As global demand for critical minerals continues to rise, the mining industry faces a pivotal challenge: how to scale responsibly in a world where environmental sustainability is imperative.
At Wood, we believe that the future of mining lies partly in rethinking how we manage water, one of our most precious resources. In northern Chile, where most of the country’s mining activity is concentrated, water scarcity is a daily reality. This has driven us to explore innovative solutions that reduce freshwater consumption and restore balance back to local ecosystems.
A recent conceptual study conducted around a copper project for a mining company in the north of Chile presents a transformative approach to water stewardship, one that turns contacted acid water from mining operations into a resource that can be safely returned to nature.
The Challenge: Increasing water demand with limited supply
Modern mining beneficiation plants are increasingly water intensive, particularly due to leaching, solvent extraction, electrowinning and the concentrators. As ore grades decline and throughput increases, water consumption per ton of product has amplified. In Chile’s dry north, this poses a serious challenge.
While mining companies have made improvements by adopting seawater and desalination technologies, these solutions only address part of the problem. The next step is reclaiming and reintegrating water impacted by mining.
The Solution: Treating contacted water for environmental reuse
Our proposed solution involves a multi-stage treatment process designed to purify acid drainage water to meet Chilean environmental standards, specifically NCh 1333 for irrigation-grade water. The process includes:
- High Density Sludge (HDS): Neutralises acidic water using lime slurry, precipitating heavy metals and sulfates as solid waste.
- Softening: Removes excess calcium to prevent scaling and improve downstream efficiency.
- Reverse Osmosis (RO): Employs advanced filtration and pH adjustment to produce clean, reusable water.
The result is clean water that can be safely returned to rivers and streams, helping to restore natural flows and reduce the mine’s net freshwater consumption.
This approach goes beyond regulatory compliance. It reflects a regenerative mindset, one that seeks to minimise harm and to restore and enhance natural systems. By returning treated water to rivers and streams, mining companies can help rebalance local hydrology, support agriculture, and build trust with surrounding communities.
The Future: Leading with sustainable mining solutions
The mining industry is at a turning point in how it manages water. By investing in advanced treatment technologies and adopting circular water strategies, mining operations can move towards sustainable growth.
Although the conceptual study is theoretical and requires further validation, it offers a strong and adaptable framework for future implementation. As water scarcity intensifies, especially in regions with competing agricultural needs, solutions like this will be essential to balancing industrial development with environmental responsibility.
The mining industry has challenges ahead. With pressure to reduce its environmental footprint, the integration of advanced water treatment technologies offers a path forward. Our conceptual study is a compelling example of how engineering ingenuity can align with sustainability goals, ensuring that mining remains both economically viable and environmentally responsible.
As global industries grapple with climate change and resource scarcity, Chile’s approach to water management in mining could serve as a model for other nations. By turning waste into a resource, the sector is protecting the environment and securing its own future.