Blast furnace Schwelgern 2, owned by diversified industrial group ThyssenKrupp Steel Europe, produced its seventy-millionth ton of hot metal in February.

“The first furnace reline for Schwelgern 2 is scheduled for next year and preparations are already in progress,” says Schwelgern blast furnace plant head Wolfgang Wiese.

The Schwelgern blast furnace plant in Duisburg, Germany, is home to blast furnace Schwelgern 2, Europe’s largest blast furnace and one of the biggest of its kind in the world.

“The cost-effective and environment-friendly blast furnace, with its 540-strong crew, went into operation in 1993 and has been producing high-quality hot metal for the two basic oxygen furnace (BOF) melt shops, Bruckhausen and Beeckerwerth, for 19 years,” explains Wiese.

“With the iron produced so far, one could build almost 3 000 copies of Cologne’s famous steel monument, the Hohen-zollernbrücke Bridge, which is more than 400 m long and about 30 m wide.”

The furnace has a 5 513 m3 capacity with a hearth diameter of 14.9 m. Hot air is injected into the large-scale furnace through its 42 tuyères, creating a high temperature ideal for smelting.

The furnace produces around 12 000 t/d of hot metal and about 3 300 t/d of ground granulated blast furnace slag, which is used as a basis for cement manufacture.

An estimated 12-million cubic meters of top gas is used in the mill’s energy network a day.

Production Process
The 90-m-tall blast furnace produces about 12 000 t/d of hot metal from about 19 000 t of processed iron-ore, with up to 4 000 t of coke charged into the top of the furnace.

The solid mass is melted by the injection of hot air at a temperature of 1 200 °C and coal dust to create temperatures of up to 2 000 °C.

The hot metal flows into the bottom section of the furnace, where it is removed from two of the four tap holes.

From there, the molten metal is transported in refractory vessels by rail to one of the two BOF melt shops and further processed into high-quality crude steel, which is subsequently used to make car parts or domestic appliances such as washing machines and dishwashers.

Sophisticated Design
ThyssenKrupp Steel Europe operates four blast furnaces at its 9 km2 site in Duisburg. The furnaces produce around 11.5-million tons of hot metal a year.

Blast furnace Schwelgern 2 was put into operation after ThyssenKrupp had gained a wealth of experience in building blast furnace 1, the world’s first large blast furnace.

“Blast furnace 2 has an extremely sophisticated design, in terms of its refractory lining and furnace cooling system, and is still up to date with the latest technologies,” says Wiese.