TW232712B - Method for producing steel - Google Patents

Abstract

A steel making process is disclosed that utilizes solid ferrous metallic material as a substantial part of the metallic charge and uses heat released by combustion of two different types of carbonaceous materials and steel scrap that have been strategically charged inside of at least a partially refractory lined steel making vessel. One of the carbonaceous materials contains a high content of volatile hydrocarbons and is primarily responsible for early preheating and partial melting of the solid ferrous material. The second carbonaceous material contains a low content of volatile hydrocarbons and is primarily responsible for providing a reducing capability to the slag, for carburizing the melt and for providing additional heat generated by combustion which is used to enhance heating and melting of solid ferrous materials. This method of steel making also consists of the controllable introduction of oxygen rich oxidizing gas which initially is used for combustion of the hydrocarbons in the carbonaceous materials to melt solid ferrous metallic material and further is used for ignition and burning of a part of preheated solid ferrous metallic material located in central zone of the furnace and for refining the accumulated molten pool of ferrous material before tapping. Slag forming material is used at the bottom of the furnace to provide for continuous refining of molten ferrous material including removal of phosphorus and sulfur throughout entire steel making process. Liquid ferrous materials also can be charged in some embodiments of this method of steel production. Electrical energy may be used as an additional heat source to increase the metallic yield.