Pore structure and network analysis of filter cake

Filtration is an important solid-liquid separation technology employed wide ly in the mineral processing industries. The effectiveness of the filtratio n operation can be influenced by numerous variables, related to the particu late phase, the slurry rheology and the equipment. Continuous filtration of fine particles involves filter cake formation and removal of surface moist ure by drawing air through the pore structure network. In order to gain a b etter understanding of the complex transport phenomena that occur in the fi lter cake, analysis of the effect of the three-dimensional pore geometry on the effective transport properties of the filter cake is necessary. In thi s regard, analysis of the pore connectivity in a packed bed of particles sh ould allow for a detailed description of fluid flow and transport in the fi lter cake structure. Two interrelated approaches, namely computer simulatio n and experimental measurement, can be used to gain knowledge of pore micro structure and its correlation to macroscopic cake properties. In this regar d, a three-dimensional Monte Carlo method was used in this work to simulate cake structure. As the resolution and the techniques for three-dimensional geometric analysis have advanced in the last decade, experimental measurem ents are now possible to specify in detail the pore structure in three-dime nsional digital space using high-resolution X-ray microtomography. Thus in addition to computer simulation, this paper presents preliminary experiment al findings of pore structure in three-dimensional using X-ray microtomogra phic techniques. These experimental results are contrasted to results from computer simulation. (C) 2000 Elsevier Science B.V. All rights reserved.