DEPHOSPHORIZING METHOD OF MOLTEN IRON

摘要

PURPOSE:To progress satisfactorily a dephosphorization reaction with decreased fuel consumption by injecting a powder material for refining with a gas enriched with oxygen as a carrier to under the surface of a molten iron from a single pipe nozzle attached to a vessel body. CONSTITUTION:A single pipe nozzle made of refractories is attached to a vessel body in such a way that the nozzle port thereof is positioned at the level coinciding with the inside surface of the furnace bottom. A powder material for refining contg. >=50% in total calcium oxide and iron oxide is bottom-blown from said nozzle into the vessel with the gas enriched with oxygen having 50- 90vol% oxygen concn. as a carrier gas so that the material is injected to under the surface of the molten iron in the vessel. The bottom blowing is executed at a ratio of 4-50 solid-gas ratio (kg/Nm<3>) between the carrier gas and the powder material for refining. The rate of dephosphorization is increased with the amt. of the flux to be used decreased and the effect of obviating decrease in the temp. of the molten iron, etc. is attained according to the above-mentioned dephosphorizing method.