Beshir M. Mohamed and John H. Sharp
The kinetics of the reaction for the formation of monocalcium aluminate (CaAl2O4) using 1:1 molar mixtures of A.R. grade calcium carbonate and A.R. α-Al2O3 or gibbsite have been investigated in the range 1150–1400 °C using quantitative X-ray diffraction analysis. The phases Ca3Al2O6 and Ca12Al14O33 were found to be intermediates in the formation of CaAl2O4 , whereas CaAl4O7 was formed via an initial side reaction. The formation of CaAl2O4 from the oxides was found to fit well with the diffusion controlled model of Ginstling and Brounshtein. The activation energy for the formation of CaAl2O4 from the amount of CaAl2O4 formed from the reaction of calcite with α-Al2O3 was determined to be 205±10 kJ mol-1 .