The effect of mixing on stability and break-up of aggregates formed from aluminum sulfate hydrolysis products

The structure of aggregates formed from aluminum sulfate hydrolysis product particles (HPP), their stability, break-up and re-growth, under the action of shear (stirring the dispersion at different rates) have been studied. The effect of main variables such as the hydrolyzing salt dose, pH, alkalinity and ionic strength of the water on the growth, breakage and re-growth of HPP aggregates has been investigated. It has been shown that the aluminum sulfate hydrolysis product particles formed in a model water with parameters that facilitate appearance of small particles with relatively high charge and ζ-potential values, low degree of hydration and interaction of particles predominantly in the primary minimum, are stronger and more easily reformed after their breakage by intense stirring, than aggregates built of particles with lower charge, higher initial particle size and hydration, aggregating in the secondary minimum.