Double chamber ball mills for the cement industry come in various designs: For bearings, either slide or slide shoe bearings can be chosen. Possible drives include gear rim/pinion, lateral, or central drives. If the processing material is wet, cement mills can also be equipped with a drying chamber. The drying chamber can be integrated into the mill or flange-mounted to it. It is equally simple to design the mill shell in one piece or in several parts (for transport reasons).