Turbulent aggregation of alumina in water and n-heptane

Aggregation of alumina powder in water and n-heptane is followed by turbidimetry in situ. The experiments are carried out under turbulent conditions. They are discussed in the framework of a model which takes into account the hydrodynamic and physicochemical aspects of aggregation. A good agreement between measured and predicted turbidity is found provided the aggregates are considered as noncompact and liable to undergo fragmentation. Recent models of aggregation and fragmentation of fractal-like clusters are successfully tested. The aggregate morphology seems to depend on the nature of the liquid medium, however, not on the stirring rate. (C) 1998 Academic Press.