DE1955170C - Process for the production of largely metallized iron ore pellets - Google Patents

Description

The invention relates to a method for producing largely metallized pellets with a

Iron content of at least W)% through reduction «Jn iron ores in three stages, with the reduction through carbon monoxide and hydrogen-hooked hot gases and in the second stage as a reducing agent a rotary kiln is used.

The invention thus relates to rv, i a process which does not serve to erzeu- liquid metal - _s, but ^K ei the contrary, de! The oxygen content of the ore is reduced and the metal content --c increased so far that ·: ¹ · a blast furnace charged with the related products. Siemens-Martin furnace, electric reduction furnace. Fiu-sj ^ -S.iuer- $ toff furnace or the like in relation to air 's:.; _: ve Kapazi ·.:.!: and its efficiency are better exploited -. ^ n-: ■;

A method to the Vorrcdo / ierc: ¹ \ <- n h-ener /; - · _Z .B aj- the USA.-Pater.tschr; ·; 4-; :;: -, -, _^. \ ' _eu e' · 'Developments are :: -. ..: · Π · Ju ^ eJ - "Metal · June 1966, p 7 ^ s ■ ·, _{·,,. -_:} - _Λγ · - ^ - ν .... reduxier th iron ore pellets . Stand .- IeJv--. ··. · ■ :; - γ; B. Mclcher and MM Fine b: -.: .-; r η ' ^v . · ' - "■ - can: ^: have procedure. : ί!; τϋ.: - ^ ·!. ·. \ v _:: -. _v h.; "; lichkei: .τ iron production r _: .:.: :: -, · -.:-.,-. ..-- eh '"- the dimensions can be improved:. Da- H ::" :: ■: ■■: -: ■ ::' -. ei _: e: Vorre ^: .ik; ion of iron ores H - · ■.:! ■ <j. ·· ■ .... ■■:> ::. ^ - sufficiently high MetaiiiMere.r .- ^ ::.:. ¹ ■ · ■■ · _ ■ ■■ - .. at the expense of e. so that d - ,: rc ^! · V _: - _:; . _; ■ _. . of Prod: · .tionskosten in the \ ^era:; - '::: l · ■ · ^ί. ·;' ■■ ■ '_- i or JdI the total cost p ^r .: ._ · ^·;. :. - ■■ _ ■ '...- j: - .: ■ abaes'.; / T be.

Ε- ■ - .; already a three -: -. '.:. ·. ! · .-. · -! ■ '.... · ..:.:> ■■■ - procedure known (German ¹ J: .-!:.'. :: '"■" _ <:. at d -.- :; reduction by t: r ".:! (I ₁ ^: - :: -: '.-.- schic ·-iiic. ieführte kohlenmor.i · λ I- ^::: · ¹ V..: ■ -_: - :. ¹ U-halti-hot gases occurs and :: ·. Der, · ■■ -. ■ .. ■ ·. · ..-. ^S ::;: e . ·, As F.duktionsaggregat em D: :: ■ -; ■ '-.: E- ■ .. ·: ■. ··. -: ..: o · with these well-known Veriai.-en: -t ■ ': _. - ..:. ·: Sufficient efficiency to e - /; ek ".

The aim of the invention is! s> mi 'then, em method of the type mentioned at the beginning /. : h: \\ - fen. at which such a high degree of metallization can be achieved at low costs. that the total costs of the Eisenhersrell'.iP.j; herabees · - ;; - _t are.

Zj: Frini.lung sees the solution to this task Kon; Hi nation the following procedure: - i ", ernnaie % or. after which

a) in the first stage the pellets in themselves As is known, dried on a traveling grate using the exhaust gases from the second stage and preheated to achieve a sufficient Hüru for subsequent treatment will.

b) using these pellets in the second stage of partially consumed reducing gas conducted in countercurrent to the feed are pre-reduced from the third reduction stage.

c) these pre-reduced pellets are completely reduced in the third stage on a rotating grate. wherein the carbon monoxide and hydrogen-containing reduction .. _; : as. which is generated in a known manner by splitting hydrocarbons, passed through the feed located on the rotating grate and then get in two partial streams: 'It is supplied, one of which is fed to the rotary kiln of the second stage and the other in the circuit to the fresh supplied to the third stage Reducing gas is admixed.

Due to this process, a particularly economical use of the heat and of expensive reducing gases. whereby the cost of the pre-reduction are so reduced that the final cost of iron making is also substantially reduced.

According to a preferred embodiment, the feed is adjusted in the rotary kiln to a discharge temperature of about 48O C ^c. This temperature represents an optimum with regard to the economy and the quality of treatment of the pellets. The reducing gas is expediently fed to the third stage at a temperature between 815 and ^ 30 ° C.

A preferred embodiment for improving economic efficiency is characterized by the fact that the ratio of carbon monoxide to gas in the reducing gas is set in such a way that the endothermic reduction with hydrogen is withdrawn from the process Heat of reaction is compensated by the heat of reaction of the exothermic •• reduction with carbon monoxide. This embodiment is particularly important because an excessively strong reduction by carbon monoxide based on the reliance on the reduction by hydrogen causes the charge unit to overheat and melt, so that gas-impermeable mass can arise. On the other hand, too strong a reduction by hydrogen in relation to the Betras: the reduction by carbon monoxide cools the charge. so that the rate of production becomes less economical.

Another major advantage of the invention is that not only one end product with high degree of metallization is achieved. but that the pellets obtained also have a high strength, which was followed during the process ··· "Knstall bridge formation within the pellets is. What is surprising, however, is that, in contrast to the known, by bridging solidified iron ore pellets, the network of the invention produced pellets largely meialli- ■:;. see has character.

Characterizes another preferred embodiment in that the emerging from the third reduction stage and to be recycled Partial flow Freed from water and carbon dioxide through heat exchange with the reiled Charging heated up and with fresh reducing gas mixed is fed back to the third reduction stage.

The particularly preferred device for performing the method according to the invention with an essentially horizontal traveling grate, an inclined rotary kiln, the upper end of which adjoins the discharge end of the traveling grate, and a hood around the discharge end of the rotary kiln. ^Fi i 'is characterized according to the invention by a rotary tube arrangement connected to the discharge end of the Drearohr furnace by means of the hood and a chute with connections for the supply and discharge of the ^{reducing gas generated in a system for splitting coals f} > 5 hydrogen and by a connection on the hood for the supply of a partial flow of the gas emerging from the rotating grate.

5 6

A particularly economical execution is arranged below the chambers 6 and 7, respectively. An approximately shape is designed so that the Drehrostanord- chute 10 promotes the output from the grate 3 circumferentially in a the connections up- pellets to the inlet of a rotary kiln 12. Send Reducers and a heat recovery win- The rotary kiln 12 is from the Chute 10 is divided into a voltage and cooling zone. S hood 14 inclined downwards, which encloses the discharge direction η ekln direction of rotation is preferably immediately in front of that of the furnace 12 and to which a fall mouth of the chute over the rotary grate arrangement shaft 15 from the furnace 12 z \ x an annular rotation Feeding belt for steel balls, which is connected to the coarse grate arrangement 16. More than the pellets are arranged. The steel balls The rotating grate arrangement 16 is so as in Fig. 2 are used to partially arrange the heat from the reducing gases io shown below the outlet of the furnace 12 after flowing through the pellet bed and contains the actual gas-permeable, absorb and in this way recover. horizontal, annular rotating grate 17, which according to In this embodiment, the connection for Fig. 2 has a plurality of grate segments 18, the supply of the Reduküonsgase above and the connection Rotary grate 15 (only one shown in each figure of the drawing) is provided. wear, according to F i g. 2 with a flange part 20 in

The draining engagement emerging from the rotating grate assembly is in place.

The rotating grate 17 is driven by a motor 21 with

gen divided, one of which the Tetistrom driven to a pinion 22, which with a ring

The hood and the other is in engagement via a carbon dioxide gear 23 on the rotating grate 17. One

Washer a connection on the heat-resistant cover 24 encloses the rotating grate 17. The

extraction and cooling zone of the rotating grate assembly cover 24 has partitions 26 which the

leads. Rotary grate arrangement 16 into a reduction zone 27

The outlet connection to the heat recovery and to a heat recovery and cooling zone

The cooling and cooling zone is advantageously divided over 15 28!

Pipes, a fan and a heat exchanger to the A first feed hopper 29 in the cover Reducing gas supply pipeline. 24 is used to load the rotating grate 17 with steel balls while the pellets 2 from the furnace 12 according to further improve the heat utilization is according to an expedient execution form. in front of Fig. 2 by the straight back in the direction of rotation seen that the heat exchanger the flue gases from 30 the funnel 29 opening chute 15 on the the fission system receives and the exhaust gases from the top of the previously formed steel ball layer from the heat exchanger are still used to generate steam. The steel balls are bigger than that will. Pellets 2. The rotating grate arrangement 16 is also nv.t The steel balls are expediently provided with a material emptying station 29 a formed by the largely metallized iron ore according to US Pat. No. 2256017 Pellets separated that can be below the Entleeningsstation.

the rotary grate arrangement is provided with a sieve, which A system 30 for splitting hydrocarbon

the reduced ore separates from the steel balls, the substances is provided with an inlet port 31 for a gas

Hydrocarbon fuel such as methane is returned to the feed hopper through a conveyor belt. be promoted. 40 an inlet opening 32 for air and an inlet opening

Appropriately in the hood in the area 33 are provided for steam. She also points

of the part connected to the first branch line, an outlet 34 for the formed hydrogen and

electricity connection two further connections for the carbon monoxide rich reducing gas to a first

direct supply of fuel or air upstream of the pipeline 35, which is connected to a pipe 35 at the reduction point in order to achieve the desired temperature zone 27 above the rotating grate 17 at this point.

to be able to set tur conditions. circuit 25 α is connected A second pipeline

The reducing gases point at the supply connection 36 with one at the reduction zone 27 below

preferably about the same temperature as the connection 25 b provided for the rotating grate 17

Pellets in the reduction zone. bound. The invention is illustrated below, for example, on So the second pipeline 36 includes a pipe 37 which Hand of drawing described; in this shows: the gases from connection 25 6 via a cyclone 38. 1 shows a schematic, partially sectioned tube 39 and a condenser 4 · a fan Side view of a device according to the invention 42 feeds. Downstream of fan 42 is the

and second pipeline in two branch lines 51,52 Fig. 2 is a plan view of the rotating grate of the divided in 55. The first branch line 51 is with a hood

Fig. 1 shown device, with some components 14 connected to a part of the reducing gases:

broken away for clarity of illustration. from the reduction zone 27 through the rotary kiln

A powdered iron ore will pass through a non-12. The second branch line 52 includes one

Granulatf romtrommel shown z. B. after the USA.- Carbon dioxide scrubber 53, which is known from a Patents 1 994718 and 2411 873 to pellets 2 60 device can consist of potassium carbonate unc

shaped, according to Fi g. 1 on a gas-permeable vapor to separate carbon dioxide from a

Traveling rust 3 are deposited. A housing 4 am gas flow is used. A pipe 54 delivers the out

closes at the space above the grate 3. A separating washing reducing gas to one in the area 21

wall 5 jumps from the roof of the housing 4 up to the connection arranged below the rotating grate 17 a predetermined distance above the grate 3 according to 63 25 c. A pipe 55 is practiced with one in the zone 28

downward and divides the provided by the housing 4 environmentally the rotary grate 17 terminal 25 d vei

closed space in a drying chamber 6 and bound and receives the gas from the pipe 54, the durc

a preheating quay 7. Wind boxes 8 and 9 are the steel ball layer and the pellet bed on top of the

lrehiosi 17 has gone. This gas flow arrives .lanu dutch a GeMäsc 56 and a pipe 57 in one Heat exchanger 58. its outlet at 59 in the first Pipeline 35 opens. The heat exchanger 58 receives the heat through the medium of the system 30. · of a pipe 6 (1 / led flue gas. The through the W.iimetauscher 58 arriving flue gas can then still delivered through a pipe 61 / u to a boiler 62 where steam is formed, of d; -. m a part through a pipe 63 together with something at 33 injected methane is fed to the system 30.

Lin sieve 70 below the line emptying station 29 ″ of the rotary tube arrangement 16 separates the relatively large stool balls from the smaller reduced pellets. Lin conveyor belt 71 guides the balls to the feed hopper 29 (FIG. 1), which is indicated by line 72.

The hood 14 also has ports 75. 76 for the supply of fuel (methane) or Lu ^f t. which form a reducing atmosphere with the reducing gas of the branch line 51 which has a temperature such that the temperature of the ore in the furnace 12 is approximately ¹ > XO "C in the vicinity of the emptying end Blower 77, a pipe 78 and an annular distributor Ί9 air is blown through radial openings 80 into the furnace 12. The air is blown in in such an amount that the reducing becomes an oxidizing 3: · The cias flow as it moves from the rotary kiln into the preheating chamber 7 of the housing 4. The lines 81 and 82 indicate additional feeds of fuel (CH ₁ ) or air in chambers 7, whereby a temperature level is maintained that the pellets after they have been in the Chamber 6 have been dried, are pre-fired in an oxidizing atmosphere until they have sufficient internal strength to withstand the agitation in furnace 12. Fine such festivities ness is achieved at Eisenerzpelleis characterized in that the grain growth and development of Brükkenbildung in the pellets according to the US Patent 2 ^q 25 336 is triggered.

The gases in the preheating chamber 7 are in einci * 3 in the I SA Patent 3,313,534 mentioned manner by a fan 83 through the material on the grate 3 in the chamber 7 and preferably also by a Nebcnleitung to the material on the grate 3 sucked through in the chamber 7. Accordingly, a pipe 84 connects the wind chamber 9 to a cyclone 85 and the separating device 85 is connected to a fan 83 by a pipe 86. The secondary line has an outlet opening 87 in the housing 4 above the material located on the grate 3 and a secondary pipe 88. which has an arrangement for admitting Ternper air at 89. The secondary piping 88 is connected in such a way that gases are supplied from above the material bed in the chamber 7 to a cyclone 85 without these gases passing through the material bed into the chamber 7.

Gases that have passed through the material on the grate 3 into the chamber 7, and gases that are attached to the material on the grate 3 in chamber 7 vorbeigelcitct WUR. are by the fan 83 in a Rohrlcitunu90 lowers, which the gases of the drying chamber 6 / i'iluhrt fin fan 91 then draws the guest through the bed of material on the rust 3. the chamber 8 and a pipe 92 to the line 93 and with it into the atmosphere.

In the following, the method is described in accordance with the LrImdung using the device described, for example. The operation and the process are described in more detail for the conversion of about I (I (I tons of llematite iron ore (Fe "O") per day into pellets ⁽ > U "above metallization).

Powdered hematite ore is prepared for the process by pelletizing in a drum (not shown) into pellets with a diameter between O. '^ Em and L''cm. The iron pellets are piled into a first gas-permeable piece of plastic on the grate 3 in chamber 6. The individual pellets are at rest relative to one another within this moving body on the grate 3. The pellets in chamber 6 are dried by gases with 260 ° C to 4Κ (Γ C, which come from the pipeline 90 through the Pclletbett on the grate 3 in chamber 6 and into the wind box 8. The grate 3 carries the pellet bed through the Chamber 7, where the pellets are preheated by gases from the rotary kiln 12 and by gases fed to the chamber according to lines 81 and 82. The temperature of the pellets is increased in chamber 7 to between 870 ° C uiul ⁽ > 80 ° C If the heart was initially a magnetite or a mixed ore, at these temperatures it is converted into "heriate!" At these temperatures, bridges begin to form between adjacent hematite grains, as in FIGS. 4 and 5 of the preceding USA. -Palentcript 2 ⁽ '2s: 33fi is shown. Such bridges give the individual pellets sufficient strength and sufficient resistance to disintegration to withstand the circulation in a rotary kiln.

If the pellet body on the grate 3 has achieved the required degree of strength and resistance to disintegration without impairing the porosity, it is conveyed via the chute 10 into the rotary kiln 12 and broken down again into individual pellets. As the pellets travel in the inclined furnace 12, they are exposed to the reducing gases which are hot enough to ensure that the pellets in the furnace 12 ^{are heated to about 1} > 80 "C. The gases are sufficiently rich in H. , and CO. to initiate at least part of the reduction of the Fe _-1 O ₁ to Ft O.

At the hood 14, the pellets are discharged from the grate 3 at about 980 ° C. from the furnace 12 and fall through the chute 15. The funnel 29 deposits a layer of relatively cool steel balls 95 on it the rotating grate 17. and the pellets falling through the chute 15 are closed a second time a gas permeable body deposited on top of the steel ball layer 95 and around the annular Web moved around within the rotating grate assembly 16. While the pellets around the annular Web are transported inhibited on the grate segments 18, they are carried through the reduction zone 27.

In order to reduce the oxygen content of the pellets as they pass through the reduction zone 27 To reduce the degree of metallization, the Di climcsser must and the speed of rotation of the rotary east assembly 16 are chosen so that a proportionate Long residence time of the pellets in zone 27

. • is corrected. The strongly reducing gas flow from the reforming plant 30, which optionally works with a nickel-binding catalyst, passes through the outlet opening 34 via a valve 08 to the first pipeline 35 at 59, where it mixes with one of the pipeline 57 again that has passed through the heat exchanger 58. in order to provide a cias flow of approximately 815 ° C. to 930 ° C. in the first pipeline 35 leading to the zone 27 of the rotary grate arrangement 16; for the example described, the throughput is approximately 61.5 kg-mol / min, with the gas approximately 56.8 ⁰ O water. Contains 37.8% carbon monoxide, 4.7% carbon dioxide and 0.7% residual methane.

The gases from the first conduit 35 pass within the zone 27 through the pellets on the Rotating grate 17 to reduce the oxygen content of the pellets and thus to the desired level Provide metallization, strength and resistance to decay; then the gas flow passes through the steel ball layer 95. If no steel ball layer 95 is used, the reducing gases can too bottom up through the pellets in the zone

27 stream.

In the case of the arrangement containing the steel ball layer 95 the temperature of the reducing gases flowing down in zone 27 changes during Very little flow through the pellets since the pellets emptied from furnace 12 are pretty much the same Temperature like that in uit zone 27 jrcJangcndcn Have reducing gases. However, while the reducing gases pass through the steel ball layer, transfer much of their heat to the balls and gradually heat the balls to approximately 815 ° C. until the balls move from zone 27 to zone

28 arrive. While the steel balls are being heated, the temperature of the gas stream falls, and the temperature of the gases in the pipe 37 of the second Pipeline averages about 370 ° C to 43O ^ Γ. The gases in the pipe 37 are used for Zyklon 38 delivered and included at this stage of the process for the example described approximately 61.9 kg / mol / min gas containing 48.10% hydrogen. 35.24% carbon monoxide, 7.04% carbon dioxide and Has 9.62% water as mist or vapor.

These gases pass through the pipe 39 to the condenser 40, where the water is removed. The blower 42 blows the gases to branch lines 51 and 52. Branch line 51 supplies part of the gas flow to the hood 14 at the discharge end of the furnace 12, and branch 52 supplies gas to carbon dioxide scrubber 53. The removal of water by the condenser 40 and of carbon dioxide by the scrubber 53 has a gas flow in the pipe 54 to the Sequence which consists essentially entirely of hydrogen and carbon monoxide. The total of the Gas is diminished by removing water (steam) and carbon dioxide, but that's how it is remaining gas richer in carbon monoxide and hydrogen than that coming from the reduction zone 27 consumed gases.

The enriched flow of expensive gases is a sizable economic investment, and so is it it is therefore desirable to reuse these gases to the utmost extent possible. To F i g. 1, these gases are directed upwardly from the pipe 54 through the zone 28 While these gases get up through the steel ball layer, the heat stored in the ball is recovered; then the gases · pass up through the from /.one 27 to /.one 28, now metallized and Ie compliant pellets to make these peI-lets Alvu-cool in a non-oxidizing atmosphere and further to heat the gases. Since this gas flow through the Sialilkugclschicht in the / one 28 is reheated before it cools the pellets in this zone 28, the l'e-containing pellets of

ίο the range from about ¹ ) 25 ^{° C to 1} ) 80 ° C "only cooled down to the range from about 205 ° C to 260" C *. This lowering of the temperature of the metallized pellets is sufficient, however, further cooling by means of storage in the open air or by means of

is spraying with water without the risk of renewed To allow the hisene to oxidize. Will the procedure carried out without a steel ball layer, the metallized pellets are much lower Temperatures with significantly cooler gases.

ao cools. The omission of the steel ball layer, however, results in less heat recovery for the process because the gases from zone 27 to condenser 40 are much hotter and more heat is lost by removing water from the gas stream. Either a maximum heat recovery for the process (ie with a steel ball layer) is used or a maximum cooling of the reduced pellets with reducing gases (ie without a steel ball layer). Both methods can be used, each with their own advantages. In the present example, in which the rotating grate 17 ^{delivers approximately 815 kg of steel balls per minute at approximately 38 1} C (100 ° F) and approximately 500 kg per minute of pellets at approximately 205 ° C to 260 ° C, the zone 28 in the Tube 55 incoming Gasirom preheated to about 425 ° C. I'm this gas flow on the temperature. To bring the composition and amount corresponding to the values of the flow in the first pipeline 35, the gas flow is led from the pipe 57 through the heat exchanger 58, where it is heated by the flue gas supplied by the plant 30. Mixing then takes place at 59. The heat transferred by the exchanger 30 and the hot additional gas mixed in at 59 provide a gas flow of quantity, mixture and temperature in a continuous manner. as it is necessary for supplying the zone 27 through the first pipe 35 in order to reduce the oxygen content of the pellets and the

5 © to achieve the desired degree of metallization.

The gas flow of the rotary grate arrangement 16 is deliberately not fed back into the system JO because then much more steam would be required to prevent carbon breakdown and degradation to prevent the catalyst.

The iron-containing, cooled pellets are carried through the rotating grate structure 17 to the emptying station 29 α, where each grate segment 18 after F i g. 1 is inclined. to both the metallized pcI-lets as well as emptying the steel ball layer onto a sieve 70. The steel balls that are much larger than the pellets and the openings in the sieve 70 are shown in FIG. 1 via the sieve 70 to a conveyor belt 71 and along the strongly balanced by dis

Line 72 shown ball track back to the first hopper 29, where the rotating grate 17 is loaded again will. The metallized pellets pass through the sieve 70 to a conveyor belt 79.

1 sheet of drawings

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Claims (15)

i 955 170 claims: 1. Process for the production of largely metallized pellets with an iron content of at least 9O ° o by reduction of iron ores in three stages, the reduction being carried out in countercurrent hot gases containing carbon monoxide and hydrogen that are fed to the feed are carried out and in the second stage a rotary kiln is used as a reduction unit, marked υ net by the combination of the following procedural features, according to which a) in the first stage the pellets in a known manner on a traveling grate using the exhaust gases of the second stage ^! 5 dried and heated to achieve a hardness sufficient for the subsequent treatment. b) these pellets in the second stage using countercurrent to re-delivery led, partly spent r here Reduction gas from the inside reuction stage be pre-reduced. c) these pre-reduced pellets are reduced in the third stage on a rotating grate be, with the carbon monoxide and hydrous reducing gas, which is known in Wuse by splitting hydrocarbons is generated. 1'irch the on the Rotating grate located feed out and then divided into two T ilströmc one of which is fed to the rotary kiln of the second stage and the other i'.i Circuit is added to the fresh reducing gas supplied to the third stage. 2. The method according to claim I, characterized in that the charging in the rotary kiln is set to a discharge temperature of about 980 ^c C. 3. The method according to claim I or 2. characterized in that the reducing gas with einci Temperature between 81 5 and 930 ° C of the third stage is fed. 4. The method according to any one of the preceding claims, characterized in that im Reducing gas the ratio of carbon monoxide to hydrogen is adjusted so that the The heat of reaction withdrawn from the process by the endothermic reduction with hydrogen by the heat of reaction of the exothermic reduction with carbon monoxide is balanced. 5. The method according to any one of the preceding claims, characterized in that the from The oil stream of water emerging from the third reduction stage and to be recycled and carbon dioxide released, heated by heat exchange with the reduced feed and, mixed with fresh reducing gas, is fed back to the third reduction stage. 6. Device for performing the method according to one of claims 1 to 5, with a essentially horizontal traveling grate, an inclined rotary kiln, the upper end of which is attached Connect the discharge end of the traveling grate and a hood around the discharge end of the rotary kiln, characterized by a means of Hood (14) and a chute (15) connected to the outlet end of the rotary kiln (12), rotating grate arrangement (16) with connections (25 a, 25 b) for the supply and discharge of the hydrocarbons generated in a system (30) Reducing gas and through a connection on the hood (14) for the supply of a partial flow of the gas emerging from the rotating grate. 7. Apparatus according to claim 6, characterized in that the rotating grate arrangement (16) is subdivided circumferentially into a reducing zone (27) having the connections (25 a. ISh ) and a heat recovery and cooling zone (28). 8. Apparatus according to claim 7, characterized in that in the direction of rotation immediately in front of the mouth of the chute (15) via d, rotating grate arrangement (.16) a feeder (Z9) for steel balls (95). which are larger than the Pdlets (2) is arranged. 9. Device according to one of the claims
and H. characterized in that the Ansch'ui '. (25 α) for the supply of the reducing gases uk-rhalb and the connection (25 b) for the AbleiiLnc provided below the rotating grate annulus (16) is 10. Device according to one of claims. · T \ to 9, characterized in that the Ab ·.: - processing pipeline (36) is divided into two branch lines (5Ϊ ~. 52). one of which (51) de: · partial flow to the skin x (14) and the other üKr a carbon dioxide scrubber (53) a view (25 c) at the heat recovery i: nd cooling zone (28) of the rotating grate arrangement (16) iu! ·. ;; 1 1. Apparatus according to claim 9, characterized in that the Auslaßarisehluß (25 d : n of the heat recovery and cooling zone. 28) via tubes (55, 57), a fan (56) and e ^ en heat exchanger (58) to the Reducing gas feed pipe (35) leads 12. The device according to claim 10, characterized characterized in that the heat exchanger (58 j receives the flue gases from the cleavage plant (30) and the exhaust gases from the heat exchanger i? 8) can still be used to generate steam 13. Device according to one of claims S to 11, characterized in that below a sieve (70) is provided for the emptying station (29 a) of the rotating grate arrangement (16). the the separates reduced ore from the steel balls, which are carried by a conveyor belt (71) to the feed hopper (29) can be returned. 14. Device according to one of claims 6 to 10, characterized in that in the hood (14) in the area of the partial flow connection two connected to the first branch line (51) further connections (75, 76) are provided for the direct supply of fuel or air. 15. Device according to one of claims 7 to 11, characterized in that the reducing gases at the feed connection (25 a) about the same temperature as the pellets in the reduction zone (27) have.