Conditioning characteristics of kaolin sludge with different cationic polyelectrolytes

This study investigates the conditioning behaviors of kaolin sludge with different cationic polyelectrolytes. The work entails measuring the capillary suction time (CST), measuring the streaming current (SC), determining the moisture content of dewatered sludge cake and measuring the flee size. According to these results, The rate of dewatering (CST measurement) does not significantly differ from polyelectrolyte molecular weight above 6.6 x 10(6), and as well as a charge density exceeding 15%. The amount of polyelectrolyte dosage that minimized the CST value is independent of the molecular weight of the four polyelectrolytes used. In addition, the moisture content of dewatered sludge cake depends on polyelectrolyte dosage, molecular weight and charge density. When the dosage approaches a value such that the SC becomes zero, the moisture content of dewatered kaolin sludge cake reaches the maximum of comparable values for different polyelectrolytes. (C) 1998 Elsevier Science B.V. All rights reserved.