Grinding media is used in wet milling and dry milling operations. Grinding Media is typically a bead of uniform size, shape, and density. The media is agitated in high concentration with a slurry (or mill base) to be ground. In a small media mill a central shaft agitates the media and slurry. Energy is transferred from that shaft to the nearest layer of beads and from that layer to subsequent layers of beads. It is within that power transmission that the mill base is exposed to extremely high shear and impact forces.
Media Size is chosen both based on the type agitated equipment or mill and the agglomerate size of the slurry. For best stress transfer in a mill it is traditionally recommended that media diameter to particle diameter be 10:1 or greater. Large media enhance impact forces while small media cause more collisions.
Media Density affects impact energy in the mill. Denser media impart higher impact forces. However, there are limits. Mill base viscosity must be sufficient to support these high densities. Dense media in low viscosity mill base can result in increased media packing, temperature rise, and mill and media wear.
While some mills will use cylinder and other shaped media, Bead mills use spherical media. The overall quality of the sphere is still important. It plays a role in the mill wear and heat generation. A quality sphere produces the best milling performance in a small media mill.
All grinding media is not created equal. DisperseTech offers a broad range of media for you wet milling operation. We can assist with media selection for your particular products and production equipment. Whether you operate sand mills, horizontal mills, basket mills, attritors or vertical mills, we have the media you need. From inexpensive sand, to glass, zirconium silicate, zirconia oxide, chrome steel and steel shot we carry a braod range of products. We can assist in determining the appropriate material and charge for you mill.