AN EMPIRICAL-MODEL OF THE EFFICIENCY OF COMMERCIAL POLYELECTROLYTES ON SECONDARY SETTLERS DESIGN

Several commercial flocculants have been tested with coal slurries in batch settling experiments in order to establish a quantitative criter ion for their selection in preliminary design and throughout plant rou tines. Statistical analysis of the data using the quadratic Yates meth od allows the correlation to be made between two functions: settling r ate and concentration of the thickened slurry, chosen to represent the effectiveness of flocculation-sedimentation, and three parameters: co ncentration of particles, dosage of the additive and intensity of mixi ng selected as design or controlled variables. This protocol, though g enerally applicable, was carried out for brown coal slurry and a given commercial flocculant.