Synthesis of 伪-Al₂O₃ platelets and kinetics study for thermal decomposition of its precursor in molten salt

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• 作者：Yingheng Huang^a ; ^b ; Yao Xia^a ; Sen Liao^a ; ^{liaosen@gxu.edu.cn" class="auth_mail} ; Zhangfa Tong^a ; Gang Liu^a ; Yu Li^a ; Zhipeng Chen^a
• 关键词：Alumina (伪-Al2O3) ; Kinetics ; Synthesis ; Thermal decomposition ; Thermogravimetry
• 刊名：Ceramics International
• 出版年：July, 2014
• 年：2014
• 卷：40
• 期：6
• 页码：8071-8079
• 全文大小：1178 K

文摘

The precursor, ammonium aluminum carbonate hydroxide (AACH) was synthesized via solid-state reaction at 60 掳C. The experimental results show that the AACH is orthorhombic NH₄Al(OH)₂CO₃, and the calcined powder products are hexagonal platelets of 伪-Al₂O₃ which can be obtained from calcining AACH in molten salt at 1000 掳C. The linear and nonlinear methods were used to calculate the activation energies of the thermal process of AACH. The calculated results indicated the decomposition process involved two stages which were single-step kinetic processes. The most probable reaction mechanisms of the two stages were estimated by two comparative methods. The values of pre-exponential factor A of the two stages were obtained on the basis of E_伪 and the reaction mechanisms.