Automated measurement of slurry surface settlement

Abstract

An automated float method for measuring slurry surface settlement is described. The system consists of a Perspex float which is denser than water but lighter than the slurry into which it penetrates slightly and floats on the slurry/water interface. Settlement of this float is then automatically tracked using an LVDT. Comparison with direct cathetometer measurement demonstrates that except for the initial penetration the float's depth of embedment into the slurry surface is unchanged as settlement progress. Hence it is able to follow the settlement of the slurry surface. This method is then used to measure quickly and accurately the surface settlement of kaolin during self-weight consolidation tests under single drainage condition. The initial rate of settlement is then used to determine the permeability of the slurry, which is not an easy property to measure using other methods.