Particle-size characterization of flocs and sedimentation volume in electrolyte clay suspensions

The variation of the particle size of the flocs in a clay suspension with the salt concentration and the correlation of the particle -size with the sediment behavior of the suspensions have been studied. The particle-size distribution of the flocs was determined by means of a sedimentation balance. Due to an increase in the salt concentration in the suspensions, the particle size of the flocs showed marked increases for the salt concentration range of 0 to 0.01M, followed by smaller increases for salt concentrations higher than 0.01M. A negative correlation was observed between the mean particle diameter of the flocs in the suspensions and the zeta potential. The sediment volume of clay suspensions of pH 7 was found to be positively correlated with the mean particle diameter of the flocs. The void ratio of the sediment exhibited a rapid decrease with increasing depth at the surface zone and a subsequent slow decrease at greater depths.