The recent study “Coal Ash Resources and Potential for Rare Earth Element Production in the United States” reveals a novel approach to reduce foreign dependence on critical mineral supply. The source? Burned coal, its ash waste.

Coal ash, the byproduct of coal combustion in power plants, contains concentrated levels of rare earth elements (REEs), the critical components for renewable energy technologies, electric vehicles, and defense systems. The study says approximately 1.87 billion tons of potentially accessible coal ash have been dumped into U.S. landfills and storage facilities, with an estimated REE value of $8.4 billion.

This finding has interesting national security implications. The U.S. depends heavily on imports from China for REEs (e.g. from the DRC), creating an obvious vulnerability in supply chains for advanced technologies. The Department of Energy estimates that while conventional U.S. REE reserves are just 1.4 million tons, unconventional sources like coal could deliver another 11 million tons.

The study found REE concentrations vary significantly by source:

• Appalachian Basin coal ash contains the highest REE levels (median 431 mg/kg)
• Illinois Basin coal ash contains moderate levels (282 mg/kg)
• Powder River Basin coal ash has lower concentrations (264 mg/kg) but higher extraction efficiency (70% vs. 30%)

Beyond securing critical minerals, developing coal ash as an REE resource offers environmental benefits to these regions.

Coal ash contains contaminants like mercury, cadmium, and arsenic that threaten local water sources. REE extraction could be sold as a way to offset remediation costs for environmentally vulnerable ash impoundments. Finally a reason to have clean water!

As the U.S. transitions towards more modern ethical energy sources, the strategic development of its massive waste sites full of toxic coal ash resources presents a dual opportunity: strengthening national security through domestic REE production while addressing obvious environmental and health dangers from coal power generation.

This research highlights how garbage in can mean treasure out. A little more health regulation might have helped make the discovery sooner. Innovative approaches, forced by necessity, can transform “garbage” into strategic resources, enhancing health, economic and national security.