VDEh Institute of Industrial Researches GmbH (Düsseldorf, Germany):

Bartush H., Dr., Project Engineer, e-mail: hauke.bartusch@bfi.de
Hauck T., Dr., Head of Department Process Technology Ironmaking

Hüttenwerke Krupp Mannesmann GmbH (Dortmund, Germany):
Grabietz H.-G., Mag. Eng., Senior Division Manager Process Technology

Chlorine compounds in the top gas lead to corrosion at pipes, hot stoves and tuyères of the blast furnace. However, chlorine issues in the blast furnace have been only little investigated. On the base of the results obtained from special measurements, mass balance and equilibrium calculations carried out by the specialists of Hüttenwerke Krupp Mannesmann (HKM), this contribution discusses main chlorine inputs and the behaviour of chlorine within the blast furnace process. Suggestions for the handling of chlorine in the process are reflected. Concluding, the literature study and the investigations of the HKM blast furnaces showed that the origin of the hydrochloric acid in the top gas are chlorine compounds which are charged mainly as alkali chlorides to the furnace by the material flows of coal, coke and sinter. Chlorine loads in the top gas are not measured in most plants. So, high loads remain unknown, until sudden corrosion damages of components in contact with the top gas appear. This can be avoided if chlorine concentrations in the different materials are monitored and, if possible, high chlorine loads are avoided. This contribution should encourage blast furnace operators to investigate their individual chlorine levels in the blast furnace process.

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