Crossflow Membrane Filtration of Slurries

Crossflow microfiltration is an effective method for the dewatering and concentration of slurries. The performance of a crossflow filtration process is very dependent on particle size and membrane type. For fine colloids (<0.1m) the process tends to cake control, which is illustrated by the ultrafiltration of colloidal silica. As particle charge, or zeta potential, increases flux is significantly raised and this can be explained by electrokinetic effects. For the microfiltration of submicron - to -micron sized particles the process could be cake or membrane controlled. Improved flux may be observed at low particle charge due to particle aggregation, and also at high charge due to electrokinetic effects. For (super)micron sized particles the process tends to membrane control, with flux sensitive to P, but insensitive to crossflow velocity and concentration.