桨型对超细铁黄制备的影响

Effects of Paddle's Types on the Preparation of Ultrafine goethite Particles

选取代表径向流、轴向流以及轴径向流的典型搅拌叶轮,考察了不同类型搅拌叶轮对铁黄制备过程的影响.实验结果表明,一定通气量及转速条件下,代表轴径向流的PBT(45°斜叶桨)叶轮具有良好的分散性能和整体混合性能,使得整个体系的表观反应速率增大.并且随着反应时间的增长,反应体系的粘度先上升,然后趋于某一稳定的值,最后又呈现上升的趋势.同时,使用斜叶桨制得的铁黄粒子的粒径分布范围较窄,粒子的形貌较齐整,枝晶较少.

Typical stirring paddles inducing radical flow and axial flow as well as axial and radical flow were selected in order to investigate their effects on the process of goethite preparation. Experimental results show that PBT (pitched blade turbine) inducing axial and radical flow reveals good dispersibility and complete mixing properties, and makes apparent reaction rate of the system larger. Moreover, with the increase of reaction time, the viscosity value of reaction system becomes large at first, and then amounts to a plateau, increases again at last. At the same time, ultrafine goethite particles prepared by PBT are with narrow particles' size distribution, uniform morphology and few dendrities.