Speaker
Description
Lowering emissions of pollutants and carbon consumption has become increasingly imperative in our society nowadays. The worldwide growing restrictions of waste gas emissions on integrated steelworks are the focal motivation of this work. The sintering process is a highly energy-intensive, and a vast material-consuming process unit in the hot metal production. Iron ore sintering depends on the raw mixture, sinter plant geometry, and operational conditions. The difficulties for an accurate description of the off-gas properties in the wind boxes lie in their varying temperatures, changing composition, and different mass flows. A detailed description of the off-gas properties will give a profound basis for decision for required raw mixture compositions, wind box geometries, and operational settings for a selective waste gas recirculation (SWGR).
A sinter model based on temperature profiles and mass distributions was developed and implemented in an existing model library for iron and steel production. This unique approach allows flowsheet simulations for different plant geometries, with and without SWGR, and various operational conditions. The model contains (i) a burner model describing the combustion conditions underneath the ignition hood, (ii) a black-box model including the main sintering reactions and a gas-solid separation, and (iii) a wind-box model that splits the off-gas into a stack-gas and a recycle-stream.
The simulation results were validated on plant data and literature. The influence of temperature profiles on wind box gas composition was investigated by focusing on coke consumption and trace element emissions of a sinter strand. Differences and short comings of the developed model compared to models in literature are discussed.