By Nick Gilbert
ThyssenKrupp Steel Europe’s Duisburg-Beeckerwerth BOF meltshop celebrated its 50th anniversary in June 2012. This mill started its operations during 1962 and had been developed as a green field project within a period of two years. So far, the mill has manufactured crude steel of approximately 209 Mt.
The Duisburg-Beeckerwerth meltshop is capable of producing 5.9 Mt of steel in a year, having 265 t of average heat weight. It was equipped with two converters during its construction phase. In 1971, a third converter was added to the meltshop. The company had built the first continuous caster during 1974 and closed some ingot casting capacity. It commenced operations at a second continuous caster in 1980 and completely stopped ingot casting in 1986. Restructuring of the meltshop was carried out in 1987 using new primary and secondary dust collection systems and a converter gas recovery system. Simultaneously, the company operated a first steel degassing system, wherein a second system was put into operation in late 2001.
Many phases are involved during hot metal processing. Hot metal are tapped from Schwelgern and Hamborn blast furnaces and supplied in torpedo ladles and is processed in a number of stages to yield liquid steel of the desired quality. Phosphorus, silicon and sulfur are the impurities present in hot metal. Refining process removes all these impurities. Addition of steel scrap, having 10% to 30% of the entire heat weight, cools the boiling steel. The blowing process exists for approximately 18 minutes. The temperature of the molten steel ranges from 1,650°C to 1,720°C, when tapped into a pouring ladle. Tapping process also includes the addition of alloying agents. Secondary metallurgy has to be carried out in order to produce high-quality steel. Then, the steel is cast into slabs, which are up to 2,400 m thick and 255 mm thick, on one vertical bending-type and bow-type continuous caster.
The Beeckerwerth BOF shop manufactures high-quality starting material for use in the automotive industry, and tinplate and steels for use in the packaging industry.