DE102022209958A1 - Metallurgical plant and process for producing a molten metallic composition - Google Patents

Abstract

The present application relates to a metallurgical plant (1) for producing a molten metallic composition, which can be provided after a degassing and/or refining step of a continuous casting plant (2), comprising:i) at least one electrically operated melting unit (4) for melting a metallic Raw material and/or material (5);ii) at least one electrically operated secondary metallurgical unit (7) for secondary metallurgical treatment of the metallic raw material and/or material (5) melted into a molten metallic composition; andiii) a degassing device (3) for degassing and/or refining a pouring jet (14) comprising the molten metallic composition (2), the degassing device (3) comprising at least one vacuum container (8) partially lined with refractory material and having at least one vacuum connection ( 15) and in its vacuum container ceiling (9) an inlet opening (10) for vacuum-tight connection to a pan (6) and in its vacuum container bottom (11) an outlet opening (12) arranged in alignment with the inlet opening (10). , via which the degassed and/or refined molten metallic composition of the continuous casting plant (2) can be provided.

Description

The present invention relates to a metallurgical plant for producing a molten metallic composition, which can be provided after a degassing and/or refining step of a continuous casting plant, and to a method for producing a molten metallic composition, preferably by means of the metallurgical plant according to the invention, which can be provided after a degassing step. and/or refining step of a continuous casting plant is provided.

Electric steel production, particularly using direct reduction technology, is becoming increasingly important due to its lower CO2 footprint. With direct reduction technology, iron ore is not melted, but is reduced directly in its solid state to metallic iron, which is then used in the form of a so-called DRI (“Direct Reduced Iron”) or in the form of HBI (“Hot Briquetted Iron”) in electric steel production is used. Such methods and systems are basically known from the prior art. For example, this reveals WO 2017/207472 A1 a process and a system for producing liquid pig iron from such a directly reduced iron product (DRI), which is then melted in an electric arc furnace (EAF).

The liquid pig iron produced according to such a route is usually subjected to secondary metallurgical treatment before casting and then to vacuum treatment. The aim of such a vacuum treatment is primarily to reduce the hydrogen, nitrogen and oxygen content in the melt. The so-called Ruhrstahl-Heraeus process (“RH process”) and vacuum degassing (“Vacuum Degassing”) have long been known from the prior art. In order to protect the then vacuum-treated melt against renewed contamination by hydrogen, nitrogen and oxygen during transport to the continuous casting plant, it is typically covered with a covering powder. However, this shows that the concentration of hydrogen, nitrogen and oxygen - despite the use of covering powder - increases again during transport in the melt.

Against this background, the present invention is based on the object of providing a metallurgical plant that is improved over the prior art and a process for producing a molten metallic composition that is improved over the prior art, in particular a metallurgical plant and a process for producing a molten metallic To provide a composition that, in addition to a more efficient and sustainable degassing of hydrogen, nitrogen and oxygen, also enables a reduction in non-metallic inclusions.

Description of the invention

According to the invention, the object is achieved according to a first aspect by a metallurgical plant with the features of patent claim 1.

1. i) zumindest ein elektrisch betriebenes Einschmelzaggregat zum Einschmelzen eines metallischen Roh- und/oder Werkstoffs;
2. ii) zumindest ein elektrisch betriebenes sekundärmetallurgisches Aggregat zum sekundärmetallurgischen Behandeln des zu einer schmelzflüssigen metallischen Zusammensetzung erschmolzenen metallischen Roh- und/oder Werkstoffs; sowie
3. iii) eine Entgasungsvorrichtung zum Entgasen und/oder Raffinieren eines die schmelzflüssige metallische Zusammensetzung umfassenden Gießstrahls, wobei die Entgasungsvorrichtung zumindest einen teilweise mit Feuerfestmaterial ausgekleideten Vakuumbehälter umfasst, der zumindest einen Vakuumanschluss sowie in seiner Vakuumbehälter-Decke eine Eingangsöffnung zum vakuumdichten Verbinden mit einer Pfanne und in seinem Vakuumbehälter-Boden eine in einer Flucht zu der Eingangsöffnung angeordnete Ausgangsöffnung aufweist, über die die entgaste und/oder raffinierte schmelzflüssige metallische Zusammensetzung der Stranggießanlage bereitstellbar ist.

The metallurgical plant according to the invention is intended for producing a molten metallic composition, which can be provided after a degassing and/or refining step of a continuous casting plant, and comprises:

1. i) at least one electrically operated melting unit for melting a metallic raw material and/or material;
2. ii) at least one electrically operated secondary metallurgical unit for secondary metallurgical treatment of the metallic raw material and/or material melted into a molten metallic composition; as well as
3. iii) a degassing device for degassing and/or refining a pouring jet comprising the molten metallic composition, the degassing device comprising at least one vacuum container partially lined with refractory material, which has at least one vacuum connection and, in its vacuum container cover, an inlet opening for vacuum-tight connection to a pan and in its vacuum container base has an outlet opening arranged in alignment with the inlet opening, via which the degassed and / or refined molten metallic composition can be made available to the continuous casting system.

In an inventive manner, a system is thus proposed which combines the process of vacuum treatment and the subsequent provision of the degassed and/or refined molten metallic composition of the continuous casting system, and thus the risk of re-contamination of the melt due to the entry of hydrogen and possibly nitrogen and /or oxygen prevented. The degassing device integrated into the continuous casting system means that the technically complex transport of the ladle from the conventional degassing device to the continuous casting system can be dispensed with. This has a particularly beneficial effect on process times, which are reduced by up to an hour per pan can. In addition to the associated significant reduction in operating costs, investment costs can also be significantly reduced.

Another advantage of the system is that the degassing device can also be used to significantly increase the degree of purity of the melt, thereby increasing the productivity of the metallurgical system. The openings of the degassing device, which are arranged in alignment, enable free passage for the casting jet, which extends from the ladle in the direction of the continuous casting system and can therefore be fanned out over a larger, maximum length by means of the vacuum, which leads to a significant increase in the surface area of the casting jet . This means that the volatile components dissolved in the metallic melt, such as hydrogen, nitrogen and/or oxygen, can be separated off almost quantitatively.

In addition, the degassing device enables the removal of harmful trace elements that have a high vapor pressure such as lead, arsenic bismuth, tin, zinc and copper during the degassing and/or refining step.

Further advantageous embodiments of the invention are specified in the dependent claims. The features listed individually in the dependent claims can be combined with one another in a technologically sensible manner and can define further embodiments of the invention. In addition, the features specified in the claims are specified and explained in more detail in the description, with further preferred embodiments of the invention being presented.

The electrically operated melting unit can be designed in the form of an electric arc furnace (EAF), a submerged arc furnace (SAF) or an induction furnace (IF).

The electrically operated secondary metallurgical unit, on the other hand, can be designed in the form of a ladle furnace (LF) or an induction furnace (IF).

The pan can consist of a steel housing and/or be formed from a composite material, in particular from a glass fiber reinforced plastic (GRP).

For the purposes of the present invention, the term “metallic raw material” is understood to mean a directly reduced iron product (DRI product) which has an iron content of at least 75.0% by weight. In a preferred embodiment variant, the directly reduced iron product (DRI product) can have an iron content of at least 80.0% by weight, more preferably an iron content of at least 85.0% by weight. This can basically be fed to the melting unit in hot form as an HDRI product, in cold form as a CDRI product, in hot briquette form as an HBI product and/or in particulate form, preferably with an average particle diameter of a maximum of 20.0 mm. Such a DRI product is typically, as already described in the prior art, produced in a direct reduction system and can be fed directly to the melting unit, for example via a conveyor device under a protective atmosphere.

For the purposes of the present invention, the term “metallic material” is understood to mean a material which is formed from a non-ferrous metallic material. The non-ferrous metallic material can preferably be selected from the series comprising a nickel-based material, a cobalt-based material, a copper-based material, an aluminum-based material and/or combinations thereof. Such materials are produced, for example, via galvanic manufacturing processes and have a purity of at least 98% by weight.

In an advantageous development, the degassing device comprises an intermediate container via which the degassed and/or refined molten metallic composition can be made available to the continuous casting system, the intermediate container being arranged below the outlet opening of the degassing device and connected to it in a vacuum-tight manner. The intermediate container can preferably comprise a container trough with two areas separated from one another by a dam-weir system, with the first area more preferably forming a vacuum area and comprising an inlet opening arranged in its container trough cover, which can be connected to the degassing device in a vacuum-tight manner. This advantageously ensures that the tundish is not only used as a storage container between the ladle and the continuous casting system, as is usual in the prior art, but can also be used as a metallurgical vessel for degassing and refining.

It is preferably provided that the intermediate container is also at least partially lined with refractory material. For this purpose, refractory materials known to those skilled in the art, such as A1203 (so-called sausages), can be used.

In contrast to the first area, which is designed as a vacuum area, the second area can be designed to be open, so that the degassed and/or refined molten metallic composition can be covered with a slag and, if necessary, additionally with a covering and/or insulating powder. The dam-weir system of the intermediate container is preferably designed in such a way that the vacuum seal with respect to the second open area can only be achieved from a filling level above its passage. In an alternative, advantageous embodiment variant, the second region can also be designed to be sealable in a gas-tight manner with respect to the external environment and form an inert gas region. This alternative solution makes it possible to dispense with the use of covering powder and to prevent contamination of the vacuum-treated melt by the covering powder and the effects of the atmosphere.

It is particularly preferably provided that the second region forms a further vacuum region and comprises at least one outlet opening, which is arranged in a container trough bottom of the second region and can be connected to the continuous casting system. This creates a completely vacuum-compatible intermediate container, so that the use of covering powder and/or protective gas for the entire tundish can be dispensed with. It is preferably provided here that the intermediate container has an integrated (vacuum-compatible) control unit for the outlet opening.

In order to enable metering of the degassed and/or refined molten metallic composition into the continuous casting plant, it is preferably provided that the at least one outlet opening of the intermediate container can be closed or opened in a controllable and/or controllable manner with a stopper and/or slide.

The two areas can basically be of the same size within the intermediate container. However, it is preferably provided that the first area has a volume that is smaller than the second area, which then enables more effective degassing and/or refining of the pouring jet and additionally reduces the risk of leaks when the vacuum capacity is low.

In this context, it is preferably provided that the first area designed as a vacuum area has a volume in the range of 5 to 50% based on the total volume of the intermediate container.

In a further advantageous embodiment variant, the vacuum container can have in its interior two vacuum chambers separated from one another via an intermediate floor, each of which is provided with at least one vacuum connection, the intermediate floor comprising a through opening arranged in alignment with the inlet and outlet openings, which can be opened and closed via a locking device. By dividing the vacuum container into two separate vacuum chambers in which independent pressures can be set, a lock function is made possible, which leads to a shorter evacuation process, for example when changing a ladle, and accordingly improves the degassing and/or refining process compared to from the Systems known from the prior art are significantly shortened.

The two vacuum chambers can basically be of the same size within the degassing device. However, it is preferably provided that the upper of the two vacuum chambers (lock chamber) has a smaller volume than the lower vacuum chamber, whereby the evacuation process, particularly when changing the ladle, can be reduced again. In this context, it is particularly preferred that the upper vacuum chamber has a volume of a maximum of 40%, even more preferably a maximum of 20%, and most preferably a maximum of 5%, based on the total volume of the degassing device to be evacuated.

In a further advantageous embodiment variant it is provided that the closure device comprises a lid with a slag pot. This can be used to collect the slide sand that occurs when changing the ladle before the degassed and/or refined molten metallic composition is fed to the intermediate container as a pouring jet. This allows the output losses to be reduced, which can further increase the productivity of the system. In this context, it is particularly preferably provided that the degassing device comprises a slag collecting pot arranged in the upper vacuum chamber, via which the slag received by the slag pot can be temporarily stored and removed from the degassing device. For this purpose, the slag pot can, for example, be provided with a spout through which the collected slide sand can then be poured into the slag collecting pot during the lid opening process.

In order to enable variable distance and height adjustment from the degassing device to the pan during operation, it is advantageously provided that this comprises a first, preferably elastic, sealing unit arranged on the outside of the vacuum container ceiling, via which the pan can be connected to the degassing device in a vacuum-tight manner. The sealing unit can preferably be biased by means in such a way that the contact of a pan against the sealing unit creates a temporary, ie essentially for the duration of the emptying of the degassed and/or refined molten metallic composition, vacuum-tight connection. The sealing unit can be designed in such a way that it spatially encompasses the outlet nozzle of the pan, the entire pan slide, or at least part or the entire pan base, or a connecting flange of the pan. In this respect, it can advantageously be provided that the pan has a connecting flange, for example on the outer cylinder surface.

Furthermore, the degassing device can comprise a second, preferably elastic, sealing unit arranged on the outside of the vacuum container base, via which the degassing device can be connected to the intermediate container in a vacuum-tight manner and via which variable distance and height adjustment is made possible. The second sealing unit can also preferably be prestressed by means.

Furthermore, the first sealing unit can each have a connecting flange at its end opposite the vacuum container lid and/or the second sealing unit at its end opposite the vacuum container bottom, which optionally comprises a sealant, such as a high-temperature-resistant seal. The connection flange can also be water-cooled in order to cool any sealant that may be present. In addition to this, the pan and the intermediate container can preferably each comprise a connection flange, possibly water-cooled, via which the pan is connected to the inlet opening of the degassing device, in particular the first sealing unit, and/or via which the intermediate container is connected to the outlet opening of the degassing device, in particular the second sealing unit, can be connected in a vacuum-tight manner.

In a particularly advantageous embodiment variant, it is provided that the first and/or the second, preferably elastic, sealing unit is designed in the form of a metallic bellows.

1. i) Bereitstellen eines metallischen Roh- und/oder Werkstoffs);
2. ii) Einschmelzen des metallischen Roh- und/oder Werkstoffs, ggf. in Gegenwart weiterer metallhaltiger- und/oder kohlenstoffhaltiger-Komponenten, in einem elektrisch betriebenen Einschmelzaggregat, so dass eine schmelzflüssige metallische Zusammensetzung gebildet wird;
3. iii) Überführen der schmelzflüssigen metallischen Zusammensetzung, vorzugsweise mittels einer Pfanne, in ein elektrisch betriebenes sekundärmetallurgisches Aggregat, in dem die schmelzflüssige metallische Zusammensetzung sekundärmetallurgisch behandelt wird; und
4. iv) Überführen der sekundärmetallurgisch behandelten schmelzflüssigen metallischen Zusammensetzung, vorzugsweise mittels einer Pfanne, in eine Entgasungsvorrichtung, mittels derer die sekundärmetallurgisch behandelte schmelzflüssige metallische Zusammensetzung in Form eines innerhalb der Entgasungsvorrichtung ausgebildeten Gießstrahls unter Vakuum entgast und/oder raffiniert sowie anschließend der Stranggießanlage bereitgestellt wird.

In a further aspect, the present invention also relates to a method for producing a molten metallic composition, preferably by means of the metallurgical plant according to the invention, which is provided after a degassing and/or refining step of a continuous casting plant. The method according to the invention includes the steps:

1. i) Providing a metallic raw material and/or material);
2. ii) melting the metallic raw material and/or material, possibly in the presence of further metal-containing and/or carbon-containing components, in an electrically operated melting unit, so that a molten metallic composition is formed;
3. iii) transferring the molten metallic composition, preferably by means of a ladle, into an electrically operated secondary metallurgical unit in which the molten metallic composition is subjected to secondary metallurgical treatment; and
4. iv) transferring the secondary metallurgically treated molten metallic composition, preferably by means of a ladle, into a degassing device, by means of which the secondary metallurgically treated molten metallic composition is degassed and/or refined under vacuum in the form of a pouring jet formed within the degassing device and then provided to the continuous casting system.

In an advantageous embodiment variant, the molten metallic composition formed according to step ii) is adjusted in the electrically operated melting unit to a carbon content of a maximum of 1000 ppm, a phosphorus content of a maximum of 250 ppm and a sulfur content of a maximum of 100 ppm, which then advantageously dephosphorus and Desulfurization in the subsequent electrically operated secondary metallurgical unit is no longer necessary. Any necessary decarburization can then be carried out via the reaction of dissolved oxygen in the melt with carbon during jet degassing.

For the purposes of the present invention, the term “metal-containing and/or carbon-containing components” is understood to mean all scrap known to a metallurgist, such as steel scrap, copper scrap, electrical scrap, etc.

As already explained, the volatile components can be separated off almost quantitatively using the system according to the invention or using the method according to the invention. The degassing step and/or the refining step is therefore preferably carried out in such a way that the molten metallic composition has a hydrogen content of a maximum of 2 ppm, more preferably has a hydrogen content of a maximum of 1.5 ppm, and most preferably a hydrogen content of a maximum of 1.0 ppm and a nitrogen content of a maximum of 60 ppm.

In order to improve the degassing and/or refining step, this can advantageously be supported using an inert gas, in particular argon.

Furthermore, at least one metallic trace element, which is preferably selected from the series comprising arsenic, lead, tin, zinc, bismuth, copper and/or combinations thereof, can advantageously be removed from the pouring jet during the degassing and/or refining step.

In a further advantageous embodiment variant of the method, at least one oxide-containing inclusion, which is preferably selected from the series comprising calcium oxide, aluminum oxide, silicon dioxide, titanium dioxide, manganese oxide, chromium oxide, nickel oxide and/or combinations thereof, can be removed during the degassing and/or refining step be removed by the pouring jet.

In a further advantageous embodiment variant of the method, during the degassing and/or refining step, at least one sulfide-containing inclusion, which is preferably selected from the series comprising zinc sulfide, tin sulfide, lead sulfide, mercury sulfide, arsenic sulfide, antimony sulfide, iron sulfide, manganese sulfide, nickel sulfide, cobalt sulfide , molybdenum sulfide and/or combinations thereof, are removed from the pouring stream.

In a further advantageous embodiment variant of the method, at least one nitride-containing inclusion, which is preferably selected from the series comprising aluminum nitride, chromium nitride, titanium nitride, vanadium nitride, niobium nitride and/or combinations thereof, can also be removed from the casting jet during the degassing and/or refining step become.

Figure name

• 1 eine erste Ausführungsvariante der erfindungsgemäßen metallurgischen Anlage in einer schematischen Darstellung,
• 2 eine zweite Ausführungsvariante der erfindungsgemäßen metallurgischen Anlage in einer schematischen Darstellung, und
• 3 eine Ausführungsvariante der in 2 gezeigten Entgasungsvorrichtung in einer schematischen Darstellung.

The invention and the technical environment are explained in more detail below using the figures. It should be noted that the invention is not intended to be limited by the exemplary embodiments shown. In particular, unless explicitly stated otherwise, it is also possible to extract partial aspects of the facts explained in the figures and to combine them with other components and findings from the present description and/or figures. In particular, it should be noted that the figures and in particular the proportions shown are only schematic. The same reference numbers designate the same objects, so that explanations from other figures can be used in addition if necessary. Show it:

• 1 a first embodiment variant of the metallurgical plant according to the invention in a schematic representation,
• 2 a second embodiment variant of the metallurgical plant according to the invention in a schematic representation, and
• 3 an embodiment variant of the in 2 Degassing device shown in a schematic representation.

In 1 a first embodiment variant of the metallurgical plant 1 is shown, which has a degassing device 3 integrated in a continuous casting plant 2. In the present embodiment variant, the system 1 comprises an electrically operated melting unit 4, which can be designed, for example, in the form of an electric arc furnace and is used to melt a metallic raw material and/or material 5. The metallic raw material and/or material 5, for example a DRI product, can be melted down as a mixture with other metal-containing and/or carbon-containing components in accordance with the desired material quality to be cast. For example, an advantageous mixture can contain 80 - 90% by weight of a DRI product and 10 - 20% by weight of common steel scrap. As soon as the feed materials have been melted down and the respective melt analysis in the melting unit 4 has been set, for example to the extent that the molten metallic composition has a carbon content of 600 ppm, a nitrogen content of 200 ppm and a sulfur content of 800 ppm, it is tapped and using a pan 6 transported to the next station.

In the present embodiment variant, the system 1 comprises, as the next station, an electrically operated secondary metallurgical unit 7, which is designed in the form of a ladle furnace. In the ladle furnace 7, the molten metallic composition is then treated by secondary metallurgy, for example by reducing the sulfur content, so that the molten metallic composition, which is then treated by secondary metallurgy, has a carbon content of 600 ppm, a nitrogen content of 200 ppm and a sulfur content of 100 ppm. This is then tapped off again and transported by means of the pan 6 to the degassing device 3, which in the present case is integrated into the continuous casting system 2 and by means of which the secondary metallurgically treated molten liquid metallic composition, hereinafter referred to as melt, can be degassed and/or refined under vacuum.

This includes the in 1 Degassing device 3 shown has a vacuum container 8, which is partially lined with refractory material, especially at the points that can come into contact with the hot melt. The vacuum container 8 has an inlet opening 10 arranged in its vacuum container cover 9, through which the melt is fed to the degassing device 3. Axially opposite the vacuum container ceiling 9, the vacuum container 8 also has an outlet opening 12 arranged in its vacuum container base 11, via which the melt is then discharged from the degassing device 3 after the degassing and/or refining process and fed to an intermediate container 13. As per the 1 can also be seen, the two openings 10, 12 are arranged in a common alignment, so that there is a free passage for an open pouring jet 14 between the ladle 6, via which the melt is fed to the degassing device 3 for degassing and / or refining, and the intermediate container 13 is made possible. The degassing step and/or refining step can preferably be carried out in such a way that the melt has a hydrogen content of a maximum of 2 ppm and a nitrogen content of a maximum of 60 ppm. In order to evacuate the vacuum container 8, it is provided with a vacuum connection 15 which is connected to a vacuum pump 16.

The intermediate container 13, also known as distributor or distributor trough in technical jargon. Called tundish, in the present embodiment variant it comprises a container trough 17 that can be closed from the external environment and has two areas 19, 20 separated from one another by a dam-weir system 18. Both areas 19, 20 of the intermediate container 13, which are filled with the degassed and/or refined melt are in contact, are lined with refractory material. The first area 19 forms a vacuum area within the intermediate container 13, which is connected to the degassing device 3 via an inlet opening 22 arranged in a container trough ceiling 21 of the first vacuum area 19. The second area 20, which is separated from the first area 19 via the dam-weir system 18, also forms a vacuum area in the present embodiment variant. The second vacuum region 20 comprises an outlet opening 24 arranged in a container trough base 23, which in turn is connected to the continuous casting system 2. So that the second vacuum area 20 can also be evacuated, it also has a vacuum connection 25. In order to enable metering of the degassed and/or refined melt into the continuous casting plant 2, the intermediate container 13 can also be closed and opened by means of an adjustable and/or controllable stopper 26 and/or an adjustable and/or controllable slide 27.

Furthermore, the degassing device 3 in the present embodiment variant comprises a first and a second sealing unit 28, 29, each in the form of a metallic bellows, which enables variable distance and height adjustment to the pan 6 and to the intermediate container 13. The first metallic bellows 28 is arranged on the outside of the vacuum container cover 9 and has a connecting flange 30 at its end axially opposite the vacuum container cover 9, via which a vacuum-tight connection between the degassing device 3 and the pan 6 is achieved. The second metallic bellows 29, on the other hand, is arranged on the outside of the vacuum container base 11 and also has a connecting flange 31, via which the vacuum-tight connection between the degassing device 3 and the intermediate container 13 is achieved.

In 2 a second embodiment variant of the metallurgical plant 1 according to the invention is shown in a schematic representation, which, in contrast to the previous embodiment variant, has a vacuum container 8, which in its interior comprises two vacuum chambers 33, 34 which are separated from one another via an intermediate floor 32. Both vacuum chambers 33, 34 are connected to one another via a through opening 35 embedded in the intermediate floor 32, which is also positioned in alignment with the inlet and outlet openings 10, 12 and can be closed in a vacuum-tight manner by means of a closure device 36 arranged in the upper of the two vacuum chambers 33, 34 is.

In order to ensure the shortest possible pan change time, the two vacuum chambers 33, 34 are of different sizes and are each provided with their own vacuum connection 15, 37, which is each connected to a vacuum pump (16, 38). It is provided here that the upper of the two vacuum chambers 33, 34 has a smaller volume than the lower vacuum chamber 34 and therefore forms a lock function in the degassing device 3. Furthermore, the degassing device 3 can comprise a control device (not shown), via which the pressure level in the respective vacuum chamber 33, 34 can be individually controlled and/or regulated.

3 shows the in 2 shown embodiment variant of the degassing device 3 in an enlarged schematic representation. As per the 3 recognizable, the closure device 36 has a lid 39, which can be opened and closed via a folding mechanism 40. In an alternative embodiment variant, the closure device 36 can also be equipped with a movable and/or displaceable cover element (not shown), via which the through opening 35 can be closed in a vacuum-tight manner. As can also be seen from the dashed illustration, in a further embodiment variant the cover 39 can comprise a slag pot 41 which is positioned below the inlet opening 10 of the degassing device 3. For example, the slide sand flowing out of the pan 6 in a first fraction can be collected via the slag pot 41, if this is desired by the system operator. Furthermore, the vacuum container 8 can comprise a slag collecting pot 42 arranged in the upper vacuum chamber 33, via which the slide sand received by the slag pot 41 can be temporarily stored and can be removed from the degassing device 3. For this purpose, the slag pot 41 can be provided with a spout (not shown), through which the collected slide sand can then be poured into the slag collecting pot 42 during the lid opening process.

Reference symbols

1

metallurgical plant

2

Continuous casting plant

3

Degassing device

4

Melting unit

5

metallic raw and/or material / DRI product

6

Pan

7

secondary metallurgical aggregate/ladle furnace

8th

vacuum container

9

Vacuum container blanket

10

Entrance opening

11

Vacuum container bottom

12

Exit opening

13

Intermediate container

14

pouring jet

15

(first) vacuum connection

16

vacuum pump

17

container tray

18

Dam-weir system

19

first area / vacuum area

20

second area / vacuum area

21

Container pan ceiling

22

Entrance opening

23

Container tray bottom

24

Exit opening

25

(second) vacuum connection

26

Plug

27

Slider

28

first sealing unit / bellows

29

second sealing unit / bellows

30

Connection flange

31

Connection flange

32

intermediate floor

33

first vacuum chamber

34

second vacuum chamber

35

Passage opening

36

Closure device

37

(third) vacuum connection

38

vacuum pump

39

Lid

40

Flap mechanism

41

cinder pot

42

Slag collection pot

QUOTES INCLUDED IN THE DESCRIPTION

This list of documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• WO 2017207472 A1 [0002]

Claims (30)

Metallurgical plant (1) for producing a molten metallic composition, which can be provided after a degassing and/or refining step of a continuous casting plant (2), comprising: i) at least one electrically operated melting unit (4) for melting a metallic raw material and/or material (5); ii) at least one electrically operated secondary metallurgical unit (7) for secondary metallurgical treatment of the metallic raw material and/or material (5) melted into a molten metallic composition; as well as iii) a degassing device (3) for degassing and/or refining a pouring jet (14) comprising the molten metallic composition (2), the degassing device (3) comprising at least one vacuum container (8) partially lined with refractory material and having at least one vacuum connection ( 15) and in its vacuum container ceiling (9) an inlet opening (10) for vacuum-tight connection to a pan (6) and in its vacuum container base (11) an outlet opening (12) arranged in alignment with the inlet opening (10). , via which the degassed and/or refined molten metallic composition of the continuous casting plant (2) can be provided. Metallurgical plant (1) according to Claim 1 , wherein the degassing device (3) comprises an intermediate container (13) via which the degassed and / or refined molten metallic composition of the continuous casting system (2) can be provided, the intermediate container (13) being below the outlet opening (12) of the degassing device (3) arranged and connected to it in a vacuum-tight manner. Metallurgical plant (1) according to Claim 1 or 2 , wherein the vacuum container (8) has two vacuum chambers (33, 34) separated from one another via an intermediate floor (32), each of which is provided with at least one vacuum connection (15, 37); and wherein the intermediate floor (32) comprises a through opening (35) arranged in alignment with the entrance and exit openings (10, 12), which can be opened and closed via a closure device (36). Metallurgical plant (1) according to Claim 3 , wherein the upper of the two vacuum chambers (33) has a smaller volume than the lower vacuum chamber (34). Metallurgical plant (1) according to one of the Claims 3 or 4 , wherein the closure device (36) has a lid (39) with a slag pot (41). Metallurgical plant (1) according to one of the preceding Claims 3 until 5 , further comprising a slag collecting pot (42) arranged in the upper vacuum chamber (33), via which the slide sand received by the slag pot (41) can be stored temporarily and removed from the degassing device (3). Metallurgical plant (1) according to one of the preceding claims, further comprising a first, preferably elastic, sealing unit (28) arranged on the outside of the vacuum container ceiling (9), via which the pan (6) can be connected to the degassing device (3) in a vacuum-tight manner is. Metallurgical plant (1) according to one of the preceding Claims 2 until 7 , further comprising a second, preferably elastic, sealing unit (29) arranged on the outside of the vacuum container base (11), via which the degassing device (3) is connected to the intermediate container (13) in a vacuum-tight manner. Metallurgical plant (1) according to Claim 7 or 8th , wherein the first sealing unit (28) has a connecting flange (30, 31) at its end opposite the vacuum container ceiling (9) and / or the second sealing unit (29) at its end opposite the vacuum container bottom (11). Metallurgical plant (1) according to Claim 9 , whereby the connecting flange (30, 31) is water-cooled. Metallurgical plant (1) according to one of the preceding claims, wherein the electrically operated melting unit (4) is designed in the form of an electric arc furnace (EAF), a submerged arc furnace (SAF) or an induction furnace (IF). Metallurgical plant (1) according to one of the preceding claims, wherein the electrically operated secondary metallurgical unit (7) is designed in the form of a ladle furnace (LF) or an induction furnace (IF). Metallurgical plant (1) according to one of the preceding Claims 2 until 11 , wherein the intermediate container (13) comprises a container trough (17) with two areas (19, 20) separated from one another by a dam-weir system (18). Metallurgical plant (1) according to Claim 13 , wherein the first area (19) is a vacuum area and comprises an inlet opening (22) arranged in its container trough ceiling (21), which can be connected in a vacuum-tight manner to the degassing device (3). Metallurgical plant (1) according to Claim 13 or 14 , wherein the second area (20), which preferably forms a further vacuum area (20), comprises at least one outlet opening (24), which is arranged in a container trough bottom (23) of the second area (20) and connected to the continuous casting system (2). is connectable. Metallurgical plant (1) according to Claim 15 , wherein the first area (19) has a volume that is the same or smaller than the second area (20). Metallurgical plant (1) according to one of the preceding claims, wherein the pan (6) consists of a steel housing and/or of a composite material, in particular of a glass fiber reinforced plastic (GRP). Method for producing a molten metallic composition, preferably by means of a metallurgical plant (1) according to one of the preceding claims, which is provided after a degassing and/or refining step of a continuous casting plant (2), comprising the steps: i) providing a metallic raw material and/or material (5); ii) melting the metallic raw material and/or material (5), possibly in the presence of further metal-containing and/or carbon-containing components, in an electrically operated melting unit (4), so that a molten metallic composition is formed; iii) transferring the molten metallic composition, preferably by means of a ladle (6), into an electrically operated secondary metallurgical unit (7), in which the molten metallic composition is subjected to secondary metallurgical treatment; and iv) transferring the secondary metallurgically treated molten metallic composition, preferably by means of a pan (6), into a degassing device (3), by means of which the secondary metallurgically treated molten metallic composition is degassed under vacuum in the form of a pouring jet (14) formed within the degassing device (3). and/or refined and then provided to the continuous casting plant (2). Procedure according to Claim 18 , wherein the molten metallic composition formed according to step ii) is adjusted in the electrically operated melting unit (4) to a carbon content of a maximum of 1000 ppm, a phosphorus content of a maximum of 250 ppm and a sulfur content of a maximum of 100 ppm. Procedure according to Claim 18 or 19 , wherein the degassing step and / or refining step according to step iv) is carried out such that the molten metallic composition has a hydrogen content of a maximum of 2 ppm and a nitrogen content of a maximum of 60 ppm. Method according to one of the preceding Claims 18 until 20 , wherein the degassing and/or refining step is supported by an inert gas, in particular argon. Method according to one of the preceding Claims 18 until 21 , wherein during the degassing and/or refining step at least one metallic trace element, which is preferably selected from the series comprising arsenic, lead, tin, zinc, bismuth, copper and/or combinations thereof, is removed from the casting jet (8). Method according to one of the preceding Claims 18 until 22 , wherein during the degassing and / or refining step at least one oxide-containing inclusion, which is preferably selected from the series comprising calcium oxide, aluminum oxide, silicon dioxide, titanium dioxide, manganese oxide, chromium oxide, nickel oxide and / or combinations thereof, is removed from the pouring jet (8). becomes. Method according to one of the preceding Claims 18 until 23 , wherein during the degassing and/or refining step at least one sulfide-containing inclusion, which is preferably selected from the series comprising zinc sulfide, tin sulfide, lead sulfide, mercury sulfide, arsenic sulfide, antimony sulfide, iron sulfide, manganese sulfide, nickel sulfide, cobalt sulfide, molybdenum sulfide and/or combinations thereof , is removed from the pouring jet (8). Method according to one of the preceding Claims 18 until 24 , wherein during the degassing and/or refining step at least one nitride-containing inclusion, which is preferably selected from the series comprising aluminum nitride, chromium nitride, titanium nitride, vanadium nitride, niobium nitride and/or combinations thereof, is removed from the casting stream (8). Method according to one of the preceding Claims 18 until 25 , wherein the metallic raw material and/or material (5) is formed from a directly reduced iron product and/or from a non-ferrous metallic material. Procedure according to Claim 26 , wherein the directly reduced iron product (DRI product) has an iron content of at least 75.0% by weight. Procedure according to Claim 26 or 27 , wherein the directly reduced iron product is supplied to the melting unit (4) in hot form as an HDRI product, in cold form as a CDRI product, in hot briquette form as an HBI product and/or in particulate form, preferably with an average particle diameter of a maximum of 20.0 mm , is supplied. Method according to one of the preceding Claims 26 until 28 , whereby the DRI product is produced in a direct reduction system and fed directly to the melting unit (4) via a conveyor under a protective atmosphere. Procedure according to Claim 26 , wherein the non-ferrous metallic material is selected from the series comprising a nickel-based material, a cobalt-based material, a copper-based material, an aluminum-based material and / or combinations thereof

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