EP0118149A1 - Process for fire-hardening green pellets on a pellet-burning machine - Google Patents
Process for fire-hardening green pellets on a pellet-burning machine Download PDFInfo
- Publication number
- EP0118149A1 EP0118149A1 EP84200152A EP84200152A EP0118149A1 EP 0118149 A1 EP0118149 A1 EP 0118149A1 EP 84200152 A EP84200152 A EP 84200152A EP 84200152 A EP84200152 A EP 84200152A EP 0118149 A1 EP0118149 A1 EP 0118149A1
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- Prior art keywords
- hot gases
- drying
- pellets
- pellet
- stage
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- 239000008188 pellet Substances 0.000 title claims abstract description 43
- 238000000034 method Methods 0.000 title claims abstract description 9
- 239000007789 gas Substances 0.000 claims abstract description 50
- 238000001035 drying Methods 0.000 claims abstract description 38
- 238000010304 firing Methods 0.000 abstract description 8
- 238000009833 condensation Methods 0.000 description 7
- 230000005494 condensation Effects 0.000 description 7
- 238000001816 cooling Methods 0.000 description 5
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 4
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 4
- 230000009172 bursting Effects 0.000 description 3
- 238000002474 experimental method Methods 0.000 description 3
- 229910052742 iron Inorganic materials 0.000 description 2
- 238000005453 pelletization Methods 0.000 description 2
- 238000007669 thermal treatment Methods 0.000 description 2
- 239000000440 bentonite Substances 0.000 description 1
- 229910000278 bentonite Inorganic materials 0.000 description 1
- SVPXDRXYRYOSEX-UHFFFAOYSA-N bentoquatam Chemical compound O.O=[Si]=O.O=[Al]O[Al]=O SVPXDRXYRYOSEX-UHFFFAOYSA-N 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 239000000571 coke Substances 0.000 description 1
- 238000002485 combustion reaction Methods 0.000 description 1
- 239000012141 concentrate Substances 0.000 description 1
- 238000007599 discharging Methods 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 239000011261 inert gas Substances 0.000 description 1
- JEIPFZHSYJVQDO-UHFFFAOYSA-N iron(III) oxide Inorganic materials O=[Fe]O[Fe]=O JEIPFZHSYJVQDO-UHFFFAOYSA-N 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 239000010450 olivine Substances 0.000 description 1
- 229910052609 olivine Inorganic materials 0.000 description 1
- 239000000256 polyoxyethylene sorbitan monolaurate Substances 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 230000000717 retained effect Effects 0.000 description 1
- 238000005245 sintering Methods 0.000 description 1
- 239000004449 solid propellant Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000011144 upstream manufacturing Methods 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
- C22B1/00—Preliminary treatment of ores or scrap
- C22B1/14—Agglomerating; Briquetting; Binding; Granulating
- C22B1/24—Binding; Briquetting ; Granulating
- C22B1/2413—Binding; Briquetting ; Granulating enduration of pellets
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F27—FURNACES; KILNS; OVENS; RETORTS
- F27B—FURNACES, KILNS, OVENS OR RETORTS IN GENERAL; OPEN SINTERING OR LIKE APPARATUS
- F27B21/00—Open or uncovered sintering apparatus; Other heat-treatment apparatus of like construction
- F27B21/06—Endless-strand sintering machines
Definitions
- the invention relates to a method for hard burning green pellets on a pellet burning machine with hot gases being passed through the pellet bed, the pellets first being dried in a drying zone with the gas flow directed downwards.
- pellet burning machines have - seen in the direction of travel - different treatment zones, namely drying zone, thermal treatment zone and cooling zone. These zones can be subdivided, for example into pre-drying and post-drying zones, heating zone, pre-firing zone, main firing zone, post-firing zone, first and second cooling zones.
- the green pellets made from the material to be agglomerated, aggregates and possibly solid fuel under humidification have a low strength and are therefore carefully loaded onto the traveling grate. In the drying zone, the difficulty then arises that the hot G receives as during the drying of the first layers according to its inlet temperature water, then in the adjacent
- drying as suction drying be carried out as slowly as possible.
- Such a process is known, for example, from GB-PS 690 668, in which drying is carried out with hot gases of approximately 260 ° C. This drying can largely prevent bursting, but not the strong condensation of water in the lower layers.
- DE-PS 10 31 328 it was proposed to carry out drying up to about 300 C by means of an upstream unit, such as a feed bunker or conveyor belt.
- an upstream unit such as a feed bunker or conveyor belt.
- strong condensation cannot be avoided if these moist gases cool down in cold pellet layers.
- the invention is based on the object of avoiding the impermissible over-moistening of layers of the pellet bed and bursting of pellets when drying the green pellets as far as possible and with as little effort as possible.
- This object is achieved according to the invention by drying in a first stage using hot gases at 60-180 ° C. and then increasing the temperature of the hot gases to 280-400 ° C. within 2 to 5 minutes.
- the gas temperature always refers to the entry temperature of the gas into the p ellet bed.
- the time always refers to the start of drying.
- the top layer of the pellet bed is first dried and with an inlet temperature of the gas of 60-180 ° C T-drying front moves into the next layer of the pellet bed.
- the increase in the inlet temperature of the gases after this first stage is regulated in such a way that the gases give off so much heat to the already dried pellets that they always arrive at the drying front at approximately the same temperature as possible. Ideally, this would require a continuous increase in the temperature profile of the gases across the drying zone. However, such a continuous increase is complex in practice, so that a gradual increase is carried out.
- Cooling air or exhaust gas from the combustion zone are generally used as hot gases, which are selected at the appropriate temperature or cooled to the required temperature by mixing with cold air or colder gases.
- the drying zone extends a certain length beyond the point where the hot gases with the highest entry temperature first enter the bed. The usual hard firing then takes place at temperatures from above 1000 ° C to above 1300 ° C.
- a preferred embodiment is that the temperature of the hot gases is increased in several stages. An approximation to a continuous increase in the temperature profile can thus be achieved in a simple manner.
- the number of stages is selected depending on the respective operating conditions in such a way that inadmissible over-moistening of layers of the pellet bed is avoided. This can be determined empirically by tests on a sintering pan, since these results can be transferred to the traveling grate.
- the setting of the temperatures in the individual stages is possible, for example, by arranging a gas hood above the drying zone, which is divided into several sections in the running direction of the traveling grate. A stream of hot gases is introduced into the gas hood and the desired gas temperature is set in the individual sections by controlled addition of colder gases. It is also possible to arrange a common gas hood over the entire moving grate and the one in the second K endeavourease resulting warmed cooling air under the ceiling of the G ashaube to conduct under adjustment of the desired temperatures in the drying step.
- a preferred embodiment consists of drying in the first stage for up to 60 seconds using hot gases at 60-120 ° C., in a second stage up to 120 seconds using hot gases in the range of 120-180 ° C., in a third stage up to 180 sec using hot gases from 180 - 220 ° C and in a final stage using hot gases from 280 - 350 ° C. This gives particularly good results.
- the tests were carried out on a pan with a diameter of 26 cm.
- the green pellets were produced on a pelletizing plate with a moisture content of 8.75% and an average diameter of 12.5 mm, and were placed in a layer height of 30 cm on a 10 cm rust coating from pellets which had already been fired.
- the pan was equipped with a gas hood and a wind box for supplying and discharging the gases.
- the pellets were made from a mixture of iron ore concentrate with the addition of bentonite, olivine and coke breeze and had the following chemical analysis and grain size:
- B was racing shows a pelletizing plant as precisely as possible traced.
- Pressure drying of 4.5 minutes at 350 ° C. gas temperature was started, followed by suction drying of 4 minutes with likewise 350 ° C. gas temperature.
- the firing took place at a temperature of 1320 ° C, then the pellets were cooled to an average drop temperature of 120 ° C.
- the quality characteristics of the pellets produced in this way largely correspond to the values obtained in the trailing operating system.
- the advantages of the invention are that drying without inadmissible over-moistening of pellet layers and without bursting of the pellets is possible in a simple manner only in the suction process.
- the quality of the pellets produced is at least as good as that of the processes using the combined pressure-suction drying.
- the length of the drying zone can be shortened, thereby increasing the throughput of the machine. Good use of the heat of the exhaust gas is possible.
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- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Chemical & Material Sciences (AREA)
- Geochemistry & Mineralogy (AREA)
- Geology (AREA)
- Life Sciences & Earth Sciences (AREA)
- Manufacturing & Machinery (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Materials Engineering (AREA)
- Environmental & Geological Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- General Engineering & Computer Science (AREA)
- Manufacture And Refinement Of Metals (AREA)
Abstract
Description
Die Erfindung betrifft ein Verfahren zum Hartbrennen von Grünpellets auf einer Pelletbrennmaschine unter Hindurchleiten von heißen Gasen durch das Pelletbett, wobei die Pellets zunächst in einer Trockenzone mit abwärts gerichteter Gasströmung getrocknet werden.The invention relates to a method for hard burning green pellets on a pellet burning machine with hot gases being passed through the pellet bed, the pellets first being dried in a drying zone with the gas flow directed downwards.
Die thermische Behandlung von Pellets, insbesondere das Hartbrennen von Eisenerzpellets, erfolgt meistens auf Wanderrosten mit Gashauben, die als Pelletbrennmaschinen bezeichnet werden. Die Pelletbrennmaschinen haben - in Laufrichtung gesehen - verschiedene Behandlungszonen, nämlich Trockenzone, thermische Behandlungszone und Kühlzone. Diese Zonen können unterteilt sein, wie z.B. in Vortrocknungs- und Nachtrocknungszone, Aufheizzone, Vorbrennzone, Hauptbrennzone, Nachbrennzone, erste und zweite Kühlzone.If the thermal treatment of the pellets, especially the firing of iron ore pellets, usually in moving grates with G ashauben, referred to as a pellet burning machines. The pellet burning machines have - seen in the direction of travel - different treatment zones, namely drying zone, thermal treatment zone and cooling zone. These zones can be subdivided, for example into pre-drying and post-drying zones, heating zone, pre-firing zone, main firing zone, post-firing zone, first and second cooling zones.
Die aus dem zu agglomerierenden Material, Zuschlagstoffen und eventuell festem Brennstoff unter Befeuchtung hergestellten Grünpellets haben eine geringe Festigkeit und werden deshalb in schonender Weise auf den Wanderrost chargiert. In der Trockenzone tritt dann die Schwierigkeit auf, daß das heiße Gas bei der Trocknung der ersten Schichten entsprechend seiner Eintrittstemperatur Wasser aufnimmt, dann in benachbartenThe green pellets made from the material to be agglomerated, aggregates and possibly solid fuel under humidification have a low strength and are therefore carefully loaded onto the traveling grate. In the drying zone, the difficulty then arises that the hot G receives as during the drying of the first layers according to its inlet temperature water, then in the adjacent
Schichten der Taupunkt des feuchten Gases infolge Abkühlung unterschritten wird und Wasser in diesen Schichten auskondensiert. Dadurch kann in diesen Schichten die Gesamtfeuchtigkeit so stark erhöht werden, daß eine starke Verformung der Pellets erfolgt, die bis zum Zerquetschen führen kann. Dies gilt insbesondere für die Saugzugtrocknung, weil die Kondensation in unteren Schichten erfolgt, auf denen das Gewicht der oberen Schichten und der Druck des Gases lastet. Außerdem führt ein schnelles Trocknen bei manchen Pellets zu einem starken Zerfall infolge starker Dampfentwicklung innerhalb der Pellets. Dies hat zur Folge, daß kein einwandfreies Produkt erzeugt wird und ein großer Teil wieder zurückgeführt werden muß.Layers below the dew point of the moist gas due to cooling and water condenses in these layers. As a result, the total moisture in these layers can be increased to such an extent that the pellets are strongly deformed, which can lead to crushing. This is especially true for suction drying, because the condensation takes place in the lower layers, on which the weight of the upper layers and the pressure of the gas are loaded. In addition, rapid drying of some pellets leads to severe disintegration due to the development of steam within the pellets. As a result, a perfect product is not produced and a large part has to be returned.
Es wurde deshalb bereits vorgeschlagen, die Trocknung als Saugzugtrocknung möglichst langsam durchzuführen. Ein solches Verfahren ist z.B. aus der GB-PS 690 668 bekannt, bei dem die Trocknung mit heißen Gasen von etwa 260 °C erfolgt. Diese Trocknung kann zwar ein Zerplatzen weitgehend verhindern, aber nicht die starke Kondensation von Wasser in unteren Schichten. In der DE-PS 10 31 328 wurde vorgeschlagen, die Trocknung bis zu etwa 300 C mittels eines vorgeschalteten Aggregates, wie z.B. einem Aufgabebunker oder Transportband, durchzuführen. Auch hier kann eine starke Kondensation nicht vermieden werden, wenn diese feuchten Gase sich in kalten Pelletschichten abkühlen. Für die Direktreduktion von Pellets auf einem Wanderrost wurde vorgeschlagen, zunächst metallisierte Pellets von geringem Durchmesser herzustellen, diese als Kern zu verwenden und Erz auf diese Kerne zu pelletieren und dann erneut auf den Wanderrost zu chargieren. Die Trocknung erfolgt mit inerten Gasen von 149 - 316 °C (US-PS 3 333 951). Abgesehen von der erforderlichen Rückführung der kleinen Pellets, kann auch hier eine starke Kondensation in den unteren Schichten nicht vermieden werden. In der DE-PS 20 41 533 wurde vorgeschlagen, die Grünpellets an mindestens zwei hintereinander liegenden Stellen aufzugeben und jede Schicht vor Aufgabe der nächsten Schicht mit heißen Gasen von 200 - 350 C zu trocknen. Dadurch wird zwar eine Kondensation von Wasser in den unteren Schichten weitgehend vermieden, es sind jedoch mehrere Aufgabestellen erforderlich.It has therefore already been suggested that drying as suction drying be carried out as slowly as possible. Such a process is known, for example, from GB-PS 690 668, in which drying is carried out with hot gases of approximately 260 ° C. This drying can largely prevent bursting, but not the strong condensation of water in the lower layers. In DE-PS 10 31 328 it was proposed to carry out drying up to about 300 C by means of an upstream unit, such as a feed bunker or conveyor belt. Here too, strong condensation cannot be avoided if these moist gases cool down in cold pellet layers. For the direct reduction of pellets on a traveling grate, it was proposed to first produce metallized pellets of small diameter, to use them as the core and to pellet ore on these cores and then to charge them again on the traveling grate. Drying is carried out with inert gases at 149-316 ° C (US Pat. No. 3,333,951). Apart from the need to recycle the small pellets, strong condensation in the lower layers cannot be avoided here either. In DE-PS 20 41 533 it was proposed to give up the green pellets at at least two points in a row and to dry each layer with hot gases of 200-350 ° C. before feeding the next layer nen. This largely avoids condensation of water in the lower layers, but several feed points are required.
Zur Verhinderung der unzulässigen, starken Kondensation wird deshalb in der Praxis weitgehend mit einer Trocknung gearbeitet, bei der zunächst in einer ersten Drucktrocknungsstufe heiße Gase von unten nach oben durch das Pelletbett geleitet werden und danach in einer zweiten Saugzugtrocknungsstufe heiße Gase von oben nach unten durch das Bett geleitet werden (US-PS 3 333 770, US-PS 3 172 754). Dadurch wird zwar die unzulässige Uberfeuchtung durch starke Kondensation weitgehend vermieden, es ist aber ein größerer Aufwand erforderlich.For preventing unacceptable, strong condensation is therefore worked in practice largely with a drying, wherein the first first in a pressure drying stage, hot gases from the bottom upwards through the P are passed elletbett and then in a second Saugzugtrocknungsstufe hot gases from top to bottom through the bed are routed (U.S. Patent 3,333,770, U.S. Patent 3,272,754). In this way, the impermissible over-humidification due to strong condensation is largely avoided, but a greater effort is required.
Eine weitere Möglichkeit, die Überfeuchtung von Pelletschichten zu vermeiden, besteht darin, die Pellets vorgewärmt mit einer Temperatur von etwa 40 - 70 C auf die Maschine aufzugeben. Dies bedingt aber einen beträchtlichen Aufwand.Another way to avoid over-humidification of pellet layers is to put the pellets preheated on the machine at a temperature of around 40 - 70 ° C. However, this requires considerable effort.
Der Erfindung liegt die Aufgabe zugrunde, die unzulässige Uberfeuchtung von Schichten des Pelletbettes und ein Zerplatzen von Pellets bei der Trocknung der Grünpellets möglichst weitgehend und mit möglichst geringem Aufwand zu vermeiden.The invention is based on the object of avoiding the impermissible over-moistening of layers of the pellet bed and bursting of pellets when drying the green pellets as far as possible and with as little effort as possible.
Die Lösung dieser Aufgabe erfolgt erfindungsgemäß dadurch, daß die Trocknung in einer ersten Stufe mittels heißer Gase von 60 - 180 °C erfolgt und danach die Temperatur der heißen Gase innerhalb von 2 bis 5 min auf 280 - 400 °C gesteigert wird.This object is achieved according to the invention by drying in a first stage using hot gases at 60-180 ° C. and then increasing the temperature of the hot gases to 280-400 ° C. within 2 to 5 minutes.
Die Gastemperatur bezieht sich immer auf die Eintrittstemperatur des Gases in das pelletbett. Die Zeit bezieht sich immer auf den Beginn der Trocknung. In der ersten Stufe wird zunächst die oberste Schicht des Pelletbettes mit einer Eintrittstemperatur des Gases von 60 - 180 C getrocknet und die Trocknungsfront wandert in die nächste Schicht des Pelletbettes. Die Steigerung der Eintrittstemperatur der Gase nach dieser ersten Stufe wird so geregelt, daß die Gase an die bereits getrockneten Pellets so viel Wärme abgeben, daß sie an der Trocknungsfront immer mit möglichst etwa der gleichen Temperatur ankommen. Im Idealfall wäre dazu eine kontinuierliche Steigerung des Temperaturprofils der Gase über die Trocknungszone erforderlich. Eine solche kontinuierliche Steigerung ist jedoch in der Praxis aufwendig, so daß eine gestufte Steigerung durchgeführt wird. Als heiße Gase werden im allgemeinen Kühlluft oder Abgas aus der Brennzone verwendet, die mit entsprechender Temperatur ausgewählt oder durch Vermischen mit Kaltluft oder kälteren Gasen auf die erforderliche Temperatur abgekühlt werden. Die Trocknungszone erstreckt sich noch eine gewisse Länge über die Stelle hinaus, wo die heißen Gase mit der höchsten Eintrittstemperatur zuerst in das Bett eintreten. Anschließend erfolgt das übliche Hartbrennen bei Temperaturen von über 1000 °Cbis zu über 1300 °C.The gas temperature always refers to the entry temperature of the gas into the p ellet bed. The time always refers to the start of drying. In the first stage, the top layer of the pellet bed is first dried and with an inlet temperature of the gas of 60-180 ° C T-drying front moves into the next layer of the pellet bed. The increase in the inlet temperature of the gases after this first stage is regulated in such a way that the gases give off so much heat to the already dried pellets that they always arrive at the drying front at approximately the same temperature as possible. Ideally, this would require a continuous increase in the temperature profile of the gases across the drying zone. However, such a continuous increase is complex in practice, so that a gradual increase is carried out. Cooling air or exhaust gas from the combustion zone are generally used as hot gases, which are selected at the appropriate temperature or cooled to the required temperature by mixing with cold air or colder gases. The drying zone extends a certain length beyond the point where the hot gases with the highest entry temperature first enter the bed. The usual hard firing then takes place at temperatures from above 1000 ° C to above 1300 ° C.
Eine vorzugsweise Ausgestaltung besteht darin, daß die Steigerung der Temperatur der heißen Gase in mehreren Stufen erfolgt. Dadurch kann auf einfache Weise eine Annäherung an eine kontinuierliche Steigerung des Temperaturprofils erzielt werden. Die Anzahl der Stufen wird in Abhängigkeit von den jeweiligen Betriebsbedingungen so gewählt, daß eine unzulässige Uberfeuchtung von Schichten des Pelletbettes vermieden wird. Dies kann durch Versuche auf einer Sinterpfanne empirisch ermittelt werden, da sich diese Ergebnisse auf den Wanderrost übertragen lassen. Die Einstellung der Temperaturen in den einzelnen Stufen ist z.B. in der Weise möglich, daß eine Gashaube über der Trocknungszone angeordnet ist, die in Laufrichtung des Wanderrostes in mehrere Abschnitte unterteilt ist. In die Gashaube wird ein Strom von heißen Gasen eingeleitet und in den einzelnen Abschnitten durch geregelte Zugabe von kälteren Gasen die dort gewünschte Gastemperatur eingestellt. Weiterhin ist es möglich, über dem gesamten Wanderrost eine gemeinsame Gashaube anzuordnen und die in der zweiten Kühlstufe anfallende erwärmte Kühlluft unter der Decke der Gashaube unter Einstellung der gewünschten Temperaturen in die Trocknungsstufe zu leiten.A preferred embodiment is that the temperature of the hot gases is increased in several stages. An approximation to a continuous increase in the temperature profile can thus be achieved in a simple manner. The number of stages is selected depending on the respective operating conditions in such a way that inadmissible over-moistening of layers of the pellet bed is avoided. This can be determined empirically by tests on a sintering pan, since these results can be transferred to the traveling grate. The setting of the temperatures in the individual stages is possible, for example, by arranging a gas hood above the drying zone, which is divided into several sections in the running direction of the traveling grate. A stream of hot gases is introduced into the gas hood and the desired gas temperature is set in the individual sections by controlled addition of colder gases. It is also possible to arrange a common gas hood over the entire moving grate and the one in the second K ühlstufe resulting warmed cooling air under the ceiling of the G ashaube to conduct under adjustment of the desired temperatures in the drying step.
Eine vorzugsweise Ausgestaltung besteht darin, daß die Trocknung in der ersten Stufe bis zu 60 sec mittels heißer Gase von 60 - 120 °C erfolgt, in einer zweiten Stufe bis zu 120 sec mittels heißer Gase von 120 - 180 °C, in einer dritten Stufe bis zu 180 sec mittels heißer Gase von 180 - 220 °C und in einer Endstufe mittels heißer Gase von 280 - 350 °C. Dadurch werden besonders gute Ergebnisse erzielt.A preferred embodiment consists of drying in the first stage for up to 60 seconds using hot gases at 60-120 ° C., in a second stage up to 120 seconds using hot gases in the range of 120-180 ° C., in a third stage up to 180 sec using hot gases from 180 - 220 ° C and in a final stage using hot gases from 280 - 350 ° C. This gives particularly good results.
Die Erfindung wird anhand von Beispielen näher erläutert.The invention is explained in more detail by means of examples.
Die Versuche wurden auf einer Pfanne von 26 cm Durchmesser durchgeführt. Die Grünpellets wurden auf einem Pelletierteller unter Einstellung einer Feuchtigkeit von 8,75 % mit einem mittleren Durchmesser von 12,5 mm hergestellt und in-einer Schichthöhe von 30 cm auf 10 cm Rostbelag aus bereits gebrannten Pellets aufgegeben. Die Pfanne war mit einer Gashaube und einem Windkasten zur Zuführung bzw. Ableitung der Gase ausgerüstet.The tests were carried out on a pan with a diameter of 26 cm. The green pellets were produced on a pelletizing plate with a moisture content of 8.75% and an average diameter of 12.5 mm, and were placed in a layer height of 30 cm on a 10 cm rust coating from pellets which had already been fired. The pan was equipped with a gas hood and a wind box for supplying and discharging the gases.
Die Pellets wurden aus einer Mischung von Eisenerzkonzentrat unter Zusatz von Bentonit, Olivin und Koksgrus hergestellt und hatte folgende chemische Analyse und Korngröße:
Im Versuch Nr. 2 wurde die Trocknung in der erfindungsgemäßen Weise durchgeführt. Alle anderen Parameter wurden beibehalten. Die Trocknung wurde in folgenden Stufen durchgeführt:
Der Wärmeverbrauch für den Versuch Nr. 2 lag gegenüber dem Versuch Nr. 1 um 6,9 % niedriger.The heat consumption for the experiment N r. 2 was 6.9% lower than Test No. 1.
Die Vorteile der Erfindung bestehen darin, daß eine Trocknung ohne unzulässige Uberfeuchtung von Pelletschichten und ohne Zerplatzen der Pellets in einfacher Weise lediglich im Saugzugverfahren möglich ist. Die Qualität der erzeugten Pellets ist mindestens so gut wie die der mit der kombinierten Druck-Saugzug-Trocknung arbeitenden Verfahren. Die Länge der Trocknungszone kann verkürzt werden und dadurch die Durchsatzleistung der Maschine erhöht werden. Es ist eine gute Ausnutzung der Wärme des Abgases möglich.The advantages of the invention are that drying without inadmissible over-moistening of pellet layers and without bursting of the pellets is possible in a simple manner only in the suction process. The quality of the pellets produced is at least as good as that of the processes using the combined pressure-suction drying. The length of the drying zone can be shortened, thereby increasing the throughput of the machine. Good use of the heat of the exhaust gas is possible.
Claims (3)
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19833306684 DE3306684A1 (en) | 1983-02-25 | 1983-02-25 | METHOD FOR THE THERMAL TREATMENT OF GREEN PELLETS ON A PELLET BURNING MACHINE |
| DE3306684 | 1983-02-25 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| EP0118149A1 true EP0118149A1 (en) | 1984-09-12 |
| EP0118149B1 EP0118149B1 (en) | 1986-09-03 |
Family
ID=6191856
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| EP84200152A Expired EP0118149B1 (en) | 1983-02-25 | 1984-02-03 | Process for fire-hardening green pellets on a pellet-burning machine |
Country Status (7)
| Country | Link |
|---|---|
| EP (1) | EP0118149B1 (en) |
| AU (1) | AU563419B2 (en) |
| BR (1) | BR8400801A (en) |
| DE (2) | DE3306684A1 (en) |
| IN (1) | IN160995B (en) |
| MX (1) | MX160178A (en) |
| ZA (1) | ZA841333B (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0204355A1 (en) * | 1985-06-01 | 1986-12-10 | Metallgesellschaft Ag | Process for hard firing iron pellets on a travelling grate |
| WO2000039351A1 (en) * | 1998-12-23 | 2000-07-06 | L & C Steinmuller (Africa) (Proprietary) Limited | Eaf dust treatment by pelletising and fluidised-bed reduction |
| WO2014015403A1 (en) * | 2012-07-23 | 2014-01-30 | Vale S.A. | Process for the optimized production of iron ore pellets |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EA011459B1 (en) * | 2007-03-28 | 2009-04-28 | Открытое Акционерное Общество "Научно-Исследовательский Институт Металлургической Теплотехники" Оао "Вниимт" | Method for thermal treatment of iron ore pellets |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3172754A (en) * | 1965-03-09 | anthes | ||
| DE1209132B (en) * | 1962-06-07 | 1966-01-20 | Dravo Corp | Process for agglomerating finely divided iron ores |
| DE2041533A1 (en) * | 1970-08-21 | 1972-03-30 | Metallgesellschaft Ag | Pellet production |
| US4049435A (en) * | 1976-04-22 | 1977-09-20 | Valery Efimovich Lotosh | Method for obtaining a lump product |
| EP0003665A1 (en) * | 1978-02-03 | 1979-08-22 | Nippon Kokan Kabushiki Kaisha | A method of producing cold agglomerates for use in iron making |
-
1983
- 1983-02-25 DE DE19833306684 patent/DE3306684A1/en not_active Withdrawn
- 1983-06-28 IN IN799/CAL/83A patent/IN160995B/en unknown
-
1984
- 1984-02-03 EP EP84200152A patent/EP0118149B1/en not_active Expired
- 1984-02-03 DE DE8484200152T patent/DE3460581D1/en not_active Expired
- 1984-02-22 BR BR8400801A patent/BR8400801A/en not_active IP Right Cessation
- 1984-02-22 MX MX200425A patent/MX160178A/en unknown
- 1984-02-23 ZA ZA841333A patent/ZA841333B/en unknown
- 1984-02-24 AU AU25026/84A patent/AU563419B2/en not_active Ceased
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3172754A (en) * | 1965-03-09 | anthes | ||
| DE1209132B (en) * | 1962-06-07 | 1966-01-20 | Dravo Corp | Process for agglomerating finely divided iron ores |
| DE2041533A1 (en) * | 1970-08-21 | 1972-03-30 | Metallgesellschaft Ag | Pellet production |
| US4049435A (en) * | 1976-04-22 | 1977-09-20 | Valery Efimovich Lotosh | Method for obtaining a lump product |
| EP0003665A1 (en) * | 1978-02-03 | 1979-08-22 | Nippon Kokan Kabushiki Kaisha | A method of producing cold agglomerates for use in iron making |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0204355A1 (en) * | 1985-06-01 | 1986-12-10 | Metallgesellschaft Ag | Process for hard firing iron pellets on a travelling grate |
| WO2000039351A1 (en) * | 1998-12-23 | 2000-07-06 | L & C Steinmuller (Africa) (Proprietary) Limited | Eaf dust treatment by pelletising and fluidised-bed reduction |
| WO2014015403A1 (en) * | 2012-07-23 | 2014-01-30 | Vale S.A. | Process for the optimized production of iron ore pellets |
Also Published As
| Publication number | Publication date |
|---|---|
| AU2502684A (en) | 1984-08-30 |
| AU563419B2 (en) | 1987-07-09 |
| BR8400801A (en) | 1984-10-02 |
| IN160995B (en) | 1987-09-05 |
| DE3460581D1 (en) | 1986-10-09 |
| EP0118149B1 (en) | 1986-09-03 |
| DE3306684A1 (en) | 1984-08-30 |
| ZA841333B (en) | 1985-10-30 |
| MX160178A (en) | 1989-12-19 |
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