**2. Investigations and Modeling of the Dead Man**

The internal state of the BF, as schematically illustrated in Figure 1, has been gradually revealed by extensive dissection investigations [2,3], which confirmed that there exists a stagnant column of coke particles in the lower part of the furnace. The stagnant column, where coke particles move downwards with a highly reduced velocity, was called "dead man" because it was earlier assumed to exert negligible influence on the whole ironmaking process [4]. However, this assumption was later been found to be incorrect. As a matter of fact, it is nowadays commonly believed that the dead-man state significantly affects the gas and liquid flows in the BF lower part, which, in turn, determine the temperature distribution within the hearth, the liquid drainage, as well as wear of the hearth lining [5]. In addition, the dead man appears to be rather "active" since it is usually claimed to have an average porosity of ε = 0.3 − 0.5 [2], and can be renewed in periods varying between a few days and some weeks.

**Figure 1.** Schematic vertical cross-section of the ironmaking blast furnace and its hearth.
