Study Of The Impact Of Pyrotechnic Material Particle Size On The Initial Reaction Temperature

The particle size of the reactants is an important factor affecting the chemical reaction. Changing the particle size of the reactant can to some extent change the nature of the chemical reactions, such as the reaction rate, the reaction temperature, the conversion rate, etc.Te is the ignition temperature of combustion reaction of the pyrotechnic composition, which is the corresponding temperature of a transient state from a slow oxidation state to the reaction that can be automatically accelerate to a high speed combustion. This thesis based on100,200,200-325,325and400-mesh magnesium powder, particularly studied the oxidation of magnesium powder with different particle sizes and the initial reaction temperature Ti of it, and the oxidizer(potassium nitrate, strontium nitrate, potassium perchlorate) within the same particle size range via differential thermal analyzer by analyzing and extrapolating the initial reaction process before the Te. In the same experimental conditions, when the relatively specific surface area of magnesium powder were97.99,78.88,44.38,54.35,25.7/m2/Kg, we get the initial reaction temperature of the magnesium powder with different particle sizes; respectively, the initial combustion temperature of magnesium powder with potassium nitrate of the same particle size; and the initial combustion temperature of magnesium powder with strontium nitrate; and the initial combustion temperature of magnesium powder with potassium perchlorate; and the initial combustion temperature of magnesium powder with Barium peroxide. The experimental results show that, with magnesium powder particles increasing, the initial reaction temperature of the reaction is substantially lower.In order to better observe the impact of particle size on the initial reaction temperature, this article also analyzed black powder with seven kinds of grain. In the condition of one variable, the particle size, the start reaction temperature of black powder was236.5,228.4,223.8,219.0,218.3,213.4and220.3℃, respectively, when the particle size is continuously reduced. The same result is also seen, except the No.7black powder, the initial reaction temperature declined with the particle size decreasing.