| 摘要 |
PURPOSE:To prevent damage to the refractory wall of a vessel by using oxygen- enriched air in place of pure oxygen as gaseous oxygen for refining at the time of forming a recess by a rotating magnetic field on the surface of the molten metal in the vessel and supplying raw material ore, carbonaceous material and gaseous oxygen for refining therein to reduce the raw material ore. CONSTITUTION:The molten iron 1 in the vessel 2 is rotated by a rotating magnetic field generating device 3 to form the recess in the central part. The raw material such as iron ore and carbonaceous material is thrown from a raw material adding hole 4 into the molten slag 7 in the recess and the oxygen-contg. gas for refining is blown from a lance 5 into the furnace to burn the CO-contg. reactive gas in the recess, by which the heat is generated and the iron oxide reduction reaction of an endothermic reaction is accelerated to reduce the iron component in the ore at a high yield. The iron-component is recovered into the molten iron 1. The air or oxygen- enriched air contg. <90% concn. of O2 is used in place of the pure oxygen as the refining gas 6 to be ejected from the lance 5 in this case. The heating-up of the exhaust gas to an abnormally high temp. and the consequent erosion of the refractories of the vessel 2 are thus prevented. this method usable for refining of Mn and Cr ores as well.
|
