Mixing Characteristics of industrial flotation columns

Abstract Flotation columsn are counter-current bubble columns that have recently been applied to froth flotation separation of minerals. A unique feature of a flotation column is the water stream applied at the top of the column for the purpose of washing entrained nonfloatable particles from the floatable bubble-particle aggregate, consequently permitting high upgrading in a single separation stage. The objective of our work is the development of a scale-up methodology for flotation columns, and as a first step toward this objective we have measured the dispersion parameters of large industrial columns. Pulsed tracer tests were performed with both liquid and solid tracers on 0.46 and 0.91 m square columns, each 13 m high. The liquid axial dispersion coefficient appears to be linearly dependent upon column radial dimension. As well, it is confirmed that the axial dispersion coefficient of mineral particles is the same as that of the liquid, and that the residence time of solid particles is unaffected by a bubble swarm.