A study of 2,200 samples of lignite coal in North Dakota from the Bear Den and Rhame Bed formations have returned exciting results during research into rare earth element deposits in the western part of the state, according to State Geologist Edward Murphy.

Murphy gave a presentation regarding recent developments in the exploration into rare earth element deposits in western North Dakota during the American Petroleum Institute’s Bakken Chapter quarterly meeting in Minot on Thursday.

Rare earth elements (REE) are a group of metals used in nuclear reactors, atomic batteries and missiles as well as in other critical purposes.

Murphy said at this time in the United States, the only mining of REE is taking place at Mountain Pass in California.

“When we started this project, the highest reported concentration of rare earths in the coal of North Dakota was 169 (ppm), and now we have samples over 4,000 (ppm). We think to be economic is anything over 300,” Murphy said. “It’s easier to get these rare earths out of coal or lignite, because it’s not held very strongly.”

Murphy said the research has identified 18 sites with high concentrations of REEs, which also differ from the California deposits as they contain a mixture of light and heavy varieties. North Dakota lignite was found to contain large percentages of Scandium, which is used for high-performance applications such as aerospace components and sports equipment.

“The heavies are worth more than the lights are. North Dakota coals have some of the heavies. If you go just by costs, the rare earths in North Dakota coals are worth more than the rare earths coming out of Mountain Pass. The difference is they have more material to work with,” Murphy said.

Murphy said a phase II of the project has been proposed to drill 50 more holes to further explore the beds to determine their viability.