脱硫石膏与碳酸铵反应过程及反应机理

以烧结烟气脱硫石膏资源化循环利用为目的,碳酸铵为原料制备碳酸钙和硫酸铵,对该反应过程进行研究,探索其反应机理及反应的动力学方程。通过热力学计算可知本反应是常温下即可发生的放热反应,该反应符合缩芯模型。由实验得知,当反应时间是2 h,脱硫石膏粒度不大于0.125 mm,搅拌速率不小于250 r/min时,该反应为固相产物层扩散控制;在此条件下,求取反应动力学方程,确定反应速率常数与温度的关系。

Reaction process and mechanism of reaction between FGD gypsum and ammonium carbonate

In order to study the resource utilization of sintering flue gas desulfurization gypsum,the reaction of ammonium carbonate and the sintering flue gas desulfurization gypsum was involved to prepare calcium carbonate and ammonia sulfate.The process of the reaction was investigated,and the reaction mechanism and the reaction kinetic equation were explored in this study.The result of thermodynamics calculation shows that the reaction is an exothermal reaction which could proceed at room temperature.And the reaction process is in accordance with the shrinking core model.Under the experimental conditions of the reaction time of 2 h,the grain size of desulphurization gypsum of 0.125 mm or smaller,and the stirring rate of 250 r/min or higher,the reaction process is controlled by solid phase product layer diffusion,which is generated from the combination of experiment results and theory analysis.The reaction kinetic equation was obtained and the relationship between the reaction rate constant and temperature was determined from above experiment.