Well-regulated sulfide mining can be done effectively – by Rolf Westgard (Minn Post.com – January 27, 2014)


Rolf Westgard is a professional member of the Geological Society of America and is guest faculty on energy subjects for the University of Minnesota’s Lifelong Learning program. His 2013 fall-quarter class was “Minnesota’s Volcanic Geologic History; from Mountain Building to Minerals.”

The dispute over mining Minnesota’s world-class mineral deposits is drawing big crowds to the public hearings on the new Supplemental Draft Environmental Impact Statement (SDEIS ) on the proposed NorthMet Project. All those minerals — including copper, nickel, cobalt, gold and platinum — lie in a band, meandering from southwest to northeast, adjacent to the Archean granite of Minnesota’s Iron Range.

They arrived a billion years ago in the magma during northern Minnesota’s active volcanic history. They are concentrated out of the magma by liquid sulfur, which acts as a “collector,” because these elements prefer the sulphide liquid to the magma by a factor of 1,000 times more.

One of the proposed Minnesota mining ventures is by PolyMet Mining Corp. of Canada. PolyMet’s group includes Swiss commodity and mining giant Glencore, which now owns 18 percent of PolyMet shares. Glencore and PolyMet will need to be financially accountable for shutdown and monitoring of the mine site after closure.

PolyMet’s project expects annual metal production of 39,000 tons of copper, 9,000 tons of nickel, 400 tons of cobalt, 22,000 ounces of platinum, 87,000 ounces of palladium and 13,800 ounces of gold from its lease. A 2009 714-page draft environmental impact statement (DEIS) on the company’s NorthMet Project was released by the Minnesota DNR and the U.S. Corps of Engineers.

That DEIS notes that any effluent from the project will end up in the drainage areas of the Partridge and Embarrass Rivers. Those rivers flow south to the St. Louis River and Lake Superior, not north to the Boundary Waters. The DEIS was generally positive about the project, and it suggested that if all of PolyMet’s commitments are met, there is no serious impact on the environment. The Environmental Protection Agency disagreed and called the draft statement inadequate.

General agreement with ’09 report

A new 1,000-plus page document has just been released by the MN DNR, Corps of Engineers, and U.S. Forest Service in response to EPA concerns. The new SDEIS generally concurs with the 2009 report, stating, “The project is not predicted to result in any significant changes to groundwater and surface water flows when compared to existing conditions.”

For the rest of this column, click here: http://www.minnpost.com/community-voices/2014/01/well-regulated-sulfide-mining-can-be-done-effectively

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