Modeling interactions between grinding bodies having different shape during milling

The process of grinding in drum mills is directly dependent on the dynamic forces occurring in the free movement of the grinding bodies in the volume. The subject of discussion are the potential impacts between grinding bodies having different shape and equal weight in a drum mill  that has a diameter of 1,200 mm.

The study utilized ball grinding bodies having a diameter of 120 mm and tetraballpebs having a conditional diameter of 120mm. The study was carried out using the Solid Works Simulation software.

The following cases were examined:

  • Impact between two identical grinding bodies
  • Impact between a grinding body and the shell surface

The study provided numerical values for impact force, kinetic energy of impact, linear speed of impact, linear displacement of the center of gravity and duration of impact deformation. the impact force of the balls  is approximately 179,000 N. The impact force of the tetraballpebs with typical vertices, edges and spherical surfaces depending on the area of impact is 177,000 to 185,000 N.  Upon impact between two spherical surfaces of tetraballpebs, the contact area is 263.55 mm2 which is more than twice the contact area upon impact between two balls, which is 114.39 mm2.  This determines better conditions for the transmission of kinetic energy by reducing opportunities for over-grinding.