Research

Flocculation of Fine Particles in Suspension

Water resource management is an issue of growing concern for Australia. This research group is seeking to improve the efficiency of water use in industry. Significant amounts of water are lost during processing, by passing out in the spent tailings from mines, for instance, or in sewage sludge. The researchers are looking for ways to reduce losses by controlling filter cake and sediment properties, using polymer flocculation, depletion flocculation and hetero-coagulation.

This group is seeking a good fundamental understanding of the factors required to form aggregates of desired properties (ie, size, compactness and strength) in order to optimise many industrial solid-liquid separation applications. Their approach involves direct aggregate structure measurements, detailed particle interaction force and interfacial absorption studies. They also work on the production of dense hydrophobic aggregates for flotation, a core project of the Centre since its inception, where they have made considerable progress. The scope is now being broadened to consider other properties of flocs and sediments, with the results being applied to solve industrial dewatering and filtration problems.

Multiphase Phenomena

This program investigates the behaviour of particles and bubbles, particularly the flotation process for separating particulates suspended in water. The researchers aim to find improved ways to separate coarse and ultrafine particles, based on their surface properties. They are particularly interested in the effect of particles and frothers on the stability of foams, but are also looking more generally at fluid phenomena of froths, bubbles and jets. Their projects examine the hydrodynamics of liquid drainage in froths and foams, and methods of producing small bubbles with minimum energy losses, for use in mineral processing and biological aeration.