| 摘要 |
PURPOSE:To make uniform the erosion of a bubbling lance to be used in a ladle refining furnace by molten slag and to extend the life of the lance by moving vertically the bubbling lance so that the part thereof in contact with the molten slag is constantly changed. CONSTITUTION:The lance 6b for stirring a molten steel 4 tapped from a converter is immersed into the molten steel 4 and the bubbling by blowing an inert gas such as gaseous Ar is executed in the case of subjecting the molten steel to refining such as component adjustment, dephosphorization and desulfurization in the ladle refining furnace 1. A slag line part 7 where the lance 6b contacts the molten slag 5 is segmented in 3 stages at 200mm pitch and is moved upward and downward at said pitch at every specified time. The point where the part 7 contacts with the molten slag layer 5 is changed at every charge. The part 7 is further. continuously moved upward and downward at a prescribed speed to make uniform the erosion in the part 7 by which the service life of the lance 6b is extended. |
