PURPOSE: To improve the ratio of Mg effectively consumed to desulfurizing by feeding an Mg base wire into molten iron kept in an inert gas atmosphere.
CONSTITUTION: An upper cover 3 inserting a supplying tube 9 is fitted to a ladle 2 incorporating the molten iron 1 and an upper space 6 above the molten iron 1 is kept in the inert gas atmosphere, and the Mg base wire 8 is fed into the inner part of the molten iron 1 as desulfurizing agent. Infiltration of the outer air into the upper space 6 is prevented by applying the air-tight seal 10 and/or keeping the atmospheric pressure in the upper space 6 in higher than the atmospheric pressure at the outside of the ladle 2. The upper space 6 is desirable to keep in the inert gas atmosphere having ≤0.5vol% oxygen concn. and ≤0°C dew point. As Mg of metallic state is fed into the molten iron without reacting the oxygen and moisture, the desulfurizing of the molten iron is improved.
NAKAJIMA YOSHIO
GENNAI KIYOTAKA
