As demand for critical minerals rapidly increases to power the energy transition, data centres, key infrastructure, and economic growth, current extraction and processing methods present notable economic and environmental concerns for the mining industry. The mining industry is also contending with converging challenges including an increasing emphasis on domestically-supplied minerals, decline of ore quality, and liabilities from mine waste.
At the same time, current mining operations are failing to capitalise on by-product recovery that could bolster domestic supply chains. Critical mineral mining operations are also incredibly water intensive. Large volumes of water required for the beneficiation process ultimately becomes wastewater rich in diverse minerals. Today’s methods are incapable of recovering both these valuable by-products and the massive volumes of water, all of which simply accumulates in large waste ponds. As mining operations seek viable mineral and water recovery technologies and processes to meet growing demand while keeping operational risks low, investment in these technologies will significantly improve resource efficiency and mitigate risks across global mining supply chains this decade and beyond.
Understanding the challenge at hand
With significant amounts of water required to mine copper, nickel, cobalt, rare earth elements (REEs), and other critical minerals needed to support energy security and critical infrastructure, mining and mineral recovery account for some of the highest freshwater withdrawals in the industrial sector. To add to the challenge, high productivity mining regions are often located in areas with water scarcity, with at least 16% of the world’s critical mineral mines, deposits, and districts located in areas facing high or extremely high levels of water stress. This number is projected to increase to 20% by 2050. Large quantities of water withdrawal can deplete nearby surface and groundwater supplies, such as at sites like Chile’s Salar de Atacama, where lithium and copper extraction have consumed over 65% of local water supply.
In addition to scarce water supply, today’s mining operations must also grapple with vast and accumulating quantities of tailings water. It is estimated that mining generates 13 billion square tonnes of tailings each year globally and water accounts for a significant portion of this output. Further, waste management failures and accidents can cause environmental devastation, human health impacts, and even casualties, with dams containing extractive waste having a failure rate significantly higher than water supply reservoir dams. In many countries and regions, regulators are already tightening discharge limits and reuse requirements due to the significant risks posed to both mining operations and local communities and ecosystems near the mines.
Despite the immense value of critical minerals in mine tailings and wastewater, these resources are not often recovered. Wastewater streams are ultra-complex and large-volume, while the critical minerals they contain can often be dilute relative to primary mining streams and leachates. No incumbent technology is capable of recovering critical minerals from such streams in an economically viable manner.
Without efficient and cost-effective technologies that unlock both wastewater treatment and reuse as well as effective critical mineral recovery, a high percentage of the water consumed by mining operations will continue to accumulate as mineral-laden wastewater. Mines must scale improved methods of water reuse and mineral recovery that support the growth of domestic and global mineral supply chains while mitigating water and waste management risks.
Enabling efficiency in recovery and resource use to mitigate risks
While current mining operations are forced to contend with significant risks and liabilities, waste streams also contain trillions of dollars worth of valuable minerals and materials globally. As waste accumulates and poses greater threats to operations and nearby communities, there is also an opportunity to turn these liabilities into assets.
As technologies emerge that enable the simultaneous valorisation and remediation of complex, acidic waste streams, raw waste water can be fed directly into processing systems that recover materials with significantly reduced water input compared to standard methods. In many cases, critical minerals are available for the taking in existing wastewater with no further processing. By recovering them and delivering clean water for reuse, mines can offset their freshwater consumption. This also mitigates financial and regulatory compliance risks associated with clean up efforts. Producing high-purity, market-ready critical minerals that were previously going unrecovered in waste streams can offset remediation costs and, in some cases, establish new revenue sources for mining operations.
As these technologies continue to be tested and validated at global mine sites, solutions can be integrated into existing operations and represent a scalable, affordable solution to increase output and reduce operational risks. By investing in these technologies, we can boost resource efficiency and lessen risks across the world’s mining supply chains.
Author bio
Brendan Smith is the Co-Founder & CEO of SiTration, Inc., an advanced materials startup that aims to drastically reduce cost and resource consumption of critical minerals’ recovery on a global scale. Spun out of MIT in 2020, the company is developing their core technologies, ultra-durable silicon electro-extraction and membrane filtration, to impact the mining, refining, and recycling verticals. Brendan earned a Ph.D. in materials science & engineering from MIT and a B.S. in nanotechnology engineering from the University of Waterloo, and is motivated by working with passionate teams to develop better solutions to big challenges.