By Kelly House
The Great Lakes News Collaborative includes Bridge Michigan; Circle of Blue; Great Lakes Now at Detroit PBS; Michigan Public, Michigan’s NPR News Leader; and who work together to bring audiences news and information about the impact of climate change, pollution, and aging infrastructure on the Great Lakes and drinking water. This independent journalism is supported by the Charles Stewart Mott Foundation. Find all the work HERE.
EAGLE MINE, MARQUETTE COUNTY — Deep beneath the earth’s surface in the nation’s only nickel mine, Katy Dorfschmidt trains her headlamp on a chunk of ore underfoot.
Silvery flecks glint on the dark gray rock.
“This is our semi-massive sulfide,” explains Dorfschmidt, technical services superintendent at the Upper Peninsula mine, adding that its nickel content is about 1%.
Mining is a notoriously inefficient pursuit.
For every pound of ore that’s blasted from underground, hauled to the surface, crushed, purified and then shipped to Canada for smelting, just a fraction of an ounce becomes valuable metal, and the waste left behind could pose significant risks to the environment.
Flecks of metal sulfide glint off ore inside the Eagle Mine in Marquette County. In this particular section of the mine, valuable nickel makes up about 1% of the ore. (Bridge photo by Ryan Stephens)
Yet mines such as Eagle are central to the nation’s energy transition, which has increased demand for “critical” minerals like nickel. Worried about limited supplies, government and industry are rushing to establish new mines and make existing mines more efficient, while looking for ways to alleviate environmental concerns that fuel public opposition to the industry.
Eagle Mine, located in Marquette County and owned by Canada-based Lundin Mining Co., is ground zero for the mission.
There, a $145 million federal grant and $50 million in state funding have been committed to an effort to squeeze valuable metals and sulfuric acid out of the powdered waste rock called tailings.
Today, that waste bears no monetary value but plenty of environmental risk. The tailings contain iron sulfide that, if stored improperly, could react with air and water to produce the sulfuric acid that causes dangerous “acid mine drainage.”
Fear of that outcome is a big reason why “the willingness to support those extraction activities is going down as the demand is going up,” said Nathan Manser, professor of geological and mining sciences at Michigan Technological University.
But if valuable materials can be obtained from the tailings, the mine’s waste stream would become smaller and more chemically benign, boosting profits and mineral output while curtailing environmental risk.
Officials involved in the project, a partnership between Eagle Mine and Houghton-based Revex Technologies Inc., say they hope it will extend Eagle Mine’s lifespan while making it easier for new mines to open up in the UP.
A critical-minerals imbalance
The rush to innovate comes as the government and industries respond to the climate crisis by encouraging people to swap gas-powered cars — and electricity generated by burning fossil fuels — for electric vehicles and renewable energy.
That will take lots of metals that aren’t currently mined at scale in the US, because EV batteries require more and different minerals than gas-powered cars, from cobalt and lithium to nickel and copper.
Concerned with ensuring ample supplies, the US government has labeled those minerals “critical” to the economy and national security, and is heavily subsidizing a push to boost domestic production.
As Bridge has previously reported, that’s luring a rush of prospectors to the UP in search of nickel and copper. But while some celebrate a potential mining revival, others fear destruction from an industry that has a history of polluting the peninsula and failing to clean it up.
Theodore ‘Austin’ Ayres, a tribal council member for the Keweenaw Bay Indian Community, has concerns about new mines repeating the industry’s history of pollution in the UP, but is optimistic about an effort to re-process mine waste to extract more metal while reducing its potential to cause acid mine drainage. (Bridge photo by Ryan Stephens)
“There’s this sour taste in our mouths from historical mining,” said Theodore “Austin” Ayres, a tribal council member for the Keweenaw Bay Indian Community, which is beset by mining pollution on its reservation and fishing grounds.
“So when a company like that comes around, we all kind of have the feeling that ‘Great, we’re going to be dealing with these issues again.’”
Experts say a successful EV transition will require the mining industry to repair that reputation, while confronting the reality that critical minerals are a finite resource.
Eagle Mine, Manser said, is already considered a model for environmental stewardship because its tailings are stored in an underwater basin where iron sulfide can’t readily oxidize to produce acid mine drainage.
As a result, he said, “other companies see Michigan as a location, at least geopolitically, where another mining system could be permitted successfully.”
A push for a circular economy
The new partnership between Eagle Mine and Revex aims to further improve mining’s economic margins and environmental profile.
First, Eagle Mine will use some of the federal grant dollars to create a piping system so tailings can backfill the mine, rather than being treated purely as waste.
That will preserve space in the tailings basin and reduce operating costs, making it financially feasible to mine areas of Eagle Mine that contain lower-grade ore. Doing so could extend the mine’s life by at least a year, to 2030, said Eagle Mine Managing Director Darby Stacey.
Meanwhile, Revex promises to build a nearby facility capable of superheating a mineral that Eagle Mine currently treats as waste rock, transforming it into marketable sulfuric acid and nickel that could be used to make EV batteries.
At the Humboldt Mill, which processes ore from the Eagle Mine, piles of ore wait to be crushed and purified to separate valuable metal concentrates from waste rock that will be stored in a nearby tailings basin. (Bridge photo by Ryan Stephens)
Processing the mineral, called pyrrhotite, will boost the mine’s output, while simultaneously shrinking its waste load and ridding it of the chemicals that cause acid mine drainage.
At a separate facility in Marquette County, Revex plans to recycle spent lithium-ion EV batteries, preserving the “black mass” metals needed to make new batteries.
“The major auto companies are looking for that supply,” said Revex CEO John Rockwell.
“We’ll be one of the few states that can say we produce the minerals … that go into EVs that are made in Michigan, and then the batteries are recycled in Michigan,” he added.
If all goes well, the system will be operational by 2027, producing enough new nickel to make 462,000 EVs annually, according to federal estimates. The project is expected to create a combined 115 jobs at Eagle and Revex, while retaining existing jobs by extending the mine’s life.
In the long run, officials said they hope processing pyrrhotite will become standard practice for any future sulfide ore mines in the UP. That could make it easier to win public support for new mines, given that tailing pollution is a leading concern of mining opponents.
“We will take care of the number-one long-term liability that the communities around there are worried about,” Rockwell said.
Beyond being an acid mine drainage liability, tailings basins are eyesores that require hundreds of acres of land apiece. Freeing up more room at the Eagle Mine’s basin could avoid the need to dig new ones to serve future mines in the UP.
And if other mines copy Eagle’s plan to pipe tailings back underground, “you might not need tailings facilities at all,” said Lei Pan, associate professor in chemical engineering at Michigan Tech.
Tensions persist
Ayres, of the Keweenaw Bay Indian Community, said to the extent those promises bear out, he sees the Eagle Mine/Revex project as “potentially a great project.”
“We’re talking about the reduction of acid-producing sulfides on the landscape,” he said. “At least from my perspective, that’s better than just leaving a big pile of it somewhere.”
Kathleen Heideman, an anti-mining activist in the UP, doesn’t believe the federal government should subsidize the Eagle/Revex project without first studying its environmental impacts. (Bridge photo by Kelly House)
But some UP mining opponents have expressed concern about the project, seeing it as a ploy to justify new mines that come with plenty of other environmental concerns, from noise pollution to air emissions.
“All of the funding stuff starts happening before we even see a permit related to anything like a black mass facility grinding up batteries,” said Kathleen Heideman, who leads a UP mining opposition movement called the Mining Action Group. “That’s a potential concern, in terms of the environment.”
Eagle officials feel differently. Together, the mine and an associated ore-processing mill employ about 470 people. Unless a new mine opens by the time Eagle closes, those jobs will disappear, delivering a shock to the local economy.
“Ten years ago,” Stacey said, “there was nobody mining nickel in the US. Now we have global expertise right here in Marquette County … if we invest in it, we can keep it, and get a bridge until somebody finds something more. Or it’s going to scatter to the four winds.”
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Featured image: Katy Dorfschmidt, center, converses with colleagues Andy Vaughn, left and Meagen Morrison, right, inside the Eagle nickel and copper mine in Marquette County. (Bridge photo by Ryan Stephens)
