The separation of fine minerals in the synergy between the vertical fluidization section and inclined channels of the reflux classifier

Abstract

AbstractIn the gravity separation of fine minerals, the misfit phenomenon caused by particle size cannot be completely overcome, which makes it difficult to effectively recover useful minerals of a given density. In this paper, a novel reflux classifier (RC) experimental equipment was designed in which the cross‐sectional area of the inclined channel is smaller than that of the vertical portion. As the rising water entered the inclined channel, its velocity increases, leading to a higher shear rate. A series of particle fractionation experiments were conducted in this paper to examine the effect of synergy between the inclined and vertical sections of the RC on weakening the segregation arising from the particle size range. Sand, glass bead, and magnetite particles were used in separate investigations. An empirical equation for predicting the rising water fluidization flow rates that put the particles in a critical state was developed to describe the broad range of experimental data. The results show that the novel RC system creates a more suitable fluid environment through the synergy of vertical and inclined sections, allowing for the complete separation of sand and magnetite mixtures, as well as the separation of particles with different particle sizes but the same terminal settling velocity at the same flow rate. This indicates a reduced dependence on particle size for separation. The theoretical model can accurately predict the fluidization rate and the particle size composition of the separated product.