Rare-earth elements could potentially be concealed within coal mines.

Researchers have recently made an eye-opening discovery: rare earth elements necessary for batteries, touchscreens and other modern technologies may exist in abundance near fossil fuel sources. An extensive study of Utah and western Colorado coal mines uncovered rock layers rich with elements such as scandium, yttrium and neodymium that are associated with coal seams. Rare-earth elements play an essential role in modern technology such as smartphones. Additionally, their presence is essential to green energy technologies like wind turbines and hybrid cars. Since most rare earth elements are currently mined and processed in China, the U.S. Department of Energy is supporting efforts in America to locate these rare earth elements to increase domestic production and support more jobs in our economy. “Development of these minerals domestically is increasingly vital,” according to Lauren Birgenheier, a geologist from University of Utah and co-author of this research paper. She told Live Science that there was “an urgent societal imperative” behind it all. Birgenheier and her team, inspired by research that had identified rare earth elements associated with coal in Appalachian regions, took samples from six active and four idle mines across central Utah and western Colorado for testing. Researchers employed two geochemical analysis techniques – X-ray fluorescence and mass spectrometry – to search for signs of the 17 metallic rare earths elements found within samples. Related Article: Discoveries in Radioactive Promethium After 80-Year SearchThe researchers discovered that 24% to 45% of shale and siltstone rocks adjacent to coal seams contained at least 200 parts per million (ppm) rare earth elements while 100% of volcanic rocks sampled contained them at that level or higher. Discover some of the world’s greatest discoveries delivered straight to your inbox! “They exist within shale or gray units above and below coal seams,” Birgenheier noted, suggesting if mining were already taking place there might also be ways to include extracting some of those “muddy gray units”. Birgenheier and her team set their target concentration of rare earth elements at 200 parts per million for exploratory reasons; further work must be conducted to ascertain which deposits could potentially support mining operations. Birgenheier explained that coal beds in western Colorado and Utah likely formed in peat swamp environments, where rare earth elements from volcanic eruptions became integrated with rock layers via volcanic ash that settled onto swamp floors or from living organisms that collected metals before dying and being transformed by heat and pressure into coal deposits. Over millennia, metals may have leached out of coal itself into nearby rocks. Coal beds across the nation each have unique histories, she noted; other research groups are conducting similar investigations in other locations ranging from the Gulf Coast and Wyoming coalfields in Illinois coal fields – these findings were published April 26 in Frontiers in Earth Science journal.