Metallgesellschaft Aktiengesellschaft

Mannesmann Aktiengesellschaft

Harry Serbent

Wolfram Schnabel

Martin Hirsch

Gerhard Reuter

Heinz Eichberger

Lothar Formanek

Heribert Koenig

Hermann Lommert

Horst Steinhofel

Klaus-Dietrich Fritzsche

Lothar Reh

Hans Beisswenger

Ludolf Plass

Gero Rath

Friedrich Rosenstock

Peter Fischer

Werner Kaas

Georg Daradimos

Herbert Lausch

Fritz Rose

Detlev Schlebusch

Gunter Kossek

Justus Kuhn, Deceased

Gunter Kotzschke

Detmar Arlt

Karl-Heinz Fischer

Kurt Meyer

Ernst Scheu

Disclosed is a process for the production of reduced iron oxide-containing materials. Iron oxide and solid carbonaceous reducing agent are charged into a first expanded fluidized bed, which is supplied with an oxygen-containing fluidizing gas. The gas residence time selected is controlled in the reactor containing the first fluidized bed so that the reduction potential will result in a reduction of the iron oxide material not in excess of the FeO stage. A gas-solids suspension discharged from the first fluidized bed is supplied to a second expanded fluidized bed, which is supplied with a strongly reducing fluidizing gas. Strongly reducing gas and a major portion of the resulting devolatilized carbonaceous material are discharged from the upper portion of the second fluidized bed. Reduced material having a metallization of 50 to 80% and the remaining devolatilized carbonaceous material are discharged from the lower portion of the second fluidized bed.

Process of reducing fine-grained iron-containing material by means of

Disclosed is a process to effect a reduction to a desired, constant degree as exactly as possible and to achieve a low surplus of carbon. The reduction by treatment with carbonaceous reducing agents is effected in such a manner that fine-grained solids, which contain higher metal oxides, are calcined at 800.degree. to 1100.degree. C. with hot gases in which the solids are suspended. The calcined solids are reduced at a temperature in the range of from 800.degree. to 1100.degree. C. to form low metal oxides in a stationary fluidized bed, which is supplied with carbonaceous reducing agents and oxygen-containing gases. The carbonaceous reducing agents are supplied to the stationary fluidized bed at such a rate so as to reduce the higher metal oxides to low metal oxides, while maintaining the reduction temperature in the stationary fluidized bed and insuring that the discharged matter has the desired carbon content. The stationary fluidized bed exhaust gas is supplied as secondary gas to the calcining step, and fuel is supplied to the calcining step at a rate such that the total of the heat generated by the combustion of the fuel and of the heat suplied by the exhaust gas provides the heat which is required for calcination.

Process of reducing higher metal oxides to lower metal oxides

Sponge iron is produced by a direct reduction with solid carbonaceous reducing agents. In order to permit a melting of the sponge iron, particularly of that part thereof which is inferior in metallurgical properties, in a process which is as simple and economical as possible, the exhaust gas from the direct reduction process is used to produce electrical energy, which is supplied to the electric reducing furnace, and sponge iron at a rate corresponding to the electrical energy that is produced is charged to the electrical reducing furnace and comprises at least part of the sponge iron which is inferior in metallurgical properties.

Process of producing liquid carbon-containing iron

The melting operation is carried out in an elongated horizontal reactor, in which sponge iron is charged onto the molten material in an intermediate region of the reactor, carbonaceous fuel and high-oxygen gases are blown into the molten material and slag and sponge iron are tapped at opposite ends of the reactor. To permit an economical melting of sponge iron having a large particle size range with the aid of virtually only solid carbonaceous fuels, the sponge iron is charged into the reactor in an intermediate region of 20 to 40% of the total length of the reactor, fine-grained carbonaceous fuel and high-oxygen gas are blown into the molten material from below in that region, the rates of oxygen and carbon are so controlled that a molten iron containing 1 to 3% carbon is produced, the remaining carbon contained in the molten material is reacted in the melt to produce CO, and the remaining energy required in the process is produced in that the CO and hydrogen are virtually completely burnt above the molten material as a result of a supply of oxygen-containing gases into the free space of the reactor.

Continuous process of melting sponge iron

Sponge iron produced by direct reduction is melted in an electric arc furnace, in which a pool of liquid metal is maintained. To ensure that liquid carbon-containing iron for forming the pool is available in adequate quantities and that the process can be carried out with the highest possible economy, the sponge iron is reacted in an electric arc furnace on a bath of liquid carbon-containing iron (hot metal), which has been produced from sponge iron or from partly reduced ore in an electric reducing furnace, and in dependence on the electric load changes which are due to the operation of the electric arc furnace the operation of the electric reducing furnace is so controlled that a virtually constant load on the electric power supply system is maintained.

Process of making steel by melting sponge iron in an electric arc furnace

In the operation of the rotary kiln provided at its charging end with a central burner, solid reducing agents having a high content of volatile constituents are used and the charge and the gas atmosphere are conducted in cocurrent streams. To avoid a high heat load per unit of volume in the heating-up zone and yet to increase the heating-up rate, a solid carbonaceous reducing agent having a high content of volatile constituents is charged together with the iron oxide-containing material into the charging end of the rotary kiln, oxygen-containing gases are blown through nozzle blocks into the free gas space and into the charge in the heating-up zone, and oxygen-containing gases are blown through nozzle blocks into the free kiln space in the reducing zone.

Process of producing sponge iron by a direct reduction of iron

In a process of simultaneously producing fuel gas and process heat from carbonaceous materials wherein the carbonaceous materials are gasified in a first fluidized bed stage and the combustible constituents left after the gasification are subsequently burnt in a second fluidized bed stage the throughput rate and the flexibility are increased in that the gasification is carried out at a pressure of up to 5 bars and a temperature of 800.degree. to 1100.degree. C. by a treatment with oxygen-containing gases in the presence of steam in a circulating fluidized bed and 40 to 80% of the carbon contained in the starting material are thus reacted. Sulfur compounds are removed from the resulting gas in a fluidized state at a temperature in the range from 800.degree. to 1000.degree. C. and the gas is then cooled and subjected to dust collection. The gasification residue together with the by-products which have become available in the purification of the gas, such as laden desulfurizing agent, dust and aqueous condensate, are fed to another circulating fluidized bed and the remaining combustible constituents are burnt there with an oxygen excess of 5 to 40%.

Method of producing fuel gas and process heat fron carbonaceous materials

Fine-grained material which contains iron oxide is prereduced in a fluidized bed and is subsequently completely reduced in a rotary kiln. In order to avoid agglomeration and incrustation in the rotary kiln, the prereduction is carried out to effect a metallization of 50 to 80%.

In order to avoid incrustation and an excessively strong thermal attack on the afterburning chamber, the exhaust gases which contain gaseous and solid constituents which are combustible are afterburned in a plurality of stages, which are connected in series. The rate at which oxygen is supplied to each stage is so controlled that part of the combustible constituents is afterburned in each stage. The gas which is about to enter each succeeding stage is cooled by injected water.

Process of afterburning combustible constituents of exhaust gases from

In the treatment of bulk materials with hot gases below the melting point of the charge component it is desired to prevent a formation of undesired crusts during normal operation and when the rotary kiln is operated at a reduced speed during short-time trouble. For this purpose, a controlled dissipation of heat is effected in several sections of the rotary kiln in that the shell of the kiln and the refractory lining are cooled so that the temperature of that portion of the inside surface of the rotary kiln which is submerged below the charge is always maintained at or up to 50.degree. C. below the temperature of the charge disposed thereover.

Process of thermally treating bulk materials in a rotary kiln

Residual materials which become available in metallurgy and contain oxides and volatilizable non-ferrous metals or compounds thereof are treated in a rotary kiln with solid carbonaceous reducing agents and are thus directly reduced in a high proportion to sponge iron whereas a substantial part of their non-ferrous metal content is volatilized. The solids discharged from the rotary kiln are sieved with a parting size of about 3 to 10 mm, depending on the feed grading of the residual materials and their disintegration characteristics, so that a major part of the unmagnetic material is included in the fine fraction. The coarse fraction is subjected to an electro-slag resistance process. The fine fraction is subjected to an electro-magnetic separation. The magnetic fraction is subjected to the resistance slag-refining process. The unmagnetic fraction is incorporated in and bonded to the feed mixture for the rotary kiln by a tumbling or pelletizing operation.

Steel making process

An improved process for briquetting sponge iron-containing material wherein as binder there is employed dilute sulfuric acid and the sponge iron-containing material contains at least 40% by weight metallic iron.

Process of briquetting sponge iron-containing material

An improved process for the direct reduction of iron oxide-containing materials to form sponge iron which takes place in a rotary kiln by treatment with a solid carbonaceous reducing agent having a high content of volatile combustible constituents is disclosed. The charge is moved through the rotary kiln opposite to the direction of flow of the kiln atmosphere. Oxygen-containing gases are blown at controlled rates through nozzle blocks into the charge disposed over the nozzle blocks in the heating-up zone in that region thereof defined by the occurrence of ignitable particles of the solid reducing agent and ending before the reduction zone. Oxygen-containing gases are blown in at controlled rates through shell tubes into the free kiln space at least in that region. In accordance with the invention, at least a part of the solid carbonaceous reducing agent comprises disintegrated waste rubber. Preferably more than 80% of the solid carbonaceous reducing agent comprises waste rubber.

Direct reduction process in a rotary kiln

When in the direct reduction of iron-oxide-containing materials in a rotary kiln solid, carbonaceous reducing agents having a high content of volatile constituents are charged to the rotary kiln at its charging end, a reoxidation of the sponge iron can readily occur in the final portion of the reduction zone unless a definite surplus of solid reducing agent is there maintained. To reduce the required surplus while still positively avoiding reoxidation, reducing gases and/or liquid hydrocarbons are introduced in said final portion by means of tubular air nozzles at least partially into the charge located above the air nozzles beginning with at least 75 percent metallization.

Process of directly reducing iron oxide-containing materials

In a Waelz process of volatilizing zinc and lead from iron-containing and oxide-containing material in an inclined rotary kiln, which is charged at its upper end with the material together with solid carbonaceous reducing agent having a high content of volatile combustible constituents, wherein the reduction and volatilization are effected below the softening point of the charge, metallic iron-containing material is discharged from the lower end of the rotary kiln, combustion air is sucked into the lower end of the rotary kiln, and the exhaust gases are sucked from the upper end, the improvement which comprises blowing oxygen-containing gases through tubular air nozzles into the charge disposed over said tubular air nozzles in that region of the heating-up zone which begins where ignitable particles of the solid reducing agent begin to occur and which terminates at up to 50 percent of the length of the kiln.

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Hanau, Germany

Harry Serbent