POWDER INJECTION LANCE AND METHOD OF REFINING MOLTEN IRON USING SAID POWDER INJECTION LANCE

摘要

A top-blowing lance with which the hot metal blend ratio can be reduced and a method for refining molten iron and a smelting reduction method for molten metal using the injection lance are proposed. The top-blowing lance includes a refining oxygen gas blowing nozzle having a plurality of ejection openings through which oxygen gas is blown into an iron bath in a reaction vessel, the ejection openings being disposed along a circular orbit at intervals, and a burner nozzle having an axis coaxial with the central axis of the circular orbit, forming a flame inside the refining oxygen gas blowing nozzle, and having ejection openings for blowing a powder heated by the flame into the iron bath, wherein an indicator A that indicates the positional relationship between the ejection openings of the refining oxygen gas blowing nozzle and the ejection openings of the burner nozzle satisfies the following condition: A = 1.7 �¢ R - r - d / 2 / L + tan ¸ - 12 �¢ ° - 0.0524 > 0
where R denotes the pitch circle radius of the ejection openings of the refining oxygen gas blowing nozzle (mm),
r denotes the radius of the ejection openings of the burner nozzle (mm),
d denotes the diameter of the ejection openings of the refining oxygen nozzle (mm),
¸ denotes the angle (inclination) between the axis of the refining oxygen gas blowing nozzle and the central axis of the circular orbit (°), and
L denotes the lance height (mm).