Revisiting a flotation cell benchmark

Developing a flotation benchmark to compare different flotation systems has been challenging due to the variation that exists in flotation cell types, geometry, and internal hydrodynamics. Parkes et al (2022) focused on the product flux passing through the upper surface as a Performance Measure, interpreting a batch mechanical cell as a steady-state plug flow device, equivalent to infinite steady-state tanks in series. This work reveals a conundrum that arises out of the tanks in series analysis when applied to a system of fixed total volume. The free surface of the system increases with the number of stages, therefore leading to a decline in the product flux and hence the Performance Measure. This Technical Note resolves the issue by always using tanks of one size, comparing the result for N tanks in series with an equivalent number of batch cells operating in parallel. The analysis provides a much stronger and clearer framework for the flotation benchmark.