Mg-based desulfurizing agent and method for manufacturing ultra-low sulfur steel in which the molten steel desulfurization step is omitted

摘要

The present invention relates to a Mg-based desulfurizing agent for stably controlling extremely-low sulfur content of ultra-low sulfur (S) steel (0.008% of product sulfur) in a steel plate and thermal steel, and a process for producing a very low sulfur steel using the same.;The present Mg-based desulfurizing agent and a method for preparing the ultra-low sulfur steel using the same are 20-50% of Mg, 70-90% of CaO,₂: 1-10%, wherein the Mg-based molten iron desulfurizing agent having excellent desulfurizing ability is introduced into a molten iron together with nitrogen gas to control sulfur in the molten iron; and a slag A second step of removing the slag by a slag cutting mechanism and a slag dispenser, and a third step of charging and refining the molten iron from which the slag is removed in the second step.