Ignition Mechanism of Boron Particle

To explore the ignition and combustion characteristics of boron particles, Macek and Semple conducted combustion experiments on crystalline boron with a diameter of 34.5–124 μm using a flat-flame burner and a CO2 laser igniter. The experimental results showed that the burning rates of samples are correlated to the diffusion rate of gaseous oxidants from the surface of samples. The burning time decreases with the increment in ambient gas temperature and oxygen mole fraction, consistent with the gas-phase diffusion theory. In addition, shock-tube technology was used by Uda in the ignition of crystalline boron particles with a diameter of 30–50 μm. The study shows that the ignition temperature strongly correlates to the air pressure, increasing with the air pressure drop. To explain the above experimental phenomena, King proposed the King ignition model based on the diffusion mechanism, where oxygen diffuses through liquid boron oxide to the B (s)-B2O3 (l) interface and reacts with boron. In this diffusion mechanism, Mohan and Williams proposed a planar model to illustrate the ignition stage of boron; the limiting oxygen mass fraction predicted by this model is very close to the result observed by Prentice. The critical ignition temperature of boron particles calculated by the ignition stage model proposed by Meinkohn and based on the King model is 1900 K, which is in good agreement with the experimental results of Macek. Based on King's model, Gaponenko and Meese also proposed their models and achieved good prediction accuracy. If you are looking for high quality, high purity, and cost-effective Boron powder, or if you require the latest price of Boron powder, please feel free to email contact mis-asia.