| 摘要 |
<p>Steel is produced in an open-hearth furnace by the process which comprises charging the furnace with solid ferrous metal such as steel scrap, directing an oxygen-fluid fuel flame down upon the ferrous metal from a lance in an elevated position, lowering the lance, e.g. to a position 3 or 4 feet above the ferrous metal when the charging is completed so as to melt a major proportion of the ferrous metal, then lowering the lance further to a position just above, e.g. 6 inches above, the bath surface and discharging only oxygen (fuel, e.g. natural gas, being shut off) to remove such elements as C, Si, P and S from the bath during refining. More than one water-cooled lance may be used. Burnt lime may be charged with the solid ferrous metal. The furnace is preferably also fired alternately from either end using oil as fuel with oxygen enriched air supply during the melting of the ferrous metal and subsequent charging of molten iron. Ferruginous material, such as ferrous metal (iron and steel scrap) or iron ore, may be added to control the exothermic heat generated by the oxidation of C and Si.</p> |
