ThyssenKrupp Steel Europe AG (Duisburg, Germany):

Rüther P., Dr., Production Hot Metal
Peters M., Dr. Eng., Head of Production Hot Metal, e-mail: m.peters@thyssenkrupp.com

After nearly 21 years of campaign life and a production of more than 78 million t of hot metal in the blast furnace 2 at Schwelgern works, this blast furnace was relined in summer 2014. The main criteria for achieving such a long campaign like raw material quality, furnace layout, refractory concept, cooling and opera-tional influence are described. The authors give an overview of the preparations before the reline and show the execution of the reline project, the salamander tap, the hot wrecking of the hearth together with the findings regarding the wear pattern inside the furnace. The design of the working platforms inside the furnace for the parallel lining work made it possible to carry out the whole reline in 91 days. The entire furnace campaign of 21 years has by far exceeded all expectations. Without going into negative features strongly impacting the furnace durability like the number of stoppages, defective tuyères, production reduction, poor raw material quality, it can be said that the lining concept has proven successful. Given the durability of the ceramic cup of nine years and further 12 years with the carbon lining, it is currently considered to increase the ceramic side wall from 400 to 600 mm. In future it will remain difficult to use positive information directly for relinings. Apart from the methods previously employed, campaign lives of 20 years call for novel methods of checking the furnace condition.