Hüttenwerke Krupp Mannesmann GmbH (Duisburg, Germany):

Urban W., Mag. Eng.
Weinberg M., Dr.-Eng.

Cappel Stahl Consulting GmbH (Meerbusch, Germany):
Cappel J., Dr.- Eng., Head of Ironmaking Shop, e-mail: juergen.cappel@cappel-consult.de

The removal of phosphorus from the furnace charge is a well understood process today and is described by using the phosphorus partition ratio between metal and slag L_P = (% P₂O₅)/[% P]. The detailed analysis of the effect of corresponding chemical and thermodynamical parameters on the base of industrial tests is given. The L_P depends on the melt temperature, the Fet content in the slag, slag basicity, slag vo lume, MgO content in the slag and the steel carbon content. Other para meters are the phoshorus input with the hot metal and the phosphorus content of the steel product specifi cation. Furthermore the results also vary with the individual plant equipment available and the dephosphorization strategy applied. Basic oxygen shops using combined blowing (top oxygen tuyere and bottom stirring with inert gas) have some kinetic advantages comparing with the shops supplied with only top tuyere. As soon as dephosphorization reaction is far from is thermodynamical equilibrium state due to high productivity of industrial processes with blowing, it is necessary to take into account during simulation features of the equipment of an individual basic oxygen shop. Therefore, each basic oxygen shop should have its own dephosphorization model on the base of statistical data evaluation.

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