Ball Mills and stirred mills are applied across a wide range of applications, but for each ore there is optimum efficient range. The figure to the left shows the typical application ranges for ball mills and stirred mill. The Vertimill is always more efficient than a ball mill with energy savings ranging from 30% to greater than 50%. The transition point from the Vertimill to an SMD/IsaMill varies depending on the ore properties but generally is in the range of 20 to 40 microns. A detailed test program can be carried out to determine the optimum energy efficient circuit.