DESCRIPTION OF CAKE STRUCTURE AND ITS IMPACT ON CAKE FILTRATION AND SEDIMENTATION

摘要

Fine particle separation is enhanced by polymeric flocculants. The generated flocs are characterized by their size, fractal structure and floc strength, which all impact the cake / sediment micro-properties and thus, the separation by sedimentation, compaction and filtration. Analysing those for developing a model for the effect on filtration performance improves the understanding of filtration and separation techniques. rnWe will present detailed analysis for various techniques for floc structure analysis (laser light scattering, image analysis – 2D and 3D, volume obscuration and focus beam refractance measurement). The comparison of those techniques provides pro and con for different applications. Further floc strength measurements by model supported techniques will presented to round up the characterization of floc micro-structure. rnFilter cake characterization using image analysis, X-ray tomography and capillary pressure curve measurement will reveal the filter cake micro-properties such as pore size distribution. A model will be presented that uses floc micro-properties information (size, structure and strength) to determine filtration and cake properties. Validation of the model by experimental results will be provided.