ELECTROKINETIC DEWATERING OF A PHOSPHATE CLAY

The principles of electrokinetic dewatering are: (1) electrophoresis, the movement of colloidal particles in a direct current electric field ; (2) dielectrophoresis, the movement of colloidal particles in a non- uniform electric field; and (3) electro-osmosis, the water flow in por ous media in a direct current electric field. Electrokinetic dewaterin g of a phosphate clay was investigated in an experimental program. The results show that the velocity of sedimentation is controlled by the applied current density and that electro-osmotic permeability dominate s the effectiveness of electrokinetic consolidation. The intermittent current and polarity reversal can significantly improve the effectiven ess of electrokinetic dewatering and reduce energy consumption and adv erse electrode reactions. (C) 1997 Elsevier Science B.V.