Scamont Engineering has been servicing the deepest mines in South Africa for over 40 years. Eight of the ten deepest underground mines in the world are situated in South Africa!
Most of the mines mentioned in Figure 1 utilize a conventional underground dewatering system. In these conventional systems all the dirty water from the mining operations, as well as the fissure water, transfers down to the shaft bottom where the underground settlers (sometimes referred to as clarifiers) are situated.
Before the dirty water reaches the settlers, it is pre-conditioned in two ways:
- The grit (typically consisting of particle sizes ranging upwards of 500 µm) is removed to ensure that it does not cause blockages downstream.
- Hydrated lime is dosed to correct the pH, to ensure the water remains pH neutral, thus preventing corrosion.
Once the water is preconditioned in this manner it is ready to be clarified in the settler. In the settler solids are separated from the water by means of gravity. The process is assisted by dosing various flocculants and coagulants, which agglomerates the finer particles so that they are able settle out easier.
The overflow from the settler, known as “clear water,” reports to the clear water dam/s, and the underflow from the settler, known as “mud,” reports to the agitated mud dam/s.
The clear water can now be re-used underground for mine service water (MSW) or pumped to surface to be used in the process plant. If there is excess water, it is typically discharged into the environment if it meets the environmental discharge limits. Some mines treat the excess water to potable standards, which can then be used in the hostels, offices and for chemical make-up in the processing plant.
Due to the depth that some of these underground mines need to go to reach the reef, the dewatering pumps are required to operate at high pressures, while ensuring the power input is kept to within the mine’s requirements. It is therefore imperative that the pumps selected for the system can operate at a high efficiency, and more importantly can maintain that efficiency over the lifespan of the pump.
For this reason, the pumps, and services we offer our customers include:
Multistage clear water pumps:
Positive displacement mud pumps:
Services:
References:
Mining Review Africa (2018), https://www.miningreview.com/top-stories/deepest-mines-world-south-africa-canada/
