Rare earth elements power smartphones, wind turbines, and electric vehicles, yet producers struggle to extract them cleanly and cheaply.
U.S. researchers said on Friday that a new technique could unlock large supplies trapped inside coal mining waste. A team led by Northeastern University has developed a method that pulls rare earth elements, or REEs, from coal tailings.
The approach can achieve up to three times higher extraction efficiency than existing techniques. Coal tailings are the muddy leftovers of coal processing, made of ground rock, water, and residual coal particles. Additionally, operators store vast volumes of this waste in ponds and pits to prevent environmental contamination.
Most U.S. coal tailings eventually become filler in construction materials or end up dumped indefinitely. However, scientists estimate these landfills contain more than 600 kilotons of recoverable rare earth elements.
That amount could be extracted from roughly 1.5 billion tons of waste using improved processing methods. Consequently, coal tailings have emerged as an unconventional but promising domestic resource.
The new method relies on two tightly linked processing steps. First, researchers treat coal tailings with an alkaline solution while heating them using microwaves. Subsequently, the material undergoes nitric acid treatment to separate rare earth elements from surrounding rock. Additionally, laboratory tests showed the alkaline stage itself releases very little of the target material.
Instead, the pretreatment changes how rare earth elements bond within the mineral structure. Researchers explained that the alkali and microwave heating alter the solid matrix encasing the elements.
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Magnet metal recovered by process
As a result, the treated tailings become more porous and chemically accessible. Furthermore, the altered structure allows acid digestion to release far more rare earth material. Previous extraction attempts struggled because rare earth elements remain tightly locked inside clay minerals.
Consequently, many research efforts shifted toward alternative sources like hard rock mining or recycling. The Northeastern team found their combined approach weakens those mineral bonds without extreme temperatures. Meanwhile, microwave heating accelerates structural changes that would otherwise require lengthy processing.
Neodymium represents one of the elements the process can recover. Neodymium enables high-strength magnets used in electric vehicles, wind turbines, and computer drives. Additionally, demand for neodymium continues rising as energy systems electrify worldwide. Supply constraints have therefore raised concerns about long-term access to critical materials.
Despite promising efficiency gains, significant hurdles remain. However, the process remains expensive and may prove difficult to scale commercially. Coal tailings vary widely in mineral composition depending on their geological origin. Consequently, operators would need to fine-tune the process for each site. Pennsylvania alone holds an estimated two billion tons of coal tailings. Additionally, those deposits differ chemically across mining regions and coal seams.
The waste also contains other valuable elements beyond rare earths. For example, magnesium appears in many tailings and could improve project economics. However, extracting multiple elements simultaneously adds technical complexity. Researchers acknowledged that integrated recovery strategies remain under development.
The team emphasized that efficiency gains still matter amid surging global demand. Furthermore, domestic recovery could reduce reliance on foreign rare earth supply chains.
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Federal government taking steps to improve REE supply
Rare earth elements have become a growing flashpoint in global geopolitics as demand accelerates and supply chains tighten. These materials underpin electric vehicles, advanced weapons, renewable energy systems, and critical electronics.
China maintains a dominant position across rare earth mining, processing, and refining. Consequently, Beijing exerts significant leverage over downstream industries worldwide. China controls roughly 60 per cent of global rare earth production and nearly 90 per cent of processing capacity. Additionally, it has used export controls and licensing rules to signal its strategic advantage.
U.S. policymakers increasingly view that concentration as a national security risk. As a result, Washington has moved to diversify supply and rebuild domestic capability.
The federal government has begun directly backing selected mining and processing projects. Additionally, agencies have taken equity stakes and offered long-term procurement commitments. Programs like FAST-41 aim to accelerate permitting for strategically important resource projects. Meanwhile, defense and energy departments coordinate funding to reduce project financing risk.
One beneficiary is Perpetua Resources (NASDAQ: PPTA) (TSE: PPTA). The company’s Stibnite project in Idaho hosts both gold and antimony, a defense-critical mineral.
Antimony is essential for ammunition, flame retardants, and military electronics. Consequently, the U.S. government has identified Stibnite as strategically important. Another emerging player is Military Metals Corp (CNSX: MILI) (OTCMKTS: MILIF) (FRA: QN90). The company focuses on antimony and tin assets aligned with Western defense supply chains.
Meanwhile, NevGold Corp (CVE: NAU) (OTCMKTS: NAUFF) (FRA: 5E50) illustrates shifting exploration priorities. Although nominally a gold company, NevGold increasingly emphasizes antimony potential.
That pivot reflects broader recognition that strategic metals drive future valuations. Consequently, rare earths and allied materials now sit firmly at the center of economic security planning.
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