Mining in Manitoba
Natural Ventilation
Mine Development
Natural ventilation is still used whenever possible. As air warms it becomes lighter and tends to rise. Cold air gets heavier and tends to sink. Shallow mines can often take advantage of these air properties.
Levels can be ventilated naturally if proper conditions exist. Warmed air tends to rise and flow along the back. The longer the level becomes, the less effective the natural ventilation because the air will short circuit and not flow into the face.
Raises are difficult to ventilate naturally. As the raise is blasted, hot gases form and tend to stay in the back of the raise. Eventually the gases may cool and settle out of the raise. A shaft will usually ventilate well if coll air is brought to the collar. The cool air will flow down to the bottom and the warm air rises causing relatively good ventilation.
