A Tale of Taconite

Let's begin this article by sweeping away a misconception: Taconite is not the Thursday-night special at your neighborhood Mexican restaurant.

Hibbing Taconite is one of seven such operations on Minnesota's famed Iron Range.

Yes, we're being a little facetious here. But it's a facetiousness born of frustration, for whenever we stray from our northern Minnesota home - and we don't have to stray very far - we learn that the extraordinarily valuable material known as taconite is little known and poorly understood outside of iron mining and steel making circles.

We'll define extraordinarily valuable by asking a question: Did you know that two-thirds of the steel made in America originates as taconite from the mines of Minnesota's famed Iron Range? That's how valuable and important taconite is.

Iron mining equipment comes in one size - XXXXXXXXXXXXXL.
Photo courtesy of the Iron Mining Association.

And now we'll start at the beginning.

Taconite, simply put, is iron-bearing rock. The name was first applied to formations in the Taconic Mountains in Vermont and Massachusetts.

Taconite poses at least two challenges to steelmakers who would use it. No. 1, its iron content is modest. Only about 30 percent of the rock is iron, thus creating the need for separating the iron from chaff. And, No. 2, it is harder than a used-car salesman's heart. As a result, extracting taconite from the earth and iron from the taconite and turning it into pellets - a material ready for use in a steel mill - is one big job.

(Before we go on, we'll answer a question that might have occurred to you: Why go to the trouble of dealing with taconite when natural ore - red ore in mining parlance - is easier to extract? The answer: Because supplies of red ore are virtually depleted, especially in North America. Without taconite, and the technology to capitalize on its presence, America would be without an iron mining industry - and that would put punishing pressures on America's steelmakers, and on the American economy. Further, steelmakers prefer the uniform size, strength and content of modern pellets over natural ore, which can contain more impurities and burn unevenly in the blast furnace.)

The techniques vary somewhat from company to company among the seven iron mining and pellet making operations on Minnesota's Iron Range, but the science and the process at each are essentially the same. Here, with apologies to those who actually apply the science and the sweat - 24 hours a day, seven days a week, year-round in every condition that the climate of northern Minnesota can impose on those tough enough to challenge it - is a simplified account of how an iron ore pellet is made.

It begins with using earth-moving equipment to remove the overburden and expose the ore body. In the Mesabi Range formation, which runs 110 miles north-easterly from near Grand Rapids to Babbitt, the body is one to three miles wide and up to 500 feet thick.

Once the body is exposed, the process of turning a seemingly impenetrable geologic formation into big rocks, and big rocks into little rocks, begins. It starts with an electric-powered rotary drill that makes a series of precisely located holes. In most cases, as at LTV Steel Mining Company in Hoyt Lakes, the holes are 16 inches across and 45 deep. Explosives are pumped into the holes, preparations are completed and someone who knows exactly what he or she is doing touches off the explosion. Crump is a sound well known on the Iron Range.

With the formation broken apart for the first time since its creation millions and millions of years ago, the taconite goes on a journey.

Shovels capable of scooping up as much as 80 tons of rock pick up pieces as large as a CEO's desk and transfer them to, depending on the mine, rail cars or trucks. Trucks in the latest generation of haulers on the Range are capable of carrying 240 tons of taconite. Your bedroom would fit comfortably in the bed. Its tires alone are 12 feet tall and weigh 3 3/4 tons. A big job calls for big equipment. That big equipment delivers the rock to crushers, which, in stages, reduce it to about three-quarters of an inch.

Next grinders - at LTV each one is powered by two 6,000-horse electric motors - and concentrators, where the rock is mixed with water and then ground to the fineness of m'lady's face powder. M'lady should be careful how she uses this powder, though, because it is black as coal and hard as the devil to get off of fingers, faces and anything else to which it has been applied.

Next comes the separator, which, using powerful magnets, pulls the iron from the powder. This critical stage increases the percentage of iron in the concentrate to about 67 percent. From here, the non-metallic material, now reduced to tailings, is pumped away to an environmentally sound disposal basin. The metallic concentrate is pumped to the pellet plant. There, the concentrate is filtered to remove all but 9 to 10 percent of the water, mixed with bentonite clay and rolled into balls about the size of a marble. Or, if you're familiar with the great outdoors, about the size and color of a deer pellet.

Once formed, the balls are moved to furnaces where they are heated at 2,350 to 2,450 degrees Fahrenheit. Once removed from the furnaces, they begin to cool. As they cool, they harden. And once hardened, they are iron ore pellets - today the basic raw material with ideal physical characteristics to feed the nation's blast furnaces.

Now they're ready for shipment to steel mills. They go by boat across Lake Superior and down the lower lakes system to East Chicago, Burns Harbor and Gary, Ind. And to Cleveland and Middletown, Ohio. And to Pittsburgh, Pa., and Granite City, Ill. About 18 percent of the Range's annual production goes by direct rail to Ogden, Utah, and Fairfield, Alabama. The Port of Duluth-Superior handled about 16.5 million tons of taconite pellets last year and expects to move about the same this year.

The industry - fired by economic pressures that are as hot as its fierce blast furnaces - has become highly modern, productive and efficient. Minnesota's Mesabi Range mines and plants are capable of producing about 48 million tons of taconite pellets a year.

They are vital to the economy of Minnesota. They have annual payrolls of $393 million and generate the purchase of goods, energy and support services of more than $900 million a year. In 1995, with mining royalties and state taxes factored in, iron mining meant $1.3 billion to Minnesota's economy.

Over the years, more than $4 billion has been dedicated to the development of taconite-mining and pellet-making processes. This will continue. "Minnesota iron mining has enough ore to keep mining for centuries, and we're committed to investing the capital needed to ensure that we can remain competitive well into the future," said Ann Glumac, director of the Iron Mining Association.

More than 20,000 jobs in more than 200 Minnesota communities rely on the industry, with only about a third of those workers actually engaged at a mine or processing plant. The rest - often hundreds of miles away - are involved in supporting roles. None of them, we might add, in a Mexican restaurant.