EP0021465B1 - Process for briquetting a material containing sponge iron - Google Patents
Process for briquetting a material containing sponge iron Download PDFInfo
- Publication number
- EP0021465B1 EP0021465B1 EP80200433A EP80200433A EP0021465B1 EP 0021465 B1 EP0021465 B1 EP 0021465B1 EP 80200433 A EP80200433 A EP 80200433A EP 80200433 A EP80200433 A EP 80200433A EP 0021465 B1 EP0021465 B1 EP 0021465B1
- Authority
- EP
- European Patent Office
- Prior art keywords
- sulfuric acid
- briquetting
- sponge iron
- iron
- dilute sulfuric
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21B—MANUFACTURE OF IRON OR STEEL
- C21B13/00—Making spongy iron or liquid steel, by direct processes
- C21B13/0086—Conditioning, transformation of reduced iron ores
-
- 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
Definitions
- the invention relates to a method for briquetting material containing sponge iron produced by direct reduction in the cooled state with the addition of a binder before the briquetting.
- Materials containing sponge iron are obtained in the direct reduction or rolling of iron oxide-containing materials, in particular iron ore and non-ferrous metals, by means of solid, carbon-containing reducing agents or reducing gases in a rotary kiln, shaft furnace or retort furnace.
- the material containing sponge iron is further processed on pig iron or steel after it has been separated from other feed components. This happens e.g. B. by use in electronic shaft furnaces, blast furnaces or arc furnaces.
- a minimum grain size of the material is required, which, however, does not contain the material containing sponge iron or only partially.
- the fine-grained material - which is generally understood to mean the grain size below about 6 mm - is also extremely sensitive to weather influences during storage and transport. The entry of water should absolutely be avoided, but this is not always possible.
- the handling of material containing sponge iron, which contains large amounts of fine-grained material, is also associated with disruptive dust generation.
- the long-known briquetting is suitable for this.
- the improvement in lumpiness achieved is also a prerequisite for the use of these materials in the blast furnace.
- the briquetting can be done hot or cold. The aim is to work “in the heat”, but in many cases this is not possible.
- the pressing pressure which strongly influences tool wear, can be reduced by using certain binders and trying to achieve the necessary mechanical strength of the pressed articles by subsequent aging.
- the binder is selected taking into account availability, price, dosage, necessary aging time and behavior of the compacts during the subsequent thermal treatment.
- Known binders which are mainly considered for cost reasons, are lime, molasses, sulfite waste, bitumen and starch. However, they always require a minimum outsourcing time of around 24 hours. Some also cause the compacts to disintegrate during the subsequent thermal treatment of the briquettes.
- the object of the invention is to briquette materials which contain sponge iron produced by direct reduction, after-treatment of the briquettes before their use in metallurgical furnaces being unnecessary.
- dilute sulfuric acid is added as a binder and the material contains more than 40% metallic iron.
- dilute sulfuric acid means aqueous solutions that contain free sulfuric acid. The dilute sulfuric acid is expediently added before a mixing process.
- a preferred embodiment is that the dilute sulfuric acid has a free sulfuric acid content of 10 to 30% by weight. This concentration range gives particularly good strength values.
- a preferred embodiment is that the dilute sulfuric acid in an amount from 3 to 15% by weight, preferably 5 to 10% by weight, based on dry material, is added. This amount gives good mixing with the material and good strength values. With higher levels of metallic iron, the addition of dilute sulfuric acid can be kept in the lower ranges.
- waste sulfuric acid is used as the dilute sulfuric acid.
- a waste product can be used economically.
- Briquettes were made with the addition of waste sulfuric acid from the TiO z production.
- the pressure was 5 t / cm roll width.
- the briquettes were pillow-shaped and weighed approximately 100 g. It was 23 mm high, 43 mm wide and 46 mm long.
- briquettes with such a high compressive strength and abrasion resistance can be produced in a simple manner immediately after leaving the press that they can be transported without further treatment and used in metallurgical furnaces.
- they have a low sensitivity to water and good dimensional stability during thermal processing.
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- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Materials Engineering (AREA)
- Organic Chemistry (AREA)
- Geology (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Manufacturing & Machinery (AREA)
- Environmental & Geological Engineering (AREA)
- Life Sciences & Earth Sciences (AREA)
- Geochemistry & Mineralogy (AREA)
- Metallurgy (AREA)
- Mechanical Engineering (AREA)
- Manufacture And Refinement Of Metals (AREA)
- Manufacture Of Iron (AREA)
- Cleaning Implements For Floors, Carpets, Furniture, Walls, And The Like (AREA)
- Mattresses And Other Support Structures For Chairs And Beds (AREA)
Abstract
Description
Die Erfindung betrifft ein Verfahren zur Brikettierung von durch Direktreduktion erzeugtem Schwammeisen enthaltendem Material im gekühlten Zustand unter Zusatz eines Bindemittels vor der Brikettierung.The invention relates to a method for briquetting material containing sponge iron produced by direct reduction in the cooled state with the addition of a binder before the briquetting.
Schwammeisen enthaltende Materialien fallen bei der Direktreduktion oder dem Wälzen von eisenoxidhaltigen Stoffen, insbesondere von Eisenerzen und NE-Metalle enthaltenden Hüttenwerksreststoffen, mittels fester, kohlenstoffhaltiger Reduktionsmittel oder reduzierender Gase im Drehrohrofen, Schachtofen oder Retortenofen, an. Das Schwammeisen enthaltende Material wird nach einer eventuellen Abtrennung von anderen Beschickungsbestandteilen auf Roheisen oder Stahl weiterverarbeitet. Dies geschieht z. B. durch Einsatz in Elektroniederschachtöfen, Hochöfen oder Lichtbogenöfen. Dazu ist aber eine Mindestkorngröße des Materials erforderlich, die jedoch das erzeugte Schwammeisen enthaltende Material nicht oder teilweise nicht aufweist. Das feinkörnige Material - worunter im allgemeinen die Korngröße unter etwa 6 mm verstanden wird - ist außerdem bei der Lagerung und beim Transport außerordentlich empfindlich gegen Witterungseinflüsse. Der Zutritt von Wasser müßte unbedingt vermieden werden, was jedoch nicht immer möglich ist. Die Handhabung von Eisenschwamm enthaltendem Material, das größere Anteile von feinkörnigem Material enthält, ist außerdem mit störender Staubentwicklung verbunden.Materials containing sponge iron are obtained in the direct reduction or rolling of iron oxide-containing materials, in particular iron ore and non-ferrous metals, by means of solid, carbon-containing reducing agents or reducing gases in a rotary kiln, shaft furnace or retort furnace. The material containing sponge iron is further processed on pig iron or steel after it has been separated from other feed components. This happens e.g. B. by use in electronic shaft furnaces, blast furnaces or arc furnaces. For this purpose, however, a minimum grain size of the material is required, which, however, does not contain the material containing sponge iron or only partially. The fine-grained material - which is generally understood to mean the grain size below about 6 mm - is also extremely sensitive to weather influences during storage and transport. The entry of water should absolutely be avoided, but this is not always possible. The handling of material containing sponge iron, which contains large amounts of fine-grained material, is also associated with disruptive dust generation.
Diese Nachteile können durch eine Verminderung der Oberfläche des Materials beseitigt werden. Hierfür ist die seit langem bekannte Brikettierung geeignet. Die dabei erzielte Verbesserung der Stückigkeit ist darüber hinaus Voraussetzung für den Einsatz dieser Materialien in den Hochofen. Die Brikettierung kann auf heißem oder kaltem Wege durchgeführt werden. Angestrebt wird ein Arbeitsgang «in einer Hitze», der jedoch in vielen Fällen nicht möglich ist. Bei der Kaltbrikettierung kann der den Werkzeugverschleiß stark beeinflussende Preßdruck dadurch vermindert werden, daß man bestimmte Bindemittel einsetzt und versucht, die notwendige mechanische Festigkeit der Preßlinge durch anschließende Auslagerung zu erreichen. Die Auswahl der Bindemittel erfolgt unter Berücksichtigung von Verfügbarkeit, Preis, Dosierbarkeit, notwendiger Auslagerungszeit und Verhalten der Preßlinge bei der anschließenden thermischen Behandlung. Bekannte Bindemittel, die vor allem auch aus Kostengründen in Frage kommen, sind Kalk, Melasse, Sulfitablauge, Bitumen und Stärke. Sie erfordern jedoch stets eine Mindestauslagerungszeit von etwa 24 Stunden. Einige bewirken außerdem bei der anschließenden thermischen Behandlung der Briketts einen Zerfall der Preßlinge.These disadvantages can be eliminated by reducing the surface of the material. The long-known briquetting is suitable for this. The improvement in lumpiness achieved is also a prerequisite for the use of these materials in the blast furnace. The briquetting can be done hot or cold. The aim is to work “in the heat”, but in many cases this is not possible. In cold briquetting, the pressing pressure, which strongly influences tool wear, can be reduced by using certain binders and trying to achieve the necessary mechanical strength of the pressed articles by subsequent aging. The binder is selected taking into account availability, price, dosage, necessary aging time and behavior of the compacts during the subsequent thermal treatment. Known binders, which are mainly considered for cost reasons, are lime, molasses, sulfite waste, bitumen and starch. However, they always require a minimum outsourcing time of around 24 hours. Some also cause the compacts to disintegrate during the subsequent thermal treatment of the briquettes.
Aus der DE-B-10 71 733 ist eine Kaltbrikettierung von Schwammeisen enthaltendem Material bekannt, die ohne Bindemittelzusatz erfolgt. Die erzeugten Briketts werden mit C02 unter Zufuhr von Feuchtigkeit behandelt. Die feuchten, C02 enthaltenden Briketts werden dann anschließend in Gegenwart eines sauerstoffhaltigen Gases gealtert. Dieses Verfahren ist aufwendig und erfordert eine beträchtliche Zeit.From DE-B-10 71 733 a cold briquetting of material containing sponge iron is known, which takes place without the addition of a binder. The briquettes produced are treated with C0 2 with the supply of moisture. The moist briquettes containing C0 2 are then aged in the presence of an oxygen-containing gas. This process is complex and takes a considerable amount of time.
Aus der DE-C-1270 054 ist es bekannt, den gesamten Ofenaustrag so zu kühlen, daß im wesentlichen eine Martensitbildung vermieden wird und dann bindemittellos zu brikettieren. Dieses Verfahren erfordert eine spezielle Abkühlung des Eisenschwamm enthaltenden Materials.From DE-C-1270 054 it is known to cool the entire furnace discharge in such a way that martensite formation is essentially avoided and then to be briquetted without a binder. This process requires special cooling of the material containing sponge iron.
Aus «Neues aus der Technik», Vogel-Verlag, Würzburg, Jahrgang 1977, Nr. 2, Seite 1 ist es bekannt, das Austragsmaterial eines nach dem Wälzverfahren arbeitenden Drehrohrofens zu brikettieren. Dem Austragsmaterial wird Sulfitablauge in solchen Mengen zugegeben, daß der Feststoffgehalt der Sulfitablauge 2 bis 5 %, bezogen auf das Austragsprodukt, beträgt. Das gemischte Material wird gemaukt und brikettiert. Die Briketts werden mindestens 2 Stunden, vorzugsweise 12 bis 72 Stunden, bei Raumtemperatur ausgehärtet. Dieses Verfahren benötigt einen Maukprozeß und eine Aushärtung.From “News from Technology”, Vogel-Verlag, Würzburg, born in 1977, No. 2, page 1, it is known to briquette the discharge material of a rotary kiln using the rolling method. Sulfite waste liquor is added to the discharge material in such amounts that the solids content of the sulfite waste liquor is 2 to 5%, based on the discharge product. The mixed material is bricked and briquetted. The briquettes are cured at room temperature for at least 2 hours, preferably 12 to 72 hours. This process requires a curing process and curing.
Aus der AT-B-221 588, der DE-B-11 40 592 und DE-C-11 43 837 ist es bekannt, Feinerz, Gichtstaub oder dergleichen pulverförmige Materialien mit einem Gehalt von nicht mehr als 15 % feinstpulverigem metallischem Eisen unter Zusatz von Schwefelsäure und/oder wäßrigen Eisensulfatlösungen zu brikettieren, die Briketts zu wässern und anschließend an der Luft auszuhärten. Über 13 % Gehalt an metallischem Eisen tritt keine wesentliche Verbesserung der Festigkeit mehr ein, während jedoch die Anfangsfestigkeit zu gering ist. Deshalb werden vorreduzierte Erze mit höheren Gehalten an metallischem Eisen mit anderen Stoffen so gemischt, daß der Gehalt an metallischen Eisen dann zwischen 2 und etwa 10 % liegt.From AT-B-221 588, DE-B-11 40 592 and DE-C-11 43 837 it is known to add fine ore, gout dust or similar powdery materials with a content of not more than 15% of finely powdered metallic iron Briquetting of sulfuric acid and / or aqueous iron sulfate solutions, watering the briquettes and then curing in air. Above 13% metallic iron content, there is no significant improvement in strength, but the initial strength is too low. Therefore, pre-reduced ores with higher contents of metallic iron are mixed with other substances in such a way that the content of metallic iron is then between 2 and about 10%.
Der Erfindung liegt die Aufgabe zugrunde, Materialien, die durch Direktreduktion erzeugtes Schwammeisen enthalten, zu brikettieren, wobei eine Nachbehandlung der Briketts vor ihrem Einsatz in metallurgische Öfen nicht erforderlich ist.The object of the invention is to briquette materials which contain sponge iron produced by direct reduction, after-treatment of the briquettes before their use in metallurgical furnaces being unnecessary.
Die Lösung dieser Aufgabe erfolgt erfindungsgemäß dadurch, daß als Bindemittel verdünnte Schwefelsäure zugesetzt wird und das Material mehr als 40 % metalisches Eisen enthält. Unter dem Begriff «verdünnte Schwefelsäure» sind wäßrige Lösungen zu verstehen, die freie Schwefelsäure enthalten. Der Zusatz der verdünnten Schwefelsäure erfolgt zweckmäßigerweise vor einem Mischvorgang.This object is achieved according to the invention in that dilute sulfuric acid is added as a binder and the material contains more than 40% metallic iron. The term “dilute sulfuric acid” means aqueous solutions that contain free sulfuric acid. The dilute sulfuric acid is expediently added before a mixing process.
Eine vorzugsweise Ausgestaltung besteht darin, daß die verdünnte Schwefelsäure einen Gehalt an freier Schwefelsäure von 10 bis 30 Gew.-% aufweist. Dieser Konzentrationsbereich ergibt besonders gute Festigkeitswerte.A preferred embodiment is that the dilute sulfuric acid has a free sulfuric acid content of 10 to 30% by weight. This concentration range gives particularly good strength values.
Eine vorzugsweise Ausgestaltung besteht darin, daß die verdünnte Schwefelsäure in einer Menge von 3 bis 15 Gew.-%, vorzugsweise 5 bis 10 Gew.-%, bezogen auf trockenes Material, zugesetzt wird. Diese Menge ergibt eine gute Vermischung mit dem Material und gute Festigkeitswerte. Bei höheren Gehalten an metallischem Eisen kann der Zusatz an verdünnter Schwefelsäure in den unteren Bereichen gehalten werden.A preferred embodiment is that the dilute sulfuric acid in an amount from 3 to 15% by weight, preferably 5 to 10% by weight, based on dry material, is added. This amount gives good mixing with the material and good strength values. With higher levels of metallic iron, the addition of dilute sulfuric acid can be kept in the lower ranges.
Eine vorzugsweise Ausgestaltung besteht darin, daß als verdünnte Schwefelsäure Abfalischwefelsäure eingesetzt wird. Dadurch kann ein Abfallprodukt in wirtschaftlicher Weise verwendet werden.A preferred embodiment is that waste sulfuric acid is used as the dilute sulfuric acid. As a result, a waste product can be used economically.
Die Erfindung wird anhand von Beispielen näher erläutert.The invention is explained in more detail by means of examples.
Es wurden Briketts unter Zusatz von Abfallschwefelsäure aus der TiOz-Produktion hergestellt. Der Preßdruck betrug 5 t/cm Walzenbreite. Die Briketts waren kissenförmig und hatten ein Gewicht von ca. 100 g. Ihre Höhe betrug 23 mm, die Breite 43 mm und die Länge 46 mm. Die Abfallsäure hatte folgende Eigenschaften :
Die Briketts hatten die in der Tabelle angegebenen Eigenschaften. Die Versuche Nr. 1 und 2 sind Vergleichsversuche.The briquettes had the properties shown in the table. Experiments No. 1 and 2 are comparative experiments.
Eine Auslagerung führte praktisch zu keiner Verbesserung der Eigenschaften. Eine Wässerung der Briketts verschlechterte praktisch die Eigenschaften nicht, d.h. die Briketts sind weitgehend witterungsbeständig.Outsourcing led to practically no improvement in properties. Soaking the briquettes practically did not deteriorate the properties, i.e. the briquettes are largely weatherproof.
Die Vorteile der Erfindung bestehen darin, daß Briketts mit einer solch hohen Druckfestigkeit und Abriebfestigkeit unmittelbar nach Verlassen der Presse in einfacher Weise hergestellt werden können, daß sie ohne weitere Nachbehandlung transportiert und in metallurgische Öfen eingesetzt werden können. Außerdem haben sie eine geringe Empfindlichkeit gegenüber Wasser sowie eine gute Formbeständigkeit bei der thermischen Weiterverarbeitung.
Claims (4)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| AT80200433T ATE329T1 (en) | 1979-05-12 | 1980-05-08 | PROCESS FOR BRIQUETING MATERIAL CONTAINING SPONGE IRON. |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE2919272 | 1979-05-12 | ||
| DE19792919272 DE2919272A1 (en) | 1979-05-12 | 1979-05-12 | METHOD FOR BRIKETTING MATERIAL CONTAINING SPONGE IRON |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| EP0021465A1 EP0021465A1 (en) | 1981-01-07 |
| EP0021465B1 true EP0021465B1 (en) | 1981-10-21 |
Family
ID=6070619
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| EP80200433A Expired EP0021465B1 (en) | 1979-05-12 | 1980-05-08 | Process for briquetting a material containing sponge iron |
Country Status (7)
| Country | Link |
|---|---|
| US (1) | US4308055A (en) |
| EP (1) | EP0021465B1 (en) |
| JP (1) | JPS55161032A (en) |
| AT (1) | ATE329T1 (en) |
| AU (1) | AU526919B2 (en) |
| CA (1) | CA1141164A (en) |
| DE (2) | DE2919272A1 (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| BRPI0711527A2 (en) * | 2006-06-12 | 2011-11-01 | Murrin Murrin Operations Pty Ltd | crowding method |
| JP5303727B2 (en) * | 2008-12-09 | 2013-10-02 | 新日鐵住金株式会社 | Method for producing reduced iron agglomerates for steelmaking |
| RU2463362C2 (en) * | 2010-11-30 | 2012-10-10 | Государственное образовательное учреждение высшего профессионального образования "Санкт-Петербургский государственный горный институт имени Г.В. Плеханова (технический университет)" | Method to prepare iron ore for metallurgical processing |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US933269A (en) * | 1909-09-07 | Wilhelm Schumacher | Manufacture of agglomerated bodies from blast-furnace dust. | |
| DE1071733B (en) * | 1959-12-24 | |||
| US2711951A (en) * | 1951-08-02 | 1955-06-28 | Illinois Clay Products Co | Process for producing a briquette of iron ore |
| US2793109A (en) * | 1954-04-09 | 1957-05-21 | Surface Combustion Corp | Induration process for powdered iron oxide containing material |
| DE1039546B (en) * | 1957-10-02 | 1958-09-25 | F J Collin Ag Zur Verwertung V | Process for the utilization of sulfuric acid iron salt solutions, in particular pickling waste liquors |
| DE1140592B (en) * | 1959-04-27 | 1962-12-06 | Maximilianshuette Eisenwerk | Process for the briquetting of powdery substances |
| DE1533852B2 (en) * | 1967-03-29 | 1973-10-04 | Metallgesellschaft Ag, 6000 Frankfurt | Briquetting of sponge iron |
-
1979
- 1979-05-12 DE DE19792919272 patent/DE2919272A1/en not_active Withdrawn
-
1980
- 1980-05-08 AT AT80200433T patent/ATE329T1/en not_active IP Right Cessation
- 1980-05-08 EP EP80200433A patent/EP0021465B1/en not_active Expired
- 1980-05-08 DE DE8080200433T patent/DE3060046D1/en not_active Expired
- 1980-05-09 US US06/148,476 patent/US4308055A/en not_active Expired - Lifetime
- 1980-05-09 CA CA000351768A patent/CA1141164A/en not_active Expired
- 1980-05-12 JP JP6266680A patent/JPS55161032A/en active Pending
- 1980-05-12 AU AU58321/80A patent/AU526919B2/en not_active Ceased
Also Published As
| Publication number | Publication date |
|---|---|
| AU526919B2 (en) | 1983-02-03 |
| EP0021465A1 (en) | 1981-01-07 |
| DE3060046D1 (en) | 1981-12-24 |
| ATE329T1 (en) | 1981-11-15 |
| JPS55161032A (en) | 1980-12-15 |
| AU5832180A (en) | 1980-11-20 |
| US4308055A (en) | 1981-12-29 |
| CA1141164A (en) | 1983-02-15 |
| DE2919272A1 (en) | 1980-11-27 |
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