Kinetics and modeling of diffusion phenomena occurring during the complete oxidation of zinc powder: influence of granulometry, temperature and relative humidity of the oxidizing fluid

摘要

The kinetics of the complete oxidation of zinc powder by oxygen or air has been investigated from thermogravimetric studies under isothermal conditions in the range 772-1107 K. Particles size and hygrometry were chosen in the 65-375 #mu#m and 0-50percent ranges, respectively. We have been able to carry out the powder oxidation above the zinc metal melting point without coalescence of the particles. A quantitative interpretation based on the diffusion of reactants through the oxide layer has been proposed. The activation energy calculated from the Arrhenius law is close to 130 kJ mol~(-1)