Old Gold Rush Era Mines Scoured For Rare Earth Metals

July 23rd, 2013 by


The U.S. Geological Survey and the Department of Energy are scouring the past of Gold Rush-era mines in the American West, to find solutions for the nation’s future. They are hoping the tailings and ore samples of old abandoned mines may hold traces of rare earth metals, used in everything from MRI machines and smart phones to modern weapons systems and hybrid cars.

The goal is to break the Chinese monopoly on these metals, and secure domestic supplies. China has already used it’s stranglehold on rare earth minerals as a political tool, cutting off Japan’s access to elements needed for the manufacture of hybrid cars such as the Prius, during an argument over territorial rights in the East China Sea between the two nations.

In 2011, the Chinese hiked the prices of rare earth metals. For example neodymium, used in high tech magnets, went from $15/kg to $500/kg, and dysprosium oxide, used in lasers, went from $114/kg to $2,830/kg.

The USGS and DoE are examining over 2500 ore samples taken across the Old West during the gold rush days and stored at University of Nevada Reno and the Colorado School of Mines for traces of rare earth minerals. Teams are also testing the tailing piles of abandoned mines. These piles of waste rock have been considered toxic waste and an eyesore, but should they contain rare earths, it would be a win/win situation for the U.S., yielding vital resources while cleaning up waste sites over 100 years old.

These ore samples and tailings were never tested for anything other than the ore that the old miners were looking for – usually gold or silver. “If we could recycle some of this waste and get something out of it that was waste years ago that isn’t waste today, that certainly is a goal,” said Alan Koenig, the USGS scientist in charge of the tailings project.

The project has already yielded surprising results, finding traces of rare earth minerals in company of common ores in combinations never seen before. For example, iridium has been found in abandoned copper mines – something that had never been seen before.

Associated Press article