In-Flight-Melted Soda-Lime-Silica Glass by RF Induction Thermal Plasma

• Published in: Journal of the American Ceramic Society 2008-12, Vol.91 (12), p.3908-3914
• Main Authors: Funabiki, Fuji, Yano, Tetsuji, Yao, Yaochun, Watanabe, Takayuki
• Format: Article
• Language: English
• Subjects: Alkalies; Applied sciences; Building materials. Ceramics. Glasses; Ceramics; Chemical industry and chemicals; Diffraction; Exact sciences and technology; Glass; Glasses; Manufacture; Materials science; Plasma; Silica
• ISSN: 0002-7820; 1551-2916
• DOI: 10.1111/j.1551-2916.2008.02768.x

Granulated raw materials with a particle size of 20–80 μm were prepared from a slurry of Na2CO3, CaCO3, and SiO2 (quartz) by the spray‐dry method, and injected with carrier gas into a radio‐frequency induction thermal plasma. Spherical particles 5–60 μm in size were obtained and analyzed. Thermo‐gravimetric analysis and X‐ray diffraction analysis showed that during the short flight of the order of milliseconds, all carbonates were decomposed and >95% quartz was reacted into a noncrystalline state. Glass transition was clearly observed by differential thermal analysis. Increase of the carrier gas from 3 to 6 L/min led to a decrease in the volatilization ratio of Na2O from 46% to 18% with a slight decrease of the reaction ratio of quartz in trade balance. Electron probe microanalysis showed that the volatilization could be attributed to an excess heating of small particles