and the other indirectly from the fit-calculations. Based on these results, the thermal hazards of these two mixtures were analyzed preliminarily.