Thermal Dehydration Kinetic Mechanism of Aluminum Sulfate Hydrates
Thennal dehydration kinetics of aluminum sulfate hydrates was studied with TG/DTA under static open air environment. It was found that the thermal dehydration of the aluminum sulfate hydrates was a two-stage process. The first stage happened in the temperature range from 90 to 300℃ with 13 water loss. The second stage happened in the temperature range from 300 to 380℃ with 2 water loss. Activation energy and former factor of each staged were obtained by regression the TG/DTA data with 19 differential and integral functions based on nonisothermal Achar method as well as Coats-Redfem method. The result indicated that the mechanism for the first stage dehydration was the proliferation of three-dimensional,spherical symmetry,3D,D3,slowα-t curve,n = 2, reaction is reaction 2. The mechanism of the second stage dehydration was random nucleation and subsequent growth,A3,S-shaped α-t curve,n=1/3,m = 3,reaction is reaction 1/3. Identified that the most likely mechanism of Al2(SO4)3·15H2O dehydration is 2 and 1/3 reactions two process.
Aluminum sulfate hydrates Thermal dehydration Kinetics DTA-TG
BAI Guang-hui XU Peng LI Peng-cheng WANG Tong-song
School of Science,XiAn University of Architecture and Technology,XiAn 710055,China
国际会议
Frist Annual Meeting on Testing and Evaluation of Inorganic Materials(第一届全国无机材料测试与评价学术年会)
南昌
英文
238-244
2010-04-28（万方平台首次上网日期，不代表论文的发表时间）