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What Is Mine Dewatering And Why Is It Important?

The success of a mining site is dependent on a suitable and adequate pump for water removal.

What Is Mine Dewatering?

Dewatering relates to the process of removing ground or surface water from a mine site. By lowering the water table, mining companies can ensure mining operations continue efficiently and to a safe standard.

In mining applications, dewatering is an ongoing process and is crucial in accessing targeted underground minerals like iron ore. Water is often an impediment for excavation activities, and if the water table is not controlled can have significant negative impacts on the project. Uncontrolled water in a mine site not only compromises the safety of the workers, but also the economic viability of the mine.

What Is A Mine Dewatering Pump?

Mine dewatering pumps are a type of specialised pumps installed below the groundwater level, which helps to reduce water levels initially and then maintain the desired level.

By ensuring a suitable dewatering solution is installed on site, mining companies can experience substantial cost savings. With dewatering pump systems, less explosives are required to clear areas, ore and waste materials are easier to transport due to being dry, improved working conditions and greater structural integrity of the mining areas are achieved.

What Are The Benefits of Mine Dewatering?

Implementing dewatering processes is highly necessary and beneficial for a majority of mine sites and applications across Western Australia.

Reduction of Down Time

By controlling water levels, mining organisations are proactive in preventing flooding, which aids in reducing the amount of downtime experienced on a project. Dewatering assists in creating more efficient working conditions for mine operators on site, which in turn leads to faster project completions.

Increasing Overall Site Safety

Effective control of excessive groundwater helps to guarantee both the stability and safety of the mine site throughout the mining process, as well as underground activities.

Reduced Haulage Costs

Reduced process water content in both the various types of mined resources and waste materials helps to reduce transportation costs away from the site due to the decreased weight from water removal.

Reduced Blasting Costs

Utilising a dewatering pump to lower groundwater levels ahead of blasting procedures is highly beneficial and cost effective. When the water level is reduced, dry holes are formed which do not require expensive emulsion explosives.

Improved Overall Mine Production & Potential Mine Life

The dewatering techniques used during a mining operation are critical to its success and progression. This is due to the vulnerability of the site if soils and exposed rock absorb large amounts of water, essentially making the site unsafe. Many mine sites have been abandoned in the past due to poor groundwater management and flooding.

What Should Be Considered When Selecting A Dewatering Pump?

The selection of a suitable dewatering pump is paramount for success. A pump that is too small, or an insufficient number of pumps, can lead to flooding of the site, which leads to significant maintenance costs, lost equipment and operational time.

Static Head Requirements

To achieve the required flow, the dewatering pump needs to produce enough pressure to overcome the vertical distance the water must travel. This is known as the static head, and it must be determined as with any pump.

Flow Rate

The flow rate required to properly remove the water from the mine site must be determined. During this stage the style of pump required for the application should be considered. If a self-priming pump is selected, then the length of the suction line must be defined. The size of the suction line should be equal to, or greater than, the size of the inlet port, helping to reduce the possibility of suction cavitation which causes significant wear on the pump.

Capabilities Of The Pumping System

Due to the nature of dewatering pumping activities, pump efficiency can be altered. As pressures change due to wear and tear, or alternative factors, the performance of the pump can move away from its best efficiency point (BEP).

Dewatering pumps that are too small can often lead to flooding or a loss of critical equipment at the site. If pumps are too large, this can lead to a burn out of the pump motor due to insufficient cooling time between starts. In these instances is often where suction cavitation of the pump can occur, due to the pump ‘starving’ for water.

Dewatering For Different Mine Types

The dewatering method can look different depending on a particular operation’s mine type. Here we take a look at the differences in water management procedures for both underground and open pit mines.

Underground Mines

Underground mines require the removal of sediment-laden water and abrasive fluids. Stable walls of the underground mines allow the water to be pumped from the bottom, utilising selected pumps. Unstable walls and permeating water can reduce productivity of the mine, unless there are solid dewatering systems in place.

Peripheral water wells can increase the stability of mine walls by controlling the water seepage. This dewatering method eliminates or limits water in some mine galleries, with drainage of the galleries highly-cost effective.

Open Pit Mines

One method used for dewatering open pits is to pump water from the lowest levels of the mine. However, this is generally not enough on its own – The groundwater table around the mine area needs to be lowered to ensure the pit doesn’t continually fill up with water.

Generally speaking, the deeper the mine, the more water that will be encountered. A dewatering plan should anticipate extracting additional volumes to maintain a workable mining operation. The simplest solutions is to ensure the perimeter of the mine has suitable wellpoint dewatering systems, aiding in keeping the groundwater levels low.

How Can Prestige Universal Mining Pumps Help?

With over 40 years of mining industry experience, Prestige Universal Mining Pumps are best equipped to help you find a pump solution that suits your sites requirements. Our extensive range of pumps are offered at competitive rates, and our knowledgeable team can use their experience to find a suitable pump to hire for your project.

As a leading manufacturer of dewatering pumps and related equipment, Prestige Universal Mining Pumps take great pride in assisting clients by providing suitable dewatering solutions. We will work with you to identify your site needs and determine the most efficient dewatering equipment that aligns with your operations plan. Get in touch with us today!