Relier Pairs GRINDING MACHINESVersion en ligne Types of Mills par Jhony Guillermo Montesinos Cossio 1 SAG Mill 2 Ball Mill 3 Rod Mill 4 Autogenous Mill 5 What is a mill? 6 High Pressure Roll Mill It 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. It is an acronym for semi-autogenous grinding that also uses grinding balls like a ball mill.