Sulfide Mining in Minnesota

Northern Minnesota’s wild forests and pristine lakes are the focus for new mine proposals that could forever change the region. These new mines, much different than Minnesota’s traditional iron mines, would extract copper, nickel and other metals from sulfide ore.

Two major mine projects in Minnesota are currently in the pipeline.  With several companies conducting exploratory drilling across northern Minnesota, additional mine projects are likely to be proposed.  The mining industry is heralding this as the beginning of a new sulfide mining district in the state which will exceed the iron ore industry in size.

Map of sulfide mining activity in northeastern Minnesota

Click to view larger map (PDF)

PolyMet Mining Corp.

PolyMet Mining logoPolyMet Mining Corporation has proposed a sulfide mine called the “NorthMet Project” between Babbitt and Hoyt Lakes, Minnesota.  The company proposes to develop an open-pit mine to extract copper, nickel and other metals. It would be located near the Embarrass and Partridge Rivers, which flow into the St. Louis River and then Lake Superior.

In 2010, the U.S. Environmental Protection Agency called PolyMet’s environmental review “inadequate and unacceptable.” In 2014, the EPA said the second draft of their proposal contained “insufficient information” and noted 37 problems that needed to be fixed.

The potential mine site is on public land in the Superior National Forest on a location that has never been mined. PolyMet plans to transport the ore to a former taconite processing facility about eight miles west.  Mine tailings are proposed to be disposed of in basins already in place from the former operation and which are adjacent to the processing buildings.

Over 58,000 public comments were submitted on the second draft of PolyMet’s environmental review, the largest number of public comments on a DNR project in Minnesota history. A Mining Truth analysis of the comments found that 98% of them were opposed to the mine proposal.

More about PolyMet …

Twin Metals LLC

Twin Metals logoA second sulfide mine has been proposed for northern Minnesota by Twin Metals Minnesota LLC. Twin Metals is owned by Antofagasta PLC, a Chilean-based mining company. This company is considering an underground mine located near Birch Lake, southeast of Ely, Minnesota. They are considering several ore deposits near Birch Lake, just a few miles from the Boundary Waters Canoe Area Wilderness.

Twin Metals spokespeople describe it as the largest underground mine in Minnesota’s history and “like an underground city.” A July 2014 pre-feasibility study found that an underground mine was marginally profitable. Upon acquiring 100% of the Twin Metals project in January 2015, Antofagasta announced that it would “optimize” the mine design and revisit the pre-feasibility study.

More about Twin Metals …

Additional exploration

Mineral exploration by other companies is occurring throughout northeastern Minnesota. Prospecting is focused on areas on the southern edge of the Boundary Waters, and near the communities of Stony River Township and Isabella. This area is part of the “Duluth Complex,” a mineral area of interest that stretches across the Arrowhead region.

Never before has this forest been the focus of so much mining activity. If mines are developed, this national forest will undergo a dramatic change in both how it appears and can be used by the public.