Abstract: A method of producing steel from ferrous hot metal containing carbon includes the steps of delivering oxygen and a surrounding sheath of hydrocarbon shielding fluid to the metal and beneath its surface to elevate the temperature to at least 1350.degree. C. Iron material taken from the group consisting of prereduced iron ore, prereduced iron pellets and iron ore or combinations thereof are then delivered to the metal at controlled rates. The rate of charging is balanced with the heat input to the bath, in order to maintain or increase the bath temperature. The heat input is supplied by the simultaneous injection of carbon and oxygen through bottom tuyeres. The rate of carbon injection is also regulated to maintain the carbon content in the bath at the desired level.

Abstract: The device consists of a retractible tuyere which can be used with different types of steel melting furnaces, or any other metallurgical vessel. Said tuyere is introduced in the liquid steel bath to make the controlled refining of the same by means of gaseous oxygen injection with any other innert gas, generally argon.The retractible tuyere consists of two concentric pipes. Through the annular gap between the pipes a cooling gas or liquid fluid is injected, which is generally an hydrocarbon.Through the center pipe a refining gas mixture is injected. The system also consists of a cooled tuyere holding box and a fluid control and injection system.The tuyere is generally introduced through an opening made in the side wall of the furnace, in a way that the tip of the same is located below the liquid steel level. Due to the retractible characteristic of the tuyere, the same is introduced in the bath only during the time required by the process.

Abstract: A method of producing steel from ferrous hot metal containing carbon includes the steps of delivering oxygen and a surrounding sheath of hydrocarbon shielding fluid to the metal and beneath its surface to elevate the temperature to about 1350.degree. C. Pelletized iron material and carbon are then simultaneously delivered to the metal at controlled rates with the rate of carbon delivery being regulated so that the carbon level within the metal maintains in substantial equilibrium. After charging of the pellets has been completed, the delivery of carbon is terminated while the delivery of oxygen and hydrocarbon shielding fluid is continued until the metal carbon level is reduced a desired level.