Aluminum and boron ignition intensification

Effect of $\mathrm{K}_2\mathrm{CO}_3$ and $\mathrm{KCl}$ additives on the process of high-temperature oxidation and ignition of conglomerates of powdered boron and aluminum particles and on the critical conditions for the ignition of air-gas mixtures of these metals is studied experimentally. It is revealed that the mixtures of boron and aluminum particles covered (encapsulated) with salts ignite at temperatures lower than the ignition temperatures of mechanical mixtures of metals with these salts in appropriate proportions and significantly lower ignition temperatures of pure boron and aluminum. This indicates the active role of salts in the process of heterogeneous ignition. It is established that, for boron conglomerates, the accelerating effect of salt additives on the oxidation of conglomerates is noticeable at all investigated concentrations and compositions starting from $1\%$ (by weight). For aluminum, an increase in the reaction rate is noticeable only for $\mathrm{KCl}$ additives at concentrations of $3\%$ and above.