An operation line for Anshan-type magnetite in the east of Hebei Province was studied and the line's comminution process included blasting, crushing and grinding.

Its chief suspensibility can be raised to 70% from 34%, because of using airstream comminution process instead of conventional Raymond mill, and selecting suitable adjuvants.

For a closed-circuit comminution process composed of comminution and classification operations, the steady-state can be calculated by means of simulating the process with converging locked-cycles.