Mill (grinding) - WikipediaA mill is a device that breaks solid materials into smaller pieces by grinding, crushing, or cutting. Such comminution is an important unit operation in many processes. There are many different types of mills and many types of materials processed in them. Historically mills were powered by hand (e.g., via a hand crank),.ball mill overviewball mill operationball mill appliion,Planetary Ball Mill PM 100 - RETSCH - highest finenessThe extremely high centrifugal forces of a planetary ball mill result in very high pulverization energy and therefore short grinding times. . paper, pigments, plant materials, polymers, quartz, seeds, semi-precious stones, sewage sludge, slag, soils, tissue, tobacco, waste samples, wood, . continue to application database.