Continuous prodn of steel from iron sponge - in an induction furnace under a liq slag of constant basicity

摘要

Steel is produced in an induction furnace from iron sponge by charging the furnace continuously with iron sponge in an amt. corresponding to the max. melting capacity of the furnace, and adding lime or dolomite in an amt. to give a slag of constant basicity of (CaO MgO)/(SiO2 Al2O3) is approx. = 1.5. The C content of the liquid steel is kept in the range 0.05-0.15%, and is pref. controlled by the C content of the iron sponge depending on the degree of metallization, following the relation (% Fe total-% Fe metal) 12/56 = %C. Process ensures the continuous presence of a liquid slag and does not require the usual slag removal which interrupts production. Excess slag is allowed to run off continuously. The steel has a low P content.