Non-isothermal crystallization kinetics for CaO–Fe2O3 system

The CaO–Fe2O3 system is the most significant liquid phase for fluxed sinter. However, the crystallization kinetics of CaO·Fe2O3 (CF), which directly contributes to the physical and metallurgical properties of sinter, is rarely reported. In this study, the crystallization kinetics of CaO·Fe2O3 system was analyzed using the mean of non-isothermal crystallization kinetics. Various cooling rates (10, 15, 20, and 25 K/min) were investigated for the crystallization of the samples. Results showed that the crystallization process mainly includes two reaction stages, namely liquid–solid transition and peritectic crystallization of CaO·Fe2O3. The activation energy of the two stages was determined using Ozawa and KAS analyses, where the value of Eα lies at −382.38, −373.83 kJ mol−1 (Ozawa model) and −455.39, −480.93 kJ mol−1 (KAS model), and the same model function: f(α) = (1−α)2 for the two stages was determined according to Malek analysis. The reaction of CaO·Fe2O3 crystallization is promoted and the liquid–solid transition is inhibited as the cooling rate increases.