Particle Size Reduction Primer

Particle size reduction can mean many things performed by many different types of equipment, ranging from crushing huge boulders at a mining operation to fine grinding for a nano particle application.


At its most basic, particle size reduction simply means the use of force to decrease the size of a solid mass. In one form or another, it’s been around for millennia. For our discussion here, we’ll restrict our parameters to fine grinding applications.


Particle size reduction offers a wide range of benefits, such as:

  • Consistent size
  • Improved drying
  • Increased surface area
  • Improved absorption and dissolution rates
  • Uniform dispersion

The process of particle size reduction can be completed by cutting, crushing, milling or grinding, depending on the particle size required.


The particle size reduction equipment that completes those tasks is varied. Typical examples include:

  • Ball mills, in which a container is filled with grinding media and is rotated on its own axis.
  • Planetary ball mills, in which a ball mill is attached to a disc that rotates in the opposite direction of the container. This unique construction takes advantage of centrifugal force and the Coriolis effect to grind materials.
  • Stirred ball mills, in which a shaft with attached arms stirs the media in a stationary tank. Because only the shaft moves, this type of equipment is more energy efficient than a standard ball mill.
  • Attritors, a subset of stirred ball mills that offers specific features like jacketed tanks to allow for more precise temperature control.

Applications for Attritors include grinding:

  • Pigments
  • Pharmaceuticals
  • Ceramics
  • Cosmetics
  • Chemicals
  • Industrial coatings

We’ve also developed specialty Attritors for applications as diverse as chocolatelimestonelime-slaking and tungsten carbide as well Attritors specifically for cryogenic grinding. Depending on the application, Attritors can grind particles down to nano size.

With our vast experience in designing and manufacturing Attritors for a wide range of applications, Union Process has the expertise to develop the grinding solution you need. Contact us now to start the process.