Khaberni - American researchers have revealed that coal plant waste in the United States may contain an estimated billions of dollars' worth of rare earth elements, which could be a vital local source of these strategic materials without relying on imports or costly mining operations.
In a study published in 2024, a group of geologists estimated that the ash produced by burning coal in American power plants since the 1950s could contain rare earth elements worth a total of 165 billion dollars, of which about 97 billion dollars could be practically extracted.
The researchers, led by scientists from the University of Texas at Austin, describe this process as a perfect example of "from trash to treasure," as it allows for the conversion of waste into resources while reducing environmental impacts.
Rare earth elements, which include 17 elements such as lanthanides, yttrium, and scandium, are classified as "critical minerals" in the United States. They are used in the manufacture of batteries, electric vehicles, smartphones, and wind turbines, according to the sciencealert website.
The United States currently depends on imports for these elements, with about 70% coming from China, but the new study indicates that 52 billion tons of coal ash produced in the country could provide an important local source for these minerals.
The researchers explain that coal, being a plant fossilized over millions of years, contains trace amounts of other minerals, but burning coal leaves behind ash in which concentrations of rare earth elements are multiplied by 4 to 10 times compared to the original coal. Although the concentrations are not on par with commercial ore levels, extracting them from the ash is economically viable because it requires no new mining.
Estimates by the team suggest that 11 million tons of rare earth elements could exist in ash deposits available between 1985 and 2021, which is nearly eight times the current reserves of the United States.
The total theoretical value of the 15 lanthanide elements in American ash is about 56 billion dollars, and can reach a total extractable value of 97 billion dollars when yttrium and scandium are added.
These figures are theoretical so far as extraction methods are still being researched, yet the findings have attracted the attention of both the American government and scientists alike.
The researchers indicate that developing these resources could boost the country's energy and economic security and help fund the remediation of sensitive environmental waste sites.
Scientists are also exploring other sources for rare earth elements, including volcanoes and plants capable of extracting minerals from the soil.
The researchers describe these methods as "green strategies" that could provide sustainable supplies of these vital resources.
This research comes at a time when global markets are facing environmental and geopolitical challenges that threaten the stability of rare earth element supplies, making every local opportunity for these materials of utmost strategic importance.
