超细高磷赤铁矿粉流态化特性的试验研究

Experimental Study on Fluidization of Ultra-Fine High Phosphorus Hematite Powder

基于流态化理论设计出了符合本试验研究要求的流化床反应器,并用其对不同粒度的高磷赤铁矿粉,尤其是平均粒径为2μm左右超细粉的流态化流动规律进行了一些冷态的基础试验研究,给后续高磷铁矿石的脱磷研究和试验提供了一定的参考。试验中实现了各常规粒度级矿粉颗粒的流态化过程,且临界流化速度试验测量值与理论计算值相差不大。其中,0.074 mm以下细矿、平均粒度为2μm超细矿粉颗粒的流化过程为:在低气速时,矿粉颗粒床层首先出现沟流;气速增加,沟流加剧,有时形成节涌;气速达到一个远超过理论初始流化速度的临界值(崩裂速度)时,床层突然分裂成许多小的聚团体,这些小的聚团体和细小颗粒呈现出较为均匀的流化状态。

Based on the theories in fluidization,the fluidized bed reactor was designed.In order to provided some references for the follow-up studies and experiments of the phosphorus reduction of high phosphorus hematite,the cold-state-based researches were carried out for different size of hematite fines,especially for the particle size less than 2 μm.As a result,the fluidization process of conventional size of hematite fine was achieved,and the difference between critical fluidization velocity measured and calculated value was close.The fluidization processes of particle size less than 0.074 mm and the ultra-fine with the average size of 2 μm are as follows： at low velocity,the ore powder particle bed appears channeling at first;the channeling is creasing with increase in gas velocity;slugging is formed sometimes;when gas velocity much more than the theoretic initial fluidization velocity of the critical value（crack speed）,the bed suddenly splits into many small groups,these small groups and small particles show a good uniform fluidized state.