PURPOSE: To manufacture efficiently a very low S and very low P steel by refining only in a converter provided with a double-tubed tuyere at the bottom by removing molten slag after finishing the blowing of a refining gas and by blowing a desulfurizing agent with an inert gas.
CONSTITUTION: When molten pig iron is refined in a converter provided with a double-tubed tuyere having refining gas and cooling gas paths at the bottom, molten slag is removed after the blowing of a refining gas from the refining gas path is finished. A desulfurizing agent is then blown into the molten pig iron with an inert gas to desulfurize the molten pig iron. It is preferable that the molten pig iron used is dephosphorized beforehand. Thus, a very low S and very low P steel can be manufactured by refining only in the converter, and the refining time is shortened.
KATO YOSHIHIDE
FUJII TETSUYA
KAKIO YASUHIRO
SUDO FUMIO
