Asea Aktiebolag

Stora Kopparbergs Bergslags Ab

Stora Kopparbergs Bergslags Aktiebolag

Asea Brown Boveri Inc.

Allmanna Svenska Elektriska Aktiebolaget

Bjorn Widell

Sven-Einar Stenkvist

Per Harald Collin

Sune N Flink

Martin Hirsch

Lothar Reh

Per H Collin

Gote Tallback

Erik A Bengtsson

Bernt Ling

Hans-Gunnar Larson

An inductive heating unit for a magnetically permeable ladle containing molten steel has a cylindrical permeable wall for receiving the ladle and on which is wound an induction coil with an outer cylindrical permeable wall surrounding and enclosing the coil. The coil is wound from a conductor formed by a plurality of superposed flat metal strips which are insulated from each other. The outer wall is formed with a vertical channel in which a power lead for the coil is positioned.

Inductive heating unit

Apparatus for reducing finely divided iron oxide material

Iron-chromium alloys, such as stainless steels, are made in a direct arc DC electric arc furnace with a bath of molten steel scrap in the hearth and functioning as the anode with the arcing electrode cathodic, while feeding chromium-oxide to the bath at the arc spot on the bath's surface under conditions causing reduction of the oxide and addition of chromium to the bath.

Method for making iron-chromium alloys

An arc furnace has an arcing electrode through which a feeding passage is formed for feeding metal oxide particles through an arc and to a melt in the furnace. The arc is powered by DC power with the electrode cathodic and the melt anodic. Carbon is fed as required to reduce the oxides. Electric currents passing through the melt and the arc to the electrode are capable of causing magnetic forces forcing the arc to acquire an angular deflection in a downward direction away from alignment with the electrode's outer periphery and towards the side wall of the furnace in one direction subst antially continuously, during continuous operation of the furnace. Means are provided for electromagnetically causing the arc to continuously rotate, with its deflection, around the electrode.

Arc furnace for reducing metal oxides and method for operating such a

A DC arc furnace has a cathodic tubular graphite electrode forming an arc with an anodic carbonaceous iron melt in the furnace. A mixture of iron oxide and carbon particles is fed to the melt via the electrode's interior with the mixture's carbon content being in excess of that stoichiometrically required to reduce the iron oxide content of the mixture, the upper end of the electrode's feeding passage being blocked so that furnace gases cannot flow upwardly and impede the mixture's downward feeding flow.

Furnace and method for the melt reduction of iron oxide

A DC arc furnace having one or more arcing electrodes and a melt contact electrode transversely offset from the arcing electrode is provided on the outside of the furnace with control electromagnets which are supplied with DC for the purpose of keeping the arc substantially axially aligned with the arcing electrode. For more positive control of the arc direction, radiation sensing devices are provided and which are arranged to receive more or less radiation from the arc if it wanders away from its desired vertical alignment with the arcing electrode. In turn, these devices are used to control the power supplied to the control electromagnets to alter the strength of their magnetic flux, so that if it wanders from axial alignment with the arcing electrode, the arc is substantially immediately returned to that alignment.

DC arc furnace arc control

The invention relates to a method of combined production of electrical energy and crude iron and provides a further improvement over a method described in U.S. Pat. No. 3,985,544, issued Oct. 12, 1976; particularly, this method finds application when particulates of .ltoreq. 1 mm in size are being used in practicing the further improved and described process.

Method for simultaneous combined production of electrical energy and

Fine-grained iron oxide reduction in a fluidized bed; a reducing agent in the form of fine-grained solid carbonaceous material containing volatile constituents is introduced into at least one zone of the fluidized bed; in said zone the volatile constituents are driven off, and a tarry material is temporarily formed on the surface of the particles of the carbonaceous material; the fine-grained iron oxide to be reduced is introduced into said zone; iron oxide particles adhere to the tarry carbonaceous particles; in this manner micro-aggregates which are especially desired are formed; but the formation of bigger aggregates is prevented.

Method of reducing finely grained material containing iron oxides in a

A method for reducing finely divided iron ore supplied to a ferrous melt, comprises inductively heating part of the melt at a heating rate higher than any heating of the balance of the melt so as to form in the melt an electrically heated part of the melt putting heat into the balance of the melt. The ore is injected substantially directly into this electrically heated part of the melt while the melt is supplied with carbonaceous material. The heating rate is maintained to keep the electrically heated part of the melt at a temperature sustaining the endothermic reaction between the iron ore and the carbonaceous material as required to reduce the ore to iron which then becomes a part of the melt.

Melt reduction of iron ore

A method of reducing a pulverized material containing iron oxides mixed with carbonaceous material wherein: (a) a circulating fluidized bed is maintained in a vertically elongated reaction zone by supplying it with suitable quantities of pulverized material containing iron oxides, pulverized solid carbonaceous material and optionally liquid carbonaceous material, and gas containing molecular oxygen and that gas and solid material leaving the reaction zone are separated, the solid material being returned to the reaction zone; (b) the pulverized material containing iron oxides, the carbonaceous material and the gas containing molecular oxygen are supplied to an intermediate section of the reaction zone; (c) the flow of carbonaceous material fed to the bed is controlled so that there is always sufficient coke in the bed to prevent interference of the fluidization caused by sticking or agglomeration; (d) gas and solid material leaving the reaction zone are extracted from the upper part of the reaction zone, the solid material being separated from the gas and being returned to the intermediate section of the reaction zone; (e) a portion of the gaseous reaction zone exhaust, after dust separation and elimination of most of carbon dioxide and water, is fed to the lower part of the reaction zone as fluidizing and reduction gas; and (f) solid material containing completely or partially reduced iron oxides is drawn from the lower part of the reaction zone.

Method for reducing material containing iron oxides

In the reduction of finely divided material containing metal oxide in the presence of a carbonaceous material in a reactor, a gas containing molecular oxygen is supplied to the material and a gas mixture containing carbon monoxide, hydrogen, carbon dioxide and water is removed from the reactor. Part of the gas mixture is returned to the reactor unchanged, while another part is supplied with steam which is caused to react with the carbon monoxide to form carbon dioxide in the presence of a catalytic material. The carbon dioxide is removed from this part of the gas mixture and this part is returned to the reactor. The amount of steam supplied is sufficient to produce an amount of carbon dioxide in this part of the gas mixture, before the carbon dioxide is removed, which is at least as great as the total amount of carbon dioxide in those parts of the gas mixture removed from the reactor which are returned to the reactor.

Method for reduction of finely divided metal oxide material

A tubular electrode contains a feeding tube forming an annular passage between its outside and the inside of the electrode. With the electrode forming a cathode, an arc is formed between it and a carbonaceous iron bath in an enclosed hearth having a gas outlet. Iron oxide material in flowable form is fed through the inner tube to the arc while a non-oxidizing gas is fed via the passage formed between the two tubes, to the arc. The carbonaceous iron bath is made the anode and the action of the current forms an upward bulge in the metal in the arc, gravitationally freeing the bath from any slag at the arc. In this way the iron oxide material is melt reduced, the iron component being continuously added to the bath which may be continuously tapped to provide a supply of crude iron.

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Vasteras, Sweden

Bjorn Widell