Grinding and energy input in stirred media mills are studied as functions of grinding time, stirring speed, media size and density, solid concentration, impeller and tank dimensions and design, and other relevant variables. Ground product size and surface area are determined with respect to the above variables. Changes in energy input and media/pulp theological properties during grinding are described. The best conditions for grinding limestone in the laboratory stirred media mills have been identified. Equations for correlations involving power and modified Reynolds numbers have been established.