Dewatering, as the name suggests, is removing water from construction, utility and especially mining sites. Mine dewatering is an essential part of resource extraction, as it lowers the water table around the mine or quarry.
Mine dewatering is usually undertaken for several reasons but following are the main two reasons.
Ensure stability of mine walls during and after excavation
In open-pit mines, a water table that is too high can destabilize mine walls, haulage roads, and slopes. Water pressure reduces the stability of mine walls and can lead to sliding and collapse of materials in the slope. In underground mines, the inflow of water must be controlled to prevent flooding, however, a balance must be maintained so that groundwater levels are not needlessly depleted.
Optimise mine production and reduce operational costs
Effective dewatering operations create dry conditions so that low-strength aquifer sequence materials (sands, gravel, and clays) can be safely excavated, reducing drilling and blasting costs. Additionally, wear and corrosion on equipment is minimized, and the possibility of pump burn out is reduced by accurately monitoring drawdown.
One of the best dewatering methods is by deep wells. A deep well typically consists of a borehole fitted with a slotted liner and an electric submersible pump. Water will then be pumped from the deep well till there is little or no water remaining.
Recently, All Pumps was approached to manufacture a turnkey solution for a mining site’s dewatering project. The aim of this project is to allow the mine operations to mine lower into the ground.
Complete dewatering package with 4 x 45kw bore pumps
We supplied a complete dewatering package with 4 x 45kw bore pumps, head works, and generators. The borehole pumps are running off VSD headworks units and a control panel was also provided to allow them to vary pump pressure as the aquifer drops. The bore pumps are set at 150m down and doing 15 – 20 litres per second.