| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a refining method of molten iron, which inhibits slag formation even when a large amount of AlOas slag formation accelerator is added to a refining furnace, and can inhibit erosion of refractory material.SOLUTION: Molten iron being preliminarily treated for desiliconization and dephosphorization in advance is fed into a refining furnace. AlOis then added into the refining furnace for performing decarbonization treatment. Subsequently tapping of molten steel and discharging of slag from the refining furnace are performed in the refining method of molten iron. A source of AlOis added into the refining furnace such that the AlOconcentration in the slag within the refining furnace after decarbonization treatment reaches 3.5 mass% or more. An MgO-containing slag making material, which contains MgO in excess of 7 mass% in total based on the mass of slag in the refining furnace after decarbonization treatment, is further added therein. Further, the time required from the initiation of charging the refining furnace with molten iron to the completion of tapping of molten steel with discharging of slag is set to within 30 minutes.</p> |
