Combined microflotation of fine minerals: theory and experiment

A theory of combined microflotation is proposed which reasonably accurately describes the kinetics of fine particles flotation utilising small quantities of fine bubbles in combination with the coarse bubbles. The theory has been applied to analyse the experimental findings of fine quartz flotation by the method of combined microflotation. The theory predicts the capture efficiency of particles and fine bubbles by the coarse bubbles and the efficiency of hetero-aggregation of particles and fine bubbles in the non-uniform hydrodynamic field of a flotation cell. It is shown that the optimal size of the fine bubbles increases approximately linearly with increase of the size of particles and diameter of the coarse bubbles; the dependence on the size of particles is stronger than on the diameter of the coarse bubbles. A theoretical explanation is offered for the linear dependence of the combined microflotation rate constant on the volume dosage of fine bubbles per weight unit of solids.