TURBULENT AGGREGATION OF ALUMINA IN WATER AND N-HEPTANE

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