Multidisciplinary Approach to Water Usage Efficiency in Mines

on, maximising re-use and recycle and extending the lifecycle of mine water. These solutions require environmental planning.

Water makes up a small but vital part of a mine’s operations. Adding more water helps create substantially more lucrative output than the additional water’s cost. According to Chetan Mistry, Strategy and Marketing Manager at Xylem Africa, water is ever present in mines. Mines are either removing water or using water to manage the site such as reduce dust, combat fires or move slurry or tailings.

Water consumption and planning don’t command as much attention as other parts of a mine’s complicated operations. However, this scenario is fast changing, strained resources are making it harder for mines to secure more water sources. With water being a scarce commodity all industries especially the mining sector must look at how to conserve and optimally use this resource.

It is thus essential to improve the current level of water use efficiency and to implement Water Conservation and Water Demand Management (WC/WDM) measures as a vital aspect of norms and codes of good practice in water management by all sectors.’

Several initiatives, driven mostly by the International Council on Mining and Metals (ICMM), such as the raw water savings targets, have been designed to focus on understanding the fundamentals of water. For instance, what makes clean water, what is dirty water, and where the water usage is highest. At the core of these is the need to have a proper inside-out monitoring programme in place. This must be capable of drawing data and highlighting the engineering of the right solutions to accomplish these goals. Solutions such as the building of new pumps and dams or improving targeted water treatment for reuse in the optimal application.

Furthermore, much of the process of effective water stewardship links to the lifecycle of water within the mine. The development of any mine is dependent on having access to water resources. Part of this is permitting extraction and discharges from the facility into the surrounding environment.

Water Recycling and Re-use

Of course, water has an intrinsic value to it, and every person has the right to access clean water as well. This is where catchment studies come into play, by looking at the broader picture of society, water needs, and water access. Innovative solutions around water stewardship therefore must focus

Other innovative solutions include building treatment plants. Key plant processes within the water and wastewater operations can now be digitised, which can generate 20-40% in cost savings. This is good news, especially for an industry under pressure to both lower operating expenditure (OpEx) and manage an aging workforce. Unfortunately, active treatment plans are expensive and energy intensive, giving rise to other concerns. This has seen preference given to passive and semipassive treatments, as these reduce the load discharged into the rivers. Passive and semi-passive treatments are defined as treatments that use no or few chemicals and mechanical equipment, making the process more economical and less environmentally harmful.

The use of passive or semi passive treatments, particularly for mine closing, fits well with the lifecycle of mine water approach to water stewardship as it allows water to become a functional resource in another sector.

The benefits of becoming water stewards include greater operational sustainability and efficiency, and better relationships with communities and governments. They become more attractive to investors who link water stewardship with future-minded mining operations.

By leveraging AI, mines can reuse water intelligently for specific processes such as minimising water intake, tailing storage, and effluent discharge volumes; thus hugely reducing overall consumption. Improvements in using water to transport waste, extracting water from tailings ponds, and capturing water at seepage spots, also deliver significant savings.

By using modern modular water treatment systems, mines can recycle and reintroduce clean water for various objectives. Recycled water can support on-site personnel, supply local communities, be safely reintroduced into the environment, or store for later use.

Many of these interventions are not new. But modern improvements in engineering, materials and technologies provide mines with more choice.