METHOD FOR MELTING IRON-CONTAINED COLD MATERIAL

PURPOSE:To reduce bottom blowing equipment cost, etc., compared with the conventional method and to melt iron-contained cold material by specifying temp. of molten iron, carbon content in the molten iron and bottom blowing oxygen ratio in a converter and also blowing the bottom blowing oxygen into molten iron bath while giving this twisting. CONSTITUTION:The iron-contained cold material is supplied into the molten iron 16 in the converter 15 having triplex pipe nozzle 1 at the furnace bottom, and non-oxidizing gas and carbonaceous material from the inner pipe 2 in the nozzle 1, oxygen from the intermediate pipe 3 and non-oxidizing gas for cooling from the outer pipe 4 are blown, respectively and also the oxygen is supplied from a top blowing oxygen lance 14 to melt the iron-contained cold material. Then, the temp. of the molten iron 16 is held to >=1450 deg.C and [C] in the molten iron is held to >=3% in the melting process, and the bottom blowing oxygen ratio is made to >=10% and