Synthesis of mullite precursors in molten salts. Influence of the molten alkali nitrate and additives |
| |
| Affiliation: | 1. Equipe Microstructure et Physicochimie des Matériaux, Faculté des Sciences Aı̈n Chock, BP 5366, Maa ̂rif, Casablanca, Morocco;2. CEMES-CNRS, 29 rue J. Marvig, 31055 Toulouse, France;1. School of Materials Science, Engineering, Dalian University of Technology, Dalian 116085, China;2. Suzhou Nuclear Power Research Institute, Suzhou 215004, China;1. M.V. Lomonosov Moscow State University, 119991 Moscow, Russia;2. Institute of Problems of Chemical Physics RAS, Academician Semenov av. 1, Chernogolovka, Moscow District 142432, Russia;1. Department of Materials, Royal School of Mines, Imperial College London, SW7 2AZ, UK;2. Centre for Nuclear Engineering, Department of Materials, Imperial College London, SW7 2AZ, UK;1. Graduate School of Science and Technology, Hirosaki University, Hirosaki, Aomori 036-8561, Japan;2. Photon Factory, Institute of Materials Structure Science, Tsukuba, Ibaraki 305-0801, Japan;3. Graduate School of Science, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8526, Japan;4. Graduate School of Engineering, Osaka Prefecture University, Sakai, Osaka 599-8531, Japan |
| |
| Abstract: | Silica gel and aluminium salt, in the stoichiometric ratio for mullite (Al/Si=3), have been used to prepare the mullite precursor by reaction in molten alkali nitrates at 450°C. The influence of the nitrate (NaNO3, KNO3 or mixture NaNO3–KNO3) and the additives (Ca2+, Ba2+, Bi3+) on the phase transformations has been followed between 1000 and 1400°C. It appears that molten NaNO3 favours the crystallization of cristobalite and α-Al2O3 whereas KNO3 inhibits the formation of silica and mullite. The mixture NaNO3–KNO3 seems to be the best choice. Addition of foreign cations improves the mullite formation and favours the synthesis of θ-Al2O3, especially in the case of Bi3+. But the crystallization temperature of mullite is not changed. |
| |
| Keywords: | |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
