An Integrated Mathematical Model for Ironmaking Blast Furnace

Abstract

This paper presents an integrated model by combining the raceway combustion model, the process model, and the hearth flow and heat transfer model for simulating an entire ironmaking blast furnace (BF). This integration eliminates major assumptions at the boundaries shared by these sub-models and enables linking the model with operating parameters at the BF top and bottom directly. The applicability of this integration is first examined through various applications. On this base, the usefulness of the integrated model is demonstrated by studying the effect of burden distribution on the in-furnace states of a 5000 m3 industrial BF. The simulation results with and without the integration are compared. Also, via the integrated model, the effect of the ore-to-coke (O/C) radial profile at the burden surface is evaluated in terms of internal flow and thermochemical behaviors as well as overall process performance. It is shown that for given BF conditions except for the O/C radial profile, the indirect reduction in the upper furnace increases with the improvement of uniformity in the radial profile, leading to higher top gas utilization and lower productivity. Meanwhile, the hearth center tends to develop lower temperatures and stronger natural convection that reduces the heat loss through hearth walls. This integrated model would open up a cost-effective method to examine the effect of top and bottom factors on BF performance under different conditions in a comprehensive matter.