(114a) Particle-particle interaction in non-aqueous liquids – effect on processing properties

It is well known that the intra particulate forces dominate the structure of filter cakes the more the PSD is shifted to fine products. Usually the Zeta-potential is used to describe the influence of fine particles in a suspension on each other. Due to its definition the Zeta-potential is exclusively valid in aqueous systems ?Therefore the research on cake structure, suspension properties and interaction of liquid (water) and solid surface cannot be transferred directly from the aqueous to the non-aqueous field. For this reason experiments are made to quantify the effect of the non-aqueous suspension liquid on the cake built up and the final cake properties during filtration processes. Polar and non-polar solvents are used. The cake properties cake resistance, media resistance, porosity, capillary entry pressure are measured. The change in pore structure from aqueous to non-aqueous is caused by additional effects other than different viscosity and change in porosity. The interaction of particles in a non-aqueous liquid is described from the microscopic point of view. Therefore the properties of the solvent itself and all possible interacting forces and fields between the surface of the solid particle and the fluid and the particles in vicinity are taken into consideration.

Keywords: cake filtration, compressibility, cake resistance, permeability, capillary pressure, porosity.