Stephen Neethling

Research Interests My main research interest are in the modelling and simulation of multi-phase flow. My main applications are in minerals processing and, in particular froth flotation and heap leaching. My research forms part of the Advanced Mineral Processing Research Group. Froth Flotation One of my main research focuses is on the behaviour of foams and froths, with particular application to the modelling of Flotation Cells, which are widely used as a separation technology in the Minerals Industry. We carry out both fundamental level studies on various aspects of foam behaviour, as well as experimental and modelling studies of industrial foams and froths. We have not only developed mathematical models of foams, but also a variety of experimental techniques to test the model predictions, including image analysis and tomographic methods. The main application of the research is the study of the froth phase of mineral flotation cells, but the fundamental nature of the approach has allowed us to model, amongst other things, food foams, foams in water treatment plants and undesired foams in the nuclear industry. Heap Leaching Another major area of research is heap leaching My particular interest is in the fluid flow and mass transport through the heaps. This involves multi-scale modelling and simulation. In particular, I use Smooth Particle Hydrodynamics to study the particle scale flow (see below) and mass transport behaviour and Finite Element/Finite Volume methods to model the behaviour at the heap scale. SMOOTHED PARTICLE HYDRODYNAMICS As part of my aim of being able to model and simulate minerals processing systems I have developed a new massively parallel SPH simulator. This simulator has specifically been taylored to multi-phase systems and can handle fluids with large density contrasts and with interfacial tensions and contact angles between the phases (see above simulation). In addition a DEM module has been implemented within the SPH simulator, which allows seamless 2-way coupling between the DEM based solid particle models and the SPH based fluid models.