PREDICTION OF SOLID CONCENTRATION AND HEIGHT IN A COMPRESSIBLE FILTERCAKE

Solid concentration profiles of a crushed dolomite mineral during cons tant pressure filtration have been measured experimentally by means of electrode pairs positioned in the wall of a filter cell, and a calibr ation between electrical conductivity and solid content. Accepted equa tions and techniques for modelling compressible filter cakes have been investigated. The solid concentration profile of the dolomite mineral was predicted using these. The difference, or error, between calculat ed and measured cake heights was less than 20%. Incorporating a mass b alance as a check on the calculated solids concentration profile, with consequent adjustment of the cake height until the mass balance was s atisfied, reduced the error to less than 6%. An iterative and numerica l technique to predict the cake height, concentration profile, resista nce, filtrate volume and rate based only upon the physical properties of the liquid and solid plus the constitutive equations between both s pecific resistance and concentration with solids pressure, without emp loying average values of these, is described.