Measurement of slurry solids content by electrical conductivity

Abstract

Electrodes positioned within a sedimenting and flowing suspension have been used to measure the conductivity of a dispersion and the supporting liquid. Variation in the ratio between these conductivities with solid concentration has been investigated and shown to conform to known equations for isotropic solids. Anisotropic and conducting materials had to be correlated using an empirically determined parameter. This was used to deduce solid concentration during solid/liquid separations, in situ, under carefully controlled experimental conditions, and in a system where temperature and electrolyte concentration were allowed to vary at random. Using this correlation solid concentrations up to 56% by volume were measured, during ballotini sedimentation. Sedimentation of minerals other than ballotini did not exhibit simple zone settling alone. The particle size distribution of the suspended non-conducting solids did not influence the correlation.