Flocculation of Silica by High Molecular Weight Polysaccharides

摘要

Flocculation of colloidal silica particles by naturally occurring polysaccharides is of interest to soft drink and beer manufacturers. Compounds found in floc include polysaccharides, proteins, lipids, waxes and silica. These compounds may originate from the water, sugar, yeast, other beverage ingredients or additives used in the beverage manufacture. In this paper, the flocculation of silica particles by polysaccharide extracts of cane sugar was investigated. The change in the particle size with time was monitored by small angle light scattering. Studies were performed under both static and agitated conditions. Under static conditions, it was observed that faster flocculation kinetics were obtained at higher polysaccharide loadings as the time taken to form the floc network was reduced. Higher silica concentrations resulted in larger and denser floes. The time lapse prior to the appearance of visible cottonball floc was reduced substantially when the solutions were agitated.