Erosion - Mining and the Environment: From Ore to Metal - page 795

TABLE 20.3
Dust Control Practices (CASQA 2003)

Site Condition Dust Control Practices

Permanent
Vegetation

Mulching Wet

Suppression
(Watering)

Chemical
Dust
Suppression

Gravel
or
Asphalt

Silt
Fences

Temporary
Gravel
Construction
Entrances/
Equipment
Wash Down

Haul
Truck
Covers

Minimize
Extent of
Disturbed
Area

Disturbed Area
not Subject to
Traffi c

X X X X X X

Disturbed Area
Subject to Traffi c

X X X X X

Material Stockpile
Stabilization

X X X X

Demolition X X X

Clearing/
Excavation

X X X X

Truck Traffi c on
unpaved roads

X X X X X

Mud/Dirt
carry out

X X

and mulching can be employed for areas of occasional or no construction trafi c (e.g.
reclamation areas). Preventive measures include minimizing surface areas to be disturbed,
timing the sequence of site clearing activities to coincide with actual mining activities in
each area, and controlling the numbers and activities of vehicles on a site at any given time.
Phasing of land clearing is considered to be especially critical for cleared sites greater than
40 hectares in size (Cheminfo Services 2005). Where feasible, clearing should be started at
the location that is upwind with reference to the prevailing wind direction.
All in all, however, the application of water is typically the most common dust control
method employed by mining companies across the world. Practically all mining operations
apply water to mitigate dust generation from haul roads and mine waste storage areas be it
by trucks, water pulls, water cannons, hoses or sprinklers.
A variety of chemicals are available to help suppress fugitive dust emissions. While
being more expensive than water, chemical dust suppressants are also more effective and
need to be applied much less frequently. Examples of dust suppressants include (1) liq-
uid polymer emulsions; (2) agglomerating chemicals (e.g. lignosulphonates and poly-
acrylamides); (3) cementitious products (e.g. lime-based products and calcium sulphate);
(4) petroleum based products (e.g. petroleum emulsions); and (5) chloride salts (e.g. cal-
cium chloride and magnesium chloride) (Cheminfo Services 2005).
While the application of water and chemical dust suppressants have proved to be effec-
tive options for mitigating dust, they have to be applied judiciously. Their use, while

The application of water is
typically the most common dust
control method employed by
mining companies across the
world.