| Summary: | 碩士 === 國立成功大學 === 資源工程學系碩博士班 === 97 === The coal combustion electric power plant generates total coal ash about two hundred million tons annually, and bottom ash is about 20% of all. The chemical composition of bottom ash are mostly SiO2 and Al2O3 which makes the major composition of glass raw materials. Furthermore, TiO2 can serve as nucleating agent to make glass ceramics. The glass from bottom ash then heat-treated to enhance nucleation and crystal growth to obtain crystallization glass. The use of analytical instruments (DTA, XRD) can investigate the crystal behavior of crystallization glass. The mechanics and kinetic energy of crystal growth will be studied too.
This research add 10wt% Na2CO3, 15wt% CaCO3 and 5wt% TiO2 into bottom ash, and use Na+ and Ca2+ to reduce viscosity of the melt as well as fusion point of bottom ash to enhance the phase separation of glass and promote crystallization ability of glass, and then transforming to crystallization glass by single or two step heat-treatment. It’s crystal phases are anorthite, nepheline and andradite. The temperature of maximum nucleation rate is 730oC and the most appropriate nucleation time is 2 hours. The activity energy of single heat-treatment was 156.078 KJ/mole, and of two heat-treatment was 216.744 KJ/mole. It shows the processing of single heat-treatment is more suitable for the powder of the glass ceramics.
According to DTA analysis will know that this research add 5wt% TiO2 more than previous research will help the first crystalline phase growth early, help a second crystalline phase growth and help to reduce activity energy.
|
|---|
