SALT LAKE CITY — So-called rare-earth minerals have been found in eastern Utah and western Colorado coal mines. University of Utah researchers are asking for grant money from the federal government to determine if there are enough rare-earth minerals worth mining for.
Professor Michael Free, chairman for the Department of Material Science and Engineering at the U of U., says mining these minerals is a multistep process that starts with physically separating the rare-earths from the other minerals.
“The next phase is a chemical extraction where you put in chemicals that will help to release the rare-earth or critical metal elements.”
After the minerals have been separated chemically, the refined metals are extracted from the chemical solution. But first researchers have to determine t if there’s enough material available.
Are there enough rare-earth minerals in the coal mines?
“We’ve seen some samples that look like they have more than 100, maybe up to 200 parts per million of these elements. In those kinds of cases, it might make a pretty good resource if we have enough volume” Free said.
But there’s a problem with the data they have.
“We can do some sampling and say, ‘Yeah, there’s this much here [in] this sample, … but is that sample … representative of a very large volume of material that’s there, or is it only in more isolated, high concentrations, and we just happen to be seeing more highly concentrated pockets,” said Free.
Free said if geologists find there is enough material, they would be able to use the permits they already have and the equipment that’s already in the coal mines to begin the extraction process.
“You need to essentially do [a] similar kind of mining practice to get it out of the ground. You can use some of the same equipment. We’ve had some mining engineers [who are] part of our team that we’ve been working with, [who are] looking at some ways of getting it out safely.”
Free said the U.S. hasn’t kept up with mining practices and technologies like other countries, which limit where these rare-earths can be mined.
“Materials associated with coal operations — the seams above and below — [are] elevated in concentrations of some of these things, but they’re not the best resource to go after. We do have other deposits of these kinds of materials that are higher concentrations that would be a little bit easier,” he said.
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