190
5 Main Ventilation
Raise
Transport level
Upper level
Raise
Mined zone
Filled
material
Fig. 5.11 Air circulation in the cut and fill stoping method
Mineral
Fragmented Mineral
Transport level
Raise
Raise
Upper level
R
R
Door
Regulator
Fig. 5.12 Air circulation in the shrinkage stoping method
these methods have a network of ventilation galleries located about 15–30 m below
it (Fig. 5.13). Fresh air is circulated from the injection galleries to the production
level through raises. After the sweeping of the production level, the air is conducted
again by means of raises to the air extraction level (McPherson 1993, p. 113). An
excellent review of block caving ventilation systems can be obtained from Calizaya
and Mutama (2004).
Another intermediate method between artificially supported and unsupported is
longwall mining. The most commonly used ventilation method is the U-shaped
system. Under this system, the air enters through the entry route to the face, sweeps
it, and travels back through the return path to the general circulation (Fig. 5.14).