【作者】 夏巍； 钟黄亮； 杨秀山； 孔行健； 张志业； 王辛龙；

【Author】 XIA Wei;ZHONG Huangliang;YANG Xiushan;KONG Xingjian;ZHANG Zhiye;WANG Xinlong;College of Chemical Engineering,Sichuan University;

【机构】 四川大学化学工程学院；

【摘要】 本文以研究细颗粒LiF在流化床中的流化特性为出发点,提出了添加惰性粗颗粒改善LiF流化质量的方法。通过自建的流态化实验装置开展了添加重晶石颗粒的LiF细颗粒的流态化实验研究。结果表明:单一组分的LiF颗粒(平均粒径16μm)不能实现正常流态化,易出现沟流、柱塞、聚团等不良现象。实验研究了在LiF颗粒中添加三种不同粒径(粒径为150~180μm、180~250μm、250~380μm)、不同质量比例(30%、50%、60%、70%)的重晶石颗粒所构成的二元混合体系的流态化特性。结果表明:随着重晶石颗粒添加质量比例的增加,LiF流化性能越来越好,在粗颗粒添加量为60%时能实现稳定流化。在所添加的三种粒径中,粒径为180~250μm的重晶石颗粒对LiF流化改善效果最好。在实验研究基础上分析了细颗粒LiF聚团的机理,建立了细颗粒LiF聚团模型,并对细颗粒LiF聚团颗粒的粒径进行了预测。结果表明在添加不同质量比例和粒径的重晶石后,未添加粗颗粒时LiF颗粒的聚团粒径为1646μm,而添加最佳质量比例和最佳粒径的重晶石后,LiF颗粒的聚团粒径为299μm,说明添加粗颗粒是改善细颗粒Li F流化质量的有效方法。更多还原

【Abstract】 LiP F6 which is commonly lithium battery electrolyte can be preparedwith the reaction of Li F and PF5.The method of fluidization reaction can accelerate the reaction rate and increase the reaction conversion rate per unit time.Therefore, exploring the fluidization characteristics of Li F to optimize the preparation of electrolyte Li PF6 has important theoretical significance and application value.Considering the particle characteristic of Li F,this paper proposed a method to improve the fluidization quality of Li F through adding the coarse particle.Experiment investigation on the fluidized characteristic of Li F powders by adding barite sands was conducted in the self-build fluidized bed equipment. The results showed that single component Li F powders(average diameter16μm) can’t achieve good dispersion fluidization, the phenomenon of plunger and channeling would easily occur in the process. However, single component barite(particles size 150-380μm) has a good state of fluidization.Fluidization quality of Li F powders were better with the additive proportion of coarse particles increasing in the binary mixed system of Li F powders andbarite sands. Li F powdersachieve incipient fluidizationwhen the additiveproportion of barite sands is50wt%. Li F powders can achieve good particulate fluidization when the additive proportion of barite sands is60wt%. Pressure fall-off curve of increasing flow rate and decreasing flow rate can achieve a good coincidence at this additive proportion. Li F powders can achieve the best particulate fluidization when particle size of barite sands is 180-250μm at the same additive proportion. Aggregating mechanism of Li F powders was analyzed on the basis of experimental research. And agglomeration sizes of Li F powders were calculated by Zhou-Li model. The calculation results showed that fluidized agglomeration sizes of Li F powders are much smaller after adding barite sands. It is quite good explanation on the broken and cut effect of coarse particles for Li F powders. Single fluidized agglomeration sizes of LiF powders were 1646μm at the apparent gas velocity of0.25m/s.Fluidized agglomeration size of the binary mixed system that Li F powders and 60wt% barite sands(particles size 180-250μm) was 299μm at the apparent gas velocity of 0.05m/s. Both of the experiment and calculation results showed that adding particles is an effective method for improving the fluidized quality of LiF powders.更多还原