New secondary metallurgy successfully goes into operation
08 February 2013
After two and a half years of planning and building, the new secondary metallurgy went into operation smoothly on 28th January as planned
- Total investment of 150 million euros
- 25 million euros for environmental measures
- Precise adherence to schedule and cost plan
Commenting on the 150 million euro investment, the Chairman of the Board, Dr. Karlheinz Blessing said “This is a good day for Saarstahl. The realisation of this project is a further milestone in our strategy to grow internationally in the premium segment.”
Martin Baues, Head of Engineering and Technology added: “This secondary metallurgy is unique in the world with regard to its complexity, method of construction and multi-functionality and it demonstrates our engineers’ ingenuity”.
With this investment, Saarstahl is increasing its capacity in the field of high-quality steels by more than double and is extending both its product range and product quality.
The crude steel manufactured in the steel plant is refined in the secondary metallurgy. In a precisely defined process, unwanted substances, which make the steel brittle, are extracted from the melt under vacuum conditions. Alloys are added, which give the steel increased elasticity and toughness. With the new system, Saarstahl can offer more types of steel and, above all, steels with a higher alloy content which are in particular demand from the automotive industry.
The new secondary metallurgy is in a three-section hall construction which is directly connected to the casting hall of the steelmaking plant. Here, the essential facilities such as the two twin ladle furnaces, the vacuum degassing plant, an injection unit, a central alloying plant with 34 bunkers, a water supply system and a central dust removal system are to be found. A decisive innovation for Saarstahl is the implementation of ladle furnace technology. It allows targeted heating of the steel melts in the pouring ladle instead of, as hitherto, in the converters with the result that these are considerably relieved of their burden.
Remarkable Building Project
The preparatory measures such as demolition and relocation of existing buildings and areas started in September 2010. The actual hall was then gradually constructed and grew continuously in height from May 2011 onwards. In the final stage, it is 60 meters high– the chimney is even 70 metres high -, 88 meters long and 48 metres wide. The steel construction weights approx. 3,400 tonnes. The heaviest components are the bottom sections of the six crosspillars in the transfer hall where the ladles are transferred onto transport units. Each of these parts weighs around 72 tonnes and is 12 metres in length. The platform with the 34 alloying bunkers carries a load capacity of 5,000 tonnes. In spite of the tight limitations of the building site, the fact that supply routes ran directly past it and that the assembly work was complex, production in the adjacent steelmaking plant continued to run smoothly throughout the whole duration of construction. Around 100 construction companies, of which 70 percent were from the Saarland, were involved with 600 employees. The largest portion was carried out by manufacturers of machines and systems from which, at peak times, there were 230 employees working on the construction site at one time. Thanks to careful planning there was not a single industrial serious accident. From Saarstahl’s side, 25 employees from the department for new buildings were involved in the project as well as numerous colleagues from the specialist departments and from environmental protection.
25 million euros for environmental protection measures
In this project, Saarstahl placed the greatest importance on effective environmental protection measures. A central dust removal system designed for a maximum extraction quantity of 600,000 m³/h and which undercuts the current limit for emissions by more than 75 percent, captures emissions in the form of dust directly where they occur. In order to reduce noise, the complete outer facade has been covered in a two-shell, 140 mm thick layer of insulation. Roof openings in the hall, cooling towers and the chimney are equipped with noise mufflers. Steam, which occurs as a by-product in the converter process supplies the power required for the vacuum degassing facility. An energy-efficient highlight is a newly installed turbine which is driven by the return circuit water of the cooling towers and therefore recovers part of the electrical energy consumed.