Thermal Stability of Sodium Aluminum Silicates with and without Alkali Carbonates
| Autor: | Yoshihiko Sadaoka, Hiromichi Aono, Ayuko Kuramoto, Youichi Shimamoto, Naoki Tsumura |
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| Rok vydání: | 2005 |
| Předmět: | |
| Zdroj: | Journal of the Ceramic Society of Japan. 113:269-274 |
| ISSN: | 1882-1022 0914-5400 |
| DOI: | 10.2109/jcersj.113.269 |
| Popis: | The thermal stability of solium aluminium silicates and their reactivity to alkali carbonates were investigated in view of their application as CO 2 gas sensors. A nepheline phase was very stable, since the peak position of the X-ray diffraction pattern was hardly influenced by either heat treatment or humidification up to 800°C. A distorted carnegieite phase (like-carnegieite) transformed into the nepheline phase at 500°C under a humid condition, while under a dry condition, it was stable up to 800°C but transformed into the nepheline phase at 900°C. For mixtures with alkali carbonates, the nepheline phase was most stable even under the humid condition at temperatures below 500°C. When the mixtures were heated at 600°C, the nepheline phase reverted to the like-carnegieite phase and alkali silicates, such as Na 2 SiO 3 , Li 2 SiO 3 and Li 4 SiO 4 , formed as by-products. For Na 2 O-Al 2 O 3 -4SiO 2 sintering mixtures with Li 2 CO 3 , the like-carnegieite phase transformed into the nepheline phase at 500°C. The nepheline phase was stable up to 1000°C even under the humid condition and Li 2 SiO 3 formed as a byproduct. |
| Databáze: | OpenAIRE |
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