通过高剪切粘度建立碳分过程中纳米ATH的附聚动力学模型  

Agglomeration Kinetic Model of Nano-alumina Trihydroxide in Carbonation via Viscosity at High Shear Rate

作　　者：刘艳[1] 梁磊[1] 郭奋[1] 李红[1] 陈建峰[1] 

机构地区：[1]北京化工大学教育部超重力工程研究中心,北京100029

出　　处：《材料导报》2009年第2期73-76,79,共5页Materials Reports

基　　金：国家"863"计划资助项目(2002AA302605)

摘　　要：碳分制备纳米氢氧化铝(ATH)的过程中,悬浮液粘度随ATH固含量的增加和粒度的减小而显著增大,悬浮液最终成为时变性非牛顿流体。离子浓度对悬浮液高剪切粘度的影响很小。在传统悬浮液流变模型的基础上建立了碳分过程中纳米ATH悬浮液流变模型,模型分析表明碳分过程的流变曲线接近U形,在ATH固含量达到一定程度后急剧升高。由于连续相性质对悬浮液高剪切粘度影响很小,高剪切粘度适宜建立碳分条件下的附聚动力学模型,模型分析表明附聚与过饱和度、温度和粒度等相关,附聚动力学曲线接近S形,当悬浮液ATH固含量增加和粒度减小时,附聚的倾向明显增大,模型分析与实际情况和文献相符。The viscosity of the suspension increases during the carbonation precipitation of the alumina tri- hydroxide （ATH） while the solid content rises and the particle size diminishes near nano range, and the suspension evolves to a viscous non-newtonian fluid finally. The ion concentration affects the viscosity at high shear rate little. On the basis of the conventional rheological models of suspensions, the rheological model of ATH suspension is obtained, which demonstrates a U-shape of the flow curve in carbonation by a piecewise function and a sharp rise as the solid content reaches a certain value. Since the properties of continuous phase affect little the viscosity at high shear rate, the viscosity is fit for establishing the agglomeration kinetic model. The model is then derived and the kinetics curve is similar to the shape of ＇S＇. The model analysis proves that the agglomeration is related to the supersaturation, tem- perature, morphology and particle size and its trend increases as the solid content rises and the size of ATH dimini- shes, which matches up to the practical situations and literatures.

关 键 词：纳米氢氧化铝 碳分 模型 团聚 粘度 

分 类 号：TQ03-3[化学工程] TB383[一般工业技术—材料科学与工程]