EP2488810A1

EP2488810A1 - Method and device for feeding into a smelting unit

Info

Publication number: EP2488810A1
Application number: EP10765415A
Authority: EP
Inventors: Thomas Eder; Robert Millner; Jan-Friedemann Plaul; Norbert Rein; Andreas Scherney; Karl Zehetbauer
Original assignee: Siemens VAI Metals Technologies GmbH Austria
Current assignee: Primetals Technologies Austria GmbH
Priority date: 2009-10-16
Filing date: 2010-10-06
Publication date: 2012-08-22
Also published as: BR112012008905A8; RU2012120086A; UA106508C2; KR101724268B1; BR112012008905A2; IN2012DN02795A; CA2777654C; AU2010305955B2; CN102612632B; RU2533990C2; US20140196571A1; CA2777654A1; AT508953A1; CN102612632A; AT508953B1; WO2011045212A1; KR20120094928A; AU2010305955A1; JP2013507527A; US20120279356A1

Abstract

The present invention relates to a method and a device for feeding a preliminary product for pig iron into a smelting unit. Said method and device are characterized in that part of the preliminary product, which was formed by reducing oxidic siderophores, is stored in the hot state in a reservoir tank before it is fed into the storage device (11) or feeding device directly connected to the smelting unit.

Description

Method and device for charging into a smelting unit

The present invention relates to a method and a device for charging a precursor for pig iron into a smelting unit.

In reduction process for fine-particulate iron ore, such as the FINEX ^® process, in

Fluidized bed reactors by means of a reducing gas

direct reduced iron (DRI). This direct reduced iron depends on the

Operating mode a degree of reduction of about 50 ~ 95% and is like the iron ore used feinteilchenförmig. For the complete reduction and for the production of pig iron one leads the directly reduced iron DRI after one

Compaction step, in which so-called hot

compacted iron (HCl) is obtained, a storage device or charging device, which is optionally traversed by a reducing gas, and from there to a smelting unit such as a melter gasifier. A storage device, also called HCI bin, or charging device, among other things, performs a buffering function to ensure continuous charging of hot compacted iron into the system

Smelting. Furthermore, it offers the possibility of being charged in addition to the melter

Pre-heat materials such as pellets or lump or coke through the reducing gas. The

Storage device is arranged above the smelting unit in order to allow a charging from the storage device in the smelting unit in the direction of gravity. The majority of the hot compacted iron obtained in the compacting step becomes one during normal operation

FINEX ^® system fed after compacting directly in the hot state of the storage device or charging device. Another portion of the recovered hot compacted in the compacting iron is used in the normal operation of a FINEX ^® plant after compaction to create a stored outside of the memory device or charging device stock compacted irons. This supply of compacted irons is required, for example, during startup or low driving a FINEX ^® plant. In the prior art, the hot compacted iron not directly transferred to the storage device is typically quenched with water in a quench tank and connected outdoors under atmospheric conditions

Conditions stored. Once this cooled, stored compacted iron is needed for addition to the smelting aggregate, it becomes the storage device or

Charging device supplied. In this it is preheated before being charged into the smelting unit.

The disadvantage here is that the cooled in quench tanks compacted iron tends to reoxidize during storage, and that to its preheating before charging in the

Melting unit a high energy consumption is necessary. The time required to preheat the material

also extends the duration of the startup process. Furthermore, the operation of the quenching facilities is complex and makes time- and money-consuming handling and disposal of cold briquetted iron and sludge necessary. The plant components involved must be serviced and operated cost-intensive. Of course, the same conditions apply, if not a FINEX® process with HCl as a precursor, but a process is used in which oxidic

Iron briquetted iron (hot briquetted iron, HBI) as - briquetted, that is, thus compacted - precursor is produced.

It is also in non-compacted precursors such as low-reduction iron (LRI) accordingly disadvantageous to store the precursor in a hot state.

It is therefore the object of the present invention to provide a method and an apparatus for producing pig iron from a precursor in which the disadvantages mentioned are avoided.

This task is solved by

Process for the production of pig iron in one

Melting unit of a product obtained by reduction of oxidic iron carriers by means of a first reducing gas precursor, wherein the precursor of a with the

Melting unit directly connected storage device or charging device, from which an addition takes place in the melter, is supplied, characterized in that a portion of the precursor is stored in a hot state in a storage container before it is fed into the storage device or charging device directly connected to the melter ,

The oxidic iron carriers are converted into a precursor by reduction by means of a first reducing gas

Production of pig iron, for example direct reduced iron DRI, implemented. If the product of the reduction is not lumpy, but is finely particulate, it may

Improvement of the handleability of a compaction by means of compacting devices comprising compaction machines and crusher systems are subjected. A portion of the precursor is stored in a reservoir before its supply to a with the meltdown to the

Production of pig iron directly connected

Storage device or charging device takes place. In this case, the precursor iron is not cooled by quenching, but stored in a hot condition in the reservoir. If compaction takes place, the precursor is stored in the reservoir after compaction. In this way, in the case of charging in the

Melting unit no time preheating of this material necessary.

The addition of the stored in the reservoir precursor into the storage device or charging device can be done during a startup. It can also be done during normal operation, by addition of

Pre-product for storage device or charging device quantity fluctuations in the production of the precursor

compensate.

Storage device and charging device are as

considered equivalent, since both devices for receiving delivered precursor prior to addition to the

Smelting unit are suitable, respectively

delivered material before addition to the

Melting unit a period of time in one

Charger lingers before entering the

Melter unit occurs because the passage through the

Charging device requires some time. During this time, the material is therefore in the charging device and is thus stored in it.

According to different embodiments of the

According to the invention, the oxidic iron carriers are finely particulate iron ore, or they are lump or pellets.

According to one embodiment of the method according to the invention, the precursor is hot compacted iron.

Typically, for example, one speaks of hot

compacted iron HCl, if the density of the precursor is less than or equal to 4.5 kg / dm ³ , and the metallization <88%. HCl may contain additives.

According to one embodiment of the method according to the invention, the precursor is hot briquetted iron HBI. Typically, for example, one speaks of hot Briquetted iron, if the density of the precursor greater than or equal to 5 kg / dm ³ and its metallization is greater than or equal to 88%. HBI typically contains no aggregates. According to one embodiment of the method according to the invention, the precursor is hot low-reduction iron.

Preferably, in the hot state in the

Storage container stored precursor with a

Reverse oxidation protection gas, which is a reoxidation of the

Pre-product inhibits, lapped. This way a can

Reoxidation, at worst pronounced as a fire, are prevented during storage in the reservoir. As a reoxidation gas, for example, an inert gas such as nitrogen in question or a reducing gas - in this reducing gas may be, for example, the first

Reduction gas act or to the following

introduced second reducing gas.

Accordingly, the security risk in carrying out the method according to the invention over the prior art is reduced. By the non-oxidizing, namely

For example, inert or reducing atmosphere within the reservoir, the reoxidation of the precursor is prevented and the negative impact on the

Melting unit reduced by a use of precursor with low or highly fluctuating degree of reduction.

According to one embodiment of the method according to the invention which is directly connected to the melter

Memory device or charging device flows through a second reducing gas.

In a preferred embodiment, the first reducing gas and the second reducing gas are from the same

Source, for example, the smelting unit such as a melter gasifier. In this way, the number of for the Provision of reducing gases necessary facilities reduced.

Preferably, the addition from the storage device or charging device takes place in the smelting unit in

Substantially following the gravity. In this way, the apparatus and energy costs for the transport of the precursor from the storage device or

Charging device kept small in the melter gasifier. In principle, however, the addition may also be contrary to

Gravity take place, that is, for example, such that the storage device or charging device is located below a feed opening for precursor in the melter and from there upwards, ie opposite to the

Gravity, must be transported to the addition port. Similarly, the feed opening and the storage device or charging device may be laterally spaced apart from one another, wherein the precursor must be conveyed from the storage device or charging device sideways to the feed opening, not in the direction of

Gravity. For transport sideways or upwards more energy and more equipment is required as for an addition, which essentially follows the gravity, ie downwards. The term "substantially" means that in addition to a downward movement in the addition also a sideways movement of the added

Material can be done, for example, if the opening from which the precursor the storage device or

Charger leaves, not vertically above the

Feed opening, through which it enters the melter

is admitted lies.

Another object of the present invention is an apparatus for performing a method according to any one of claims 1 to 10, comprising at least one reduction unit for the reduction of oxidic iron carriers by means of a first reducing gas, a first reducing gas line opening into the reduction unit, a Melting unit for the production of pig iron from the obtained in the reduction of oxidic iron carriers by means of the first reducing gas precursor, and a

Feed device for feeding precursor into a

Storage device or charging device connected to the smelting unit via at least one metering line

is connected, wherein the feed line with a

Feed opening in the meltdown unit opens, and wherein a feed device for the task of pre-product is present on the supply device, characterized in that a reservoir for storage of precursor in the hot state is present, and an input device for input of intermediate product in the reservoir, wherein the reservoir also connected to the supply device.

The oxidic iron carriers are in at least one

Reduction unit, which, for example, as

Fluidized bed reactor or can be designed as a fixed bed reduction shaft, reduced by means of a first reducing gas. The first reducing gas used for the reduction is supplied by means of a first reducing gas line opening into the reduction unit.

The addition line, with an addition opening in the

Melting unit opens, can also be part of the

Charging device be.

The reduction unit may be, for example, a fixed bed reactor or a fluidized bed reactor.

The optionally compacted or briquetted intermediate product obtained in the reduction of oxidic iron carriers is applied by means of a feed device to a feed device for the supply of precursor. The feeder can, for example, a chute,

Snail, conveyor trough, or a pipe. By means of

Feed device for supplying precursor, for example a hot conveyor, the precursor is in one

Storage device or charging device transported.

The storage device or charging device is connected to the smelting unit via a metering line, through which an addition of precursor from the storage device or charging device takes place directly into the smelting unit. Of course, in the metering line additional devices may be present, such as valves or lock devices. The metering line opens with an addition opening in the smelting unit, through which originating from the storage device material in the

Smelting unit occurs. Furthermore, the device according to the invention has a

Reservoir for storing precursor in a hot state. This is connected both to an input device for input of precursor into the reservoir, as well as to the supply device. The

Input device is for example a downpipe, a

Schurre, a hot conveyor, a screw conveyor, a rotary valve. Vorprodukt can therefore be entered into the reservoir Vierden, and from the reservoir - for example via screw conveyor, rotary valve, intermediate hot conveyor, valve, pipe, chute - on the

Feeder be abandoned.

The storage container is lined with refractory material. Its storage capacity should advantageously meet the demand for precursor, for example hot compacted iron HCl, for about 12-24 hours to about two days operation of the apparatus for carrying out the invention

Cover procedure. For example, a demand of 4600t HCl would correspond to a reservoir volume of about 2 x 900m ³ .

According to one embodiment, a compaction device for compaction and / or briquetting is present, wherein the compacting device between the

Reduction unit and the supply device, and located between the reduction unit and the input device. The compacting device is in each case connected to the two device parts between which it is located, "between" is in terms of

Material flow from the reduction unit to the smelting unit to understand. The removed from the reduction unit material, such as DRI, is in the

Compacting device comprising compacting and crusher systems, compacted. In this case, for example, hot compacted iron HCl or hot briquetted iron HBI is produced as precursor.

In this case, it is preferred that a feeding device for the task of compacted and / or briquetted

Precursor from the compaction device on the

Supply device is present, and that the reservoir with the compaction device via a

Input device for input of compacted and / or briquetted precursor from the compacting device is connected to the reservoir.

According to one embodiment, a second opens

Reduction gas line into the storage device or

Charging device. Due to the contact with the second reducing gas introduced through the latter, material which is located in the storage device or charging device may optionally be partially reduced or

warmed up. Here, the first reducing gas line and the second reducing gas line with an aggregate for

Reduction gas generation are connected, according to a

Embodiment, the first reducing gas line and the second reducing gas line with the same unit for

Reduction gas generation are connected.

An aggregate for reducing gas production is to be regarded as a source of reducing gas. Preferably, a Rückoxidationsschutzgasleitung opens for supplying Rückoxidationsschutzgas in the reservoir. In this way, the hot precursor present in the reservoir, for example hot compacted iron HCl, can be protected from reoxidation.

According to one embodiment, the reservoir is arranged at a lower level, for example at the level of the ground, than the feed opening into the smelting unit. This results in manufacturing material and

Steel construction savings in the construction of the reservoir or in the construction of support structures for the reservoir. In one embodiment, the melter is a melter gasifier. It can also be a blast furnace.

Compared to that carried out in the prior art

Quenching of precursor, such as HCl, before storage results according to the invention the advantage that no wet quenched precursor, such as HCl, with hot precursor, such as HCl, is mixed, creating explosion hazard by hydrogen generation

is reduced. Furthermore, by the erfindungemäße

Execution the purchase or operation of a quench tank for cooling of intermediate product is no longer required. Thus, the required process water requirement can be reduced. Another advantage of the present invention is that a storage device or charging device, such as an HCI bin, can be made smaller, because material for buffering production variations of precursor need not be present in the HCI bin but can be withdrawn from the reservoir , This reduces material and labor costs for the construction of the HCI-Bin as well as its height. Preferably, at least two storage containers are provided in order to use a redundancy container during maintenance work. Pre-product from the reservoir can also be supplied to several different meltdown units,

for example, a melter gasifier and a blast furnace.

Subsequently, the present invention with reference to two schematic exemplary figures of embodiments will be explained in more detail.

FIG. 1 shows a schematic structure of a

Device according to the invention with fluidized bed reactors. FIG. 2 shows a schematic structure of a

Device according to the invention with fixed bed reactor.

Fine particle iron ore 1 is introduced into a cascade of fluidized bed reactors 2a, 2b, 2c. A first

Reduction gas is introduced via the first reducing gas line 3 into the fluidized-bed reactor 2c, after leaving it via a connecting line 4 into the fluidized bed reactor 2b, passed after leaving via a connecting line 5 in the fluidized bed reactor 2a and withdrawn from this via a top gas line 6. The first

Reduction gas line 3 rises at the melter gasifier 7, in which pig iron is produced from hot compacted iron. From the fluidized bed reactor 2c removed product is by means of a compacting device, the

Intermediate container 8, a compacting machine 9a and a

Crushing system 9b comprises, compacted to hot compacted iron. The hot compacted iron is fed via a supply device 10 to a storage device 11, the HCI bin. The HCI bin is above the

Melter gasifier 7 arranged. The storage device 11 is connected to the melter gasifier 7 via a metering line 12, via which hot compacted iron HCl is added by gravity from the storage device 11 into the melter gasifier 7. The metering line 12 opens with a feed opening 13 in the melter gasifier 7. A second reducing gas line 14 opens into the

Storage device 11, it rises at the melter gasifier. 7

The direct application of hot compacted iron from the crusher system 9b is carried out by means of a feeder, which in the figure by means of a chute 15th

Outgoing line 16 is shown.

Hot compacted iron produced in the compacting apparatus can be directly inputted to the storage tank 19 with appropriate adjustment of the chute 15 via an input device represented by line 17 and hot conveyor 18. About a opening into the reservoir 19 Rückoxidationsschutzgasleitung 20, the inert gas nitrogen is fed into the reservoir 19. The storage container 19 is connected to the supply device 10 via the supply outlet line 21 and the hot conveyor 22. Thus, if necessary, hot compacted iron can be taken out of the reservoir 19 and supplied to the storage device 11.

In FIG. 2, device parts corresponding to FIG. 1 are provided with the same reference numerals as in FIG. FIG. 2 differs from FIG. 1 in that instead of

Fluidized bed reactors a fixed bed reactor 24 as

Reduction unit is used. In these, 23 lumps and pellets are entered as oxidic iron carriers. The fixed bed reactor is connected to the first reducing gas line 3, through which first reducing gas flows.

Used reducing gas is withdrawn via the top gas line 6. Precursor is fed from the fixed bed reactor 24 either via line 16 of the feed device 10, or fed via line 17 to the hot conveyor 18, via which the hot precursor is conveyed into the reservoir 19. Preproduct can be supplied from the reservoir 19 via the execution line 25 a blast furnace 26. LIST OF REFERENCE NUMBERS

I fine-particle iron ore 2a, 2b, 2c fluidized-bed reactors

3 first reducing gas line 4 connecting line

5 connection line

6 top gas line

7 melter gasifier

8 intermediate containers

9a compacting machine

9b crusher system

10 Kufuhrvorrichtung

II storage device

12 feed line

13 addition opening

14 second reducing gas line

15 chute

16 line

17 line

18 hot conveyors

19 storage tank

20 reverse oxidation protection gas line

21 supply outlet line

22 hot conveyors

23 oxidic iron carriers

24 fixed bed reactor

25 executive committee

26 blast furnace

Claims

Claims / Patent Claims

1) A process for the production of pig iron in a smelting unit from a obtained by reduction of oxidic iron carriers by means of a first reducing gas precursor wherein the precursor of a directly connected to the meltdown storage device or charging device, from which an addition takes place in the melter, is characterized in that a part of the precursor is stored in a reservoir in the hot state before it is fed into the storage device or charging device directly connected to the melting unit. 2) Method according to claim 1, characterized in that the oxidic iron carriers are finely particulate iron ore.

3) Method according to claim 1, characterized in that the oxidic iron carriers are lump or pellets.

4) Method according to one of claims 1 to 3, characterized in that the precursor is hot compacted iron HCl.

5) Method according to one of claims 1 to 3, characterized in that the precursor is hot briquetted iron HBI. 6) Method according to one of claims 1 to 3, characterized in that the precursor is hot low-reduced iron LRI.

7) Method according to one of claims 1 to 6, characterized in that in the hot state in the

Storage container stored precursor with a

Reverse oxidation protection gas, which is a reoxidation of the

Pre-product inhibits, is washed around. 8) Method according to one of claims 1 to 7, characterized in that the directly connected to the meltdown device storage device or charging device is traversed by a second reducing gas.

9) Method according to claim 8, characterized in that the first reducing gas and the second reducing gas originate from the same source. 10) Method according to one of claims 1 to 9, characterized in that the addition of the storage device or charging device in the smelting unit in

Essentially following gravity. 11) Apparatus for carrying out a method according to one of claims 1 to 10, comprising at least one

Reduction unit for the reduction of oxidic iron carriers by means of a first reducing gas, one in the

Reduktionsaggregat first reducing gas line (3), a smelting unit for the production of pig iron from the obtained in the reduction of oxidic iron carriers by means of the first reducing gas precursor, and a

Feed device (10) for feeding precursor into a storage device (11) or charging device, which is connected to the melter unit via at least one metering line (12), wherein the metering line (12) with a

Feed opening (13) opens into the melter, and wherein a feeding device for the task of pre-product on the supply device (10) is present, characterized

in that a storage container (19) for

Storage of precursor is present in the hot state, and an input device for input of precursor into the reservoir (19), wherein the reservoir (19) is also connected to the supply device (10).

12) Device according to claim 11, characterized in that a compacting device for compaction

and / or briquetting is present, wherein the Compaction device between the reduction unit and the supply device (10) and between the

Reduction unit and the input device is located. 13) Apparatus according to claim 12, characterized in that a feeding device for the task of kompaktier em and / or briquetted precursor from the

Compaction device on the feed device (10) is present, and that the reservoir (19) is connected to the compaction device via an input device for input of compacted and / or briquetted precursor from the compaction device in the reservoir (19). 14) Device according to one of claims 11 to 12, characterized in that a second reducing gas line (14) opens into the storage device (11) or charging device.

15) Apparatus according to claim 13, wherein the first

Reduction gas line (3) and the second reducing gas line (14) are connected to an aggregate for the reduction gas generation, characterized in that the first

Reduction gas line (3) and the second reducing gas line (14) are connected to the same unit for reducing gas production.

16) Device according to one of claims 11 to 14, characterized in that a Rückoxidationsschutzgasleitung (20) for supplying Rückoxidationsschutzgas in the

Reservoir (19) opens.

17) Device according to one of claims 11 to 15, characterized in that the storage container (19) is arranged at a lower level than the addition opening (13) in the melter. 18) Device according to one of claims 11 to 16, characterized in that the smelting unit a

Melt carburetor (7) is. 19) Device according to one of the claims 11 to 17, characterized in that the reduction unit a

Fixed bed reactor or a fluidized bed reactor (2a, 2b, 2c)