Ball Milling is a more aggressive form of grinding. Reactants are moved into an enclosure with milling media, which is agitated for an extended period of time to ensure mixing. In some cases, high-energy milling can be used to encourage chemical reactions.
Ball milling can be accomplished simply in a plastic Nalgene using either stainless steel ball bearings or Yttria Stabilized Zirconia balls.
Planetary ball mills and spex mills can be used for high energy reactions.