Agglomerated sub-micrometer-sized alumina particles were pulverized using a novel method. A high- density polyethylene (HDPE) cup equipped with stainless steel mesh turned at a 500–2000 rpm revolution rate and a 200–800 rpm rotation rate. A suspension passes through the small mesh openings, and turbulent flow and high shear stress was generated. The sample's particle size distribution before mesh treatment exhibited a broad peak at 2–70 μm, reflecting the particles' agglomeration. This suspension's viscosity was 19.8 mPa s. After mesh treatment at 2000 rpm revolution rate for 10 min, the distribution showed two peaks at 0.2 and 2–70 μm. The alumina agglomerates shrank concomitantly with increased treatment time and dispersed completely after 30 min mesh treatment. The resultant suspension's viscosity was 9.2 mPa s, which is half that of the pre-treatment suspension.