| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for manufacturing low-silicon molten pig iron, which efficiently removes silicon from molten pig iron in a blast furnace to obtain the low-silicon molten pig iron, while suppressing progression of decarburization as much as possible. SOLUTION: It was found that silicon in the molten pig iron can be efficiently removed into low concentration by means of supplying an oxygen-containing gas, of which the oxygen concentration is controlled to a low level, as a gaseous oxygen source, in at least a part of a silicon removal process, especially when silicon has been lowered to a low concentration region along with proceeding of silicon removal in the molten pig iron, while restraining decarburization as much as possible. Thereby, the objective method was completed. The method is characterized by employing the oxygen-containing gas, of which the oxygen concentration is 80% or less, as the gaseous oxygen source for supplying into a vessel, in at least a part of the silicon removal process from the molten pig iron in the vessel, as a preliminary treatment for the molten pig iron, to remove silicon in the molten pig iron to a concentration of 0.1 mass% or less.
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