Manufacture of steel

摘要

849,783. Refining iron. BRITISH OXYGEN RESEARCH & DEVELOPMENT Ltd. Feb. 20, 1959 [March 6, 1958], No. 7196/58. Class 72 Molten iron from a blast furnace and/ or cupola is allowed to fall through a reaction zone in contact with an oxidizing gas in admixture with steam, the metal being converted to steel in a steel making furnace, the gases leaving the reaction zone being fed to the lower part of the blast furnace or cupola, and hot waste gases from the steel making furnace being used to raise said steam. As shown, metal from blast furnace 1 or cupola 2 is led by conduits 4 and 5 to mixer 3 from which it may be transferred intermittently or continuously via conduit 6 to refractory lined reaction tower 7 which may be empty or filled with a packing material such as limestone and fluxing agents, and located above the steel making furnace 12. Oxygen or an oxygen containing gas, which may contain powdered fluxing agents may be injected near the top or bottom of column 7 by pairs of tuyeres set diametrically opposite each other, and fume laden waste gas is led via conduits 10 and/or 11 into the blast furnace or cupola. Column 7 may be preheated by the combustion therein of a liquid or gaseous fuel with oxygen, the gaseous products being fed to the hot blast line of the blast furnace or cupola. Metal leaves column 7 and flows into the steel making furnace 12 which may be an open hearth furnace, an electric furnace, or a converter, while heat in the waste gas from the steel making furnace is used to raise stem at 14 which is fed by a conduit 9 to column 7. In an alternative arrangement (Fig. 2, not shown), iron flows directly from the blast furnace or cupola into the reaction column from which it is collected in a ladle which conveys it to the steel making furnace. Specifications 781,116, 790,790, 817,783 and 835,159 are referred to.