Civilization as we know it wouldnโt exist without rare earth elements. No smartphones, LEDs, wind turbines, or even car batteries. REEs, such as cerium and scandium, are scattered throughout the earthโs crust. China alone produces nearly 90ย ยญpercent of the worldโs supply, and the U.S.โs only mine closed this year. But researchers could help break that monopoly with something we already have in ยญabundance: coal and its byproducts.
โEverything thatโs in the earthโs crust is also present within the coal,โ explains Evan Granite, a chemical engineer at the U.S. Department of Energy. The DOE recently funded a wave of research to boost U.S. REE production to cope with demand, which is rising about 5 percent every year. Each step of coal productionโmining, cleaning, and burningโcreates REE-enriched material. The goal is to use that waste, now sitting in landfills and storage ponds, in a way thatโs cheap and environmentally friendly.
U.S. coal-fired power plants, for example, produce 130 million tons of coal ash each year. A ยญrecent study from Duke University identified billions of dollars worth of REEs within coal burned from coal mined in the Appalachian Mountains and Wyomingโs Powder River Basin. The challenge now is extracting the metals, says Sarma Pisupati, a professor of energy and mineral engineering at ยญPennsylvania State University. His research focuses on rinsing raw shale with an ยญammonium-sulfate solvent to collect REEs early in the coal-production process.
Within a few years, DOE-funded projects will enter pilot testing at U.S. ยญcoal-processing facilities. Perhaps locally sourced smartphones wonโt be far behind.

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