Tuesday, July 3, 2012

Milestone anniversary at ThyssenKrupp Steel Europe: Duisburg-Beeckerwerth steel mill turns 50

The team at the Beeckerwerth BOF meltshop of ThyssenKrupp Steel Europe in Duisburg has reason to celebrate: Built as a greenfield project in a period of just under two years, the plant started up in 1962 and celebrated its 50th anniversary at the end of June 2012. Around 209 million tons of crude steel have been produced since operations commenced in the boom years of the "economic miracle". To illustrate the scale of this, the steel produced would be enough in theory to build around 21,000 Eiffel Towers. Heinz Liebig, head of crude steel production at ThyssenKrupp Steel Europe in Duisburg: "Together with my team, I look forward to leading this traditional yet highly modern plant into its next 50 years." To mark this anniversary, employees at the steel mill invited their families to look around the plant last Saturday.
The Duisburg-Beeckerwerth meltshop, which employs around 780 people, has a capacity of 5.9 million tons of steel a year with an average heat weight of 265 tons. It was built exactly 50 years ago with two converters; a third converter was added in 1971. With the building of the first continuous caster in 1974, some ingot casting capacity was closed. A second continuous caster was put into operation in 1980 and ingot casting was discontinued completely in 1986. In 1987 the meltshop was modernized with a converter gas recovery system and new primary and secondary dust collection systems. At the same time a first steel degassing system was put into operation. A second one began operation in late 2001.

In the Beeckerwerth meltshop, hot metal previously tapped from the Hamborn and Schwelgern blast furnaces and delivered in torpedo ladles is processed in several stages to produce liquid steel of the required quality. Here's a simplified version of what happens: Hot metal still contains impurities such as silicon, sulfur and phosphorus. The sulfur is removed from the iron in an upstream process. The other impurities are removed in the converter by top-blowing oxygen through a water-cooled lance. This process, which generates temperatures of more than 2,500 degrees Celsius, is known as refining. To cool the boiling steel, steel scrap is added in quantities of ten to 30 percent of the overall heat weight. The actual blowing process lasts around 18 minutes. When it is tapped into a pouring ladle, the molten steel still has a temperature of 1,650 to 1,720 degrees Celsius. Alloying agents can also be added during tapping. Due to the high quality requirements for the properties of the steel, it has to undergo post-treatment, referred to as secondary metallurgy. The steel is then cast into 255 mm thick and up to 2,400 mm wide slabs on one bow-type and one vertical bending-type continuous caster. The Beeckerwerth BOF steelmaking shop produces top-quality starting material for the automotive industry, steels and tinplate for the packaging industry, as well as skelp and quarto plate.  

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