MPR News Primer: Copper-nickel mining

Drill rig in BWCAW
Trucks and a drill rig drill into the ground near the Boundary Waters Canoe Area Wilderness Thursday morning near Ely, Minn. The trucks were doing exploratory drilling for Duluth Metals.
MPR Photo/Derek Montgomery

Last updated on February 28, 2013

Mining runs deep in the culture and economy of northern Minnesota. So why are people drawing battle lines over plans to build copper-nickel mines in the Iron Range? It's a new kind of mining for Minnesota and there are plenty of potential rewards -- and risks. Can a middle ground be found between economic, environmental and quality of life concerns?

Who wants to build new mines in northern Minnesota?

Two huge copper-nickel mining projects are under consideration in northern Minnesota, which holds one of the world's largest untapped copper deposits. Several other companies are exploring in nearby areas for copper, nickel and precious metals that could result in additional projects.

Better technology, together with rising copper prices the past decade, are making large scale metals mining cost-effective here and potentially very lucrative.

One company, PolyMet, wants to build an open pit operation to mine copper and other metals.

Another venture, Twin Metals, plans a massive, largely underground mine southeast of Ely -- a company official has likened it to an "underground city" -- stretching near the edge of the Boundary Waters Canoe Area Wilderness.

Called the Nokomis project, it would be one of the largest private ventures ever launched in Minnesota -- the company estimates its state investment could top $2 billion eventually, more than double the value of, say, a new Vikings stadium.

The PolyMet and Twin Metals projects have been years in the making. Each is in the process of taking a next big step.

At PolyMet, whose plans have been mired in environmental concerns, a long-awaited supplemental draft environmental review is expected to be completed this spring and released to the public in the summer.

Twin Metals is conducting a "pre-feasibility" study for the building of a mine and copper production plant. It's expected to be finished in the first or second quarter of 2014.

What makes these projects different from northern Minnesota's taconite mines?

Minnesota is new to this kind of large scale copper-nickel mining. The scope of these projects is enormous and some of the methods used to process the rock after it's dug from the earth are very different from northern Minnesota's traditional taconite operations.

In taconite mining, the mined iron ore is separated from the rock using magnetism. Copper-nickel mining involves removing copper and other metals from sulfur deposits using heat, pressure and chemicals in a controlled process.

That kind of mining creates concerns because when sulfide-containing rocks are exposed to the elements they produce sulfuric acid with the potential to poison watersheds and kill fish and plant life should it escape. The Environmental Protection Agency says acid mine drainage can be "highly toxic and, when mixed with groundwater, surface water and soil, may have harmful effects on humans, animals and plants."

The companies say they know how to keep those acid rock dangers in check by collecting the waste rock in lined basins and treating any water that would come in contact with it. Eventually the waste rock would be returned to the mined-out pits, which would be allowed to flood, says Jim Miller, associate professor of geology at the University of Minnesota Duluth. "The potential for sulfuric acid generation ends when the waste rock is submerged in unoxygenated water."

There are deep divisions over this kind of mining, to the point where advocates and critics can't agree on whether to describe it as copper-nickel mining, nonferrous mining or sulfide mining.

What are the arguments for the proposed new mining operations?

Proponents cite jobs, tax revenues and even national security. The projects promise to bring thousands of mining industry jobs to northern Minnesota, hundreds of millions of dollars in new business -- and the tax revenues and royalties that go with it.

A University of Minnesota Duluth economic analysis funded by mining groups and state agencies predicts that proposed copper-nickel projects could create nearly 1,900 permanent jobs and over 2,000 construction jobs by 2016, with an economic impact on the region of nearly $400 million.

St. Louis County officials say new, non-iron mining projects have the potential to add more than $2.7 billion to the state's economy and another 7,000 new jobs over the next 20 years. That would more than double the current number of mining and logging jobs in Minnesota now.

The industry says the projects could generate tens of millions of dollars in tax revenue each year and channel hundreds of millions in state land royalties to public schools.

The industry also argues that copper mining is a national security issue for the U.S., noting the U.S. consumes about twice the copper it produces annually.

Others argue the metals are too valuable to be left in the ground -- copper and nickel are vital elements in countless products from hybrid cars, construction to aerospace -- and that a balance can be found between this kind of mining and the environment. "We are all obligated to see that this resource is developed responsibly and with the highest environmental standards," writes the University of Minnesota Duluth's Miller.

PolyMet and Twin Metals say they will be good stewards of the Minnesota environment, using the latest technology and techniques to minimize pollution created by their mining.

What are the arguments against the new mines?

Environmental groups including the Sierra Club and Minnesota Center for Environmental Advocacy, argue, "This is not the taconite mining that made the Iron Range famous and that Minnesotans understand ... Sulfide mining has the potential to leach sulfuric acid and toxic metals into local watersheds, polluting water and wrecking wetlands."

Critics say projects in other states show sulfide mining is a risky proposition, damaging wetlands and watersheds. They argue that despite corporate commitments, taxpayers will be on the hook ultimately to pay for any long-term cleanup, as they have been elsewhere.

Skeptics are also wary of the claims of an economic bonanza, which hinges on the global prices for copper and other metals. The taconite business took a huge hit during the Great Recession.

Mining also has to be balanced with the region's tourism industry, which generates more than $750 million a year and 16,000 jobs in northeast Minnesota, as well as the concerns Native Americans have about copper mining's potential effects on the region's wild rice harvest.

What happens next?

It's a regulatory and public relations grind now for supporters and opponents of the metals mining projects.

In late May 2012, the U.S. Forest Service approved a batch of applications to prospect for copper and nickel south of Ely -- stressing that permits were for exploration only.

PolyMet has plans to buy farmland and restore it to wetlands (It must create one acre of wetland for every one it destroys or impairs). Environmentalists are skeptical. The next public milepost for the project will come in summer 2013 with the release of an environmental review of the company's plan.

Twin Metals is pushing ahead with its feasibility study and "collecting baseline environmental data across 32,000 acres the company has secured access to under which geologists say is a jackpot discovery of copper," the Duluth News Tribune reports.

For both projects, it will be a marathon dig.

MPR News reporter Dan Kraker contributed to this story