Hoogovens Groep B.v.

Estel Hoogovens Bv

Gerardus P Buhrmann

Adam Steen

Pieter J Kreijger

A liquid-cooled lance for blowing oxygen onto a bath of molten steel, has a tip (1) with at least one outlet from which a primary supply of oxygen is blown onto the bath, a central duct (2) for the supply of the primary oxygen surrounded by a double tube system (3,4) for supply and removal of cooling fluid, a plurality of secondary outlets (15) disposed around the lance in a conical widening of the lance axially spaced from the tip for blowing a secondary supply of oxygen and a plurality of secondary ducts (8, 9) extending along the lance for supply of the secondary oxygen to the secondary outlets. To obtain a high maximum possible scrap addition, and good control of final oxygen blowing temperature, there are at least eight of the secondary outlets (15) each having a diameter d.sub.s which satisfies the condition d.sub.s /1&lt;0.02 where 1 is the axial distance between the outlets for respectively the primary and secondary oxygen.

Liquid-cooled lance for blowing oxygen onto a steel bath and method of

A gas-transmitting wall element for a metallurgical vessel having a refractory lining is described which is subject to low wear, is reproducible and makes unnecessary continuous blowing of gas through it. The element has an outer sheet metal box, open at one end, and a refractory filling in the box comprising at least one brick spaced from the closed end of the box, into which a gas inlet opens. The brick contacts the metal sidewalls of the box and has grooves to allow the gas to pass to the open end of the box.

Gas-transmitting wall element for a metallurgical vessel, a

A method of producing steel by the LD process using a metallurgical vessel by blowing gas through an oxygen lance onto the top of the molten metal bath in the vessel for a period of time and during the final portion of the period blowing nitrogen directly into the metal bath through a gas-transmitting wall element. The duration of the final portion is from 0 to 2 minutes. The rate of gas supply through the wall element during the final portion is 5 to 8 Nm.sup.3 /h per ton of metal in the vessel.

Method of producing steel by the LD process

A process of producing steel in a converter, wherein the starting materials comprise pig iron and ferrous scrap, involves blowing of oxygen into the molten metal bath in the converter. Advantageous results, in particular savings of Fe and Mn and in the amount of liquid metal used, are obtained by the combination of the following process steps:

Process for producing steel in a converter from pig iron and ferrous

A liquid cooled lance is used to blow a primary supply of oxygen at the surface of a molten steel bath to form a burning spot. a central duct in the lance delivers the primary supply of oxygen to the tip. A secondary supply of oxygen is blown from nozzles around the side of the lance to burn up CO from the burning spot and so heat the bath. Several conduits run in parallel within the lance to deliver the secondary oxygen to the nozzles. There is preferably one conduit per nozzle. The conduits may run within an annular coolant duct, and preferably comprise, at least in part, pipes in the form of a winding around the lance axis. This construction has good resistance to thermal expansion stresses.

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Velsen-Zuid, Netherlands

Gerardus P Buhrmann