细颗粒LiF添加组分的流化特性实验研究

LiPF6 which is commonly lithium battery electrolyte can be preparedwith the reaction of LiF 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 LiF to optimize the preparation of electrolyte LiPF6 has important theoretical significance and application value.Considering the particle characteristic of LiF, this paper proposed a method to improve the fluidization quality of LiF through adding the coarse particle. Experiment investigation on the fluidized characteristic of LiF powders by adding barite sands was conducted in the self-build fluidized bed equipment. The results showed that single component LiF powders (average diameter 16μm) 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 LiF powders were better with the additive proportion of coarse particles increasing in the binary mixed system of LiF powders andbarite sands. LiF powdersachieve incipient fluidizationwhen the additive proportion of barite sands is50wt%. LiF 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. LiF powders can achieve the best particulate fluidization when particle size of barite sands is 180-250μm at the same additive proportion. Aggregating mechanism of LiF powders was analyzed on the basis of experimental research. And agglomeration sizes of LiF powders were calculated by Zhou-Li model. The calculation results showed that fluidized agglomeration sizes of LiF powders are much smaller after adding barite sands. It is quite good explanation on the broken and cut effect of coarse particles for LiF powders. Single fluidized agglomeration sizes of LiF powders were 1646μm at the apparent gas velocity of 0.25m/s.Fluidized agglomeration size of the binary mixed system that LiF 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.