Development of a Blast Furnace Model with Thermodynamic Process Depiction by Means of the Rist Operating Diagram

Abstract

Despite the fact that alternative processes such as Corex® and Finex® have already been established on industrial scale, the blast furnace route continues to be the most important process used to produce pig iron. Due to its importance, a variety of models of the blast furnace process have been developed in the past decades. In addition to this, a well-established analogue representation of blast furnace operation is given by the Rist operating diagram. The target of this work is to create a comprehensive blast furnace model in the simulation platform of gPROMS ModelBuilder®. Based on elemental assignments and empirical component distribution correlations, the blast furnace process is depicted by means of a black box model. The thermodynamic process boundaries are analysed in a Rist sub-model. Furthermore, an additional sub-model is used to calculate the adiabatic flame temperature in front of the blast furnace tuyeres. This modelling concept enables the description of interdependencies between the main blast furnace process, raceway conditions as well as overall thermodynamic process conditions within a single mathematical model. A detailed analysis of the model behaviour under varying coke substitution scenarios was carried out. The achieved simulation results demonstrate the applicability of the developed model for simulation of the blast furnace process under a wide range of operation conditions. The model also provides the means for simulation of different blast furnace route setups which allow for further optimisation regarding process efficiency, fuel consumption and environmental emissions of the blast furnace process.