A patented impeller with three helical blades rotates at high speed inside a matching, tubular housing. The rotating impeller creates a negative pressure differential, centrifugal shoveling and positive axial thrust - drawing materials into an intensive shear zone. The centrifugal force abruptly changes the direction of the materials and drives them against the inner surface of the toothed cylindrical liner. Sharply angled teeth on the edges of the impeller blades shear the materials and force them through a tortuous patch. The Dicon grinding action repeatedly accelerates and decelerates the materials, forcing them to undergo numerous changes in direction. The materials are crushed and subjected to eddy currents in a very high turbulence zone between the two sets of intermeshing teeth. The grinding action is continuously repeated as the materials move toward the discharge port. An optional discharge grid plate with a precisely positioned series of venturi-type orifices from 1/32" to 3/4" I.D., provides positive particle size control. Materials must exit through one of the small precision ports. The partially restricted discharge area provides easy-to-reproduce control of both dispersion and retention time.