Non-isothermal Kinetic Analysis of Spinel Phase Crystallization from Metakaolinite

摘要

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 N_2 atmosphere. The value of the apparent activation energy (E_a) was calculated using the Kissinger method. The result E_a = (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 y-Al_2O_3 type spinel phase and mullite.