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