Macrokinetic Analysis of Passivation of Pyrophoric Powders

Resumo

A model of ignition and passivation of a layer of a pyrophoric nanopowder was proposed and studied by analytical and numerical methods. Under the assumption that the passivation wave propagation is controlled by the oxidant diffusion, the dependence of the maximum nanopowder temperature on governing parameters was characterized. Passivation was proposed to be performed in two stages with increasing oxidant concentration in the gas phase, which makes it possible to reach the complete passivation of a sample several times faster at permissible temperature rise and opens up new opportunities for improving nanopowder production performance.