Rare earth elements promising, if concentrations can be foundJun 19, 2013 By Eric Blom, Staff Writer
Though the least-common rare earth element is 180 times more abundant in the Earth's crust than gold, finding a mineable deposit of the minerals is difficult.
"They have very little tendency to concentrate," Wyoming Geological Survey geologist Wayne Sutherland said. "They're kind of everywhere, but finding those concentrations, that's the trick."
Sutherland was speaking to an audience at the Wyoming State Gem Show on June 16 about the results of a study he led to pull off that trick and find where rare earth elements are most common in Wyoming.
The 17 metallic elements have an atomic structure that makes them repel each other and many other elements. Practically, their particular chemistry makes them unlikely to form veins or crystalline structures disposed to mining.
For the investigation, Sutherland and his team collected 289 samples from across Wyoming last fall, nearly double their goal of 150. This winter, the geologists sent the rocks to a lab for analysis along with 67 previously collected specimens.
The tests found concentrations of the 17 rare earth elements plus other minerals, such as gold. This spring, the Geological Survey team analyzed the results, wrote a report and published their data on the internet.
Sutherland said the team found 20 sites where rare earth elements were five times more abundant than the average in the Earth's crust. Though the survey found concentrations, it does not provide enough information to know if mining the minerals in those areas would be economically viable.
"Each sample only represents a specific volume of relatively uniform material," Sutherland said in the presentation. Though the information is not enough to start mining, he hopes it will spark an interest in prospectors.
"It indicates there might be something worth exploring," he said. "The exploration is left up to the private entities."
Digital copies of the report on the study are available from the geological survey's website, http://www.wsgs.uwyo.edu/,along with a database of the information on the samples.
In the presentation, Sutherland explained the Wyoming Database of Geology, or Wyo-DOG. It has the data from the analysis of each sample, showing the concentration of a whole host of elements.
The database also includes information and a geological description on the site where each sample was taken, and links to further information on the area.
"The idea was to put as much raw data in front of the user as possible," Sutherland said.
He said he wanted to make sure the public had access to the information because tax payer money paid for the study.
Rare earth elements are vital for modern society, Sutherland said. He described uses in mobile phones, missiles and batteries. R32;Combing a relatively small amount of rare earth minerals combined with other metals can produce super-conductors, Sutherland said, and they are fairly unique.
"Usually there's no synthetic replacement for what they can do," he said.
Some real-life examples helped illustrate the significance of the scare minerals for audience members.
A 3 megawatt wind generator, a common type of windmill in Wyoming, takes about two tons of rare earth elements, Sutherland said. The minerals help make the light-weight superconducting magnets vital to the generators, he explained.
Without the rare earth elements, the windmill would be two and one half times heavier, meaning their towers would have to be much larger, stronger and more expensive.
A Toyota Prius also contains about 25 pounds of rare earth elements, Sutherland said. They help make the hybrid car lighter as well, allowing it to have better gas mileage.
Members of the audience were keen on knowing how small outfits could prospect for rare earth elements.
Sutherland said the cost of sample analysis is not too high, for the project it was about $52 plus shipping, but depends on which tests are performed.
An obstacle for small operators could be the relative difficulty of processing rare earth elements.
"Because all the rare earths are so similar and similar to other metals, it's very difficult to separate them," he said. "It's a whole complex series of chemical reductions."
Still, with all of the information from the study available online, the playing field will be a little more even between large mining companies and weekend prospectors.