Environmental Aspects of Phosphate and Potash Mining United ...

Environmental Aspects of Phosphate and Potash Mining
Landscaping
Landscaping tends to be associated primarily with surface
mining methods and the decommissioning of
waste disposal sites. The major objective of landscaping
is to leave a stable non-eroding surface. A variety
of methods is employed to achieve this, including:
Using sand tailings to fill in the low areas between
dragline overburden spoil piles;
Shaping the sides of overburden dumps with bulldozers
to leave gentle slopes or blend with the
natural landscape;
Leaving berms (narrow benches) on steep slopes
such as pit walls or the sides of overburden dumps
with a bulldozer;
Cross-ripping slopes with a bulldozer tine;
Reestablishing surface drainage systems such as
streams.
Post-mining Landform Reshaping with Phosphate
Clay Fines
The Khouribga operation operated by Office Chérifien
des Phosphates (OCP) in Morocco extracts phosphate
rock using large-scale opencast dragline mining
method. This method leaves the overburden in steep
spoil piles.
A new method has been implemented for the disposal
of phosphate clay fines in the low areas between
the spoil piles. This technique creates a more stable
post-mining landform as well as providing a better
growing medium for vegetation.
The new disposal method reduces the water consumed
during slurrying and disposal of the fines.
Water consumption is of particular significance as the
operation is located in an arid environment with
water sourced from limited ground water supplies 90
kilometres away. The cost of disposal is also reduced
compared with the previous method.
These methods slow the rate of rainfall run-off and
prevent excessive erosion.
Landscape after extraction of ore - Office Chérifien des
Phosphates, Morocco
Revegetated overburden dump - Fosfertil, Brazil
Landscape around the mine - Office Chérifien des
Phosphates, Morocco
Placing topsoil on dam wall - Foskor Ltd, South Africa