From the Ashes: Coal Ash May Offer Rich Source of Rare Earth Elements
1 min read
Summary
Researchers from the University of Texas have estimated that 5 gigatonnes of coal ash produced in the US between 1950 and 2021 could be worth as much as $8.4bn in rare earth elements (REEs).
Although around 70% of this coal ash is accessible in landfills, the remainder is locked away in materials like concrete.
REE concentration in ash waste ranges from 264 mg/kg for Powder River coal to 431 mg/kg for coal from the Appalachian Basin.
Methods such as physical beneficiation and hydrometallurgical processes including acid leaching and ion exchange could be used to recover REEs at an industrial scale.
However, there are likely to be technical and regulatory hurdles to be overcome, including concerns about the environmental impact of disturbing long-ignored ash piles.
