Analysis of Na-and Ca-Montmorillonite Floc Structure

Abstract

The settling velocity of a single floc of Na-and Ca-montmorillonite was measured as a function of floc diameter to investigate effects of ion species and its concentration on the structure of montmorillonite floc. The structure of montmorillonite flocs were analyzed in the light of scaling relation between the settling velocity and the diameter of settling floc. In the scaling relation, the fractal dimension and the proportional constant were compared for each experimental conditions. In the case of Ca-montmorillonite, the proportional constant of lower ionic concentration turned out to be bigger than other cases. This result was interpreted as that structure unit of montmorillonite change into compact one or that size of the structure unit change into big one. This is consistent with the picture of the formation of tactoid array.