Management of water resources is a significant issue within the mining industry. To manage water resources and create an effective water management strategy, mining operators know that identifying what water is required and available is key.

While it may seem rudimentary to determine the quantity and quality of water needs and availability, this knowledge is fundamental to the development and understanding of a mine’s water management system.

What Water Is Needed?

Operators must determine water uses and quantities to fully understand actual water needs. Demands for water within a mining operation will vary from system to system and may include water for:

  • Cooling
  • Dust control
  • Flotation operations
  • Human consumption
  • Steam production

The insight gained on what water is needed should be coupled with water quality requirements for each of the systems.

Potable water will have different requirements than other uses. The quantity of the water required for cooling may vary depending upon the constituents in the water. Pretreatment for steam production will vary depending on the quality of the makeup water and the feedwater conditions for the boilers. Water used for dust control may have environmental requirements that need to be considered. All of these applications dictate water quality demands.

What Water Is Available?

Typical plant makeup water may come from local wells, rivers or lakes. Due to increasing constraints on freshwater resources, mining operations are beginning to look at other sources of water that may be available. For example, one source being used for Chilean copper mines is seawater. In this case, the salt water is desalinated, much like drinking water in other parts of the world, and transported to mines many miles away.

Some operations may opt to drill wells to produce their own potable and service water to relieve the demand from the local municipality. Well water, however, will likely require some form of filtration, as well as chlorination, to meet potable water requirements.

Other mining operations are exploring the treatment of wastewater streams, including those sourced from local sanitary systems, to make this water source suitable and available for use. Water sources may also be available from tailing ponds or discharges from other mining systems.

Regardless of the source, the potential quality of all water needs to be determined. Most available water will not be of a quality that can be used directly but will, instead, require additional water treatment to make it a viable source. For example, grey water — or treated sanitary waste — may be reused as cooling water and boiler makeup, but will need additional treatment to reduce suspended solids, phosphates, ammonia and more.

Understanding and assessing water requirements and sources for mining facilities is critical as operators work toward water management strategies that avoid detrimental business impacts.

 

Learn more about sound water management strategies that can help maximize mining operation efficiencies.

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Dennis McBride is an associate process consultant at Burns & McDonnell, specializing in water and wastewater treatment. His experience spans the power, semiconductor, mining and metal, and oil and chemicals industries with design and operations for pretreatment systems, demineralization, wastewater treatment and water conservation, including zero liquid discharge.