磷矿颗粒在振动场及添加SiO2的流化特性研究

以平均粒径为60μm、密度为2316kg/m3的磷矿颗粒为物料,采用引入振动场及添加SiO2的方法,在内径为42mm的流化床中,考察了不同振幅、SiO2添加量的情况下,磷矿颗粒的流化性能。实验结果表明:振动场与SiO2均可有效消除活塞流、抑制沟流、减小颗粒间的粘性力,显著改善磷矿颗粒的流化质量。在硅钙摩尔比为3.0时,床层膨胀比最大,临界流化速度最低;此外,随着SiO2添加量进一步的增加或降低,改善效果减弱,流化质量下降。但振幅对临界流化速度影响很小,且床层膨胀比随振幅的增加逐渐增大。采用Richardson-Zaki方程进一步对磷矿-SiO2体系分析的结果与实验现象相符。

Study on Fluidization Characteristics of Phosphate Ore Particles with Application of Vibration Field and Addition of SiO2 Particles

With application of vibration field and addition of SiO2 particles,the fluidization behavior of phosphate ore particles with mean sizes 60 μm and densities 2316 kg/m3 was studied in a fluidized bed with 42 mm in interior diameter.The effect of different amplitude and quantity of SiO2 particles on fluidization quality of the phosphate ore particles was investigated in detail.The experimental results indicated that both application of vibration field and addition of SiO2 particles can eliminate plugging,restrain channeling,reduce interparticle cohesive forces,and improve the fluidization quality dramatically.When the mole ratio of silica to lime is 3.0,the bed expansion ratio was maximum and the minimum fluidization velocity was minimal.In addition,the improving effect of SiO2 particles on the fluidization quality was weakened,and even disappeared when the mole ratio is greater or lower than 3.0.However,the effect of vibration field on minimum fluidization velocity was small while the bed expansion ratio increased with increasing amplitude.Richardson-Zaki equation was adopted to further analyze experimental results,which were agreeable with the results.