APT热分解动力学的研究

Thermal Decomposition Kinetics of APT

研究采用热重分析法，获得等速升温条件下APT失重变化与温度变化及反应时间的关系TG曲线。据APT的失重率，绘出DTG曲线，并以TG和DTG曲线为基础，采用非等温动力学的基本方程，对试验数据进行线性回归，建立了APT热分解动力学的数学模型。失重曲线表明APT的热分解是四个阶段进行，第一阶段为126.2℃左右时脱水，第二阶段为209.4℃左右时分解成无定型铵钨青铜（AATB），第三阶段为310.5℃左右时结晶成铵钨青铜（ATB），第四阶段为482.3℃左右时分解成“蓝钨”。试验结果表明：在不同的升温速率条件下，APT热分解的指前因子是随着热解温度的升高而逐渐减小。活化能在第二阶段达到最大值。反应级数在第一、二阶段在0.6～0.76，第三阶段在0.9～1.37，第四阶段为1.0左右。生产中宜采取三段控温，其他阶段控速的方式，提高生产效率，减少能耗。

The TG curve of APT weightlessness and the change of temperature and reaction time under the condition of a constant heating rate were obtained by thermo gravimetric analysis. According to the weight loss rate of APT, the DTG curve was drawn based on the TG and DTG curves. A dynamic model of the thermal decomposition of APT was practiced by using differential method. A linear regression of the experimental data was performed based on the basic equations of the non isothermal kinetics. The weightless curves showed that the thermal decomposition of APT consists of four main stages ,the first dehydration about 126.2 ℃, the second around into amorphous ammonium tungsten bronze（AATB） about 209.4℃, the third crystallized into ammonium tungsten bronze（ATB） about 310.5℃, and the last decomposed into WO3＆quot;blue tungsten＆quot;about 482.3℃. At each stage of the heating rate respectively is 2 ℃/min, 3 ℃/min and 8 ℃/min conditions. The pre exponential factors of the thermal decomposition of APT basically increase with decreased pyrolysis temperature. Activation energy reaches the maximum value at the second stage. At the first and second stages, the reaction order of APT decomposition was about 0.6-0.76, in the third stage about 0.9-1.37, in the fourth stage about 1.0.