Thermal Processing of Glass Ceramics Transformed from Coal Bottom Ash with MgCO3 and TiO2 Additive

• Main Authors: Po-HaoChen, 陳柏豪
• Other Authors: Chi-Yen Huang
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/06791356566179594199

碩士 === 國立成功大學 === 資源工程學系碩博士班 === 98 === At present, there is approximately 400,000 tons of bottom ash produced by domestic coal-burning electric power plants annually. However, the utilization rate is comparatively low. Most of it has been piled up in the ash-pond so nowadays we are facing a difficulty of space deficiency to stack the bottom ash. In this research, adding MgCO3 and TiO2 to bottom ash to form glass and to transform glass ceramics through an appropriate heat-treatment processing to achieve the purpose of recycling of bottom ash. Using DTA analysis showed that, the crystallization activation energy of 20M5T and 30M5T glass formulation of one step heat-treatment were 95.73kJ/mol 102.87kJ/mol; the crystallization activation energy of two step heat-treatment were 162.33kJ/mol and 205.2kJ/mol. The crystallization activation energy of two step heat-treatment was higher than one step, but from the SEM results showed that the crystal site of two step heat-treatment was relatively large. Cordierite and Pseudobrookite were formed with 20M5T glass formulation at 1200℃. And the coefficient of thermal expansion of two step heat-treatment was 60(10-7℃), which was close to the coefficient of thermal expansion of Cordierite glass ceramic with powder sintering. As to the quality of basic physical measurements, the glass density after heat-treatment was greater than the original glass; while the glass porosity rate after two step heat-treatment was less than the glass of one step heat-treatment, which was parallel with the result of two step heat-treatment of micrograph that showed less holes.