Simply energy efficiency is about media size. Smaller media has more surface area and higher media / particle collision frequency making it more efficient. The high intensity in the IsaMill™ means small media can break coarse particles. The large scale of the IsaMill™ makes that efficiency available to mainstream grinding.

The high energy efficiency of stirred mills compared to ball mills is well understood. The use of tower mills as an energy efficient alternative to secondary and regrind ball milling became a common inclusion in the latter part of the previous century. Traditionally the higher energy efficiency was attributed to the difference between attrition grinding in tower mills and impact grinding in ball milling. However by far the most important factor for fine grinding is media size and therefore the breakage rate. Small media has a larger surface area which translates to better transfer of energy. Although Tower Mills are full attrition grinding, they are constrained to using relatively coarse media 12-25mm balls. In contrast the IsaMill™ can operate with much finer media (e.g. 1mm) and much higher intensity of power input.


  Power Intensity
Media Size
No Balls
(per m3)
Surface Area
Ball Mill 20 20 95,500 120
Tower Mill 4 12 442,000 200
IsaMill™ 400 1 1,146,500,000



Media selection has a major influence on mill parameters such as energy efficiency, internal wear and operating costs. With the introduction of economic ceramic media the energy efficiency of IsaMills™ increases dramatically.​