Anyone passing along Werkstrasse at Salzgitter Flachstahl between blast furnace A and the power plant in May of this year would have been able to witness a new, lower furnace in the making. Staff from Pirson Montage were working directly in front of the old blast furnace and welding together the up to 70-millimeter thick annular metal rings from Ilsenburger Grobblech; Danieli Corus was selected as the main contractor for the relining project.
Technology and logistics challenges
The old furnace hearth was dismantled before the actual relining work.
The furnace was tapped via a low borehole and the residual “furnace sow” – some 160 tons of pig iron – was flushed out.
Relining and modernization in one step
When relining the furnace shell with refractory carbon bricks, Salzgitter Flachstahl took the opportunity to update the entire blast furnace so that it meets the current state of the art. This guarantees that the furnace will operate as efficiently as possible in the future.
Some examples: virtually maintenance-free, closed cassettes have now replaced the open-hearth irrigation system. Various components were replaced either in full or in part, including the gas cleanup and hot blast system, heat recovery, supply lines and the electrical equipment. The entire blast furnace, including the control technology with process visualization, now meets the current state of the art. A blast furnace campaign of fifteen years now appears realistic.
Changes have also been made to the area around the blast furnace: the new slag channels have already been laid for the granulation plant that is currently under construction; in future, the blast furnace sand for the cement industry will be produced here. The foundry was also modernized during the course of the relining work.