DE1458746A1 - Process and plant for the direct production of steel - Google Patents

Description

H58746

Investment and patent management company with limited liability in Essen

Procedure and facility for immediate Manufacture of steel

Several proposals for the direct and continuous production of steel from pig iron are already known become. The pig iron was allowed to flow through an elongated furnace vessel, for example, in which it has been freshened by means of oxygen or air lances introduced from above. One has already gone over to to provide a further, lower-lying furnace vessel in connection with this furnace vessel, in which the necessary tilling work is to be carried out be carried out on the crude steel that is also flowing through should.

Apart from the fact that with these known processes there is always a separate unit, often set up far away is required for the production of the liquid pig iron with all the disadvantages associated therewith, has so far none This well-known process for the continuous production of steel from pig iron has practically found an application, In particular, it has not been possible to refine pig iron economically with these processes. The task The present invention is to address these disadvantages of the known methods and devices for direct manufacture of steel to avoid. This purpose is achieved according to the invention in that the steel is made of ores continuously generated and the ores in a rotary kiln using the when refining the intermediate product by inflation carbon monoxide containing carbon monoxide formed from oxygen to steel

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hot exhaust gases are largely pre-reduced and heated. A particularly useful system for doing this The method is characterized in that a vibratory furnace a rotary kiln is connected upstream, both with continuously operating Möller and aggregate metering devices are provided, and that the vibratory furnace is directly followed by a continuous casting plant is.

The "method and system according to the present invention will be explained in more detail with reference to the embodiment shown schematically in the drawing. Show it

Fig. 1 shows a longitudinal section through the plant and

FIG. 2 shows a section along the line II-II in FIG. 1.

In a rotary kiln 1, the ores required for steel production, advantageously ores with more than 60 % iron, together with the reducing agents, for example coke breeze, and the. Slag-forming aggregates from storage bunkers 2 via metering belt weighers 3 * conveyor systems 4 and a feeder 5 are introduced. The feeding device 5, which is designed as a rotary feeder, simultaneously seals the Möll devices against the gas outlet 6 of the rotary kiln 1

The first, still relatively cool part of the rotary kiln 1 is expediently protruding on the inside Equipped blades or cams that are alternately inclined so that the falling Möllergut the entire Coated oven cross-section and thereby an intimate contact with the countercurrent flowing through, reducing Gas is reached.

The largely pre-reduced in the rotary kiln 1 and also heated reduction gui? preferably arrives in solid or

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even in the liquid state via a fixed, largely sealing intermediate piece J directly into a first chamber 8a of the vibrating furnace 8, which has a cylindrical shape. In this chamber 8a the solid to be reduced from the rotary kiln 1 via the intermediate piece 7 is completely reduced and liquefied by the exhaust gases from the further chambers of the vibrating furnace 8 which are switched on and which are produced when the metal is freshened and have a high content of carbon monoxide. In this stage, the heat demand still required is advantageously covered by burners 9 * which are operated with an adjustable ratio of oil and / or oxygen.

The pig iron slag that accumulates runs continuously into slag pans 12 from an overflow 10 arranged below the filling opening in the end face of the vibratory furnace 8. The liquid pig iron now passes through an opening 12a in the partition wall IjJa into the fresh chamber 8b of the vibrating furnace 8, in which it is transported by a stream of oxygen, which is blown from above by means of a lance l4, with the addition of additives, e.g. lime, which is either in the form of dust the blowing lance lk or added in pieces through openings 15 in the vault of the vibratory furnace 8 with flexible feed 16 is refined.

For the storage or supply of the aggregates in the vibrating furnace 8 are in the same way as for the Möllerstoffe of the rotary kiln 1 storage bunker 2a, weigh belt feeders 17 and conveyor systems 18 are provided.

Is, e.g. when refining phosphorus-containing pig iron, after the first freshness period in the chamber 8b, a further, second freshness period is required, so this is in the chamber 8c of the vibratory furnace 8 carried out. To this end, the metal refined in the first stage passes through the opening 12b

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in the partition IJb in the chamber 8c, which in turn with a blowing lance 14 and openings 15 in the vault of the vibratory furnace 8 for the addition of the other additives is.

After the metal has been refined to steel in the chamber 8c, the steel passes through the opening 12c in the partition 1> 3 into a further chamber 8d, in which in a last stage an opening 19 in the vault of the vibrating furnace 8 alloying agents are added according to the desired steel quality.

Through an overflow 20 in the front wall of the vibratory furnace and a subsequent intermediate channel 21, the finished steel runs continuously into the pouring funnel 22 of a downstream working casting plant in which raw steel blocks of the desired dimensions are produced.

In order to improve the heat balance of the process and the slag produced during the refining process by the run-out sausages 23 of the vibratory furnace 8 (Fig. 2) to be able to deduct, which is advantageous in certain, in quick succession Occurring time intervals, the vibrating furnace is provided with a drive, not shown, and advantageously mounted on rollers 24 such that it is sideways can be swung out at a certain angle in both directions »The slag can advantageously be used instead of in Sehlaekenpfannen 25 also directly in cinder channels can be withdrawn and processed immediately afterwards.

By blowing in additional air at different points of the rotary kiln and the vibrating furnace or by arrangement the overall efficiency can advantageously be increased by additional burners. The exhaust gases occur at the Loading side of the rotary kiln and are

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then dedusted in a furnace gas cleaning system. Up there in this way the carbon dioxide-containing carbon dioxide produced during the freshening process and dusty gases directly to the; Reduce the ore used and be cooled down at the same time, no longer apply when inflating of oxygen to cast iron baths required extensive Exhaust gas cooling and dedusting systems, while keeping the required fuel quantities to a minimum

^ i i. ■ * _ ■■■ '■', ',, »j_, ^ and / öder Rlsenschwaiain be reduced. If additional scrap / is to be melted down, it is expediently made into smaller pieces Form added continuously in the liquefaction and / or fresh stage

The performance of the steelmaking plant according to the invention can advantageously be regulated within wide limits, since the throughput speed of the goods and thus the steel production output depend only on the feed speed of the Möllers and the other substances to be fed to the steelmaking facilities · It can therefore with the advantage of the different mold shapes and GIeS-feaBchwindigleeiten be adapted to the downstream continuous casting plant ·;

The control of the new system through appropriate measuring and ReggLeniägen is expediently fully automated.

Patent claims:

# 09809/0374

Claims (1)

H58746 P a t e η t a ns ρ r ü ο h e 1. Method for the direct manufacture of steel, thereby —Λ ■ - characterized in that the steel is produced from ores continuously and using the ores in a rotary kiln the carbon monoxide that is produced when the intermediate product is freshened by blowing oxygen into steel hot exhaust gases are largely pre-reduced and heated. 2 · The method according to claim 1, characterized in that the Reduction product completely reduced, liquefied, in immediately successive stages, in one or more sections is freshened and added with alloying agents in a final stage. 5. The method according to claims 1 and 2, characterized in that that the reduction product continuously, preferably in the solid state, in the finishing and liquefaction stage is convicted. 4. Process according to Claims 1 to 5 *, characterized in that that in the final reduction and liquefaction stage the heat demand is covered by oil and / or oxygen. 5. Process according to claims 1 to 4, characterized in that ores with more than 60 % iron are used 6. Process according to Claims 1 to 5, characterized in that that in the liquefaction and / or fresh stage small pieces of scrap and / or sponge iron is melted down. In the process according to Claims 1 to 6, characterized in that the slag occurring in the individual stages is drawn off at certain short time intervals and reused or processed. 90980 9/03 7 4 - - 2 - 8. Plant for carrying out the method according to the claims TTSis ""? » characterized in that a vibrating furnace (8), a rotary kiln (l) is connected upstream, both with continuous working Möller (2 to 5) and aggregate (2a, 17, i8) metering devices are provided, and that the Sohwingofen (8) immediately has a continuous. The casting plant is switched on. 9. Plant according to claim 8, characterized in that a fixed between the vibrating furnace (8) and the rotary kiln (1) arranged, largely sealing connector (7) is arranged. 10. Plant according to claims 8 and 9 # characterized in that that the vibrating furnace (8) has a cylindrical or almost cylindrical shape and is above the bath level open and through partition walls (13) provided with openings (12) at the lowest point into several chambers (8a to d), with discharge nozzles (10, 20, 23) being provided for the discharge of the slag and the steel are. 11. Plant according to claims 8 to 10, characterized in that the vibrating furnace (8) is mounted and on rollers (24) is provided with a drive. 12. Plant according to claims 8 and 9, characterized in that the rotary kiln (l) is provided on the inner circumference with protruding cams or blades. il 909809/03 7 4