A mill is a device that breaks solid materials into smaller pieces by grinding, crushing, or cutting .... Grinding degree is the ratio of the sizes from the grain disposition. ... In materials processing a grinder is a machine for producing fine particle size reduction through attrition and compressive forces at the grain size level.
A ball mill is a type of grinder used to grind and blend materials for use in mineral dressing processes, paints, pyrotechnics, ceramics and selective laser sintering. It works on the principle of impact and attrition: size reduction is done by .... movement of the sun wheel is opposite to that of the grinding jars (ratio: 1: 2 or 1: 1).