Gazing across the craggy canyon that is the Hull-Rust-Mahoning mine in Minnesota's legendary Iron Range, it's hard to believe that our planet's most abundant element - iron - is mostly locked away in the earth's core. For here iron-bearing rock has shouldered its way to the surface in heroic quantities, and men and machines have carved out the world's largest iron-ore pit. And as it has for over a century, Range iron still forges the steel sinews of the American economy. But more than a century of mining has left Iron Country scraped and scarred, a landscape dominated by vast quarries and basins of stony waste from processed ore - tailings, which sprawl across the land like a mighty river delta. Now largely covered by scrub vegetation, these tailings are the remains of a struggle to wrest a living from the earth that began with the great Iron Rush of the 1880s. Fortune hunters from far afield flocked to the rich hematite mines of the Vermilion and Mesabi ranges, which were soon minting millionaires so fast that by 1910 regional capital Duluth was reckoned to have more than any other city in the world.I was curious what happened to them, since I hadn't heard anything since. So after a search, I came across this:
Two world wars brought boom times as the Range answered the call for iron and steel to arm the nation. And there were busts too, notably during the Depression, when output crashed from 47 million metric tons in 1929 to just 2 million metric tons in 1932. And all the time those tailings kept accumulating - a buildup that will continue until the ore runs out. Then the Range will fall silent, closing a long chapter of American history.
Or maybe not. Just west along Route 169 from the Hull-Rust-Mahoning mine, near the town of Keewatin (pop. 1,164), a vast domed structure dominates a tailings basin left by the defunct Mesabi Chief mine. The dome can't be seen from the highway, and few Rangers (and even fewer mining corporations) know it's there. Inside sits equipment that could prove to be as significant to the region as the 1950s-era discovery of a way to extract iron from low-grade taconite rock. The earlier technique arrived in the nick of time for the Range, for its hematite - known locally as "natural" ore - was almost depleted. Similarly, the dome at Keewatin is home to a revolutionary process, dubbed "magnetation," that can extract valuable iron from the tailings - just when the Range is in need of new sources of ore.
According to Magnetation, the patent-pending Rev 3™ Separator technology allows mining operators to recover a marketable, high-grade iron ore concentrate from low-grade hematite iron deposits, including material left behind from prior mining and mineral processing operations.So apparently, things are going forward with that technology. That there appears to be one of those billion dollar ideas.
The recovered product can be sold to a variety of iron-making industry customers.
As part of the agreement, Cargill has the exclusive, worldwide right to jointly develop and apply the technology with Magnetation, and the right to market the recovered iron concentrate to its international iron ore customers.
Cargill’s financial involvement will help enable Magnetation to boost its production of recovered iron in Minnesota from 150,000 to 450,000 tons per year.
Magnetation points to the promising commercial aspects of the technology internationally, as well as to the environmental benefits in transforming iron tailings basins into functioning ecological wetlands.
“This pioneering technology generates, in essence, a new source for high-grade iron concentrate from existing resources,” said Larry Lehtinen, Magnetation chief executive officer. “Cargill’s support of this iron recovery technology demonstrates the real commercial value it presents to the iron industry worldwide, as well as the promise it holds in terms of its positive environmental footprint.”
“We are pleased to contribute to the advancement of what we see as next-generation technology in iron recovery,” said Bob Mann, vice president of Cargill Ferrous International. “This agreement capitalizes on Magnetation’s iron recovery expertise and Cargill’s international commodity merchandising and asset development capabilities.”