October 2, 2017 - Research at the National Energy Technology Laboratory (NETL) could lead to more reasons to dig up coal besides the generation of electricity.
Green energy in the form of massive windmills, national defense and even games played on mobile phones all have one thing in common: A reliance on rare-earth elements, or REEs, of which 17 exist.
The 17 are scandium, yttrium, lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium and lutetium.
Thomas Tarka, REE Technical Portfolio Lead for NETL, said that, in short, the world runs on these elements.
Ten of the 17 rare-earth elements are used in the production of a single iPhone, and even the capability of digital screens to appear in red or green hues is due to REE.
Another example is windmill technology; one built with conventional metals would require 4,000 pounds of magnets, but using REEs brings that down to 500 pounds.
What makes these elements rare, Tarka said, is their low concentration.
“What we’re trying to do is find higher concentrations,” Mary Anne Alvin, NETL’s REE Technology Manager, said.
Researchers at NETL’s Morgantown lab have developed methods to extract traces of the rare metals from coal. The research was approved in 2014, got its first bout of funding ($15 million per year) in 2015 with the work starting in earnest in March of 2016.
In the span of six months, Alvin said the amount of REEs recovered from coal samples went from 300 parts per million [bits of coal] to 20,000 parts per million. What’s more, the coal in Appalachia was observed to have higher traces of rare-earth elements than the coal in the west of the country. The samples of rare-earth elements recovered from the coal sample were shown to be very pure as well.
She added there’s an environmental aspect to this as well. REEs can also be extracted from fly ash and acid mine drainage since they don’t burn up when coal is used to produce electricity, meaning cleanup efforts could lead to even more discoveries.
Looking to the future, NETL’s challenge now lies to making REE extraction from coal economical on a large scale while making also preventing environmental damage. This of course would entail development of new technology.
“We still have challenges,” Alvin said. “We want to do our due diligence.”
Tarka said America’s rare-earth elements are imported, with China controlling 95 percent the global market. While time will tell, he said a West Virginia’s coal could become a new factor if NETL’s research comes to fruition.
“There is potential for demand for rare-earth elements to grow,” he said, adding there could one day be domestic production of REEs.
Tarka said this would also maximize the uses of coal since it’s already used to make aircraft, carbon fiber for use in race cars and even jet fuel. Extracting the valuable metals from the black substance underneath West Virginia’s mountains would also mean less waste in the process of mining, using and burning the coal.