Reoxidation of Direct Reduced Iron in Stagnant Air in The Temperature Range between 150 and 450°C.

Reoxidation of DRI in stagnant air in the temperature range between 150 and 450°C has been investigated. The aim is to contribute to the kinetics of reoxidation of hot DRI on transportation from a direct reduction plant to an EAF in case of leakage in the transportation vessel. Two series of experiments were conducted in a low temperature range between 150 and 250°C and in a higher range from 300 to 450°C. At low temperature, the reaction rate is controlled by the chemical reaction at the gas–metal interface, whereas at higher temperatures, it (the reaction rate) is governed by pore diffusion. The activation energy of the chemical reaction is 59.7 kJ/mol and for pore, diffusion is 18.04 kJ/mol. The diffusion coefficient increases with the T3.359 to T3.388. Empirical equations have been derived. Calculated data are in satisfactory agreement with corresponding practical results.