都市ゴミ焼却飛灰の人工岩石に及ぼすTiO₂とNa₂O添加剤の影響

抄録

Influence of additives and hot-pressing temperature on properties of the synthetic rock was investigated, which was developed for preparing a harmless and stabilized crystalline solid of fly ash from municipal waste incinerator. Upon sintering at 1200°C for 16h, it was revealed that the addition of 20mass% TiO₂ and 1.5mass% Na₂O was necessary for the preparation of dense rock products. X-ray diffractometry showed that these additives promoted the formation of perovskite (CaTiO₃) and gehlenite (Ca₂Al₂SiO₇) minerals. During hot pressing, bulk density of the synthetic rock increased steeply with temperature between 1000 and 1100°C. On the other hand, its open porosity decreased rapidly with temperature between 1050 and 1150°C. These facts imply that a temperature of 1100-1150°C is suitable for the hot pressing of fly ash.