Al(OH)_3和ZnO合成锌铝尖晶石反应动力学的研究  

STUDY ON REACTION KINETICS OF GAHNITE SYNTHESIZED FROM Al(OH)_3 AND ZnO

作　　者：朱伯铨[1] 李享成[1] 

机构地区：[1]武汉科技大学高温陶瓷与耐火材料湖北省重点实验室,武汉430081

出　　处：《硅酸盐学报》2003年第12期1171-1174,1183,共5页Journal of The Chinese Ceramic Society

基　　金：湖北省自然科学基金(2002AB071);高温陶瓷与耐火材料湖北省重点实验室开放基金资助项目

摘　　要：采用TG—DSC和XRD等手段研究了锌铝尖晶石固相反应机理及固相反应动力学参数。结果发现:采用Al(OH)3和ZnO为原料合成锌铝尖晶石时,锌铝尖晶石固相反应的放热过程紧随着Al(OH)3的吸热过程,放热曲线与吸热曲线部分重叠,两者间没有明显的界线;锌铝尖晶石的固相反应机理函数符合Cater方程,即反应机理函数中应考虑体积效应,经过计算得到锌铝尖晶石的体积膨胀约为15％;通过Cater方程推导的反应活化能约为64.39 kJ/mol,而采用基于Ozawa方程的等转化率法得到反应活化能约为63.48 kJ/mol,两者十分接近。The solid-state reaction mechanism and kinetic parameters of zinc aluminate gahnite synthesized from Al(OH) 3 and ZnO were studied by means of thermogravimetry, differential scanning calorimetry (DSC) and X-ray diffraction techniques. The results show that the exothermic process of Al2O3-ZnO solid-state reaction is followed by the endothermic process of Al(OH) 3, which results in the partial overlapping of exothermic and endothermic curves. There is no distinguished boundary between the two curves. The function of reaction mechanism of ZnO-Al2O3 is well in accord with the Cater equation, which means that the volume expansion, calculated to be about 15% in volume for zinc aluminate gahnite, must be taken into account. The activation energy deduced from the Cater equation is about 64.39 kJ/mol, almost equal to the value of 63.48 kJ/mol obtained from the Ozawa model.

关 键 词：锌铝尖晶石 固相反应 活化能 动力学 

分 类 号：TQ-175[化学工程] TQ-174