Hüttenwerke Krupp Mannesmann GmbH (HKM)

The company Hüttenwerke Krupp Mannesmann GmbH (HKM) in Duisburg-Huckingen/Germany use an injection installation of Messrs. VELCO Gesellschaft für Förder-, Spritz- und Silo-Anlagen mbH, Velbert/Germany at their blast furnace B. The installation has been designed for the injection of fine grained solids as for instance Rutilit and carbon dust which are injected through the blast furnace tuyeres. Rutilit is a synthetic titanium oxide carrier. By the specific injection at selected tuyeres the temperature can be reduced in the blast furnace hearth at local hot spots. 

The chosen titanium dioxide carriers do principally consist of titanium dioxide and iron oxide that are coexisting in mineralogical advantageous oxidic phase. The free titanium dioxide will be reduced to titanium in the blast furnace by carbon or silicium. In the liquid iron the metallic titanium together with that in the pig iron soluted carbon and nitrogen form titanium nitrides and titanium carbon nitrides - high temperature resistant compounds that will settle at the inner refractory lining of the blast furnace. There it will result in a rapid growth of a protective layer. This protective layer shall protect the hot spots in the furnace to achieve projected lining points. Hot spots in the furnace will be located by thermal elements being installed around the furnace and then Rutilit sand will be injected via the above positioned tuyeres during the slag tap time. The injection process will be stopped when a "normal" temperature has been achieved. If Rutilit is not required, the installation can be used for the injection of carbon fines as cost-saving substitution of heavy fuel. About 4500 t of carbon has been injected in total from October 2008 - März 2009. 

The installation consists of a storage silo with a volume of 90 m³ that will be filled by silo trucks. The injection dispenser has two outlets that are connected with the lance in the tuyere by a conveying line of 70 m. The injection capacity is approx. 40 kg/min. per line.