MACSALAB Drive Rolls for Rod / Ball Mills are Rubber coated and manufactured in Double and Triple Roll models. The Rolls are 120 mm diameter x 1200 mm long and powered by a 0.37 KW 220 Volt Motor with a variable speed controller.
The Ball/Rod mills are meant for producing fine particle size reduction through attrition and compressive forces at the grain size level. They are the most effective laboratory mills for batch-wise, rapid grinding of medium-hard to very hard samples down to finest particle sizes.
A horizontal rotating cylinder (vessel) is partially filled with balls/rods (grinding media), usually stone or metal, which grinds material to the necessary fineness by friction and impact with the tumbling balls/rods. A rotating drum throws material and balls/rods in a counteracting motion which causes impact breakage of larger particles and compressive grinding of finer particles. Attrition in the charge causes grinding of finer particles.
Try to limit the size of the batch to 25% of the total vessel volume which is sufficient to fill the voids and slightly cover the grinding Media. Any larger batches cause the balls to spread out throughout the mass of solids so they cannot make effective contact with each other, because of the layers of material between them. This greatly reduces the grinding efficiency of the mill and in some cases makes it impossible to attain the desired results.
The Feed size should preferable be 8 mesh or smaller, although many operations start with much larger pieces. Having the feed material as fine as possible enables the use of smaller sizes of grinding media, which are always best for fine uniform grinding and dispersions. For hard material it is especially advantageous to start with a fairly fine product.