Patent ID: 8753423

Claim:
An operation method for mechanically stirring chrome-containing molten iron, which comprises a refining process of mechanically stirring chrome-containing molten iron contained in a refining vessel by a use of an impeller having a rotation axis in a vertical direction where the refining vessel is such that a horizontal cross section of an inner wall thereof is circular around a central axis of the vessel in the vertical direction and the impeller, as integrated with an axial rod covered with a refractory, rotates around a central axis of the axial rod, as a rotation axis thereof, wherein: a stirring mode is regularly or irregularly switched, as selected for a stirring charge, between concentric stirring mode of stirring the molten iron in a state where the rotation axis of the impeller is centered in the central axis of the vessel and eccentric stirring mode of stirring the molten iron in a state where the rotation axis of the impeller is decentered from the central axis of the vessel.