DE1048030B - Process for the production of metals or metal alloys from fine-grained, metal-containing substances - Google Patents

Description

Process for the production of metals or metal alloys from fine-grained, Metal-Containing Substances The invention relates to a method for reduction Artificial and natural metal carrier with the help of the well-known, carbon monoxide containing reducing gases or mixtures thereof, preferably for the production known types of iron and iron alloys using carbon oxide as a reducing agent suitable is.

The most important facility to date for iron production is the coke or blow furnace. However, this has various disadvantages, such as. B. the high physical and, in some cases, also chemical requirements placed on the raw materials the introduction of sulfur through the coke ash into the pig iron as well as the enrichment of the same with other accompanying elements of the iron, the compulsion for waste gas and slag recycling that has not yet been satisfactorily solved, the low reaction speed and the associated long implementation time from gout to racking, the nitrogen ballast, the low adaptability to the local conditions, etc.

There are numerous reduction processes to avoid the disadvantages of the blast furnace especially proposed for iron production. Most of the same has not gained practical importance because of its advantages over the existing ones Process by, economically more significant disadvantages are bought had to. Even those procedures that have come into practical use have only in very specific, mostly localized special cases next to the coke oven can claim.

For example, a method has become known in which fine-grained Metal oxides in a water-cooled stall. Reduction c: fen reduced and outside the oven. excreted from the exhaust gas in a reduced state will. Irin part of the exhaust gas is used to preheat the air after it has been loaded with the material to be reduced is blown into the reduction furnace.

The required reducing gas is either incomplete Combustion of simultaneously introduced carbon carriers in the reduction furnace formed, or it is taken from a reducing gas source and can be used together with the metal supports to be reduced and the air or by itself in the Be blown into the furnace.

It is also possible to use the reduction furnace in addition, if necessary part of the exhaust gas or hot air in the unloaded state or loaded blown with ore dust and carbon carriers.

The continuous introduction of oxygen into the reduction room inevitably complicates the reduction process in comparison to such processes where the reduction stage works without the addition of oxygen. Also must. at this one known processes may still be present in the exhaust gas if there is reoxidation of the reduced material is to be avoided prior to the deposition of the same.

The elimination of the various disadvantages of the previously known methods can now be carried out according to the invention by further developing those methods in which fine-grained metal oxides in a stream of carbon monoxide or carbon monoxide and Reducing agents containing considerable amounts of hydrogen are introduced, floating in it and while floating in one without the addition of oxygen working reduction stage to be reduced to metal and in which the reduced Good is finally excreted from the gas stream.

To carry out such a method, for example, a suitable one is used Reduction gas stream taken from the source and guided in a system of heated metal pipes loaded with ore powder, and this is now gradually reduced to metal, whereby it separated several times from the gas stream and again as a load for this is used.

By using metal pipes to carry the ore dust loaded reducing gas stream is the height of the possible reduction temperature naturally limited.

In another method, after the loading of the Reduction gas stream with ore dust taken from the appropriate source for as long as the Exposure to the action of the gas until the 1Zeduktio.n has taken place and the reduced Part of your gas flow can be eliminated. The speed of the gas flow must be chosen with this method in such a way that the floating particles do not move but rather sit in one with a boiling liquid. comparable Form 1> e-, vegen, and the -reduction temperature must also be below that temperature remain at which the reduced metal becomes plastic.

According to the invention it is now proposed, in these known, under Use of the direct current principle - the r-float reduction method that works too to process reducing fine-grained metal oxides continuously in one operation and also to use regenerated recycle gas for reduction.

The invention thus relates to a process for the production of metals or metal alloys by reducing oxides with the aid of gaseous carbon monoxide. or reducing agents containing carbon monoxide and hydrogen in considerable amounts, whereby fine-grained metal oxides are introduced into a stream of such reducing agents, made to float therein and, during the reduction to metal, in a reduction stage that works without the addition of oxygen, are moved on in the same direction as the gas stream, and finally the reduced material - Is separated from the gas flow, which is characterized in that the loading of the reducing gas with fine-grained metal oxides, the reduction of the same to 11 etall and the separation of the reduced material from the gas flow takes place continuously in one operation and there, ß the freed from the reduced material Gas flow after branching off the excess gas through carbon-based substances and cleaning agents materially - # 27 and thermally regenerated through the supply of heat and is used in the loop as a reducing and carrier gas for the fine-grained metal oxides.

The use of a regenerable gas cycle for reduction of oxidic ores is known per se, but has so far only been used for such processes recommended; in which ore and reducing gas move in countercurrent: The inventive- Process can take the form of a self-contained, independent generating unit operated and is in particular independent of external reducing gas sources.

Other advantages of this process are the ability to do it all in one Operation steel, pig iron, hot-press ready or - cold - iron powder from the To manufacture ore; also the adaptability to local conditions, which Possibility of creating efficient and continuously working = systems largest daily production as well as the possibility; reducing in selective form to carry out by setting the appropriate temperature, whereby z. B. Avoided the inclusion of unwanted accompanying elements in the iron -and'- a Enrichment of the same in the slag can be achieved.

The devices for performing the method of the present Invention consist of four coordinated in their constructive implementation The main constituents, namely -au: s -the actual reduction vessel, from separation devices as well as devices for moving and regenerating the cycle gas.

The implementation of the method is explained in more detail with reference to the drawings. In a reduction room A, for example, the ore dust (Fig. 1) fed in via an ore preheating drum P and blown in with the aid of an injection device C (Fig. 1) is thoroughly mixed with carbon oxide. The reduction space is designed in such a way that the reduction of the ore dust within this space is ended when the appropriate gas velocity and gas temperature are selected. The resulting mixture of CO and C 02 leaves the reduction chamber at a and carries the fine-grain iron particles with it. The separation of these particles from the gas stream is carried out by means of known processes adapted to the prevailing temperatures, e.g. B. by means of coarse separator D, fine separator E and electrostatic precipitator F. The separated particles are fed to a cooling drum G, in which cooling is carried out by cold air blown in at b: -The air that is heated there leaves the cooling drum at c and is used to preheat the Ore dust is used by introducing it into the ore preheating drum P at d. The separated iron particles can show a spongy to spherical structure by varying the temperature of the gas cycle. For the deposition of a powder with a sponge-like structure, the gas temperature must not exceed the temperature corresponding to the liquidus line of the metal or the metal alloy, while for the deposition of a powder with a spherical structure this temperature initially. exceeded and, before the deposition of the powder, the temperature corresponding to the solidus line must be fallen below. A sufficient part of the gas mixture freed from iron particles is branched off at e - the cycle gas. This is sucked in with a fan I - and fed into the K.arbu: rator K , in which at. f the solid carbon supports, e.g. B. coke, supplied and from which at g the ash is removed. Takes place in the carburator. the material regeneration of the gas. The “ heat supply” can take place by means of an arc formed between electrodes L. The regenerated gas leaves the carburator K at h. and kick. well. into a desulfurization device M filled with lime; into which at i the lime is introduced and from which at h the used lime is discharged. From there the gas becomes the. Reduction chamber A supplied after it has passed devices N for generating a vortex of the gas flow and -the injection device C was loaded with ore dust.

The. Fig. 2 shows a device for producing a liquid end product. Here, after the reduction is complete, the gas flow with the iron particles floating in it enters the melting chamber leg, in which the. The heat required for liquefaction is generated, for example, by an arc formed between the electrodes L. The separation of the liquid particles from the gas flow takes place here, for example, with the help of baffles Q :. The bath surface, for example, can also serve directly as a baffle. : These liquid particles now get into the. R collecting chamber from which the molten material is finally stiches S is poured off with the aid of the ex. - In the collecting space R, the iron bath T and the slag zone H located above it is also indicated in the drawing. The gas freed from the liquid iron particles is again subdivided at e into cycle gas and residual gas and, as described in the previous exemplary embodiment, treated further.

Not only those described can be used to move the cycle gas Facilities, but also advantageously the various systems of jet propulsion, how they z. B. in principle of the nozzle cooler, nozzle motor, rocket motor, the pulsating Thrust nozzle etc. are given, can be used.

With such jet propulsion, besides moving the circulating gas at the same time its charging with powdered carbon with the addition of industrial produced oxygen can be carried out. This is done by burning a part of the carbon is the energy for the endothermic carburization and the still generated necessary thrust, while the other part of the carbon is responsible for the conversion of the C02 to C O is available.

The diagram of an apparatus suitable for this is shown in FIG. 3. In the combustion chamber U becomes the z. B. at u with steam blown coal dust with the blown at v Mixed oxygen. Instead of the water vapor, however, a branched off can also be used Kick part of the cycle or residual gas. There can also be several injection points For example, provided with mutually perpendicular, non-radial injection directions be. A partial oxidation of the carbon to CO will take place here. By the resulting warming and volume increase is this mixture by a The gradually widening pipe attached to the combustion chamber U - the nozzle W- thrown. Further additional nozzles W1, W2 are attached to this nozzle which sucked in the circulating gas to be regenerated and at the same time with that from the Combustion chamber U ejected carbon is intimately mixed.

Fig. 4 shows this jet propulsion in connection with a device for the separation of the reduced material in the liquid state.

In Fig. 5 an arrangement is shown with which a separation of the reduced material is possible in powder form and which can be used above all for processing very ash-rich carbon carriers. From the combustion chamber U of the jet propulsion, in which, in addition to carbon, lime, for example, can also be blown in for desulfurization, the mixture formed there is passed through the nozzles; W centrifuged and thereby sucked in the cycle gas at W1 and W2. This flows through the carburator K and. then enters a device Z for cleaning the gas, the z. B. is equipped with a vortex screen. The precipitated ash particles and other solid impurities of this gas are precipitated here and can be removed at x. The cleaned gas comes now. after loading with the ore dust, by blowing in: residual gas at w and by supplying the dust. takes place at z , into the reduction chamber A and is finally sucked through the device Zl, which is also expediently equipped with a vortex screen. Here the reduced iron powder is separated from the cycle gas and can be removed from the system at y.

The known forms of jet propulsion can also be used for injection of the ore dust can be used in the reduction room.

Claims (3)

PATENT CLAIMS: 1. Verab, -ren for the production of metals or metal alloys by reducing oxides with the aid of gaseous, carbon monoxide or carbon monoxide and hydrogen in considerable amounts containing reducing agents, with fine-grained metal oxides introduced into a stream of such reducing agents, made to float therein and during the Reduction to metal in a reduction stage operating without the addition of oxygen are moved further in the same direction as the gas flow and the reduced material is finally separated from the gas flow, characterized in that in; one operation, the loading of the reducing gas with fine-grained metal oxides, the reduction of the same to metal and the separation of the reduced material from the gas flow takes place continuously and that the gas flow freed from the reduced material, after branching off the excess gas with carbon-containing substances and cleaning agents, is thermally regenerated through the supply of heat and is used in the circuit as a reducing and carrier gas for the fine-grained metal oxides. 2. The method according to claim 1 for the production of a liquid end product, thereby: gekennzeichr net that the gas flow after completion of the reduction by direct Heat supply by means of an electric arc to liquefy the entrained reduced good contains required heat. 3. The method according to claim 1 and 2, characterized in that the cycle gas is moved by jet propulsion, which simultaneously serves to charge this gas with carbon and to heat it up. Publications considered: German Patent Specifications No. 189 40'4, 440 099; U.S. Patent Nos. 1984,727, 2,365,194, 2,399,984; British patent specification No. 573 593; D u r r er, "Die Metallurgie des Eisen", 3rd edition, 1943, p. 425 to 427.