Steel Dynamics ~ Mesabi Nugget Plant

Hoyt Lakes, Minnesota

Project Description

When facing the unique challenges of the frigid, open-pit site of the world’s first commercial iron nugget plant, it’s helpful to have BoldThinking® for flexibility and imagination on your side. Steel Dynamics turned to Boldt for the first and most important foundation of the direct reduced iron plant project; the 33-ft. wide, 240-ft. diameter, ring-shaped foundation of the rotary hearth furnace.

One of the unique challenges was working with a radius foundation. This was made easier using Symons Flex-Form panels which were delivered to the job site pre-assembled to the required radius. The panels helped form the foundation's 4,200 cu. yds. of concrete which was poured vertically over 500 tons of reinforcing steel during winter conditions. Close coordination with the earthwork contractor to perform rock blasting and back-filling, was needed because portions of the foundation design were changed as work was progressing.

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Krech & Ojard

Boldt's Role

General Contractor

Key Points

  • Working on an open-pit site in northern Minnesota presented some interesting weather challenges. The weather was 20 degrees colder at the nugget site than the surrounding area.