What is an SAG mill?
AG/SAG mills are used to grind raw ore or primary crusher product into either a finished size ready for processing, or an intermediate size for final grinding in another type of mill, such as a ball mill or pebble mill. AG/SAG milling is often chosen today for primary grinding because it can result in fewer grinding stages in the preparation of ore, compared to previous technologies, and therefore results in lower overall capital and maintenance costs. It is, however, highly energy inefficient. Autogenous grinding (AG) is the size reduction of material using a tumbling mill that utilises the feed material itself as a grinding medium. The more common semi-autogenous grinding (SAG) is the same use of a tumbling mill but with the addition of supplementary grinding media. The most common supplementary medium is large steel balls. Grinding can be wet or dry, with wet grinding being accomplished with a slurry of 50 to 80% solids.
