A Chemical and Thermal Characterization Analysis of Kaolin

This study evaluates the chemical and thermal characterization of kaolin powder by means of Thermogravimetric Analysis (TGA) and Fourier Transform Infrared (FTIR) Spectroscopy. The TGA study was performed per ASTM E1131 by incrementally heating the sample from 22 °C to 1000 °C and results showed a total weight loss of 5.071 % with 4.354 % occurring between 400 °C and 800 °C as kaolinite dehydroxylated into metakaolin. A high residual mass of 94.930 % left on the basis residue at 1000 °C proved thermal stability and low volatility. Metakaolin being an amorphous aluminosilicate further improved thermal resistance and chemical inertness of the kaolin powder definitions of kaolin that had relevance reindustrial applications.In combination to the TGA study, the FTIR analysis was performed in accordance with ASTM E1252 methodology covering the infrared spectral range of 4000–500 cm⁻¹ and thus confirmed the mineralogical composition. Firstly, the presence of kaolinite was confirmed by the very sharp Al–OH bending band at 925.87 cm⁻¹ and additional minor overtone bands at 1984.25 cm⁻¹ and 2149.94 cm⁻¹ further confirmed structural composition. Furthermore, there was no significant absorption in the range of 1400–1600 cm⁻¹ providing evidence for the absence of carbonate or organic impurities and further confirming the purity of the sample.TGA and FTIR evidence shows kaolin has high thermal stability, structural consistency, and mineralogical purity that can serve applications in refractories, insulation bricks, and advanced ceramics.