The non-isothermal kinetics analysis of the thermal decomposition of kaolinite by Effluent Gas Analysis technique

The thermal decomposition of kaolin with high-content of the medium ordered kaolinite was studied by Effluent Gas Analysis (EGA) under non-isothermal conditions. This technique enables to distinguish two overlaying processes during the thermal decomposition of kaolin: oxidation of organic compounds and dehydroxylation. The kinetic of non-isothermal dehydroxylation of kaolinite is controlled by the rate of the third-order reaction. For the given reaction mechanism, the overall activation energy (EA) and pre-exponential (frequency) factor (A) values are 242 kJ mol−1 and 2.21 × 108 s−1, respectively.

Graphical abstractThe thermal decomposition of kaolin was investigated by Effluent Gas Analysis (EGA). This technique can easily distinguish the two overlaying processes: burning of organic impurities and dehydroxylation of kaolinite. Formation of water vapour during dehydroxylation slows down the combustion of organic admixtures in kaolin.Figure optionsDownload full-size imageDownload as PowerPoint slide