Fluidization of Cohesive Fluorite Particles at Ambient/High Temperatures and Enhancement Methods

Abstract

Fluidization of fine fluorite particles, classified as Geldart A/C particles, was studied at ambient/high temperatures by experiments. Results showed that fine fluorite particles could not be fully fluidized at ambient temperatures, due to the agglomeration phenomenon. What’s worse, due to the great increase of van der Waals forces with the increasing temperature, the fluidization quality was further depressed and they were totally defluidized at 723 K unless the loose gases were used during the heating process. In order to improve the fluidization quality, an enhancement method of adding cohesive calcium sulfate particles was established. The best improvements at ambient/high temperatures both appeared when the addition fraction was 20 wt %. Moreover, theoretical analysis showed that the effect mechanism of a calcium sulfate particle was the “coordination” theory. According to the “coordination” theory, the optimum addition fraction of calcium sulfate particles was calculated as 16.5 wt %–22.4 wt %, whic...