气－固反应制备超细Al_2O_3陶瓷粉

The Preparation of Ultrafine Ceramic Powder of Al_2O_3 by Gas-Solid Reaction

用固定床研究铵明矾的氨分解过程的动力学行为，变量包括气流速度、颗粒尺寸和温度，讨论过程的控制步骤，寻找该反应的动力学模型，并对模型参数进行估算，进而求得该反应的表观反应速率常数和表观活化能。提出了一种能适用于工业生产的气一固反应装置，可达到连续操作，减少外扩散传质阻力，增大气团接触面积，减少床层内物料的温差，使反应均匀，颗粒直径均匀的要求。

This paper studied the kinetics process of the gas-solid decomposition of aluminium ammonnium sulfate with NH3 in fixed bed, which included three variations: the speed of gas, the size of particles and the temperature. this paper discussed the control factors of the process, set up the kineties model of this reaction and estimated the parameters of the model. The velocity constant of apparent re action and the activation energy of this reaction were calculated. this paper put forward a kind of apparatus which could be used for industrial production. By using this apparatus, we could operate continuously, reduce the resistance of conducting quality of outdiffusion and increase the areas between gas and solid. And we could still make the reaction uniform and obtain homogeneous particles by reducing the temperature difference among reactant in bed.