Infrared and Raman Spectroscopy of Mullite Ceramics Synthesized from Fly Ash and Kaolin

Infrared spectroscopy and Raman spectroscopy were used to characterize mullite ceramics prepared from fly ash and kaolin by annealing at 1000 °C, 1100 °C, 1200 °C, and 1300 °C. IR spectroscopy confirmed the presence of SiO<sub>4</sub> tetrahedra and AlO<sub>6</sub> octahedra...

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Bibliographic Details
Main Author: Michal Ritz
Format: Article
Language:English
Published: MDPI AG 2023-06-01
Series:Minerals
Subjects:
Online Access:https://www.mdpi.com/2075-163X/13/7/864
Description
Summary:Infrared spectroscopy and Raman spectroscopy were used to characterize mullite ceramics prepared from fly ash and kaolin by annealing at 1000 °C, 1100 °C, 1200 °C, and 1300 °C. IR spectroscopy confirmed the presence of SiO<sub>4</sub> tetrahedra and AlO<sub>6</sub> octahedra in samples. The presence of mullite has been confirmed at all temperatures. The presence of quartz has been confirmed up to a temperature of 1100 °C, and the presence of an amorphous form of SiO<sub>2</sub> has been confirmed at temperatures of 1200 °C and 1300 °C. The transformation of quartz into the amorphous form of SiO<sub>2</sub> at temperatures above 1100 °C is assumed. Transformation was performed on the percentage intensity decrease of the bending vibration of Si-O-Si (at about 450 cm<sup>−1</sup>) and Al-O-Si (at about 550 cm<sup>−1</sup>). Raman spectroscopy confirmed the presence of mullite at different stages of structural ordering (a well-ordered structure at a temperature of 1100 °C and a disordered structure at a temperature of 1300 °C).
ISSN:2075-163X