EP1007748A1

EP1007748A1 - Method and equipment for processing iron- or oil-containing metallurgical waste

Info

Publication number: EP1007748A1
Application number: EP98931816A
Authority: EP
Inventors: Johann Lehner; Alexander Fleischanderl; Günter SCHREY
Original assignee: Voestalpine AG
Current assignee: Primetals Technologies Austria GmbH
Priority date: 1997-08-12
Filing date: 1998-07-15
Publication date: 2000-06-14
Also published as: BR9811891A; AT406056B; WO1999009224A1; CA2298504A1; ATA134797A

Abstract

The present invention relates to a method for processing iron- or oil-containing metallurgical waste (1) and for recycling the same in a fusion and/or reduction assembly (6). To this end, the iron- or oil-containing metallurgical waste (1) is mixed with quick lime (3), if necessary after the addition of other fractions containing oil such as used oil. The flowing fraction thus obtained (4) is introduced after an optional intermediate treatment into the fusion and/or reduction assembly (6).

Description

Process and plant for processing iron and oil-containing metallurgical remnants

The invention relates to a method for processing iron and oil-containing metallurgical residues, in particular mill scale, and for recycling the iron and oil-containing metallurgical residues in a melting and / or reduction unit, and a plant for carrying out the method.

A method of this type is known for example from DE-A-4 101 584. After adding molasses and calcium hydroxide, mill scale is briquetted as a binder and reused in the steelmaking process. This process is complex and expensive.

From DE-C-3 727 576 it is known to produce fine-grained iron-containing by-products from steelworks and metallurgical plants, such as blast furnace gas dust, blast furnace gas sludge, roll sinter and the like. The like. Mix with alumina cement as a binder and gravel, lime or slag as an additive, form into lumpy material and use in the blast furnace. The lime serves as a limestone only as a non-reactive aggregate. This process is also expensive.

A method for recycling oil-containing mill scale, which is similar to the method described in DE-A-4 101 584 and also has its disadvantages, is also known from US-A-4,585,475. Here, oil-containing mill scale is mixed with a binder, such as a mixture of molasses and calcium hydroxide or a mixture of sodium silicate and Portland cement, the mixture is agglomerated and the agglomerates formed are used in a molten steel bath. If necessary, iron oxide fine particles are also mixed into the mill scale.

A disadvantage of these known processes is that in addition to lime, in the form of limestone or calcium hydroxide, another binder must be added in any case in order to apply the appropriate binding forces for agglomeration.

The object of the invention, while avoiding a thermal oil removal route, is to improve and further develop these known processes in such a way that complete and nevertheless very economical processing of the iron and oil-containing metallurgical residues and recycling in a melting and or reducing unit by admixing only one single binder is made possible. In particular, the method according to the invention should be able to be implemented with only low investment costs. This object is achieved according to the invention in that the iron and oil-containing huttenwerkreststoffe, if necessary after admixing other oil-containing fractions, such as waste oil, are mixed with quick lime, preferably hard quick lime, and in that the πeselfbare fraction formed, optionally after an intermediate treatment, in the melting and / or reducing unit is introduced

A method for binding oils present in water (motor oils or other waste oils) or liquid chemical waste materials for the purpose of rendering them harmless with quicklime is known, for example, from AT-B-335 375. It is essential in this method that the quicklime becomes hydrophobic, which means that the 01 or the Liquid chemical waste can be finely dispersed in the pre-treated lime and placed in a landfill

A process for the disposal of mineral oil-containing wastes and sludges, whereby a water-repellent reaction product which can be used as a substructure material is formed, is known from AT-B-367 088. According to this document, mineral oil-containing material is sprinkled with a lime-containing reaction agent, as a result of which a fine-grain, water-impermeable reaction product is obtained, which can be used as a building material

According to the iron and oil-containing hut mill residues are preferably with an amount M (wt -%)

M = (A x F + B x G) + C mixed on quicklime, whereby

A is dependent on the reaction temperature and the residence time during mixing and is preferably selected from a range from 1.0 to 3.0, particularly preferably from 1.5 to 2.5,

F is the residual moisture in% by weight,

B is dependent on the properties of the quicklime, the type of oil and the residual moisture and is preferably selected from a range from 0.1 to 0.5,

G is the oil content in% by weight, and

C is dependent on the reactivity of the quicklime and the residual moisture and is preferably selected from a range from 0 to 5

The iron and oil-containing waste from the hut works are preferably processed with a residual moisture content of 5 to 15% According to a preferred embodiment of the process according to the invention, the free-flowing fraction formed from the iron- and oil-containing waste material and from quicklime, if necessary after comminution, is mixed with other waste material, in particular dust from dry filter systems and / or sludges from wet washers, and the mixture thus formed agglomerates agglomerates formed in this way are introduced into the melting and / or reducing unit, optionally after drying

According to a further preferred embodiment, the iesilable fraction formed from the iron and oil-containing waste materials and from quicklime is blown into the melting and / or reducing unit, preferably after comminution, preferably with a particle size of <5 mm

Advantageously, the πeselfahiges fraction formed from the iron and oil-containing Huttenwerkreststoffe and from quicklime is first sieved, whereby a coarse and fine fraction of the free-flowing fraction is obtained

The fine fraction, in particular with a grain size <5 mm, is preferably blown into the melting and / or reducing unit

According to another advantageous embodiment of the method according to the invention, the fine fraction, in particular with a grain size of <5 mm, is initially mixed with other hut material residues, in particular dust from dry filter systems and / or sludges from wet washers, and the mixture formed in this way is then agglomerated. The agglomerates formed in this way are introduced into the melting and / or reduction unit, if appropriate after drying

The coarse fraction is preferably introduced directly into the melting and / or reducing unit.

The coarse fraction, in particular with an oil content of <0.2%, is expediently introduced into a sintering device and used by the sintering device in a blast furnace

According to a further preferred embodiment of the method according to the invention, the iron and oil-containing waste material from the hut works together with other waste material from the hut, in particular dust from dry filter systems and / or sludge from wet washers and optionally other oil-containing fractions, such as waste oil, homogenized and mixed with quicklime, the mixture formed is agglomerated, and the agglomerates thus formed are introduced into the melting and / or reduction unit, if appropriate after drying

A plant for carrying out the method according to the invention is characterized in that a first mixer for mixing iron and oil-containing waste materials and possibly other oil-containing fractions, such as waste oil, is provided with quicklime and that the first mixer with a melting and / or Reduction unit is connected

According to a preferred embodiment, a comminution device, in particular a grinding device, is provided next to the first mixer for comminuting the free-flowing fraction

The comminution device is advantageously connected to blowing devices, in particular blowing lances, for blowing the comminuted free-flowing fraction into the melting and / or reducing unit.

A further mixer is expediently provided next to the comminution device, into which a feed line for other residues of hut works, in particular for dust from dry filter systems and / or for sludges from wet washers, is merged, and an agglomeration device for agglomerating the mixture formed in the second mixer is then connected to the second mixer and then, if necessary, a drying device thereafter

According to a further preferred embodiment, a sieving device for sieving the free-flowing fraction is provided next to the first mixer, from which a discharge for a fine fraction and a discharge for a coarse fraction originate.

The discharge line for the fine fraction is preferably connected to blowing devices, preferably blowing lances, for blowing the fine fraction into the melting and / or reducing unit

According to a further preferred embodiment, the discharge for the fine fraction merges into a further mixer, in which there is also a feed line for other hut waste, in particular for dust from dry filter systems and / or for sludge from wet washers, , and after the second mixer, an agglomerating device for agglomerating the mixture formed in the second mixer and, if appropriate, a drying device thereafter are provided

The discharge for the coarse fraction expediently merges into the melting and / or reducing unit

It is also advantageous if the discharge for the coarse fraction flows into a sintering device, which in turn is connected to a blast furnace

According to yet another preferred embodiment of the system according to the invention, a feed line for other waste materials, in particular for dust from dry filter systems and / or for sludges from wet washers, flows into the first mixer, and is an agglomeration device for agglomerating that in the first mixer after the first mixer formed mixture and then optionally provided a drying device

The invention is explained in more detail below with reference to the drawing, the process flow diagrams shown in FIGS. 1 and 2 showing preferred embodiments of the invention

According to FIG. 1, iron and oil-containing waste mill residues 1, such as mill scale, optionally together with other oil-containing fractions, such as waste oil, are mixed with quicklime 3 in a first mixer 2, for example a ploughshare mixer, with the required amount M (% by weight) Quicklime 3 depends on the residual moisture of the material to be processed and its oil content, further on the reaction temperature and residence time in the mixer 2, on the type of oil and on the reactivity of quicklime 3 The quicklime 3 serves on the one hand as a dispersion carrier for 01, which is in a finely dispersed state Phase is transferred, and on the other hand as a binder for the production of thermal shock-resistant agglomerates in the event of agglomeration, as well as for reducing the moisture content

The required amount M of quicklime 3 is preferably calculated according to the following formula

M = (A x F + B x G) + C In the above formula, A is a factor dependent on the reaction temperature and the residence time during mixing for the required amount of quicklime 3 A is preferably from a range from 1.0 to 3.0, particularly preferably from a range from 1.5 to 2 , 5, selected. F is the residual moisture of the material to be processed in% by weight. There is generally a connection that less quicklime 3 is required at a higher reaction temperature, since a larger proportion of moisture evaporates, which does not have to be bound by quicklime 3. In addition, less quicklime 3 is required the longer the mixture remains in mixer 2, since moisture evaporates for a longer time and the moisture percentage drops.

B is a factor dependent on the properties of the quicklime 3, the type of oil and the residual moisture of the material to be processed and is preferably selected from a range from 0.1 to 0.5. G is the oil content in% by weight. If quicklime 3 is very fine and easily dispersible for oils (i.e. easily wettable), little quicklime 3 is required and the factor B is small. In general, the factor B is chosen larger for a higher oil content, but smaller for a higher residual moisture

C is dependent on the reactivity of the quicklime 3 and the residual moisture of the material to be processed and is preferably selected from a range from 0 to 5. If the quicklime 3 exhibits poor dispergi behavior or reacts, a higher factor C is selected. A high factor C is also required if the material to be processed is very dry. Without the additional addition of quicklime 3, there is too little binder for subsequent agglomeration to achieve sufficient mechanical strength

For example, a mill scale fraction has a moisture content of 10% by weight and an average oil content of 5% by weight. This mill scale fraction is mixed with quicklime 3 of good quality with regard to the dispersion behavior and the hydration reaction, etc., the reaction temperature being about 70 ° C. and the residence time in the mixer 2 being a few minutes. The factors A, B and C are chosen in this example with A = 1.5, B = 0.2 and C = 1, so that the required amount M of quicklime 3 results

M = 1.5 x 10 + 0.2 x 5 + 1 = 17% by weight quicklime.

The processing of mill scale can also advantageously be carried out if the material to be processed is puncture-resistant. Since a certain proportion of binder, that is to say a certain amount of quicklime 3, is definitely required, the advantageous consistency of the is processing mill scale in the range of 5 to 15% residual moisture. However, the processing of iron and oil-containing hut material residues 1 with a residual moisture lying outside this range also poses no problems

A free-flowing, old-dispersed, dry fraction is formed in the mixer 2 by adding quicklime 3 to the iron- and oil-containing hut mill residues 1. This free-flowing fraction 4 can be further processed in various ways.

According to an embodiment variant shown in FIG. 1, the free-flowing fraction 4 is comminuted in a comminution device 5, for example a grinding device, preferably to a grain size of less than 5 mm. This comminuted free-flowing fraction 4 can be melted and melted directly, for example by means of blowing lances / or reduction unit 6, for example a blast furnace 6a, a converter 6b or into an electric arc furnace 6c

When blowing into the melting and / or reduction unit 6, dispersed hydrocarbons, ie the dispersed oils, are advantageously used as energy suppliers and the quicklime 3 as a slag former

The free-flowing fraction 4 can, however, also be combined in a second mixer 7 with other non-oil-containing waste material 8, in particular with dust from dry filter systems and / or with sludges from wet washers. Such sludges and dusts include, for example, converter dusts and sludges, blast furnace dust and sludges, dusts from electric arc furnaces, etc. Before mixing with other hut waste materials 8, it may be necessary to comminute the free-flowing fraction 4 by means of the comminution device 5. The mixing ratio of the individual metallurgical waste fractions in the second mixer 7 mainly results from the quantities of the waste material from the hut and their chemical composition.

Following the formation of a homogeneous mixture in the second mixer 7, an agglomeration process, such as pelleting, briquetting or extrusion, is carried out in an agglomerating device 9. The agglomerates formed in this way are introduced into the melting and / or reducing unit 6 in a manner known per se. Before the agglomerates are introduced into the melting and / or reducing unit 6, drying of the agglomerates can advantageously also be provided in a drying device 10. The agglomerates are preferably dried to a moisture content of less than 5% It may be necessary to screen a fine fraction 1 1, advantageously with a grain size of less than 5 mm. This fine fraction 11 can either be blown into the melting and / or reducing unit 6 or can be recycled for further processing, advantageously in the first mixer 2.

According to an embodiment variant shown in FIG. 1, the free-flowing fraction 4 is separated into a fine fraction 11 and a coarse fraction 13 by means of a sieve device 12. The coarse fraction 13, e.g. Rolling scale flakes, which have a grain size of greater than 5 mm, for example, are either introduced directly into the melting and / or reducing unit 6 or, if their oil content is less than about 0.2% by weight, fed to a sintering device 14. The coarse fraction 13 can then be returned from the sintering device 14 to a blast furnace 6a.

The fine fraction 1 1, which for example has a grain size of less than 5 mm, is either directly, e.g. by means of blowing lances, blown into the melting and / or reducing unit 6, or, as described above, mixed with other hut material residues 8, agglomerated and introduced into the melting and / or reducing unit 6 in this way.

According to an embodiment shown in FIG. 2, the iron and oil-containing waste mill residues 1 are homogenized in the first mixer 2 together with the other waste mill residues 8 and mixed with quicklime 3, optionally with the addition of water. The mixture formed in this way is fed to the agglomerating device 9, and the agglomerates thus formed are in turn introduced into the melting and / or reducing unit 6. Here, all iron-containing dust and sludge fractions occurring in a metallurgical plant with and without oil content are combined in one step into a single mixture of substances and agglomerated by adding quicklime 3.

The invention is not limited to the embodiments shown in the drawing. For example, it is also possible to agglomerate the comminuted free-flowing fraction 4 or the fine fraction 11 from the sieve device 12 without further admixing of other waste material 8 and to introduce it into the melting and / or reducing unit 6 in this way. Furthermore, the process variants described above can be used in combination if necessary (for example, very large amounts of metallurgical residues). If necessary, intermediate bunkers are provided in the line connections between the individual treatment stations (for example mixer 2, screening device 12, etc.).

Claims

claims

1 process for processing iron and oil-containing hut mill residues (1), in particular mill scale, and for recycling the iron and oil-containing hut mill residues (1) in a melting and / or reduction unit (6), characterized in that the iron and oil-containing waste materials (1), if necessary after admixing other oil-containing fractions, such as waste oil, with quicklime (3), preferably hard quicklime, and that the free-flowing fraction (4) formed, if necessary after an intermediate treatment, into the melting and / or reducing unit (6) is introduced

2 The method according to claim 1, characterized in that the iron and oil-containing hut works residues (1) with an amount M (wt -%)

M - (A x F + B G) + C on quicklime (3) are mixed, whereby

F is the residual moisture in% by weight,

B is dependent on the properties of the quicklime (3), the type of oil and the residual moisture and is preferably selected from a range from 0.1 to 0.5,

G is the oil content in% by weight, and

C is dependent on the reactivity of the quicklime (3) and the residual moisture and is preferably selected from a range from 0 to 5

3 The method according to claim 1 or 2, characterized in that the iron and oil-containing hut works residues (1) are processed with a residual moisture content of 5 to 15%.

4 The method according to one or more of claims 1 to 3, characterized in that the free-flowing fraction (4) formed from the iron and oil-containing hut mill residues (1) and from quicklime (3), optionally after comminution, with other hut mill residues (8) , in particular dust from dry filter systems and / or sludges from wet washers, is mixed so that the mixture formed in this way is agglomerated, and that the agglomerates thus formed, if appropriate after drying, are introduced into the melting and / or reduction unit (6)

5 The method according to one or more of claims 1 to 3, characterized in that the πeselfahiges fraction (4) formed from the iron and oil-containing Huttenwerkreststoffe (1) and from quicklime (3), optionally after crushing, in the melting and / or reduction unit (6) is blown in, preferably with a grain size of

<5 mm

6. The method according to one or more of claims 1 to 3, characterized in that the πeselfahliche fraction (4) formed from the iron and oil-containing hut works residues (1) and quicklime (3) is first sieved, a fine (11) and coarse fraction (13) of the free-flowing fraction (4) is obtained

7 The method according to claim 6, characterized in that the fine fraction (1 1), in particular with a grain size <5 mm, is blown into the melting and / or reduction unit (6)

8 The method according to claim 6 or 7, characterized in that the fine fraction (11), in particular with a grain size <5 mm, first with other Huttenwerkreststoffe (8), in particular dust from dry filter systems and / or sludges from wet washers, that the the mixture formed in this way is then agglomerated, and the agglomerates thus formed are introduced into the melting and / or reduction unit (6), if appropriate after drying

9. The method according to one or more of claims 6 to 8, characterized in that the coarse fraction (13) is introduced directly into the melting and / or reduction unit (6)

10. The method according to one or more of claims 6 to 9, characterized in that the coarse fraction (13), in particular with an oil content <0.2%, is introduced into a sintering device (14) and from the sintering device (14) into one Blast furnace (6a) is used.

11. The method according to one or more of claims 1 to 3, characterized in that the iron and oil-containing Huttenwerkreststoffe (1) together with other Huttenwerkreststoffe (8), in particular dust from dry filter systems and / or sludges from wet washers, and optionally other oil-containing fractions , such as waste oil, homogenized and mixed with quicklime (3), that the mixture formed is agglomerated, and that the agglomerates thus formed, if necessary after a drying process, into which melting and / or reduction unit (6) is introduced (FIG. 2).

12. Plant for carrying out the method according to one or more of claims 1 to 1 1, characterized in that a first mixer (2) for mixing iron and oil-containing waste materials (1) and optionally other oil-containing fractions, such as e.g. Waste oil, with quicklime (3) is provided and that the first mixer (2) is connected to a melting and / or reducing unit (6).

13. Plant according to claim 12, characterized in that a comminution device (5), in particular a grinding device, is provided for comminuting the free-flowing fraction (4) to the first mixer (2).

14. Plant according to claim 13, characterized in that the

Comminution device (5) with blowing devices, in particular with blowing lances, for blowing the comminuted free-flowing fraction (4) into the melting and / or reducing unit (6).

15. Plant according to claim 13 or 14, characterized in that a further mixer (7) is provided after the comminution device (5), in which a feed line for other hut works residues (8), in particular for non-oil-containing dusts from dry filter systems and / or for Sludge from wet scrubbers, flows out, and that an agglomerating device (9) for agglomerating the mixture formed in the second mixer (7) and, if appropriate, a drying device (10) is then provided after the second mixer (7).

16. Plant according to one or more of claims 12 to 15, characterized in that a sieving device (12) for sieving the free-flowing fraction (4) is provided next to the first mixer (2), from each of which a derivative for a fine fraction ( 1 1) and a derivation for a coarse fraction (13).

17. Plant according to claim 16, characterized in that the discharge for the fine fraction (1 1) with blowing devices, preferably with blowing lances, for blowing in the fine fraction (11) in the melting and / or reduction unit (6) is connected.

18. Plant according to claim 16 or 17, characterized in that the discharge for the fine fraction (1 1) opens into a further mixer (7), in which a feed line for other hut works residues (8), in particular for dusts from dry filter systems and / or for sludges from wet scrubbers, and that an agglomeration device (9) for agglomerating the mixture formed in the second mixer (7) and subsequently to the second mixer (7) optionally a drying device (10) is provided

19. Plant according to one or more of claims 16 to 18, characterized in that the discharge for the coarse fraction (13) merges into the melting and / or reduction unit (6)

20 Plant according to one or more of claims 16 to 19, characterized in that the discharge for the coarse fraction (13) opens into a sintering device (14) which in turn is connected to a blast furnace (6a)

21 Plant according to claim 12, characterized in that in the first mixer (2) a supply line for other Huttenwerkreststoffe (8), in particular for dusts from dry filter systems and / or for sludges from wet washers, and that then to the first mixer (2nd ) an agglomerating device (9) for agglomerating the mixture formed in the first mixer (2) and then optionally a drying device (10) is subsequently provided (FIG. 2)