Numerical simulation of the continuous thickening of flocculated kaolinite suspensions

The equations governing the consolidation of flocculated suspension in a ideal continuous thickener are solved numerically (using Maple 9) using the assumption that the flocculated suspension possesses a compressive yield stress Py(ϕ) that is a solely a function of the local volume fraction. Kaolinite was chosen as a representative substance since the volume fractions of kaolinite suspensions corresponding to the gel point, ϕg, had been determined under different electrolyte concentrations and pH together with the compressive yield stresses, Py(ϕ). The numerical results show that the maximum volume fraction at bottom of the thickener ϕu is a relatively sensitive function of the electrolyte concentration and pH. Hence, the separation efficiency of the thickener can be altered by changing the feed chemistry.