Executive Summary Mixing (and segregation) play a vital role in several industrial processes. In the pharmaceutical industry, the e.ectiveness of the drug is directly related to the mixture of active ingredient and excipient. Central to the low efficiency (< 5%) reported in mineral grinding processes is the inability to control the relative mix of grinding balls and small rocks in the high shear zones where most of the energy is dissipated. The canonical rotating drum system encountered in the mineral processing, food and pharmaceutical industry is well known to exhibit axial and...