The plant's process is complicated but promises to reduce the carbon footprint of steel production. When completed, the facility will receive concentrated iron ores recaptured from century-old waste tailings in northern Minnesota. A rotating railcar dumper will deposit the powdered ore into a winding system of conveyors and processing stations intended to grind, slurrify and filter the hematite-rich material; blend it with limestone, coke breeze, dolomite and bentonite; roll it into musket-sized balls; cook it to more than 2,300°F; and load it into railcars headed for AK Steel blast furnaces in Middletown and Ashland, Ky.
Efficiency is the game during construction and, eventually, operations. The owner has retained principal designers Noramco Engineering Corp. of Hibbing, Minn.; TKDA of St. Paul, Minn.; and the Pittsburgh offices of Metso Corp. and Jacobs Engineering. For construction, Magnetation is acting as its own general contractor as well as material supplier to contractors on site.
Risks and Rewards
For the contractors involved, the owner's heavy involvement is a bit unusual, though team members credit the owner for overseeing a tightly run job while remaining flexible. The mining operator is familiar with construction needs; after all, mines are built. And the relationship shifts the uncertainty of material pricing to the owner and labor risk to the contractors. "That's a huge savings to them because they don't have our material markup," says Potter. "But if we blow the labor, we don't have the markup to cover us."
Still, considering that the project is consuming 65,000 cu yd of concrete, 23,000 tons of steel, countless mechanical components and hundreds of thousands of cubic yards of excavated earth—all piled onto the owner's ambitious goal of designing and constructing a complex processing facility in a little more than a year—the builders admit that the work has called for extreme management measures. "We're going to meet their schedule, come hell or high water," says Jim Streeter, vice president with Midwest Constructors LLC, Indianapolis, which has been charged with building the railcar dumper building, framed in concrete, a massive ore barn, framed in concrete and steel—both connected by a 250-ft-long concrete conveyor tunnel rising at a steep, 12.4% slope—as well as a pellet loadout building on the downstream end.
The project hasn't necessarily been hell, but high water has, at times, slowed the effort. Soon after breaking ground last March, a hidden aquifer near the car dumper site suddenly found its way to the surface. Workers scrambled to plug the hole, which was oozing a muddy mess and eroding surrounding soil. Workers quickly dug a cutoff wall to contain the building's foundation, built a dam of large concrete blocks to slow the erosion and installed additional de-watering pumps, increasing capacity to 8,000 gallons per minute from 1,000 gpm, to move the water away from the project. Within 14 days, the site was under control again.
Teamwork saved the day, project officials say. When such challenges emerge, "a lot of times people get knocked back on their heels and sit there dazed for days and weeks," observes Neal Burnett, co-owner of Midwest Constructors. "The most impressive thing that occurred here is that the Magnetation team and our team sat down and started developing pathways immediately to solve the problem. It came down to the worst decision is no decision."
