Abstract
The settling process of Roseki clay suspension in the dispersion and flocculation states were investigated under D. C. field. The dispersed suspensions were prepared by three methods; 1) the ion-exchange treatment with Na-and OH-mixed resin, 2) the addition of dispersing agent, 3) the p H control with sodium hydroxide. These suspensions showed the same characteristic sedimentation pattern. The particles accumulated rapidly on the anode plate by the action of electrophoresis with the increment of electric current. The sediment with 65% concentration could be obtained at the state of cake. The flocculated suspension prepared by the ion-exchange treatment with H-and OH-mixed resin showed the pattern similar to compressive sedimentation. The sediment was concentrated slowly by the action of electro-osmosis with small electric current. The effects of applied potential, temperature, p H and the concentration of electrolyte on the sedimentation under D. C. field were discussed. The efficiency of the solid-liquid separation of the suspension was also evaluated.
