Improvement of process control and refractory performance of the AOD converter
For control of carbon and nitrogen content during AOD treatment, dynamic models based on thermodynamics and reaction kinetics were developed and verified with data from three different AOD plants. The effect of the melt temperature on the equilibrium conditions for decarburisation and denitrogenation was considered by an accurate dynamic energy balance. With the help of the models, the final carbon content can be calculated with an accuracy of 0.01 %, which means an improvement of a factor of 7 compared to a carbon balance based on measured off-gas values. The models are implemented within an online control system at the AOD plant of TKN Bochum, and are planned to be applied online at the TKN Krefeld plant. CSM developed an online method to determine the brick wear in the tuyere area of the AOD converter based on an infrared camera measurement of the sidewall temperature, which allows one to determine accurately the residual thickness at the end of the refractory campaign. The main mechanisms of AOD refractory wear were studied at TK AST on the basis of process data in correlation with a characterisation of post mortem dolomite bricks, and with an AOD water model. A mathematical model of the refractory wear at the slag line and in the tuyeres area was developed and validated with plant data. This model was applied within the process control system at the TK AST AOD No 2. It was used to improve the operating practices, leading to an increase of the average refractory campaign tram 85 to 98 heats.
Bibliographic Reference: EUR 21974 EN (2006), 121 pp. Euro: 25
Availability: Katalogue Number: KI-NA-21974-EN-S The paper version can be ordered online and the PDF version downloaded at: http://bookshop.europa.eu
ISBN: ISBN: 92-79-01037-9
Record Number: 200618650 / Last updated on: 2006-07-18
Original language: en
Available languages: en