Non-isothermal kinetic analysis of spinel phase crystallization from metakaolinite

Abstract

A non-isothermal kinetic analysis of the crystallization of the spinel phase from metakaolinite is carried out using the thermodilatometric analysis with heating rates from 1 °C min−1 to 10 °C min−1 in a dynamic N2 atmosphere. The value of the apparent activation energy (Ea) was calculated using the Kissinger method. The result Ea = (816 ± 27) kJ mol−1 represents the mean value for various processes, that occur during the crystallization process. The results also show that the crystallization process includes the formation of the γ-Al2O3 type spinel phase and mullite.