In this work, dynamic froth stability is used for the first time to investigate the flotation behaviour of copper
tailings. Reprocessing of material from tailings dams is not only environmentally desirable, but also increasingly
economically feasible as head grades can be high compared to new deposits. Flotation tailings, however, usually
contain a large proportion of fine (10–50 μm) and ultra fine (<10μm) material and the effect of these particle
sizes on froth stability is not yet fully understood.
For this study, samples were obtained from the overflow and underflow streams of the primary hydrocyclone
at a concentrator that reprocesses copper flotation tailings. These samples were combined in different ratios to
assess the dynamic froth stabilities at a wide range of particle size distributions and superficial gas velocities. The
findings have shown that the effect of particle size on dynamic froth stability can be more complex than previously thought, with a local maximum in dynamic froth stability found at each air rate. Moreover, batch tests
suggest that a local maximum in stability can be linked to improvements in flotation performance. Thus this
work demonstrates that the dynamic froth stability can be used to find an optimum particle size distribution
required to enhance flotation. This also has important implications for the reprocessing of copper tailings as it
could inform the selection of the cut size for the hydrocyclones