Experimental study of particle concentration under electric field

Abstract

It is difficult to remove well dispersed fine particles from dilute slurry, because filtration and evaporation process requires a lot of time and energy. Electrophoresis is known as a method of moving fine particles. Therefore, the electrophoresis technique is used to collect fine particles from such slurry as a paste of concentrated fine particles on electrodes. The viscous paste on the electrode is slowly falling down during electrophoresis process, finally drops from the electrode. This may affect recovery rate of the fine particles. In this paper, we studied transport phenomena of 5wt% alumina slurry under electric field for producing the concentrated particles from the alumina slurry. The concentration rate of the particles is evaluated from weight of the concentrated particles. Time-dependent behavior of the concentration rate shows a good agreement with the theoretical approach. Since the alumina slurry is a power-law fluid, we applied shear between electrodes. The concentration rate of the particles is successfully enhanced due to decreasing in the apparent viscosity. In addition, we measured rheological properties of the concentrated particles.