The non-isothermal kinetic analysis of the thermal decomposition of kaolinite by thermogravimetric analysis

✍ Scribed by Petr Ptáček; Dana Kubátová; Jaromír Havlica; Jiří Brandštetr; František Šoukal; Tomáš Opravil

• Publisher: Elsevier Science
• Year: 2010
• Tongue: English
• Weight: 449 KB
• Volume: 204
• Category: Article
• ISSN: 0032-5910
• DOI: 10.1016/j.powtec.2010.08.004

✦ Synopsis

The dehydroxylation of the medium ordered kaolinite was investigated under non-isothermal conditions. Samples of industrially treated (washed) kaolin with high content of kaolinite were calcined using heating rate from 1 to 40 °C min -1 . The results of thermogravimetric analysis (TGA) were supplemented by differential thermal analysis (DTA), infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM) results. The mechanism and pertinent kinetic parameters, i.e. overall activation energy (E A ) and pre-exponential (frequency) factor (A), were evaluated from the series of thermogravimetric experiments. The obtained results show that dehydroxylation of kaolinite is controlled by the rate of third-order reaction (F 3 ) under applied condition. The median values of E A and A correspond to 227 ± 1 kJ mol -1 and (9.4 ± 0.3) × 10 9 s -1 , respectively.