Mine dewatering is not a simple task. Many factors impact this application, and it is necessary to select the most appropriate pumping option to ensure efficient and reliable operation.
Assess the Application
When choosing a pump, sometimes a different approach is necessary. Each application’s requirements must be assessed to obtain a total dewatering solution, and each dewatering application is unique. Mine dewatering can happen underground or in opencast mine operations. Dewatering can be needed to remove excess water from the shaft bottom, at the working face and in the open pit itself.
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| Skid mounted pump installed on a barge in a coal mining operation |
Typical mining dewatering applications involve some solids, but abrasive and corrosive slurries would be handled differently. Inappropriate pump usage can lead to failures. In some instances, when pumps are installed in a series, a failure could have a catastrophic effect on the dewatering application and lead to flooding.
Another issue is that of load shedding and power losses. Diesel-driven dewatering pumps, although more expensive to operate, offer the security of being able to continue dewatering even when electrical power is not available.
A Submersible Solution
For efficient dewatering of the working face, a submersible pump would be used. This would feed to a shaft bottom settling dam, from which a pump, traditionally a multistage pump, would dewater to the surface. From the surface, the water is transferred, using either an end-suction or a horizontal split case pump to a reclaim dam. Factors—such as volume of water, required head and solids content in the water—play a role in pump selection. The mineral being mined in the application also dictate the pump and its materials of construction.
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| A dewatering pump moving granite-fines-laden water |
Positive Displacement Solutions
An effective alternative to multistage pumps in deep mine applications is a positive displacement pump. A hydraulically-driven diaphragm pump will raise both water and suspended solids to the reclaim dam on the surface in one single pumping stage, eliminating the need for underground settling ponds. In some cases A crankshaft-driven piston diaphragm pump will be selected which can also handle dirty mine water. Somepositive displacement pumps offer high pumping pressures up to 4,300 psi (9,500 feet of head) and solids handling capabilities and low operational costs.
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| Vertical turbine pump installation |
Other Solutions
In addition to submersible and positive displacement, other pumps and mounted or packaged pumps are available. Many of these pump units are capable of pumping against high head situations of pumping large quantities of solids and slurries, which are often encountered in mine dewatering applications.
- Centrifugal pumps
- Vertical turbine pumps
- Self-priming barge pumps
- Skid mounted, diesel-driven pumps
- Electric-driven pontoon pump units
Increased Demand
Dewatering pumps have always been important. However, the demand has increased including the need for more flexible solutions to meet a range of applications. With this increase, a need for ancillary products has also risen. Some of these parts are:
- Slurry valves
- Hydrocyclones
- Vibrating screens and screen media
- Mill liners
- Hoses
- Rubber linings
- High pressure grinding rolls
