The blast furnace Hamborn no. 4 at the ThyssenKrupp mill in Duisburg will be gone by next summer.
The furnace was built in 1964 replacing the old no. 4 that had been  partly dismantled for reparation. It has a hearth diameter of 10,70 meters and a working volume of 2030m³.
The new furnace was the  first one worldwide to be equipped with a bell less charging system. And it was the first in Germany to use coal powder injection.
Until May 2008, when the furnace was mothballed as a back up furnace it produced 43 mio. tons of iron.