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KCI 등재

Characterization of some natural materials with different morphologies and their mullitization in ceramic preparation

Journal of Ceramic Processing Research
약어 : J. Ceram. Process. Res.
2023 vol.24, no.3, pp.471 - 477
DOI : 10.36410/jcpr.2023.24.3.471
발행기관 : 한양대학교 청정에너지연구소
연구분야 : 재료공학
Copyright © 한양대학교 청정에너지연구소
33 회 열람

This study aimed to investigate the characteristics of three types of natural materials (KLC, KPT, and SSB) obtained fromregular deposits in Vietnam and their mullitization at calcinated temperatures of 1000 °C, 1200 °C, and 1400 °C. The sampleswere characterized by X-ray diffraction (XRD), X-ray fluorescence analysis (XRF), thermal analysis (the thermogravimetry/differential scanning calorimetry (TG/DSC)), and scanning electron microscope with energy-dispersive X-ray spectroscopy(SEM-EDS). The results indicated that kaolinite, halloysite, and sericite are the dominant minerals in the KLC, KPT, and SSBsamples, with particle sizes under 2 μm. These minerals' morphology was typical, with pseudo-hexagonal and stratifiedkaolinite, tubular halloysite, and thin platy sericite. The samples' chemical compositions are mainly SiO2 and Al2O3, followedby (K2O+Na2O), TiO2, and total iron content. Thermal analysis shows that the metakaolin phase is formed at differenttemperatures for the halloysite and kaolinite samples, as indicated by endothermic peaks at 411 °C for KPT and 436 °C forKLC. The quartz phase transition is also detected at different temperatures for the samples, with low-to-high temperatureendothermic peaks at 559 °C (KPT), 569 °C (KLC), and 575 °C (SSB). The mullitization process is observed to start attemperatures above 1000 °C and is critical at around 1400 °C, with well-crystal mullites appearing. The mineral compositionand morphology of the starting materials influence the size of the mullite crystals. SSB has larger mullite crystals than KLCand KPT at a sintering temperature of 1400 °C. It suggests that mineral composition, mineral morphology, and particle sizeof starting materials can also be essential factors influencing to mullitization process and ceramic products.

Pseudo-hexagonal kaolinite, Tabular halloysite, Platy sericite, Mullite, Thermal analysis, Ceramics.