Turbulent microflotation: theory and experiment

The principal factors, which limit the rate and selectivity of flotation recovery of fine particles from water (microflotation), are discussed in terms of kinetic approach. It is shown both theoretically and experimentally that the efficiency of microflotation can be improved significantly over that of the conventional technologies by way of the hydrodynamic treatment of multi-phase mixture (water/particles/microbubbles) in the turbulent flow. The main principles of ‘turbulent microflotation’ are formulated and the parameters are defined, which are responsible for high efficiency of the recovery, which are, (1) pre-aggregation (coagulation, flocculation) of particles to reach aggregate size of Dp>7 μm; (2) utilisation of microbubbles of the initial dimensions db<40 μm; (3) maintaining the microbubbles aggregation (coalescence) effectiveness αb<0.03. Experimental runs on the pilot plant prove the validity of the proposed theory of the turbulent microflotation.