DD215585A5 - METHOD AND APPARATUS FOR MANUFACTURING BINDER-FREE HOT RATED LABELS - Google Patents

Abstract

The invention relates to a process for the preparation of Verhuettung certain binderless hot briquettes of iron-containing pyrophoric, finely divided solids, such as dry filter dust steel production and feinkoernigem sponge iron from direct reduction plants. The more than 4 wt .-% metallic iron-containing finely divided dry solid having a temperature of more than 200 degrees C is blown before briquetting with oxidizing gas. The amount of gas is controlled so that by oxidation of a portion of the metallic iron, the temperature of the finely divided solid is increased to 450 to 650 degrees C. Then hot briquetting.

Description

Berlin, 27.4.1984

; AP C 22 B / 258 691/6

, .-. '''.;'.'. -. , /; ' : -; ..::. 63 370/18. .- ^: / '

Process for the preparation of binderless hot briquettes Field of application of the invention

The invention relates to a method and a plant for the production of intended for smelting binderless hot briquettes of iron-containing pyrophoric, finely divided solids, such as dry filter dust from steelmaking and fine-grained sponge iron from direct reduction plants. .. '. , , '.'. '.''-,''..''..''' .:.

Characteristic of the known technical solutions

In steelmaking, z. B, after the oxygen inflation process, fall in the CO-Rüokgewinnung deposited in filters metallized dusts ah, which depending on the proportion of Metallii iron pyrophoric or highly pyrophoric properties »Even fine-grained sponge iron, z. B _# from Oirektreduktionsanlagen, often has strong pyrophoric properties. Due to these properties, it is not possible to bunker and heat-process the mentioned finely divided solids in untreated form.

It is known to briquette conventional filter dusts or fine-grained sponge iron with the addition of .Bindemitteln »The substances previously proposed as binders are products such as bitumen and other tar products, molasses, sulfite waste liquor, etc. The disadvantage of these binders is that they by their presence the Decrease concentration of valuable components in the product and often for the

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subsequent treatment process impermissible contamination, eg. Schwefel "Bringing in sulfur or causing problems for the environment" Since they are needed in large quantities, the costs * consist of the price of the bandage itself, the transport and storage costs and a number of other costs. considerable, so that the economic efficiency is questioned *

From DE-AS 11 42 442 a process for briquetting fine ores is known in which the ore is mixed with a basic aggregate / such as magnesium hydrate, hydrated lime, limestone or dolomite and the mixture without the addition of a special binder and without the presence of clay briquetting under high pressure "According to the description, I can also apply the method to filter dust (s * Sp. 3/4, Table 1)" Whether it is filter dust with pyrophoric properties can not be found in the description herds, Die Disadvantages of the cold briquetting method are the high pre-press pressures compared with hot briquetting and the associated high power requirement for the briquetting press and uneven compaction behavior and the associated insufficient briquette space weight. In order to reuse the filter dust in the form of briquettes in converters or It is sufficient to allow electric furnaces without problems high Raumgeiivicht required, which must be much higher than that of the metallurgical slag used.

In DE-AS 11 23 351 a process for the production of briquettes has been described in the ferrous

, : AP C 22. Β / 258 691/6. ". ^':;;>"' 3. -.Λ · ... "· 63 370/18", -

such as blast furnace dust and other ferrous waste and iron compounds, including natural iron ores with partial removal of oxygen. The resulting product of iron oxides and metallic iron, is then alone by application of

Heat and pressure briquetted at a temperature below 850 C and a pressure above 687 bar. As the reducing agent, a reducing gas, such as CC or H ", an organic material such as starch or sugar, or an iron-containing compound" can vie a partially reduced to metallic iron Fe and FaG containing ore are used. The following components of this process can be seen in the fact that, before the desired preparation of the finely divided ores or other finely divided, iron-containing materials, a reduction process is necessary, as in known direct reduction processes. In the course of this reduction process, a temperature of set finely divided materials / then allows a hot briquetting. However, the application of this procedure is not transferable to the pyrophoric, finely divided filter dusts and the fine-grained sponge iron, since they are already present in a metallized state, but are cooled to such a low temperature that a hot »briquetting is no longer possible.

From DE-AS 15 33 852 a process for the production of sponge iron briquettes is known in which the porous iron sponge immediately after discharge from the rotary kiln in the hot state at temperatures of 400 to 800 ⁰ G and

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briquetting at pressures of 1500 to 3000 kgf / cm

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AP e 22 B / 258 691/6 «4 ~ 63 370/18

with the proviso that the value pairs der'Parameter temperature and pressure within the specified ranges are selected so that a density of more than 5 g / cm is achieved.

Also in the "Speech Room Technical Report" '102, Dahrgang (1978), No. 2, S, 58 to 64 is reported on the hot briquetting of sponge iron. Like the aforementioned method is based on a sponge iron, due to its Heißaustragstemperatur without additional heating of Both methods are therefore not suitable for filter dusts and sponge iron whose discharge temperature is lower than the hot briquetting ierungstemperatur »

Object of the invention. ; , , -. ·· .. '.', '· ^: ''.' , .. · ...

It is the object of the invention to provide a process with which iron-containing pyrophoric finely divided solids can be disposed of as energy-saving as possible while avoiding binding agents.

rational manner, taking into account the pyrophoric properties of the substances, can be compacted to allow for smelting »

.des, essence of

The invention has for its object to find a way to bring the iron-containing finely divided solids in an energy-saving manner to a temperature at which compacting can take place.

The object is achieved in that more

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blow ^ metallic iron containing dry finely divided solid ihit a temperature of more than 200 ⁰ C prior to the briquetting with oxidizing gas and thereby the amount of gas is so controlled that by oxidation of a part of the metallic iron the temperature of the f-piece solid - than 4 wt " increased to 450 to 650 ⁰ C and immediately followed by hot briquetting.

The oxidizing gas used is preferably air or oxygen-enriched air or technically pure oxygen. The oxidizing gas may be preheated.

The thus heated finely divided solid is compressed in a Brikettierpresse to briquettes, wherein advantageously a Walzenbrikettierpresse is used with a Walzenpreßdruck of more than 6 kN / cm iValzenbreite.

Before the briquetting press an intermediate bunker for the heated finely divided solid can be arranged in order to operate the briquetting press continuously. This has an effect on improving the briquette quality ·

If the finely divided solids to be briquetted have no or only a small proportion of lime, they are then mixed with 3 to 6% by weight before briquetting. Added lime. This allows for a calcium ferrite which leads to an improvement in the abrasion resistance of the briquettes produced.

The briquettes are in contrast to the usual process

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For example, in iron sponge batches using water cooling, cool them down to a temperature below 100 C in a stream of air to prevent reoxidation. * The briquettes are then placed in a bunker where sio is vented to prevent heat accumulation. * Off the briquettes can be taken from the bunker for use in the steel works *

The invention provides a solution to the problems associated with the further processing of the dust-like or fine-grained pyrophoric solids and makes it possible to bring the substances to hot-pickling temperature in an energy-saving manner. It was to be expected that the substances would be blown through with oxidizing gases because of their pyrophoric properties It would not be possible to do this in a self-confident way " ¹ J : 'ι.' .. ./:: . ''. '. ·.'. ^"V

A plant for carrying out the process, consisting of a Brikettierprissse with material supply »a briquette cooler and a bunker, characterized in that before the briquetting press a rotatable drum is arranged * with a arranged at one end feed for the finely divided pyrophoric dry solid, an am arranged at the other end for the heated on Heißbrikettie · »» Rüngstempefatur solid, a gas feed line for the oxidizing gas and a feed for fine lime, by regulating means the residence time of the solid in the drum, the supplied amount of oxidizing gas and the added Feinkalkmenge individually controllable are*

According to another Merksnal of the invention, the rotatable

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Drum arranged inclined and mounted on the walls of a number ^Rait: .'tüf tern equipped, the Sirid adapted for ventilation of the "finely divided solids>.

Instead of the rotatable drum according to another embodiment of the invention, a fluidized bed can be provided with gas expulsion lines to the bottom of the fluidized bed. The gas can also be introduced into a fluidized bed.

- .. 'Vv'. .-.-. , V-'V V .., .- .-. -'-. V-- ': ":.' V-. ~ '.-., -."'"- \ - - ^: ' ν. ' The briquette cooler is preferably made up of an endless belt with one or more air ducts _# The bunker used for the briquettes is equipped with one or more blowers to prevent accumulation of heat, instead of air auclr may use a vent nitrogen mixture or technically pure nitrogen as cooling medium are blown into the bunker * V ':' -V. -V '". ':' V. ^: · ·; , ''. ' V. '' -. '', - ^:

Example of embodiment

An embodiment of the process according to the invention and the plant according to the invention are described in more detail below. In the attached drawing:

Figure _# 1 and 2: the erfihdungsgemäße briquetting of-pyrö- · 'phorem filter dust from a COwRückgewin ^"1 · incineration plant einesSauerstoffaufblaskonverters

Figure 3: the briquetting of fine-grained pyrophoric sponge iron from a direct reduction plant.

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FIGS. 1 and 2 show an oxygen-to-air converter 1 equipped with a CO 2 recovery plant 2. This has a coarse filter 3 and an electrostatic filter 4 * The retained in these filters finely divided pyrophoric Filterstäub according to FIG, I a rotatable drum 5 via the feed 6 fed _# The rotatable drum 5, which is equipped with fans ti on the walls »points a line 8 for oxidizing gas and a

Zuf FiI

9 for Feirikalk on * The finely divided pyrophore

O.

dust, which has a temperature of over 200 C,

in the drum 5 is supplied with an amount of air which is supplied to the gas line 8 duri h. Due to the onset of oxidation of part of the metallic iron of the filter dust, the temperature of the filter dust is raised to the temperature of 450 ° to 650 ° C., the temperature increase being increased by the amount of air supplied per minute. The supply 6, the gas line 8, the fine lime supply 9 and a discharge I _{1 located} at the other end of the drum 5 are equipped for this purpose with unillustrated control elements that the residence time of the solid in the drum 5, the amount of oxidizing gas (air) supplied, and the trajectories of finely calcified © are individually controllable

2, instead of the rotatable drum 5, a fluidized bed 5a is arranged »which is equipped with air injection lines 8a« ':. · '';. ' , · -. ; ...

The heated to Brikettiertemperatur filter dust is at

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two embodiments of the discharge 7 of Brikettierpresse 10 fed, in which the filter dust is compressed into briquettes »The finished briquettes arrive for cooling on a briquette cooler, which is in the form of an endless belt 12. Under the belt 12 there are two air blowers 13, with which the briquettes are cooled to a temperature below 100 ⁰ C to prevent reoxygenation. The cooled briquettes then pass into a bunker 14, from which they can be removed for use in the steel mill. To prevent heat accumulation in bunker 14, it is equipped with an air blower 15 «

Fig. 3 shows a direct reduction plant 16 for the production of sponge iron * The sponge iron produced reaches the screening device 17 _t with the fine-grained fractions »can not be used directly in the steel mill, can be separated. These fine-grained fractions pass via a feed 6, as in the above-described embodiment, into a rotatable drum 5, in which the temperature is raised to the hot briquetting temperature by supplying an oxidizing gas (air) "If the sponge contains no or only little lime, Fine lime is fed from the lime bunker 18 in the drum 5 and mixed with the fine-grained sponge iron. As a result, a calcium ferrite formation is possible, which leads to the finished briquettes to improve the abrasion resistance. The further method steps correspond to those of the previously described embodiment, in which the same parts of the device have the same reference numbers.

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have been drawn »

The examples listed in the following table further illustrate the invention, Example i being the previous procedure and Examples 2 and 3 embodiments according to the invention

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Procedural steps ','. '' . - \ : ^v i · · - '' Example; -2'.; ... ^{; 3} . . ''' ^ iOO ⁰ C Filter dust discharge to CO-recoil plant Stahlwerk ... yes '3'. '-. Chem * analysis: Fe content 40-90% Fe, content 10-70 % Caü ^et content 3-20 % 65.5 % 13.0 % 8.1 % 78 ₄ 2 %. 54.7 % Particulate matter discharge temperature 150-600 c * v2oo e ~ 4ÖO / ⁰ C Filter dust humidification , in the mixer yes No No 'Moisture Content'.:>. 5 :.%. '; ·' · '-;. ; , · · '''"" V. , ^: Filter dust inlet in reaction drum with? regulated air supply no ^{': 3:'} '''* ::. Filter dust temperature output reaction drum> - is. 550 ⁰ C -60O ⁰ C Briquetting at a pressure of 1 liter (kN / cm IValzenb reite. '' "-...". 100 kN / cm 110 kN / cm Cooling the briquettes on a belt cooler * - -ClOO ° C Bunkering of the briquettes in the aeration bunker (temporary storage) - Yes

Quality of the briquettes:

ä) room weight

b)! Pressure resistance

0 g / cm ³ ** 5.5 g / cm ³

200-500 1000-5000 daN / briquette daN / briquette

lii / e 11 he is rare

Landfill steelworks steel mill

Claims (9)

27.4.1984 AP C 22 B / 258 691/6 - 12 - 63 370/18 Claim for invention 1. ancestors for the production of intended for smelting binderless Heifibriketts iron-containing
pyrophoric, finely divided solids, such as dry
Filter dust from steelmaking and fine-grained sponge iron from direct reduction plants, characterized in that the finely divided dry solid containing more than 4% by weight of metallic iron and having a temperature of more than 200 ° C. before briquetting with
blow through oxidizing gas and the amount of gas is controlled so that by oxidation of a portion of the metallic iron, the temperature of the finely divided solid is increased to 450 to 650 ⁰ C and immediately followed by hot briquetting, 2 «Method according to item 1, characterized in that air or oxygen-enriched air or technically pure oxygen is used as the oxidizing gas» 3 * Procedure according to points 1 and 2, marked with this. in that the briquetting press is a roll briquetting press with a roll pressure of more than 6 icN / cm
IValzenbreite is used. 4. Method according to points 1 to 3, characterized in that the finely divided solids before Bri- , chain 3 to 6% by weight of fine lime is added » 5, method according to points 1 to 4, characterized in that the briquettes after leaving the Bri ; AP C 22 B / 253 691/6 , '.'. '' * * 13 ^.:: * \. ':;.. - -;';. 63 370/18 ''. '· be cooled in a stream of air to a temperature below 100 ⁰ C, Units for carrying out the method according to items 1 to 5, consisting of a briquetting press with material feed, a Bäckerkühler and a bunker, characterized in that before the Brikettierpresse (10) has a rotatable. Drum (5) is arranged with a arranged at one end feeder (6) for the finely divided pyrophoric dry solid, a disposed at the other end discharge (7) for the hot briquetting heated solid, a gas supply line (8) and a feed (9 ) for fine lime, whereby by .Regelorgane the residence time of the solid in the drum (5.) * the supplied amount of the oxidizable gas and the added Feinkalkmenge are individually adjustable, 7, installation according to item 6, characterized in that the rotatable drum (5) is inclined and equipped with a number of fans (19) mounted on the walls for aeration of the finely divided solid. 8, plant for carrying out the method according to the items 1 to 5, consisting of a briquetting press with material supply, a briquette cooler and a bunker, characterized in that before the briquetting press (10) a fluidized bed (5a) is arranged, arranged with one at one end Feed (6) for the finely divided pyrophoric dry solid, a discharge (7) arranged at the other end for hot-briquetting 27 «4, ΐ984 '' AP C 22 Β / 258 691/6 .-63 -570 / 18- '' '. temperature heated solid, several gas supply lines (8a) to the underside of the fluidized bed (5a) and a feed (9) for;. 'fine lime ;, by regulating means the residence time of the solids on the fluidized bed (5a). the amount of oxidizing gas supplied and the amount of fine lime added are individually adjustable «        " '.' '.'--' -. '.'.''.'''' .  9 'installations according to items 6 and 7 or 8, characterized in that the briquette cooler consists of an endless belt (12 ^ with one or more air blowers (13), "Installation according to points 6 to 8, characterized in that the bunker (14) with one or more air blowers; , Equipped (Χ5Ϊ ": ;; _';;...' .. ·;..