Federal, private, academic, and public sectors collaborate to find critical minerals through unexpected methods.

In the quest for a sustainable and secure supply of critical minerals, North America is turning to unconventional sources that promise to redefine the landscape of resource extraction.

As the drive toward a green economy intensifies, innovative methods are emerging to harvest essential minerals through atypical means. These efforts, bolstered by significant investments and collaborative ventures among allied nations, are paving the way for a resilient and environmentally responsible supply chain crucial for the technologies of tomorrow.

The importance of critical minerals in today's technology-driven world cannot be overstated. These essential elements, such as rare earths, lithium, cobalt, nickel, and many others, are integral to the production of clean energy technologies, advanced electronics, and military equipment, directly correlating to national defense in its most literal sense.

However, the traditional supply chains for these minerals are fraught with geopolitical risks, environmental concerns, and growing demand that outstrips supply. This has led to a heightened focus on alternative, unconventional sources that can provide a more stable and sustainable supply of critical minerals.

This approach is gaining attention due to its potential to diversify supply chains, mitigate the environmental impacts of traditional mining, provide incentives to clean up old sites, and – perhaps most critically – offer a workaround to the slow timelines associated with developing new conventional mines.

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Oil and gas wells produce wastewater that must be stored. DOE is funding research into recovering critical minerals from this waste while also creating clean water.

These sources include mining waste, coal ash, acid mine drainage, pyrite in shale, and byproducts of oil and gas production, to name a few.

Additionally, more exploratory sources such as deep-sea mining, marine-derived minerals, space mining, and phytomining are being investigated.

By tapping into these overlooked critical mineral sources, we can potentially reduce reliance on geopolitically sensitive regions, while simultaneously transforming environmental liabilities into economic opportunities. For instance, recovering rare earth elements from coal ash not only provides a new supply of these essential minerals but also helps in remediating long-standing environmental hazards.

The vast potential of unconventional sources remains largely untapped, presenting a unique opportunity to harness valuable minerals from materials previously deemed as waste. Among these sources, the waste from decades of mining stands out as particularly promising.

The potential of waste

Mining waste, which consists of tailings and other residues left over from the extraction of metals like aluminum, copper, and gold, contains small amounts of critical minerals that were previously considered uneconomical to recover.

Recent advancements in extraction technologies have made it feasible to reclaim these valuable elements from what was once disregarded. This process not only provides a new supply of essential minerals but also addresses environmental concerns by reducing the need for new mining operations and mitigating the impact of existing waste sites.

A prime example of this potential can be found in the vast quantities of tailings stored at mining sites around the world.

Tailings, the remnants of crushed ore after the extraction of valuable metals, are often stored in large containment facilities. These facilities hold an estimated four billion tons of material globally, which were previously viewed as a byproduct with little to no value.

Another promising unconventional source could come from coal waste. The United States produces approximately 129 million tons of coal ash annually, a byproduct of coal combustion in power plants.

Over more than a century of coal usage, at least 5 billion tons of residual waste strewn over 1,000 storage sites have accumulated across the country, with this ash being rich in rare earth elements at concentrations comparable to some natural ore deposits.

To capitalize on this abundant resource, the U.S. Department of Energy (DOE) has launched several initiatives to fund the recovery of rare earth elements from coal waste. In recent years, DOE has invested significant resources into research and development projects aimed at transforming this environmental liability into an economic opportunity.

These efforts include funding for pilot projects and advanced extraction technologies designed to efficiently recover critical minerals from coal ash. By leveraging these innovative approaches, DOE aims to establish a sustainable domestic supply chain for these essential materials, reducing reliance on foreign imports and supporting the clean energy transition.

In addition to coal waste, acid mine drainage (AMD) presents another promising unconventional source of critical minerals.

This environmental hazard arises when sulfide minerals in exposed rock react with water and air, forming sulfuric acid that leaches metals from the surrounding material. In the United States, AMD affects over 12,000 miles of streams and pollutes significant volumes of surface and groundwater. Of note, this can occur either naturally or from mining activities.

One of the technologies that may help mitigate the residual damages from AMD comes out of Penn State University through an innovative two-stage treatment process with the ability to recover up to 70% of rare earth elements from AMD while significantly reducing its environmental impact.

By injecting carbon dioxide into the drainage, the process produces carbonatites that facilitate the extraction of rare earth elements. This method not only recovers valuable minerals but also restores polluted water bodies, showcasing the dual benefits of environmental remediation and resource recovery.

Byproducts of oil and gas production present another unconventional source of critical minerals. This includes the vast amounts of wastewater generated during the extraction and processing of fossil fuels. Traditionally considered a pollutant, this wastewater contains significant concentrations of valuable minerals such as lithium, cobalt, and rare earth elements.

Similarly, recent investigations into shale formations have found them to contain significant lithium concentrations, particularly in pyrite minerals.

With the sword of Damocles hanging over the U.S. in the form of critical mineral shortages, innovation and necessity have driven efforts toward multiple facets to bolster supplies. This urgent need has spurred advancements in various areas, aiming to secure a stable and sustainable supply chain for these essential materials.

Research vanguard

To address the looming shortages of critical minerals, a diverse array of research institutions, universities, and initiatives have risen to the challenge, developing cutting-edge technologies and innovative methods for resource extraction and processing.

These collaborative efforts span the United States, leveraging the expertise and capabilities of academic and industrial partners to create sustainable and resilient supply chains.

Among these pioneers, Missouri University of Science and Technology (Missouri S&T) exemplifies the forefront of this movement with its groundbreaking work in critical mineral and sustainable technology research.

Among their initiatives is the extraction of gallium and germanium from copper waste streams, supported by an $875,000 grant from Rio Tinto.

This innovative chemical dissolution and purification method transforms waste into valuable resources, offering new sources of critical minerals while reducing the environmental impact of traditional mining.

Additionally, Missouri S&T has secured nearly $2 million in research grants, enabling a wide range of projects focused on sustainable resource extraction and advanced manufacturing.

Their collaborations also include a $7 million project with the U.S. Department of Defense (DOD) to develop a demonstration-scale hydrometallurgical plant for cobalt and nickel separation and partnerships with US Strategic Metals, LLC to advance lithium-ion battery precursor materials.

ioneer Ltd.

An outcrop of lithium-boron mineralized clay at ioneer's Rhyolite Ridge project in Nevada.

Continuing the trend of innovative research in critical mineral recovery, the University of Utah is also making notable advancements.

University of Utah researchers have focused on extracting rare earth elements (REEs) from unconventional sources, including coal and shale formations. Identifying high concentrations of REEs in coal-adjacent formations within the Uinta coal belt of Colorado and Utah, by analyzing samples from active and historic mines, the team has demonstrated the potential for these secondary resource streams to transform waste into valuable supplies of critical minerals.

These initiatives, part of DOE's Carbon Ore, Rare Earth and Critical Minerals (CORE-CM) project, are supported by substantial funding aimed at producing high-purity rare earth oxides, salts, metals, and other critical minerals from coal byproducts using advanced separation technologies.

This work not only enhances the domestic supply of essential minerals but also contributes to environmental remediation by leveraging waste materials.

Expanding beyond academic research, federal initiatives and private-public partnerships are also playing a crucial role in this endeavor.

The benefits of capitalization

DOE's CORE-CM project is focused on developing methods for extracting rare earth elements and other critical minerals from coal, coal byproducts, and other unconventional sources.

This program has also allocated substantial funding to support advanced research and pilot projects, committing millions to various institutions and private companies to advance this field.

For instance, some of the companies that have received grant money include Tetra Tech, Inc., a consulting and engineering services firm awarded $1.5 million to develop advanced separation technologies for coal byproducts, and Winner Water Services, Inc., which focuses on water treatment solutions, also secured $1.5 million to create technologies for recovering REEs from coal ash, preparing the ash for use in the concrete market.

To further bolster the development of unconventional sources of critical minerals, the U.S. DOD has leveraged the Defense Production Act (DPA), a law that grants the President powers to prioritize and allocate resources for national defense.

Through the DPA, the DOD has provided substantial support to domestic projects, including $7 million awarded to Doe Run Resources Corp. for developing a hydrometallurgical plant for cobalt and nickel separation in Missouri.

Beyond government initiatives, private sector companies and public-private partnerships are playing a crucial role in advancing the field of unconventional critical mineral sources –collaborations that are essential in driving technological advancements and ensuring a steady domestic supply of these vital materials.

One of the key players in this arena is US Strategic Metals, which has partnered with Missouri S&T to advance research on precursor cathode active material (pCAM) for lithium-ion batteries.

This collaboration aims to leverage Missouri's natural resources and the university's cutting-edge facilities to enhance domestic production of battery materials. Under the agreement, Strategic Metals provides training for Missouri S&T personnel and students on the use of state-of-the-art extraction facilities, facilitating the development of efficient recovery processes for critical elements such as cobalt and nickel.

Ramaco Resources Ltd. has been working on extracting rare earth elements from the Brook mine in Wyoming. The company, in partnership with the DOE's National Energy Technology Laboratory (NETL), discovered significant deposits of magnetic rare earth elements in coal seams.

This project not only provides a new source of critical minerals but also repurposes dormant coal mines, contributing to environmental remediation and economic revitalization in coal communities.

Another notable example is Phoenix Tailings Inc., a company dedicated to recovering critical minerals from mining byproducts, particularly tailings.

Using advanced metallurgical processes, Phoenix Tailings extracts valuable elements such as cobalt, nickel, and rare earths from the leftover slurry from mining operations. This approach not only provides a new source of these essential minerals but also mitigates the environmental impact associated with traditional mining waste.

ioneer Ltd.

An outcrop of lithium-boron mineralized clay at ioneer's Rhyolite Ridge project in Nevada.

Although closely related to mining, recent developments in seeking unconventional sources have led companies to explore alternative deposits, such as clay. One such company is ioneer Ltd., which focuses on extracting lithium and boron from lithium clay at their Rhyolite Ridge project in Nevada.

Partnering with Korea-based EcoPro Innovation, ioneer aims to commercialize this lithium clay into refined materials for the North American EV battery supply chain. EcoPro plans to build a commercial-scale refining plant to process the clay, significantly boosting domestic lithium production and sharing profits with ioneer.

While the list of companies, partnerships, programs, initiatives and the like could go on, all this highlights a great, ongoing movement to establish unconventional sources as future conventional ones. This endeavor not only works toward securing a stable supply of these resources, it can also be done here at home and in ways that benefit more than just economically.