Initial mine development work on the Brook rare earths mine, in Wyoming, will start in the fourth quarter, Nasdaq-listed coal miner Ramaco Resources announced on Monday.

This will be the first new rare earths mine in the US since the Mountain Pass mine in California in 1952. Currently, Mountain Pass is the US’s only operating mine for these critical elements and minerals.

Besides large percentages of magnetic rare-earth oxides (REOs), there is also a possibility that the Brook deposit may contain meaningful amounts of gallium and germanium – two critical minerals that are widely used in semiconductors and defence systems. China, which controls gallium and germanium supplies, last month introduced new export controls for these two minerals.

The Brook mine – said to be one of the biggest unconventional deposits of rare earth elements (REE) discovered in the US – will target REE deposits found in coal and adjacent clays and carbonaceous material.

Ramaco has earmarked $2.5-million over two quarters for initial development of both rare earth and carbon ore/coal mining.

The development decision comes as the company announced a near-50% increase in the size of the deposit from the initial target disclosed in May. The exploration target is now 0.90-million to 1.2-million tons of total REOs, compared with 0.6-million to 0.8-million tons in May.

Ramaco noted that the US has an average domestic consumption of about 10 000 t/y of REEs over the last ten years.

The deposit is estimated to contain about 29% of primary magnetic REOs neodymium, praseodymium, dysprosium, and terbium, as well as secondary magnetic REOs. 

In conjunction with the development, Ramaco has retained a group of rare earths mining, metallurgy, mineralogy and economic experts, including leading rare earths mining consultancy SRK Consulting. These firms will work with the company and alongside researchers from the Department of Energy's (DoE’s) National Energy Technology Laboratory (NETL) to prepare mineral and metallurgical assessments, as well as initial economic assessment and prefeasibility studies.

This analysis will inform the appropriate forms and techniques of processing, separation and recovery of the rare earths and carbon ore.

Ramaco expects to also work with other DoE national laboratories, including NETL, in assessing the deposit and its potential vertical development to magnet production.

"As with all our development projects, we will take a thorough and disciplined approach to assessing the feasibility of the Brook mine. We are, however, very encouraged by the board's decision to greenlight the initial mine development of the country's first carbon ore and rare earths mine," said chairperson and CEO Randall Atkins.

"Based on our recent findings, we are more optimistic today than in May when we first announced this unconventional rare earths deposit. We have now increased the exploration target by 50% relative to our initial findings, enlisted a group of world class third-party experts to assist in our overall evaluation and will soon actually start mining for rare earths. We will continue to pursue our measured approach, as we embark on this potentially transformational opportunity."

Further, Ramaco announced that working with the DoE’s Oak Ridge National Laboratory, it has jointly developed and patented technologies to commercialise two potentially disruptive high-value carbon products using coal as their primary feedstock. These technologies were developed as part of a multi-year research partnership, and are subject to issued and pending patents.

One involves the use of coal to develop a form of activated carbon fibre as a solid adsorbent to be used in large-scale direct air capture of carbon dioxide, methane or other noxious gases. 

The second involves the use of coal to make a form of low-cost synthetic graphite, a major component in electric vehicle (EV) batteries and other energy-storage products.

The Brook mine is rich in magnetic REEs, which are used in applications that include advanced military technology, EVs and more.

The board of directors of Ramaco Resources has approved initial development of the Brook mine – the first new rare earth mine in the US since Mountain Pass mine.