Thermal kinetic analysis on oxidation of FeS based on thermal gravimetric experiments

The thermogravimetry analysis (TG) and differential scanning calorimetry (DSC) were used to study the oxidative tendency of FeS. It was shown that there were two peaks in the DSC curve of FeS sample in air, the first endothermal peak arose from the phase transformation of FeS and the second peak, which was the exothermal peak and presented at high temperature, was the result of FeS oxidation. The rule of mass constant → mass gain → mass loss → mass constant appeared in the TG curve of FeS in air with the high initial temperature and long course of FeS oxidation, which was affected by the heating rate in FeS oxidation. The kinetic parameter was calculated by the multiple scan method. The activation energy of FeS was 125.89 kJ/mol and the preexponential factor was 1.55763 × 1011 K/s-1. The oxidative reaction of FeS was up to the Avrami-Erofeev kinetic model and the conversion function was that G(x)=[-ln(1-x)]0.4124.