Wood unveils sustainable mining study in Chile to transform acid water into reusable clean resource

Wood unveils sustainable mining study in Chile to transform acid water into reusable clean resource

(IN BRIEF) Wood has developed a conceptual study in northern Chile that demonstrates how acid-impacted water from copper mining could be reclaimed, treated, and returned to the environment to meet irrigation-grade standards. Using a multi-stage process of high-density sludge treatment, softening, and reverse osmosis, the approach transforms acid drainage into reusable clean water that can safely flow back into rivers and streams. This strategy reduces freshwater demand, restores local hydrology, and builds trust with communities, going beyond compliance to embrace a regenerative mindset. While still theoretical, the study presents a scalable framework for mining operations globally as they face increasing water scarcity and growing pressure to reduce environmental impact.

(PRESS RELEASE) ABERDEEN, 1-Oct-2025 — /EuropaWire/ — Wood has unveiled a conceptual study that demonstrates how mining operations in northern Chile could transform water management by reclaiming acid-impacted water and returning it safely to natural ecosystems. As global demand for critical minerals accelerates and water scarcity becomes increasingly urgent, the study underscores the potential of advanced treatment technologies to reduce freshwater dependency while supporting sustainable mining practices.

Northern Chile is the country’s mining hub, yet it is also one of the driest regions in the world. With copper production requiring large volumes of water for processes such as leaching, solvent extraction, electrowinning, and concentrators, declining ore grades have driven even greater water consumption per ton of product. While seawater and desalination technologies have been adopted to alleviate pressure on freshwater sources, these strategies do not fully address the scale of the challenge. Wood’s study proposes a circular approach that reclaims water already impacted by mining operations.

The conceptual study centres on a multi-stage treatment process that enables contacted acid water to meet Chile’s environmental standards (NCh 1333) for irrigation-grade reuse. The treatment stages include:

• High Density Sludge (HDS): neutralising acidic water with lime slurry to precipitate heavy metals and sulfates.
• Softening: removing excess calcium to improve downstream efficiency.
• Reverse Osmosis (RO): advanced filtration and pH adjustment to deliver clean, reusable water.

The outcome is high-quality water that can be reintroduced into rivers and streams, reducing mines’ net freshwater withdrawals, restoring natural flows, and creating environmental and social benefits for surrounding communities.

Wood emphasises that this approach is not just about regulatory compliance but about rethinking mining’s relationship with natural resources. By rebalancing local hydrology, supporting agriculture, and strengthening community trust, the study presents a model for regenerative mining practices that go beyond minimising harm to actively contributing to environmental restoration.

Although still at a conceptual stage, the study provides an adaptable framework that could be applied across regions facing similar water challenges. With climate change and resource scarcity intensifying pressure on industry, the ability to integrate advanced treatment technologies offers a way for mining to remain both economically viable and environmentally responsible.

As Chile positions itself at the forefront of sustainable mining, this study highlights how engineering innovation can help turn waste into a resource, protect fragile ecosystems, and set a precedent for responsible mineral production worldwide.

Media contacts:

Ariel Queirolo
Process Engineer
https://www.linkedin.com/in/ariel-queirolo-42a11a38/

César Pedrero
Process Engineer
https://www.linkedin.com/in/cesar-pedrero-lopez-b59785b5/

SOURCE: John Wood Group PLC