voestalpine AG
voestalpine AG
03/14/2024 | News release | Distributed by Public on 03/14/2024 06:43
greentec steel: building progress above and below ground
In this article
Our new electric arc furnace (EAF) will commence operation in 2027. We are already hard at work on securing its future supply. The pressure is on to ensure the raw materials, aggregates, and green electricity are available in time for the inauguration of the EAF. With completion of the conveyor belt bridge, one of the major projects involved in achieving this goal has been ticked off the list. The conveyor belt bridge will supply the LD crucible and EAF with materials including HBI and additives, transported from a depth of 15 meters underground to more than 50 meters overground.
The bridge to green steel
This supply line at the voestalpine site in Linz runs over a distance of 800 meters, from our new raw materials warehouse to the special steel plant complex. From April 2024, the conveyor belt bridge will supply the LD steel plant and, once commissioned, the new special steel plant. The former belt system gives way to the newly constructed special steel plant, with the new belt conveyor supplying alloying materials and aggregates to the existing LD3 steel plant. This is more than just a simple switch: the new belt conveyor offers one additional belt to transport HBI-directly reduced iron ore-to the EAF.
A colossus on feet of steel
Work to build the new belt conveyor has been underway since August 2022. The supports will bear a total weight of 5,000 tons, the weight of the structure itself. Once fully operational, the weight of the transported materials will also be added to the equation: HBI, aggregates, and alloying materials.
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Even before it commences operation, the new conveyor belt bridge is helping to reduce emissions. It is sheathed in voestalpine's own greentec Edition steel: 190 tons of steel with a reduced carbon footprint is used to house the entire belt conveyor. A true bridge to the world of green steel at voestalpine.
Hannes U.
Project Manager Belt Conveyor
High voltage below ground
Pushing ahead with exciting developments. The new EAF, which commences operation in 2027, will consume large quantities of electricity. We are laying a 220 kV cable in a microtunnel situated approximately 25 meters under the plant and running from the Hütte Süd junction to the EAF to meet this demand.
The 1,800 meter tunnel will be flooded with groundwater from the wet ground immediately above. The advantage: the water cools the 220 kV high voltage power line, reducing the amount of electricity lost in transit. Targeted pumping of small quantities of water ensures efficient cooling; without cooling, temperatures in the tunnel could quickly get too hot.
Placing the supply tunnel at this depth ensures our 220 kV power line runs under all other subterranean supply and disposal canals. It is, in any case, an exciting subproject in our greentec steel program.
Christian M
Project Manager Microtunnel/Solid Construction
Precise routing underground
Four shafts, each sunk 25 meters into the ground, provide basic orientation for the tunneling. Working from the shafts, the microtunnel boring machines use hydraulic power to tunnel their way through the sedimentary rock below ground. Each day their position is checked by GPS. Precision is essential because the tolerances are as little as 1 to 2 mm. After all, the electricity supply must arrive at exactly the right place in our new special steel plant.
We start excavation work for the shafts in Q2. The boring and lining of the tunnel sections will commence in April 2025. Afterwards, the electrical fixtures will be installed in the microtunnel.Whether up high on the belt conveyor or down low through the microtunnel, we will secure the supply to the EAF and LD3 in good time to ensure Austria's largest climate protection program can be realized on schedule.
FAQs
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Why run the power line underground?
Above ground, a high voltage power line would need plenty of space: for the masts, and to keep the necessary distance from people and buildings. For that reason, we are placing the power line in a microtunnel.
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How big will the microtunnel be?
The microtunnel will have an external diameter of 2.60 meters and an internal diameter of 2 meters. It will run over a distance of 1,800 meters at a depth of around 25 meters under the plant.
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Why will the new belt conveyor feature an additional belt?
Three rather than the previous two belts will supply everything needed for steel production: alloying materials and lime, as well as several hundred tons of HBI-directly reduced iron ore-will be fed into the EAF each day. Scrap and pig iron will continue to be delivered by special vehicles.
Our focus on greentec steel
Within the framework of our focus greentec steel, we provide an overview of our concrete steps on the way towards long-term CO2-neutral steel production and the innovative processes we are using on this way. We provide information about the challenges we face and the breakthrough technologies we are already researching today in order to achieve our goal of CO2-neutral steel production by 2050.