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E. W. Davis with Silver Bay Taconite plant in background.

Taconite research conducted by E. W. Davis -- seen standing in front of the Silver Bay Taconite plant -- helped revive Minnesota's mining industry. Photo copyright by the University of Minnesota Archives.

Groundbreaking research that revitalized Minnesota's Iron Range

June 28, 2006

Today, taconite mining contributes $1.5 billion annually to Minnesota's economy. Two-thirds of the iron used to build American cars, ships, homes and bridges comes from Mesabi Range taconite mines in northeastern Minnesota.

But generations of miners considered taconite to be rubble, a waste rock, until E.W. Davis of the University of Minnesota discovered how to unlock the wealth inside it.

Taconite's an ultra-hard, flinty rock containing about 30 percent iron. That's one-third as pure as the ore that drew mining companies to Minnesota in the 19th and early 20th centuries -- and which was virtually depleted building the weaponry for fighting World War II.

When the high-grade ore ran out, the Iron Range economy took a hard hit. Taconite revived it. Davis developed a process for separating iron particles from rock using magnets, then concentrating it to a level that 65 percent pure. That made taconite mining, which most experts thought would be too costly, an economically viable proposition.

It didn't happen overnight or in a moment of inspiration. Davis developed his ideas over four decades of patient work and earned 19 patents for everything from particle washers to conveyors to furnaces. He discovered how to mix the iron with clay to form marble-sized pellets that were easier to move to Eastern steel mills then melt down once they arrived.

The methods used today to blast taconite rock, crush it into powder, separate out the iron then concentrate it into pellets follow directly from his work. Taconite supports 16,000 Minnesota jobs, including 4,000 miners who earn about $65,000 per year working the process Davis developed.

For a different view of Davis's legacy, take a drive north up Highway 61 in northeastern Minnesota. Towns like Silver Bay, with its taconite plant on the edge of Lake Superior, were built from scratch in the early 1950s once Davis had demonstrated that mining had a future in Minnesota.

The University is still doing "groundbreaking" research into mining. A team from the University of Minnesota-Duluth's National Resources Research Institute, for example, is investigating the use of taconite waste in highway construction -- showing once again that with a little ingenuity, the so-called useless rock in Minnesota mines can yield hidden treasure.