【摘要】 采用综合热分析仪在动态空气气氛条件下研究了高岭土的热分解过程,利用热重分析数据对高岭土的热分解过程进行了动力学分析。用迭代的等转化率方法获取了准确的活化能,将得到的活化能应用到Malek方法中推测其反应机理,并进一步求得了指前因子A。结果发现:高岭土在400～700℃脱去羟基过程遵循化学反应的模型,其微分和积分表达式分别为:f(α)=(1-α)n,G(α)=1-(1-α)1-n/1-n(其中:α为转化率,反应级数n=2.1,表观活化能为182.428kJ/mol),指前因子A的范围为:(4.566～4.635)×1011s-1。更多还原

【Abstract】 The thermal decomposition processes of kaolinite have been studied in dynamic air using a simultaneous thermal analysis instrument.Thermogravimetric data was used to carry out the kinetic analysis.First,the exact activation energy was calculated by the iterative method.Then,the activation energy was used in the Malek method to infer the reaction mechanism.Finally,the above data were used to obtain the pre-exponential factor A.The dehydroxylation of kaolinite in the temperature range 400-700 ℃ followed the model of chemical reaction.The functions are f(α)=(1-α)n,G(α)=1-(1-α)1-n/1-n,where α is the transformation degree and the reaction order n is 2.1.The apparent activation energy is 182.428 kJ/mol,and the range of the A is from 4.566 × 1011 to 4.635 × 1011 s-1.更多还原