Abstract:

Based on the thermodynamics and kinetics of desulphurization theory, an ultralow sulfur converter steelmaking process and operation system in the Laigang 120t converter system was analyzed. By controlling the converter resulfurization smelting, the deep desulfurization technological process was optimized. The results showed that the sulfur content can be reduced to below 0.005％. The desulphurization rate can be increased to 80％ and therefore the final sulfur content could reach to 0.001％. Consequently, low sulfur steel with sulfur content below 0.005 ％ could be stably produced. In the following LF refining, SiO2 content in LF top slag could be reduced to below 8％. The final (FeO+MnO) content could be reduced to about 1％ and the alkalinity can be controlled between 5 and 6.

Key words: converter resulfurization, top slag improvement, slag splashing protection, deep desulfurization