硫酸钙的还原热分解特性研究

Study on the Character of Calcium Sulfate Reducing Decomposition

为了有效利用工业副产石膏,降低硫酸钙分解能耗,文章对硫酸钙的还原热解特性进行了研究。采用Gibbs-Helmholtz方程、Van't Hoff方程、Kirchhoff方程分别对硫酸钙在不同还原剂中的分解热力学进行计算,结果表明加入还原剂可降低硫酸钙的分解温度。采用整体优化的多升温速率(2.5,5,7.5,10,15K/min)等转化率迭代法对硫酸钙与碳的反应进行动力学计算,求得反应活化能为259.92kJ/mol,反应机理为相边界反应,机理函数为α2/3,指前因子为3.2452×109s-1。

In order to use anhydrite effectively and reduce the energy consumption of CaSO4 decomposition,the changes of standard molar Gibbs function of reaction at proposed temperature were calculated through Gibbs-Helmholtz,Van't Hoff and Kirchhoff equations.The results showed that the addition of reductant could reduce the decomposition temperature.TG data were used to explore the mechanism of the reaction and calculate the apparent activation energy with a globally optimized iterative iso-conversion method at the different heating rate(2.5,5,7.5,10,15K/min).It had been demonstrated that the apparent activation energy was 259.92kJ/mol,the reaction mechanism belonged to the phase boundary reaction and the corresponding pre-exponential factor was 3.2452×109s-1.