Influence of Particle Properties on Filter Cake Compaction Behavior under Oscillatory Shear

Abstract

Filter cake compaction is a common method for mechanical deliquoring of compressible filter cakes. In addition to the conventional squeezing compaction method, applying oscillatory shear to filter cakes at low pressure is an alternative compaction process in cake filtration. While basic differences in terms of compaction success have already been identified for various materials, a systematic analysis of the influence of material properties on compaction behavior under oscillatory shear is missing. The present work addresses the influence of particle size distribution and increasing particle agglomeration on the compaction success of oscillatory shear to further clarify the process knowledge and applicability. The compressibility achieved by this technique was investigated for calcium carbonate materials with various particle size distributions. The results show that the compaction potential increases from 17.3% for the coarsest material (x50,3 = 23.5 μm) to 26.6% for the finest material (x50,3 = 2.3 μm) with decreasing mean particle size. The more widely distributed material exhibits a higher compaction potential of 21.7% compared to 18.4% for the narrowly distributed material. Increasing particle agglomeration to improve the slurry filterability does not affect the achievable compaction states of the material by vibration compaction at sufficiently high energy input.