Bokan ‘breakthroughs’ raise rare earth estimates
A pre-feasibility study for the Bokan Mountain rare earths mine has been delayed after significant new findings at the prospect on Prince of Wales Island. Bokan Mountain, the rocky peak at above right, is the largest U.S. deposit of valuable rare earth minerals. The deposit is located where Dodson Ridge, at above left, runs down toward Kendrick Bay.
Courtesy Ucore Rare Metals Inc.
The preliminary economic assessment on the Bokan Mountain rare earth element mine project could be completed soon after being delayed from an expected May release to allow more analysis of “fairly significant breakthroughs,” including “order of magnitude” increases of reserves of the valuable deposits.
“We have identified a resource of 5.3 million tons of total rare earth elements,” said Mark MacDonald, vice president for business development of Ucore Rare Metals Inc., on June 1.
The PEA, a critical document in the financial side of mine development, is “imminent,” MacDonald added, but he declined to specify a release date.
“What the PEA tells you is either the mine is economic or not. It is very specific. It’s like a business plan on how you’re going to take the mine to market,” MacDonald said.
Located on Prince of Wales Island, Bokan Mountain is 37.2 miles southwest of Ketchikan and 86.9 miles northwest of Prince Rupert, British Columbia. The 19 square mile project includes the former high grade Ross Adams uranium mine and has a high percentage of Dysprosium and Terbium, both among the atomically heavier, and more rare, rare earth elements.
“Bokan is the main known deposit in the United States that has a high percentage of heavier rare earth and a high percentage is somewhere between 40 and 60 percent,” Alaska Miners Association Executive Director Steve Borell told the Journal earlier this year.
In a video presentation published May 31 on “Ucore TV,” a feature of the Halifax, Nova Scotia-based company’s web site, principle geologist Jim Barker said test drilling has shown lengthy “vein dykes” of REEs.
“I have literally traced several of them as far as six kilometers of continuous strike length,” Barker said.
The vein dykes occur in at least four arrays in the Bokan Mountain property, including Dotson Ridge. Barker described vein dykes as a set of hydrothermically altered dykes that also include characteristics of traditional mineral deposit veins.
“So far our deepest drill holes have proven that the dykes do extend to at least 400 meters. That’s our deepest hole at the moment. We are targeting to intercept those dykes at approximately 800 meters, perhaps even 1,000 meters of depth,” Barker said.
Limited drilling in other portions of the project have indicated other dyke systems that have not been quantified to date but suggest “substantial resources there,” according to Barker.
“A magnitude of order (reserve increase) is what we are looking at now,” he said.
Ken Collson, Ucore’s chief operating officer and lead on the Bokan Mountain project, was in Ketchikan the last week in May 24 with company metallurgists and other technical staff to review the new technical information. In an April 18 news release, Ucore said the PEA would be released “in the near term.”
MacDonald has stopped predicting dates but noted that the PEA publication delay has been due to positive developments.
“It was delayed a little because a couple of fairly significant breakthroughs made in some of the research that we’re having done around separation technology. Those breakthroughs were significant enough that we wanted to test to see how they would affect the PEA,” MacDonald said.
“Instead of issuing the PEA with a lot of the historical metallurgical information that we’ve already had we decided to test some things to see if we couldn’t upgrade it a little bit.”
MacDonald said the May 24 session was to be the “final meeting” on metallurgy and would produce “a much more concrete understanding about release dates.”
Although the Bokan project is located on federal land managed by the U.S. Forest Service, the State of Alaska, which has shown great interest and support for the project, has jurisdiction over reclamation work and water quality and discharge issues.
“We have jurisdiction on reclamation, regardless of land ownership and also over water quality so (Department of Environmental Conservation) would regulate discharge and water quality and all that,” said Kyle Moselle, Bokan Mountain project coordinator in the Alaska Department of Natural Resources’ Office of Project and Permitting.
He also noted that if any streams that are disturbed are fish-bearing then Department of Fish and Game permits would also be necessary. Regulation of “the actual disturbance of the land” would fall to the USFS through the National Environmental Protection Act process.
“My plan is once the PEA comes out, I’m being told that’s due out relatively soon, in the next month or two, then hold agency meeting with UCore to talk about baseline studies,” Moselle said. “I’m looking to have a agency meeting with Ucore within a month after their PEA is released so we can start to identify baseline data needs and authorizations that will be required.”
He noted that baseline data collection “on average” takes two to three years, depending on the availability and age of existing relevant data.
John Bolling, Craig city administrator, said he also believes actual production is two to three years off and agreed that the prospects are good but not imminent.
“It could be a great economic shot in the arm for residents of (Prince of Wales), combined with the low environmental risk of harm,” Bolling said.
His low risk observation, he explained, is relative to larger projects like the Pebble prospect on Bristol Bay.
MacDonald said the potential for environmental impact will be minimal because Ucore plans to build a “tailings-free” mine with “very little daylight expression,” or surface disturbance.
“We may well have the first tailings free mine that anyone’s every heard of. From an environmental standpoint it’s extremely efficient,” MacDonald said.
Ucore plans to use a process adapted from diamond mining in which ore is crushed and x-rayed to separate REEs from waste rock.
“Because of the nature of the ore body, the waste rock, breaks very cleanly from the ore,” MacDonald said.
A tailings-free mine would mix waste rock with concrete and pump the mix back into mine shafts so no tailing storage or other surface disturbance would remain when production is completed.