Effect of shear rate on the heterocoagulation between coal and quartz particles in a Taylor-Couette reactor

Heterocoagulation between the valuable mineral and gangue particles is one of the significant factors that deteriorate flotation. To date, the effect of hydrodynamics on heterocoagulation is still ambiguous, so it is difficult to develop the inhibition method of mineral heterocoagulation based on flow field control. In the present work, the heterocoagulation experiments of the mixture of coal and quartz particles were carried out in a turbulent Taylor-Couette reactor, and the number of particles in the supernatant was measured to characterize heterocoagulation. It was found that the heterocoagulation between coal and quartz particles increased first then decreased with shear rate, which is due to the combined effects of shear rate on the collision of particles and the breakage of aggregates. The bubble loading of coal was measured to investigate the effect of heterocoagulation on true flotation. The results show that the bubble attachment of coal was mitigated after the heterocoagulation of quartz particles.