Selection of ball mill jar and balls

- Sep 24, 2020-

I believe that in the use of planetary ball mill, how to choose the material of grinding ball? How many grinding balls should be equipped in the ball mill jar? How big should the diameter of the grinding ball be? What is the ratio between the grinding ball and the sample? These are the problems that users are concerned about. So this article will explain the relevant issues about the use of grinding balls.


How to choose the material of grinding ball?

The material selection of grinding ball mainly depends on the ball mill jar. Generally, the material of grinding ball is the same as that of ball mill jar. When it is determined that the material of grinding ball is suitable for ball mill jar of certain material, the material of grinding ball can be determined. When the material of grinding ball cannot be the same as that of ball mill jar, it is generally the following combination:

  1. Polypropylene ball mill jar+ zirconia / alumina / Agate grinding ball

  2. Ultra high molecular weight polyethylene jar+ zirconia / alumina / Agate grinding ball

  3. Nylon ball mill jar + stainless steel / zirconia / alumina / Agate grinding ball

  4. Polyurethane ball mill jar+ zirconia / alumina / Agate grinding ball

  5. PTFE ball mill jar+ zirconia / alumina / Agate grinding ball 


What diameter of grinding ball should be chosen?

Larger diameter - 30%     medium diameter - 50%     small diameter - 20%


Grinding balls are usually available in the range of 3 mm to 40 mm in diameter. In general, we will recommend grinding balls with large, medium and small diameters. Large balls will generate more energy in the operation of planetary ball mill, which will make the sample quickly comminuted, while the small ball can improve the precision and consistency of sample grinding. In the configuration, the weight proportion follows the larger diameter - 30%, medium diameter - 50%, small straight Diameter - 20% principle.



Mass ratio of grinding ball and material:

Generally, the mass ratio of grinding ball to sample is better than 5:1, and the volume of grinding ball and sample is not more than 80% of the volume of ball mill jar, and 40% - 60% is the best.


Due to the wide application of planetary ball mill and the variety of grinding samples, the selection of the diameter of grinding ball should take into account the volume of the ball mill jar, the nature of the sample, the discharge requirements, wet grinding or dry grinding and other factors. It is suggested that in the daily repeated experiments, the specification and proportion of grinding balls for the best effect of single sample grinding should be recorded to accumulate experience.