Effect of high-speed shear flocculation on the flotation kinetics of ultrafine microcrystalline graphite

A novel process combining high-speed shear flocculation and flotation (SFF) was proposed to beneficiate ultra fine microcrystalline graphite (MG). The effect of high-speed shear flocculation on the flotation kinetics of ultra fine MG was investigated extensively by comparing with conventional flotation process. The flotation kinetics of these two processes were fitted with six flotation kinetic models using 1stOpt statistical analysis software. The results show that the flotation rate of MG in the SFF process is about 3 times as fast as that in the conventional flotation process based on the first-order model with rectangular distribution of flotabilities. On one hand, the high-speed shear flocculation process resulted in increasing size of graphite aggregates. On the other hand, it generated decreasing size of kerosene droplets, which in turn benefited the increase in the size of graphite aggregates due to the improved hydrophobicity of graphite particle surface. The increased aggregates were responsible for the increase in flotation rate of MG in the SFF process. In addition, the SFF process could also improve the concentrate grade and recovery of MG in comparison with conventional flotation. The utilization of the SFF technology to separate ultrafine MG is of great potential in industrial applications. (c) 2021 Elsevier B.V. All rights reserved.

Automated summary

A novel process combining high-speed shear flocculation and flotation was proposed to beneficiate ultra fine microcrystalline graphite. The flotation rate of MG in the SFF process is about 3 times as fast as that in the conventional flotation process, due to the increase in aggregate size and improved hydrophobicity of graphite particles. The SFF process shows great potential in industrial applications for separating ultrafine MG.