On-line solids hold-up measurement in mineral slurries by the standard addition method

This paper presents the application of the standard addition method to on-line measure the solids hold-up at the laboratory scale. The method consists in measuring the electrical conductivity (mS/cm) of a two-phase dispersion using two conductivity cells: the first containing a known amount of dielectric material plus the solid–liquid dispersion and the second containing the solid–liquid dispersion only. A system of two equations are obtained by applying the Maxwellʹs model to both cells, and the liquid conductivity and the solids hold-up may be evaluated by solving them. It is demonstrated that the studied method is a reliable option to estimate the solids hold-up on-line.