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By Shane Lasley
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Pentagon gets footing at Bokan Mountain

Department of Defense inks deal with Ucore for heavy REE deposit in SE Alaska, state-of-the-art method for extracting rare earths

 

Last updated 10/28/2012 at Noon



Ucore Rare Metals Inc. has two things the Pentagon wants - heavy rare earths and state-of-the-art technology to extract these strategic elements from the ore.

The almost magical properties of REEs - a group of 17 previously obscure metals that include scandium, yttrium and the 15 lanthanide elements on the periodic table - make them an essential ingredient to a number of avant-garde military applications such as drones, lasers, radar systems and night vision equipment. The metals are also widely used in high-tech consumer goods like mobile phones and iPods; and green technology applications such as wind turbines and hybrid cars.

Ucore's Bokan Mountain project in Southeast Alaska is considered to be the richest domestic source of three heavy rare earth elements - dysprosium, terbium, and yttrium - which are critical to several advanced weapon systems, such as stealth helicopters and precision-guided weapons.

Based on 9,550 meters of drilling completed at Bokan, Ucore released an inaugural resource estimate for the REE deposit in 2011. At a 0.4 percent total rare earth oxide cut-off grade, the property hosts an inferred resource of 5.3 million metric tons averaging 0.65 percent TREO. Some 40 percent of the rare earths in the resource are the higher value heavy rare earth oxides.

A 10,112-meter drill program carried out in 2011 focused on upgrading and expanding this resource. The 34-hole program, which has confirmed the integrity and continuity of the mineralization, is being incorporated in an updated resource estimate expected to be released in conjunction with a preliminary economic assessment due out soon.

"The United States does not yet have the capability to produce three of the heavy rare earths that occur naturally and in abundance in Bokan Mountain," said Ucore President and CEO Jim McKenzie.

To gain a foothold on the HREE-rich Bokan Mountain, the United States Department of Defense has contracted with Landmark Alaska L.P., the U.S. operating subsidiary of Nova Scotia-based Ucore.

The program, which will include mineralogical and metallurgical studies on the deposit located on Prince of Wales Island, will be managed by the DoD under the Defense Logistics Agency.

"This announcement is great news for Alaska and for the United States, where our need for a secure and domestic supply of rare earth elements is an urgent challenge," said U.S. Sen. Lisa Murkowski, R-Alaska. "These and other critical minerals are essential in the manufacturing of everything from modern defense equipment to clean energy technologies."

DoD under fire

U.S. lawmakers have taken aim at the DoD over its apparent laidback attitude toward ensuring the U.S. Military has an ample supply of the REEs critical to many of the weapons systems in its arsenal.

"Clearly, rare earth supply limitations present a serious vulnerability to our national security. Yet early indications are the DoD has dismissed the severity of the situation to date," Sen. Murkowski, Sen. Mark Begich, D-Alaska, and Rep. Mike Coffman, R-Colo. wrote in a January 2011 letter to U.S. Secretary of Defense Robert Gates.

The legislators' alarm over the potential short supply of the REEs essential to military munitions was triggered by export quotas China has levied on these elements.

China is estimated to supply between 90 and 95 percent of the world's rare earth oxides, according to a September Congressional Research Service report.

In a separate briefing published in June, Congress' think tank wrote, "In the case of REEs, the dominance of China as a single or dominant supplier of the raw material, downstream oxides, associated metals and alloys, may be a cause for concern because of China's export restrictions and growing internal demand for its REEs."

The DoD contends that REE projects outside of China, such as MolyCorp's Mountain Pass Mine in California, and other adjustments in the Western rare earth markets should ensure that there is no military or commercial shortage of these strategic elements in the United States.

"Over the past year, there have been a number of positive developments with regard to both supply and demand within the rare earth materials markets," DoD Undersecretary Frank Kendall wrote in a March 2012 letter to Congress. "Reactions to market forces have resulted in positive developments, such as prices decreasing by half from their peak levels in July 2011, increased investment and domestic supply of rare earth materials, corporate restructuring within the supply chain, and lower forecasts for non-Chinese consumption. By 2015, the department believes this will help to stabilize overall markets and improve the availability of rare earth materials."

Capitol Hill does not share the military arm's optimistic outlook.

"Although new mine production may be able to make up the difference for some lighter elements (there may be an excess supply of the lighter elements such as cerium, lanthanum, and praseodymium), several forecasts show that there will likely be shortfalls of other light rare earths and several heavier rare earth elements, such as, dysprosium, terbium, neodymium, europium and erbium," according to the June report penned by Congressional Research Service. "This potential shortfall has raised concerns in the U.S. Congress."

Though not as alarmed over the rare earth market, in general, the Pentagon has identified near-term shortages of a pair of these elements.

The DoD informed Congress that yttrium and dysprosium, two of the REEs in abundant supply at Bokan Mountain, are important elements in military equipment and are expected to be in short supply next year.

The seven metric tons of domestically produced dysprosium in 2013 is forecast to be just enough to meet defense department needs for the year. The 26 tons of yttrium projected to be mined in the U.S. next year, on the other hand, does not come close to meeting the some 119 tons of the rare earth that is projected to be used by the military.

State-of-the-art technologies

While Bokan Mountain is rich in yttrium, dysprosium and a suite of the other prized heavy rare earths, the Pentagon's interest in Ucore seems to be as much about the cutting edge extraction technology the company is pioneering as it is about the Strategic Metals stowed at its Southeast Alaska deposit.

Ucore has been working with Montana-based IntelliMet LLC to develop a state-of-the-art method for processing the rare earths, referred to in scientific circles as solid phase extraction.

Under the agreement with the defense department, Ucore will provide the Pentagon with the most up-to-date data on this proprietary bench and pilot scale solid phase extraction nanotechnology research.

"The Department of Defense's investment in the Bokan deposit and Ucore's proprietary SPE technology represents a significant step toward recapturing the rare earths technological lead surrendered to China decades ago," said McKenzie. "What's more, the DoD relationship adds a great deal of credibility to Ucore's domestic supply chain development, representing one of the largest purchasing capabilities amongst prospective customers worldwide."

Considered to be a scientific leap beyond solvent exchange extraction, the method traditionally used to separate REEs, solid phase extraction utilizes nanotechnology.

"SPE is a uniquely American technology which combines rare earth extraction from process leach solutions with a separation regime that utilizes innovative polymer nanotechnology," McKenzie said.

Though cutting edge, the SPE procedure follows a much simpler flow-sheet than traditional REE extraction methods.

In bench-scale tests, IntelliMet treated a representative sample of Bokan ore with nitric acid, generating a solution containing the rare earths and other elements contained in the ore. Before precipitating the REEs out of solution, the Montana-based lab was able to pull out more than 99 percent of the non-REE elements - including iron, uranium and thorium. Once these "nuisance" elements are removed, pure REE oxides can be precipitated out of the solution.

Follow-up tests by Intellimet successfully separated dysprosium, neodymium and erbium from the other rare earth elements suspended in a composite solution designed specifically to replicate the contents of the ore from Ucore's Bokan Mountain deposit.

"The isolation of a chemical form of dysprosium from a US-based deposit has been a 'holy grail' of sorts in the domestic rare earth industry. Now that dysprosium has been liberated at laboratory scale, our intent is to pursue this breakthrough at a pilot plant level in conjunction with the company's arrangement with the US Department of Defense," McKenzie said.

Next generation REE mine

The less-complicated SPE technology is expected to result in a smaller and more efficient facility for transforming Bokan Mountain ore into rare earth oxides.

Because these developments are likely to lower capital and operating costs - improving the economics of developing the Southeast Alaska REE project - Ucore has held off on producing a preliminary economic assessment for Bokan Mountain until this breakthrough technology can be included.

SPE is not the only cutting edge idea to be included in the upcoming economic assessment. Ucore has been testing a sorter that uses x-ray to identify REE-barren rocks and reject them as waste before the ore reaches the mill.

Tests of the dual energy x-ray transmission sorter, involving three one-ton bulk samples of Bokan Mountain ore, have demonstrated that nearly half of the feed could be rejected as waste while retaining the majority of the REE-bearing material. This essentially doubles the grade of the ore being fed into the mill.

"Our previous work on X-ray ore sorting has shown significant cap-ex and operating cost advantages, and we're anxious to optimize those advantages," said Ucore COO Ken Collison. "Previous production scale sorter tests showed that 50 percent of the material mined will be rejected as waste, while recovering approximately 97 percent of the rare earth metal content. This is a significant advantage, since a 1,500 (metric-ton)-per-day mine will theoretically require only a 750 (metric-ton)-per-day mill."

Ucore increased the scale of testing the unique ore-sorting technology with a 20-ton bulk sample extracted from three sites along its Bokan Mountain in June.

A local contractor crushed and segregated the material into four specified size fractions, prior to the samples being transported to Germany to be processed through a production scale X-ray sorter to prepare an upgraded ore sample for future metallurgical testing.

While not exactly at the cutting edge of mining technology, Ucore's plan to use long-hole stoping to mine the ore at Bokan and paste backfill as a means of disposing of the tailings are unique to REE extraction and are important developments in minimizing the environmental footprint of the proposed mine.

"Ucore has now added to the list of 'firsts' associated with the company," touted McKenzie.

"The company was the first in the rare earth industry to successfully investigate DEXRT (dual energy x-ray transmission) technology for ore sorting and waste rock removal; the first to propose a tailings-free facility at surface via state of the art paste backfill technologies; and the first to pursue long hole stoping as a means of REE ore extraction, with a minimal prospective environmental surface footprint.

Now, Ucore is the first to pursue solid phase extraction, or SPE technology, as an effective means of REE purification and liberation, and as an efficient and economical alternative to traditional solvent exchange methodologies utilized in China and elsewhere."

Finalizing tests that are expected to improve efficiencies on both sides of the mill, Ucore is putting the finishing touches on a PEA that is expected to illustrate the next generation of REE mines and processing facilities.

McKenzie said the separation technology included in the economic assessment "sets the stage for our post-PEA work towards mapping a complete mine-to-metal strategy for heavy REEs in the United States," an effort that will be supported by the might of the U.S. Department of Defense.

 

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