Analysis of Oxygen-Condensate Interactions in Metal Powder Production: Sprayed Particles in a Carrier Gas Phase

A preliminary, theoretical, analysis of the interfacial oxidization phenomena in a sprayed metal-carrier gas system was made to determine the initial conditions of the process which are compatible or not with surface saturation and the appearance of a separate oxide phase on the droplet surface. This discussion is based on previous theoretical and experimental works on single drop behavior. For the purpose of the discussion the liquid steady state, phase equilibrium and interfacial equilibrium conditions have been discussed; the material balance links of the phases and their coupling with the equilibrium equation have been examined; and the importance of the time variable and the various characteristic times has been underlined. Finally, by coupling the interface steady state conditions and oxygen material balance a set of sufficient conditions for obtaining a clean pure metallic phase has been derived.