Environmental Aspects of Phosphate and Potash Mining United ...

Overview of Phosphate Rock and Potash Mining and Beneficiation
Following beneficiation, the concentrated phosphate
rock is stockpiled prior to transport to downstream
processing plants for the manufacture of phosphate
mineral fertilizers. In some instances, phosphate rock
with suitable properties may be directly applied to
crops as a soil amendment by farmers.
Wet screening - IMC Phosphate, Florida, USA
Phosphate fertilizer plant, Conda, USA - Agrium Inc., Canada
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Grinding mills - Fosfertil, Brazil
Generally, the major waste streams produced during
phosphate rock beneficiation are clay fines, sand tailings
and significant quantities of process water.
Magnetite tailings may also be associated with igneous
orebodies. These are disposed of by a number of
means including discharge to rivers or other water
bodies, and disposal to engineered storage dams, or
mined-out areas. The process water may be recovered
and reused.
Flotation tanks - IMC Phosphate, Florida
The presence of carbonates in the form of dolomite
and calcite may cause downstream processing problems
and may reduce the quality of the end product.
They are primarily removed through the use of calcination
followed by slaking with water to remove the
CaO and MgO produced.
Iron minerals may be present in the form of magnetite,
hematite and goethite. These are typically
removed through scrubbing and size classification, or
magnetic separation.
Decantation of clarified water - Cargill Fertilizers Inc., USA