New Twin Metals plan moves processing plant site

Twin Metals Minnesota on Thursday released new details for its underground copper-nickel mine planned near Ely, including a new location for its proposed processing plant.

Twin Metals headquarters in Ely. (Clint Austin /
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Twin Metals Minnesota on Thursday released new details for its underground copper-nickel mine planned near Ely, including a new location for its proposed processing plant.

The company announced new details on its plan, which has yet to be presented for any kind of regulatory approval.

The company recently won back critical federal mineral leases from the Trump administration that had been withheld by the Obama administration. The leases cover areas at and around the proposed mine site along the Kawishiwi River and Birch Lake just outside the Boundary Waters Canoe Area Wilderness.

Under the new plans, the concentrator/processing plant - the major above-ground feature of the operation - would be located just south of the mine site, just east of Birch Lake on land that Twin Metals already owns. Earlier plans had considered a site south of the Ely airport, west of Birch Lake.

"This configuration moves the processing much closer to the mine site with a more compact footprint,'' said Bob McFarlin, Twin Metals spokesman. The processing facility will cover about 100 acres south of Minnesota Highway 1.



The mine will be connected to the processing facility by an underground tunnel that will be used to move workers and equipment into the mine and move raw ore to the processor.

The copper-nickel concentrate produced at the plant will be shipped to smelters in other regions, likely Canada or the western U.S.

The move east of Birch Lake also appears to avoid a controversy involving state lands near the original plant site. Minnesota Gov. Mark Dayton, who opposes the project's location near the BWCAW, had signed an order to stop Twin Metals from using state lands in the area.

The company on Thursday reiterated that about half its waste rock, or tailings, would be placed back in the underground mine as space develops and about half would be stored in a wet slurry in a lined tailings basin on property Twin Metals owns near the Peter Mitchell mine operated by Cleveland-Cliffs near Babbitt. That site would be outside the BWCAW watershed and in the St. Louis River watershed.

McFarlin said the company hasn't decided yet how to move the slurry from the processing plant to the tailings basin, with potential options including a pipeline or rail. McFarlin said preliminary tests by the company show the waste rock tailings would not be acidic.

The company says it will employ about 650 people in the mine and processing center and hundreds more spinoff jobs. Supporters say the project will help diversify the regional economy while critics say any potential threat to water quality in the Boundary Waters region is unacceptable - especially from potentially acidic waste rock that could taint water flowing into the BWCAW.

Critics say the new plans don't make the project any more palatable.


"Gov. Dayton was right to stop the use of state land for this dangerous proposal, and this new plan appears to end run the governor's action to protect the BWCA,'' said Kathryn Hoffman, CEO of the Minnesota Center for Environmental Advocacy. "Minnesota needs to maintain strong standards to protect our water instead of bending over backward to exempt new sulfide mining proposals from water pollution rules."

Twin Metals, a wholly owned subsidiary of Chilean mining conglomerate Antofagasta, said Thursday that the company expects to submit a formal mine plan proposal to regulators sometime in 2019, a move that will begin the environmental review process by multiple state and federal agencies as required by law.

"This is not our formal mine project proposal. It's an update of where our plans are at this point," McFarlin said. "We're trying to be as transparent as possible as we move forward."

The company is planning to mine about 20,000 tons of mineralized ore per day using underground mining operations. That's far less than the 50,000 daily tons considered in the projects' original mine plan.

Twin Metals also said Thursday that it will open a new office in Babbitt, in addition to its Ely office, and that it plans to shuttle mine workers from those offices to the mine site to avoid congestion in the area.

Twin Metals has been conducting environmental studies for more than seven years at the site and continues to do so. Environmental data will be used in the formal environmental impact statement process that will be conducted by state and federal agencies in coming years.

The U.S. Forest Service currently is conducting an environmental assessment worksheet on the potential impact of copper mining near the BWCAW watershed.

John Myers reports on the outdoors, natural resources and the environment for the Duluth News Tribune. You can reach him at
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