Abstract
The mechanism of the flocculation of kaolin suspensions by poly cations was studied. Experiments of adsorption and flocculation were carried out for the systems kaolin-methylene blue (mono cation) and kaolin-methyl glycol chitosan (poly cations).
The data showed that the adsorbed MGCh molecules had no segment extending into the liquid phase, and the optimum coverage fractions for flocculation on particle surfaces adsorbed by MB and MGCh were 0.35 and 0.03, respectively. Based on the above facts, it was proved that neither charge neutralization by adsorbed polymer nor interparticle bridging could be the mechanism leading to flocculation.
A new concept for the flocculation mechanism is proposed by considering the force acting between the surface elements for interaction of two particles and the uneven distribution of sites adsorbed by polymer flocculants.
