*2.4. Result of Stable Initial Burden Profile*

Compared with BF, the COREX MG charging process has the characteristics of smaller volume of burden dumps (or batches) and lower height of stock level (13~14 m in MG, and 1~2 m in BF). Previous physical experiments [10–12] and numerical simulation [13,14] results indicate that, in MG, it is difficult to form a stable surface with certain internal and external repose angles similar to those in the BF [15,16]. In other words, the mechanism of burden pile formation is different in the two reactors. To solve this problem, a new method based on burden pile width is proposed to calculate the growing process of the pile. The model can be used to characterize the evolution of burden surface profile and internal layer structure under various charging matrixes.

The published physical experiment [12] and numerical simulation [20] studies of the mixed charging in MG show that the stable burden profile has a high center and a low edge with the descent of the whole burden column. By regression analysis of the physical experiment and numerical simulation data, an equation for the stable burden profile in the COREX MG can be obtained, as shown in Figure 5. Such a stable burden profile is then simplified into a line of three segments, that is, the horizontal center and edge segments and the inclined middle segment.

**Figure 5.** Stable initial burden profile.
