VDEh-Betriebsforschungsinstitut GmbH (Düsseldorf, Germany):

Palm B., Project Engineer, e-mail: birgit.palm@bfi .de

Hayn S., Dr. Eng., Project Engineer

Köchner H., Dr. Eng., Head of Division

Saarschmiede GmbH Freiformschmiede (Völklingen, Germany):

Weides G., Mag. Eng., Head of Steelmaking Dept.

Haas M., Head of Electric Steelmaking Dept.

Thomassen G., Engineer, Secondary Metallurgy

The performance of many metallurgical operations is significantly influenced by the condition of the slag. In some cases, slag has to be removed as far as possi-ble or replaced to achieve optimal product quality. Online monitoring of the deslag-ging process supports the operator with objective evaluation and additional infor-mation. The control on-line system for deslagging, developed by BFI Institute, allows to realize direct observation of the melt surface, to evaluate objectively slag removal process, to control on-line the square of blowing spot, to determine amount of residual slag and to save information about each deslagging process. It assists operators in taking decisions in the end of slag removal process, providing decrease of amount of residual slag and acceleration of deslagging process. It is shown that sometimes slag is cooled down to such temperature, that it can’t be removed via ladle tilting, and large slag pieces are forming, which are the obstacles for deslag-ging. In this case, operator has to return a ladle in initial vertical position, melt is mixing, slag is heating and those large pieces are solving. The control on-line sys-tem for deslagging has been put into practice and successfully operated at Saarschmiede GmbH Freiformschmiede.

1. Mazumdar, D.; Evans, J. W.: Met. Mat. Trans. B 35B (2004) Nr. 4, S. 400/04.

2. Yonezawa, K. ; Schwerdtfeger, K.: Met. Mat. Trans. B 30B (1999) Nr. 6, S. 411/18.

3. Improvement of ladle stirring to minimise slag emulsification and reoxidation during alloying and rinsing, RFCS project RFSR-CT-2007-00009, 2007–2010.