Abstract: Apparatus is provided for the comminution of material particles dispersed in a liquid. The comminution apparatus includes a vertical cylindrical comminution vessel having a comminuting media disposed therein. A vertical agitator shaft extends into the comminution vessel and includes radially extending agitator rods at its lowermost end. A helical blade is provided on the agitator shaft to create circulation within the vortex of the comminuting media. The material may be pre-mixed with a liquid before introduction into the comminution vessel. Following comminution, the comminuted material may be removed as a slurry by a suction apparatus.