VDEh-Betriebsforschungsinstitut GmbH, Düsseldorf, Germany:

M. Schlautmann, Dr.Nat., Head of Project, martin.schlаutmann@bfi.de

B. Kleimt, Dr.Eng., Head of Department

SMS Mevac, Essen, Germany:

A. Kubbe, Dr.Eng., Head of Department

R. Teworte, Dr.Nat., General Manager

RWTH Aachen, Aachen, Germany:

D. Rzehak, Dr.Eng., Researcher

D. Senk, Dr.Eng., Prof.

SZ Acroni, Jesenice, Slovenia:

A. Jaklic, Dr.Eng., Head of Department

M. Klinar, Magister, Head Technologist 

The aspects of development and on-line application of dynamic process models for liquid steelmaking are presented in this article and their structure and functions exemplified for the Vacuum Oxygen Decarburization (VOD) process which will be described. At the VOD plant of Acroni the model is used for on-line observation and prediction of the carbon, oxygen, nitrogen and sulphur contents as well as the melt temperature. The prediction calculationsare used within enhanced dynamic process control functions for oxygen and inert gas flow rates, as well as the switching of vacuum pumps. They allow a more accurate temperature control and adjustment of final carbon and nitrogen contents with reduced slagging of chromium. For the VOD operation at Acroni, oxidation practices with combined blowing of gaseous oxygen andoxidic scale powder have been tested and included in the process model. They may enhance the decarburizationand should be applied for energetic reasons in particular for heats which are tapped fromthe EAF with high carbon contents and temperatures. At the same time this practise allows to recycle waste material from steel production in avery effective way.The on-line process monitoring and control functions based on dynamic models, which are implementedat Acroni’s VOD plant, allow a more accurate temperature control and adjustment of final carbon and nitrogen contents with reduced slagging of chromium.

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