No coal ash is the same. The composition varies depending on where the coal was mined and how it was processed, burned and disposed of. ...

Some screens deal with the composition of ash in coal, biomass or waste coal. The ash properties are: • SiO2: The percent by weight of silicon dioxide in the ash. • Al2O3: The percent by weight of ...

When Xcel Energy stopped burning coal at its Valmont Power Station in 2017, it left 1.6 million tons of toxic coal ash on the ...

According to the new study, the chemical composition of the spherules most closely resembled contaminating coal ash from human industrial practices—not alien construction materials or even a ...

Not all coal ash is created equal. The study highlights how regional variations in coal composition affect the concentration and extractability of rare earth elements.

China has pulled back its rare earths exports, which are vital to everyday technologies and American defense. But the U.S.

Millions of tons of coal ash leftover from burning the planet’s dirtiest fossil fuel sit in ponds and landfills across the US. But this waste may also be a treasure trove for the rare earth ...

Utilities, including Duke Energy, seek EPA rollbacks on coal ash cleanup and emissions rules. Advocates warn it risks public health, especially in North Carolina communities already exposed to ...

Coal ash ponds that are no longer being used — sometimes called "legacy ponds" — were originally exempt from Obama-era coal ash rules. That means some of them don't have caps or liners.

Millions of tons of coal ash leftover from burning the planet’s dirtiest fossil fuel sit in ponds and landfills across the US. But this waste may also be a treasure trove for the rare earth ...