Method of melting cold material including iron.

摘要

A method of melting an iron-containing cold material and simultaneously obtaining a low phosphorous and high carbon molten iron while maintaining a high post combustion rate, comprising the steps of: preparing a converter having a lance for top-blowing oxygen, and a bottom-blowing triple pipe nozzle (1) disposed at a bottom of the converter which nozzle is provided with an inner pipe (2), an intermediate pipe (3) and an outer pipe (4); supplying the iron-containing cold material into the converter in which a hot heel exists; introducing into the converter all of a carbonaceous material together with a non-oxidizing gas through the inner pipe (2) of the triple pipe nozzle, oxygen through a space (5) defined between the inner pipe (2) and the intermediate pipe (3),and a non-oxidizing cooling gas through another space (6) defined between the intermediate pipe (3) and the outer pipe (4), and additional oxygen through the oxygen top-blowing lance so that the cold material is melted into a molten iron under an existence of slag; maintaining both the content of carbon dissolved in the molten iron at a level of 3 to 4% in most of a period of time for the melting and the rate of bottom-blown oxygen in a range of not less than 10% but less than 20% of the total amount of the oxygen; and adding intermittently or successively iron oxide into the slag in most of a melting period of time while keeping a slag basicity defined by CaO/SiO2 in a range of 1.5 to 3.0.