硫酸铝晶体热分解行为及分解反应动力学研究

Thermal behavior and decomposition kinetics of Al_2(SO_4)_3·18H_2O

针对酸法制备氧化铝过程中Al2(SO4)3.18H2O焙烧分解工艺,通过TG-DTA曲线,研究其分解行为和分解过程的动力学.结果表明:Al2(SO4)3.18H2O的脱水分解过程分两步进行,首先脱掉15个层间水,其次脱掉3个结构水;分解过程一步完成.利用Doyle-Ozawa微分法和Kissinger积分法计算出各吸热峰反应的活化能、指前因子,得到Al2(SO4)3.18H2O分解反应的速率方程.

As the part of the process of the direct acid leach on preparation of alumina, the thermal behavior and decomposition kinetics of Al2（S04）3·18H2O were studied by TG-DTA.The results show that there are two process in the dehydration of the Al2（ SO4）3·18H2O. The interbedded water was broke away primarily, then the structural water was broke away. Two equations of Doyle-Ozawa and Kissinger were used to calculate the kinetics arameters of the decomposition of the Al2 （S04）3·18H2O. Kinetics rate equations of each endothermic peak of aluminium sulphate decompound process were obtained with Doyle-Ozawa method and Kissinger method.