USE OF HYDROCYCLONES FOR THE PROCESSING OF ORGANICS-CONTAINING DREDGED SLUDGES.

Hydrocyclones with diameters between 44 and 1000 mm were used for the mechanical processing of dredged sludges containing organic materials and contaminated with heavy metals, with the aim of separating to sand fractions virtually free of heavy metals. Investigations of the physical properties of the sludges have shown that the organic components of the sludge solids lead to a rheological behavior which differs substantially from the behavior of suspensions of pure inorganic solids. Distributions of particle concentrations inside the hydrocyclone were derived from local measurements of solids concentrations and particle distributions. The measured results of separation may be described by a model of turbulent cross-flow classifying which takes the viscosity effect into account.