John C. Hassler

KINETIC MODELING OF THERMAL DECOMPOSITION OF ALUMINUM SULFATE

The kinetics of thermal decomposition of aluminum sulfate was studied by dynamic and isothermal thermogravimetry. The nature of the solid phases was further examined by powder x-ray diffraction. Various kinetic models such as nucleation, phase boundary movement, diffusion and the homogeneous reaction were tested. Effectiveness of integral and differential methods of data reduction was evaluated. The activation energies obtained for the sulfate decomposition, calculated from different models and methods of analysis have been compared. The results indicate that aluminum sulfate decomposition can be adequately described by phase boundary movement models with an activation energy of 235 kJ/mole. It is further observed that the alumina formed at 900°C is amorphous in nature.