Air Swept, Closed Circuit with static Classifier :

A typical flow sheet for this circuit is shown alongside. The length to diameter ratio of the mill in such a system is between 1.5 to 2, and the mill is normally a single chamber mill. Even if drying is required, the mill still remains a single chamber which is then referred to, as an integral drying cum grinding chamber.

Air Lift, Closed Circuit with Dynamic Classifier:

Mills used in such a system could be a two chamber mill. Such systems are however more expensive than the air swept systems but have less running cost as electricity consumption is less. The dynamic separator has slightly better classification properties than a static classifier.

The flow sheet shown alongside also has a pre-crushing section.

Wet, Closed Circuit Rod Mill :

The flow sheet alongside is for a sand grinding mill used in sand washing, beneficiation and classification plant for the float glass industry. A rod mill was used to limit the amount of fines generated during grinding. A wet circuit grinding was possible as anyway the plant was for washing of sand.