GRAVIMETRIC AND CONDUCTOMETRIC STUDIES OF THE SEDIMENTATION KINETICS IN AQUEOUS DISPERSIONS OF KAOLINE

摘要

Using gravimetric and conductometric methods, the sedimentation kinetics in aqueous suspensions of Alekseev kaoline has been studied for pH value range from 4 to 10. It has been found that pH increasing leads to the decreasing of mean radii of flocks linearly. The polydisperse characteristics, such as the number of fractions, minimum, maximum and mean radii of flocks have been calculated for pH = 4, 6.25, 7.05, 9.05, 10. We found that sedimentation kinetics for intermediate pH values (6.25, 7.05, 9.05) can be described by scaling equations that crossover time definesd transition from a gravitational mechanism of deposition to the diffusion one.