EP0011779B1 - Procédé pour prolonger la tenue des garnissages basiques de convertisseurs lors de l'affinage de la fonte en acier - Google Patents

Procédé pour prolonger la tenue des garnissages basiques de convertisseurs lors de l'affinage de la fonte en acier Download PDF

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Publication number
EP0011779B1
EP0011779B1 EP79104513A EP79104513A EP0011779B1 EP 0011779 B1 EP0011779 B1 EP 0011779B1 EP 79104513 A EP79104513 A EP 79104513A EP 79104513 A EP79104513 A EP 79104513A EP 0011779 B1 EP0011779 B1 EP 0011779B1
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EP
European Patent Office
Prior art keywords
mgo
cao
substances containing
refining
slag
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
Application number
EP79104513A
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German (de)
English (en)
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EP0011779A1 (fr
Inventor
Gustav Dr. Mahn
Dieter Nolle
Josef Dr. Schoop
Karl-Heinz Prof. Dr. Obst
Wolfgang Dr. habil. Münchberg
Manfred Dr. Rähder
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Dolomitwerke GmbH
Stahlwerke Pein Salzgitter AG
Preussag Stahl AG
Original Assignee
Dolomitwerke GmbH
Stahlwerke Pein Salzgitter AG
Preussag Stahl AG
Priority date (The priority date 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 date listed.)
Filing date
Publication date
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First worldwide family litigation filed litigation Critical https://patents.darts-ip.com/?family=6056185&utm_source=google_patent&utm_medium=platform_link&utm_campaign=public_patent_search&patent=EP0011779(B1) "Global patent litigation dataset” by Darts-ip is licensed under a Creative Commons Attribution 4.0 International License.
Application filed by Dolomitwerke GmbH, Stahlwerke Pein Salzgitter AG, Preussag Stahl AG filed Critical Dolomitwerke GmbH
Priority to AT79104513T priority Critical patent/ATE884T1/de
Publication of EP0011779A1 publication Critical patent/EP0011779A1/fr
Application granted granted Critical
Publication of EP0011779B1 publication Critical patent/EP0011779B1/fr
Expired legal-status Critical Current

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    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
    • C21C5/00—Manufacture of carbon-steel, e.g. plain mild steel, medium carbon steel or cast steel or stainless steel
    • C21C5/28—Manufacture of steel in the converter
    • C21C5/42—Constructional features of converters
    • C21C5/44—Refractory linings

Definitions

  • the present invention relates to a method for increasing the durability of basic brick lining of converters when refining pig iron to steel using materials containing MgO or MgO and lime as aggregates, aggregates of this type being blown into the focal spot area.
  • the basic lining of converters usually consists of tempered, more rarely green tar- or pitch-bound dolomite stones, magnesite stones or dolomite / magnesite mixed stones. These bricks are subject to heavy wear during the pig iron freshening, which has physical and chemical causes.
  • the physical causes are, for example, erosion, the addition of scrap and thermal stresses due to changing temperatures in the converter.
  • the chemical influences as the main cause of wear are essentially due to the slag attack on components of the converter feed.
  • the aim of the present invention is to reduce chemical wear and thereby increase the durability of the basic brickwork, specifically by means of a targeted metallurgical control of the fresh process.
  • the chemical wear naturally depends very much on the composition of the slag during the freshening.
  • the iron oxide content of the slag should play a role in this, since a reaction takes place between the iron oxide and the carbon of the binder of the feed, so that decarburization of the feed takes place in the first wear phase.
  • the state of knowledge also includes that the ideal protection against slag attack on the converter lining would be provided if the magnesium oxide concentration of the slag could be kept at the saturation limit in every phase of the refining process, i.e. also at the beginning of refining.
  • FR-A-1 536 457 describes a process for reducing the wear of basic refractory linings from converters, in which slag saturated with magnesium oxide is used and magnesium oxide in granular form is fed continuously during the entire fresh process. A mixture of lime and magnesium oxide can also be blown through the oxygen lance.
  • the present invention has for its object to extend the feed life of basic converters, namely by increasing the dissolution rate of MgO used as an additive, in particular at the beginning of the fresh process, while avoiding the addition of flux, and also maintaining the MgO saturation of the slag throughout Fresh process, so that there is no hindrance to dephosphorization and desulphurization by a too viscous final slag and finally further avoidance of excess basic additives.
  • this object can be achieved if the MgO or the MgO-containing substances are blown into the molten pig iron in the presence of CaO or CaO-containing basic substances with the proviso that this begins with the freshening and after 15% to 35% the freshness is over, these aggregates having a grain size of less than 2 mm and the amounts of MgO and CaO are to be dimensioned such that a percentage CaO / MgO and a percentage CaO / Si0 2 ratio results in the slag, which According to Diagram 1, they belong together functionally and lie between curves A and B, while the required amount of remaining lime is added after 15% to 35% of the fresh time.
  • the MgO or the MgO-containing substances, optionally together with lime are blown in with oxygen as the carrier gas.
  • the substances to be blown are fed directly to the focal spot.
  • the blowing lance used to refresh the pig iron is set up to supply solids, the solids can be blown in with the oxygen required for the refreshing. If this is not the case, a second lance is used according to the invention, which only serves to blow in the solids. If a gas other than oxygen takes on the carrier gas function, the solids should be blown in in the area of the focal spot that arises during the fresh process.
  • the method according to the invention can be carried out not only when performing LD freshening, but also in other methods, for example in the so-called LDAC, in the AOD and also in the OBM method.
  • LDAC so-called LDAC
  • These processes sometimes use other gases besides oxygen, which can also serve as carrier gases, as well as gas mixtures with and without oxygen.
  • the method according to the invention is not limited to a selection of the technical measures described, but it is also possible to combine these measures in a technically meaningful manner, for example by using pre-formed slag and calcining fine-grained dolomite with the aid of a separate lance with oxygen Blown in carrier gas or that a lime aggregate is introduced before the start of freshening, then calcareous magnesite is struck with the aid of an inert gas via a separate lance or as part of the OBM process or the AOD process.
  • These variations are only intended to serve as examples of possible variants of the method according to the invention.
  • the required amount of remaining lime depends on the meta-juridical conditions, in particular on the silicon content of the pig iron and the basic substances that have already been added. It is easy to determine by invoice and is advantageously added after 25% of the fresh season.
  • the additions should be blown in at the start of the freshening process in order to achieve a MgO-saturated slag from the start.
  • the end of the blowing should be finished between 15% and 35% of the blowing time, preferably after about 25% of the fresh time, so that the addition of the remaining lime quantity can then begin, starting at 15% at the earliest, and 35% of the fresh time at the latest.
  • the times for the aggregates can overlap if the steel's silicon content is low. With high silicon contents, however, the MgO injection should be completed before the addition, the remaining lime quantity.
  • the amounts of MgO and lime are such that there is a percentage CaO / MgO and a percentage CaO / Si0 2 ratio in the slag, which functionally belong together according to Figure 1 and lie between curves A and B.
  • the curves can be expressed as Here F represents a factor of 0.413.
  • C takes the value 0.5
  • in curve B the value 0.2
  • the scope of the curves is between
  • the amount of the input materials can be calculated from Figure 1, if necessary with the help of diagrams, as shown in Figure 2. These calculations are illustrated by two examples on an operational scale below. When calculating the quantity of the aggregates to take into account their MgO or CaO content, of course also when using MgO-containing substances or pre-formed slag.

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Manufacturing & Machinery (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Carbon Steel Or Casting Steel Manufacturing (AREA)

Claims (8)

1. Procédé pour prolonger la tenue des garnissages basiques de convertisseurs lors de l'affinage de la fonte en acier, avec emploi de MgO ou de matières contenant du MgO, ainsi que de chaux, comme additifs, les additifs de ce type étant introduits par soufflage dans la zone du foyer, procédé caractérisé en ce que l'on introduit le MgO, ou la matière contenant le MgO par soufflage dans la fonte liquide, en présence de CaO ou d'une matière basique contenant du CaO, de telle façon que cette introduction commence avec l'affinage et se termine après que 15 à 35% de la durée d'affinage ne soit écoulés, ces additifs présentant une grosseur de grains inférieure à 2 mm, et les quantités de MgO et de CaO étant déterminées de telle sorte, que, dans la scorie, on obtient des rapports en pourcents CaO/MgO et CaO/Si02, qui sont en relation fonctionnelle selon la figure 1 et se situent entre les courbes A et B, pendant que la quantité de chaux restante nécessaire est introduite après écoulement de 15 à 35% de la durée d'affinage.
2. Procédé selon la revendication 1, caractérisé en ce que le MgO ou la matière contenant le MgO sont introduits par soufflage en commun avec la chaux.
3. Procédé selon la revendication 1, caractérisé en ce que l'on utilise de la scorie formée préalablement, de préférence sous forme liquide, et qu'ensuite s'effectue l'introduction par soufflage du MgO ou de la matière contenant le MgO.
4. Procédé selon l'une des revendications 1 et 2, caractérisé en ce que, comme matière additionnelle contenant du MgO, on utilise de la dolomie.
5. Procédé selon l'une quelconque des revendications 1 à 4, caractérisé en ce que l'introduction par soufflage du MgO ou de la matière contenant le MgO s'effectue avec l'oxygène, ou avec un mélange gazeux contenant de l'oxygène, comme gaz vecteur.
6. Procédé selon l'une quelconque des revendications 1 à 4, caractérisé en ce que l'introduction par soufflage du MgO ou de la matière contenant le MgO s'effectue avec un gaz ou mélange gazeux exempts d'oxygène comme gaz vecteur.
7. Procédé selon l'une quelconque des revendications 1 à 6, caractérisé en ce que l'introduction par soufflage du MgO ou de la matière contenant le MgO est terminé après écoulement d'environ 25% de la durée du soufflage.
8. Procédé selon la revendication 1, caractérisé en ce que la quantité restante nécessaire de chaux est introduite après écoulement de 25% environ de la durée de l'affinage.
EP79104513A 1978-12-02 1979-11-15 Procédé pour prolonger la tenue des garnissages basiques de convertisseurs lors de l'affinage de la fonte en acier Expired EP0011779B1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT79104513T ATE884T1 (de) 1978-12-02 1979-11-15 Verfahren zur erhoehung der haltbarkeit basischer ausmauerungen von konvertern beim frischen von roheisen zu stahl.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE2852248A DE2852248C3 (de) 1978-12-02 1978-12-02 Verfahren zur Erhöhung der Haltbarkeit basischer Ausmauerungen von Konvertern beim Frischen von Roheisen
DE2852248 1978-12-02

Publications (2)

Publication Number Publication Date
EP0011779A1 EP0011779A1 (fr) 1980-06-11
EP0011779B1 true EP0011779B1 (fr) 1982-04-21

Family

ID=6056185

Family Applications (1)

Application Number Title Priority Date Filing Date
EP79104513A Expired EP0011779B1 (fr) 1978-12-02 1979-11-15 Procédé pour prolonger la tenue des garnissages basiques de convertisseurs lors de l'affinage de la fonte en acier

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Country Link
EP (1) EP0011779B1 (fr)
AT (1) ATE884T1 (fr)
DE (2) DE2852248C3 (fr)

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3040630C2 (de) * 1980-10-29 1983-03-31 Stahlwerke Peine-Salzgitter Ag, 3150 Peine Verfahren zur Erzeugung von Stahl im basischen Konverter unter Verwendung von flüssiger Konverterschlacke
DD300677A7 (de) * 1989-06-20 1992-07-02 Eko Stahl Ag,De Verfahren zur erhoehung der haltbarkeit der feuerfesten auskleidung von metallurgischen gefaessen
US5340088A (en) * 1990-04-12 1994-08-23 Veitscher Magnesitwerke-Actien-Gesellschaft Metallurgical vessel and method of making the refractory lining of such vessels
AT394054B (de) * 1990-04-12 1992-01-27 Veitscher Magnesitwerke Ag Metallurgisches gefaess, sowie verfahren und vorrichtung zur herstellung der auskleidung desselben
AT394055B (de) * 1990-04-12 1992-01-27 Veitscher Magnesitwerke Ag Metallurgisches gefaess und verfahren zur herstellung der feuerfesten auskleidung solcher gefaesse
RU2545874C2 (ru) * 2012-04-27 2015-04-10 Закрытое Акционерное Общество "МагнийПром" Способ получения магнезиального флюса для выплавки стали

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3288592A (en) * 1963-01-16 1966-11-29 Pfizer & Co C Process for reducing deterioration in equipment handling molten materials
FR1346148A (fr) * 1963-01-31 1963-12-13 Centre Nat Rech Metall Procédé pour la protection du revêtement intérieur des fours métallurgiques
FR1536457A (fr) * 1967-07-07 1968-08-16 Siderurgie Fse Inst Rech Procédé pour la protection des revêtements réfractaires des récipients métallurgiques d'affinage continu
BR7302595D0 (pt) * 1972-05-09 1974-06-27 Blanq Cazaux Morales A Aperfeicoamentos em processo para fabricacao de ferro e acaperfeicoamentos em processo para fabricacao de ferro e acos os
JPS5362707A (en) * 1976-11-17 1978-06-05 Kyoei Steel Ltd Electric furnace steel making method
LU77946A1 (fr) * 1977-08-09 1979-05-23 Icm Holding Sa Procede permettant de proteger les revetements refractaires des melangeurs a fonte

Also Published As

Publication number Publication date
DE2852248B2 (de) 1981-06-04
DE2852248A1 (de) 1980-06-04
ATE884T1 (de) 1982-05-15
EP0011779A1 (fr) 1980-06-11
DE2962590D1 (en) 1982-06-03
DE2852248C3 (de) 1982-02-11

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