Minerals Engineering, Vol.115, 88-96, 2018
A capillary flow model for filtration
A filtration model has been developed by considering the two-and three-phase flows through a filter cake during the cake formation and drying cycle times, respectively. Assuming that the cake consists of well-defined capillaries of identical radius, it is possible to predict filtration kinetics from first principles using the Navier-Stokes equation and capillary pressures. The model parameters have been determined by fitting experimental data to the model using capillary radius and slip length as adjustable parameters. It has been found that use of hydrophobizing reagents greatly improves filtration kinetics and reduces cake moistures, which may be attributed to increases in capillary radius and possibly in slip lengths. Use of a polymeric flocculant also increases filtration kinetics but can cause an increase in cake moisture due to the entrapment of moisture within floc structures.
Keywords:Filtration model;MFT;Oil sands;Tailings management;Capillary pressure;Capillary flow;Dewatering aids;Contact angle;Slip;Navier-Stokes equation;Flocculent;Hydrophobizing agent;COSIA