Computational fluid dynamics (CFD) numerical simulation and particle image velocimetry (PIV) measurement of a packed flotation column

Packing is a useful method to obtain a static separation environment for a high flotation recovery and selectivity. In this study, the single-phase flow field in a packed lab-scale cyclonic-static microbubble flotation column (FCSMC) was investigated by computational fluid dynamics (CFD) simulation. Turbulence model was verified by Particle Image Velocimetry (PIV) experiment; the simulation results obtained by the RSM (Reynolds Stress Model) are closer to the experimental data. Based on this validation, RSM turbulence model was used to obtain the effect of sieve-plate on the hydrodynamic characteristics in the column flotation zone. The results show that the sieve-plate packing arrangement greatly straightens the rotation flow and decreases the turbulence. To further improve the effect of packing, two layers of sieve plates were used, and one diameter (1D = 190 mm) was selected as the reasonable distance between the two layers of sieve plates. To quantitative evaluate the effect of sieve-plate packing, the logarithm of P-dk over the logarithm of P-do was calculated based on the volume-averaged turbulence dissipation rate, increasing from 24.72 for one layer of sieve-plate packing to 216.96 for two layers of sieve-plate packing. The probability of detachment significantly decreased for two layers of sieve-plate packing, and the recovery efficiency was significantly improved.