Redesign of Industrial Column Flotation Circuits Based on a Simple Residence Time Distribution Model

The potential for improved selectivity has made column flotation cells a popular choice for upgrading fine coal. Unfortunately, recent production data from full-scale column plants indicate that many industrial installations have failed to meet original expectations in terms of clean coal recovery. Theoretical studies performed using a simple dispersion model showed that this inherent shortcoming could be largely minimized by reconfiguring the columns to operate in series as a cell-to-cell circuit. Follow-up field data showed that this low-cost modification increased flotation recovery as predicted by the dispersion model. This study presents the key findings obtained from the field investigation and provides generic guidelines for designing multi-stage column circuits.