Formation Kinetics of Calcium Aluminates

Abstract

The kinetics of formation of calcium aluminates was studied by firing the reaction mixes in the temperature range 12000° to 1460°C for reaction times from 15 to 360 min. Phases formed were determined by taking X‐ray diffractograms of the samples. It was observed that all stable calcium aluminates were formed and that monocalcium aluminate (CA) grew with calcium dialuminate (CA2) in a 1:2 reaction mix of CaO and Al2O3. CA reacted further with Al2O3 to form CA2. The formation of CA2 obeyed the rate law equation 1 ‐ (1 ‐ x)1/3=Kt/r2. The activation energy for the system (140 kJ·mol−1 (33.4 kcal · mol−1)) was determined by the Arrhenius equation. Copyright © 1990, Wiley Blackwell. All rights reserved