Interpretation on the changes of co-ordination number of Al in thermal changes of kaolinite.
スポンサーリンク
概要
- 論文の詳細を見る
Analytical results of I.R., XRF and MAS-NMR techniques applied to characterize the intermediate phases namely metakaolinite and spinel phase have been reviewed. The exhaustive analyses showed that no positive evidence has been obtained so as to conclude that the intermediate 980°C spinel is γ-Al<SUB>2</SUB>O<SUB>3</SUB>. The major drawback in arriving to a definite conclusion is probably due to unaccountability of the co-existence of a substantial amount of amorphous alumino silicate phase at 980°C. The measured AlO<SUB>4</SUB> content of 1000°C heated kaolinite by XRF analysis agrees closely with the theoretically expected global AlO<SUB>4</SUB> value of the 980°C reaction where Si-Al spinel and amorphous alumino silicate phases forms with the liberation of amorphous silica. Lastly metakaolinite does not have any fixed structure. It transforms to mullite in two parallel paths as explained from I.R. studies of successive heated kaolinites. First path corresponds to nucleation of mullite in amorphous alumino-silicate matrix and subsequent growth thereof which is related to the observation that the ratio of AlO<SUB>4</SUB> to AlO<SUB>6</SUB> does not change too much between the temperature range 1000°C to 1400°C in some kaolinite where mullitization predominantly takes place following this path.<BR>The second path corresponds to the polymorphic transformation of cubic to orthorhombic form where the global AlO<SUB>4</SUB>/AlO<SUB>6</SUB> ratio of 1000°C heated kaolinite changes and subsequently attains to the value close to 3: 2 mullite.
- 日本粘土学会の論文
日本粘土学会 | 論文
- 23.エトリンガイト生成反応を利用する土質安定方法
- 高レベル放射性廃棄物地層処分におけるベントナイト緩衝材変質現象に関する最近の研究と今後の研究展開
- P13 断層粘土の脱水反応と摩擦強度の変化
- B16 抗がん剤/層状複水酸化物ナノ複合体の合成とその細胞毒性(口頭発表,一般講演)
- A19 ペプチド修飾を施した5-フルオロウラシル/層状複水酸化物複合体の合成とその細胞輸送効率(口頭発表,一般講演)