Performance evaluation of dispersants through streaming potential measurements

Abstract

Stability of 5% (w/v) colloidal alumina suspension was examined in the presence of three organic dispersants; Dispex N-40, Darvan C, and tribasic ammonium citrate (TAC), and three inorganic dispersants; sodium tri-polyphosphate, sodium silicate, and Calgon (sodium hexameta phosphate). The performance and the required dosage for the maximum dispersibility were evaluated by streaming potential measurement. It was shown that there is a critical concentration of each dispersant indicated by the attainment of the highest streaming potential for maximum stability conditions of the suspension. Dispersion quality of the suspension in the presence of dispersant Darvan C was investigated in detail using the sedimentation technique. It was observed that the magnitude of the charge developed on a particle surface at the dosage indicated by the inflection point is the minimum dosage required for the maximum stability of the suspension.