Effective dewatering management as part of the mining process

Posted in Borehole Pumps on Feb 17, 2020

Dewatering and groundwater control is an important part of many open pit and underground mines. Dewatering should therefore form an integral part of water management at a mine.

In addition to groundwater management, it is also necessary to control the surface water. This is usually done by diverting as much surface water runoff away from the pit as possible and by pumping away the water that accumulates in the pit. 

WHAT ARE THE BENEFITS OF MINE DEWATERING? 

Where a mine dewatering schedule is put in place. Typically the mine will see several benefits, including the following: 

  • Overall improvement in working conditions and efficiency: improved trafficking and diggability, decreased pit flooding downtime.

  • Enhanced slope stability and protection: lowering groundwater levels and reducing pore water pressures can allow the use of steeper open pit slope angles, while retaining or increasing safety factors.

  • Reduced costs of blasting: dropping groundwater levels in advance of working will provide dry blast holes, reducing the need for more costly emulsion explosives.

  • Reduction in suction costs: Dry ore and waste rock weigh less than wet material, so dewatering of rock provides a suction cost saving.

  • Mine dewatering costs money, and the significant capital spending on dewatering almost always occurs early in the project during pre-production or ramp up of production. It is important that at an early stage the objectives and potential benefits for the mine in question are clearly identified. This will ensure that the most cost-effective dewatering solution can be implemented in combination with the mine plan. There may be reasons to delay the installation of certain dewatering elements in order to reduce cash flow, but it may also be a false economy to delay dewatering works until the last minute, if unforeseen geological conditions cause delays or reveal new hydrogeological problems.

WHAT DO YOU NEED TO KEEP IN MIND WHEN YOU CHOOSE A MINE DEWATERING PUMP?

A quality mine dewatering game plan requires high-quality dewatering pumps. Consider a typical application of mining in which water flowing into an underground mine may be collected in sumps from which it can be pumped to the surface. Ultimately this system pumps dirty water. Restricting the flow into the mine is not considered here, so the dirty water must be pumped constantly, except a certain surge capability within the sump system. This method prevents having dry areas near to the mine's edges, therefore affecting the efficiency and mining procedure.

ELSUMO’S RBP RANGE FOR YOUR DEWATERING NEEDS

When your aim is to drop the water table at your site, we highly recommend our fully stainless steel RBP pumps. 

RBP PRODUCT FEATURES:

  • Operating conditions:
  • Max working pressure: 38 bar
  • pH: 6.5 - 8.5
  • Max submersible depth: ≤70m

For the sake of the pump running safely and reliably, users must install the correct motor protection.

Mining below groundwater level poses many challenges which may lead to higher mining costs and lower performance. If a good hydrogeological characterization program is in place and the methods of dewatering and depressurization are carefully selected, safe and efficient mines can be constructed to great depths underneath the water table.

Elsumo provides mining water management solutions for open pit and underground mining. In addition to solar-powered pumps, Elsumo is one of Southern Africa’s leading service providers, suppliers and distributors of comprehensively tested, high-quality borehole, booster, drainage and sewage pumps. To learn more about our extensive range of RBP's, click on the following link: https://www.elsumo.co/products/borehole