反应沉淀法制备亚微米粒子的粒度分布模拟与实验验证

采用基于粒数衡算方程及物料衡算方程的数值模拟方法模拟了包括反应、成核、生长及凝并的反应沉淀制备亚微米粒子的过程，其中颗粒间的凝并过程采用分级模型来模拟，产物颗粒的粒度分布（PSD）由离散化的粒数衡算方程求得.以BaSO₄的反应沉淀体系作为研究体系，将实验测量数据与数值模拟结果进行对比，验证了所构建的数学模型的正确性与适用性.应用此模型进行分析，发现沉淀时间、产物过饱和度及凝并对粒度及粒度分布有着显著的影响.在此基础上，提出了反应沉淀法制备亚微米粒子过程中颗粒粒度及粒度分布的控制方法.

EXPERIMENTAL AND NUMERICAL SIMULATION OF PARTICLE SIZE DISTRIBUTION OF SUB-MICROMETER PARTICLES SYNTHESIZED BY REACTION PRECIPITATION

Based on population balance and mass balance, a numerical simulation model was developed to predict particle size distribution (PSD) in reaction precipitation process.By implementing the model, the reaction precipitation process in a batch reactor including reaction, nucleation, growth and agglomeration was simulated, in which agglomeration was modeled by the method of particles classes.The partial differential population balance equation was transformed into a linear differential system by the discretization method.The precipitation system of BaCl 2 Na 2SO 4 to synthesize BaSO 4 was used to verify the numerical model.Stemming from the analysis of the simulation results, it was shown that particle size and particle size distribution were controlled by supersaturation, precipitation time and agglomeration.The influences of these factors and the method for controlling particle size distribution were presented for the reaction precipitation process.