Optimization of cell depth and concentration zone height in a countercurrent flotation machine

Abstract

Due to the growing complexity of ore processing, equipment and technologies with higher separation efficiency are currently in demand. Flotation machines with a countercurrent flow of slurry and bubbles are increasingly being used. Yet still, certain issues related to optimizing flows in a flotation cell by adjusting the cell height and feed point depth remain insufficiently studied. Pilot tests of a countercurrent flotation machine with a jet-ejector aerator in rougher flotation at a facility of Phosphorit Industrial Group LLC have demonstrated an increase in separation efficiency after a chamber height adjustment from 3.5 to 5.0 m with a 1.5 m deeper feed point. The mass fraction of P2O5 in the froth product increased from 20–22 to 25–27 % with a decrease in froth yield from 32–35 to 21–24 %. The flotation tail grades correspond to those of the dump waste product (1.00 ± 0.39% P2O5 according to the data on 116 samples); the load of cleaner operations has also been normalized. An original sampler designed by B. S. Chertilin was used to test the mineral load of bubbles at different depth points in the cell. The results indicate the extreme nature of the load distribution with a monotonous increase in P2O5. This confirms the main role of the process of predominant shedding of waste rock particles from the bubbles in the concentration zone (above the feed point) with the higher separation efficiency achieved.