Numerical Simulation of Slag-metal Reactions and Desulfurization Efficiency in Gas-stirred Ladles with Different Thermodynamics and Kinetics

A computational fluid dynamics-simultaneous reaction model (CFD-SRM) coupled model has been proposed to investigate the effects of different contents of aluminum, manganese and silicon in slag and liquid steel, the arrangement of bottom blowing tuyeres and the height ratio of slag and metal on the slag-metal reactions and desulfurization efficiency in gas-stirred ladles. The results show that as the aluminum is added into liquid steel, both the desilication rate and demanganization rate decrease, and the desulfurization rate increases rapidly. Meanwhile as the initial aluminum content [%YAl](t=0) exceeds 0.01 mass%, the desulfurization efficiency increases slowly. With the increase of initial silicon content [%Y-Si](t=0), the demanganization rate decreases, while the desulfurization rate increases. When the [%Y-Si](t=0) exceeds 0.5 mass%, the effect of [%Y-Si](t=0) becomes weak. As well, the variations of manganese content in liquid steel has little effect on the desulfurization efficiency. For the initial content (%Y-i)(t=0), in slag, with the decreasing of (%Y-Al2O3)(t=0), the desulfurization rate increases rapidly, but as the (%Y-Al2O3)(t=0) is less than 23.0 mass%, the desulfurization efficiency increases slightly. With the increasing of the (%Y-MnO)(t=0), the desulfurization efficiency decreases rapidly. Furthermore, the dual blowing gives higher desulfurization efficiency in comparison with the center blowing or eccentric blowing with one tuyere. With the increasing of height ratio of slag and metal (h/H), the desulfurization efficiency increases, but when the h/H exceeds 0.4, the desulfurization efficiency changes weakly.