Kinetics of Aluminothermic Reduction of MnO2 and Fe2O3: A Thermoanalytical Investigation

Abstract

This paper presents the main kinetic parameters for aluminothermic reduction of MnO2 and Fe2O3. Aluminothermic reduction which in fact is a redox reaction requires an initial input of heat which is obtained through external reaction and/or oxidation of aluminium. In a system where oxidation as well as reduction take place simultaneously it is difficult to predict the kinetics of either reduction or oxidation. The present work aims at to describe the kinetics of reduction of MnO2 and Fe2O3 during aluminothermic reductions using simultaneous DTA/TG technique. If one understand the aluminium oxidation reaction then kinetics for the reduction of MnO2 and Fe2O3 can be obtained from DTA data for the overall reaction. Using suitable calibration constant a theoretical DTA curve is generated from the TG data to describe oxidation of aluminium. The oxidation data were deducted from the overall DTA data on redox reaction to obtain data on reduction only. The rate of generation of peak area for MnO2 and Fe2O3 thus obtained was a measure of reduction reaction rate