The crucial role of integrated water management in the global energy transition

Critical minerals are at the heart of the global energy transition – and their demand is surging like never before. By 2040, demand is expected to increase fivefold for lithium, 50-60% for cobalt and other rare earth elements, and 30% for copper. As these minerals power new, sustainable technologies, mining practices will also have to adapt.

This starts with water, specifically, water management.

Mining is highly water-intensive. From groundwater and stormwater to materials processing and discharge, water shapes nearly every step of the mining process. In the U.S. alone, mining is responsible for 4 billion gal./d of water withdrawals.

While that represents just 1% of the national total, mine water may contain toxic metals that are often handled in sensitive environments. Increasingly, concerns by local communities, alongside climate-induced drought and flooding, have made water management even more critical to mining – and, ultimately, the energy transition itself.

The latest sustainable water management practices fall under two approaches: treatment with discharge to the environment; and treatment with reuse. Though interrelated, improvements to these pillars of water management not only improve environmental outcomes. They can also drive cost efficiencies and more effective resource extraction.

Mine water treatment is already an essential practice industry-wide. For decades, environmental regulations have required mining operations to treat and manage wastewater generated onsite. Yet as policymakers and communities grapple with legacies of contamination, environmental compliance requirements have grown more stringent and treatment more costly and time-intensive. In response, many mine operators have turned to new treatment methods.

Chemical and biological approaches can augment traditional counterparts to help streamline the treatment process. Passive water treatment systems can include the use of microorganisms to transform wastes to reduce toxicity or chemical processes to minimise the solubility of materials. Advancements in these methods could significantly reduce the cost of treatment solutions in the future.

Another approach to streamlining treatment is to limit wastewater discharge to the environment entirely. Due to rainwater accumulation and groundwater influence, mines require sophisticated drainage infrastructure. While that poses complex technical challenges, it also presents opportunities – particularly in surface water management, where long-term strategies are needed.

The latest management practices have deployed new approaches, like diverting stormwater away from the mine to minimise contamination, installing engineered cover systems to reduce infiltration, and subsurface barriers to prevent groundwater contamination. In some cases tailings water can no longer be released to the environment, leading mine operators to consider dry stack methods for tailings management.

Climate change has also motivated new management practices. For instance, permafrost loss has increased groundwater intrusion in mines within or near arctic regions. This seemingly intractable challenge has led to an unlikely solution: re-freezing permafrost by installing well points with circulating coolants. Though still a nascent technology, it’s rapidly becoming cost-effective due to strict compliance requirements in sensitive locations.

Most innovation, however, has focused on water efficiency and reuse. Commonly, reuse entails employing the same water multiple times for various uses, with higher-quality water used for separation and extraction of minerals, and lower-quality water used for housekeeping and maintenance. These processes require various levels of water quality, making reuse feasible with minimal onsite treatment.

Across mine operations, water reuse offers tangible economic advantages, particularly in arid sites where water is scarce. Yet, even in regions with abundant water, reuse can reduce treatment requirement costs while also helping mitigate local impacts by minimising discharges.

Waste materials from which minerals have already been extracted also present an opportunity for reuse. Thanks to inventive chemical and mechanical processes, tailings have become a new frontier for mineral extraction. Increasingly, mine operators are recovering rare-earth minerals, like lithium, nickel, and cobalt, from tailings that would have otherwise been considered waste.

Even relatively cheap waste materials can find new life, with iron ore capable of being repurposed for uses like ink production. In addition to maximising resource extraction, reuse can also mitigate environmental and financial risks, capturing hazardous materials that pose contamination threats.

Water management has always been central to mining. Now, the energy transition has made it paramount. As minerals like lithium, cobalt and nickel have become increasingly prized, so too has the water used to mine and process them. For the mining industry to meet the objectives of the energy transition, it will not only need to extract more, but do so more safely, efficiently and sustainably. Integrated water management and reuse will be at the centre of this effort.

Read the article online at: https://www.globalminingreview.com/environment-sustainability/15092025/the-crucial-role-of-integrated-water-management-in-the-global-energy-transition/