North Dakota ramps up to mine treasure trove of rare earth minerals in coal

Coal may be a dirty word to climate zealots, but not in North Dakota. Not even in Washington, D.C., for those in the know, given the confirmation of significant reserves of strategically vital rare earth minerals in the state’s huge deposits of lignite coal. Rare earth minerals are critical to the defense, aerospace, automotive and high-tech industries, as well as anyone who uses a computer, smartphone, digital camera and other devices.

Currently the U.S. remains dangerously dependent on China and other foreign sources for rare earth mineral supplies. But Forum News says a new state survey reveals a treasure trove of commercially viable rare earth minerals embedded in the state’s coal deposits.

The North Dakota Geological Survey has drafted a report that provides a road map to explore lignite coal and organic-rich mudstone that contains enriched critical minerals.

The report, released this week, is the latest in a series of studies by state geologists exploring the extent of rare earth minerals and other critical minerals — including lithium, which is used in rechargeable batteries for electric vehicles — that officials believe could be the foundation for a new mining and processing industry in North Dakota.

“We’ve been finding high concentrations of critical minerals,” said Ed Murphy, the state geologist. “The problem has been finding them consistently along the same horizon.”

Until now, state geologists were uncertain whether the deposits in North Dakota were concentrated at levels that would be commercially viable. The latest findings, however, dispel any doubts.

North Dakota researchers have analyzed more than 1,700 samples from more than 300 mineral outcropping sites across western and south-central North Dakota — a tiny fraction of the state’s estimated 25 billion tons of lignite reserves.

Critical mineral deposits containing concentrations of 300 parts per million or more are considered economic to mine. Samples from thin lignite coals and organic-rich mudstone from the lower Bear Den Member contain up to 2,570 parts per million in rare earth elements — which the North Dakota Geological Survey believes to be the highest spot concentration yet reported from North American coal deposits.

Concentrations of several critical minerals were sometimes found in the same samples, including cobalt, gallium, germanium and lithium.

The report identifies significant deposits on federal and state government land, as well as private property in several western counties. The state legislature has funded the research with more funding to help jump start the industry soon expected to be on the way. The U.S. Department of Energy has also provided funding to develop technology for a rare earth minerals processing plant.

Murphy said the minerals could be mined using strip mining similar to conventional lignite mining or using “in situ” mining, which involves leaving the ore where it is in the ground, and recovering the minerals from it by dissolving them and pumping the solution to the surface where the minerals can be recovered.

Researchers at UND’s Institute for Energy Studies are working to develop ways to mine and process rare earth and critical minerals on a commercial scale from North Dakota lignite.

The bottom line is it’s in the national interest to ramp up mining of the rare earth minerals in North Dakota as soon as possible. Coal mines already in operation may present an opportunity to do just that.

“The discovery and description of these deposits are important steps in the development of a comprehensive exploration model for the coal and mineral industry, with the potential to one day reduce the necessity of critical mineral imports, a strategic vulnerability of the United States,” the North Dakota Geological Survey said in a statement.

No wonder University of North Dakota researchers call the rare earth deposits the state’s “diamonds in the rough.”