EP0011779A1 - 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
EP0011779A1
EP0011779A1 EP79104513A EP79104513A EP0011779A1 EP 0011779 A1 EP0011779 A1 EP 0011779A1 EP 79104513 A EP79104513 A EP 79104513A EP 79104513 A EP79104513 A EP 79104513A EP 0011779 A1 EP0011779 A1 EP 0011779A1
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EP
European Patent Office
Prior art keywords
mgo
blowing
lime
slag
cao
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.)
Granted
Application number
EP79104513A
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German (de)
English (en)
Other versions
EP0011779B1 (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
Preussag Stahl AG
Original Assignee
Dolomitwerke GmbH
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.)
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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(A1) "Global patent litigation dataset” by Darts-ip is licensed under a Creative Commons Attribution 4.0 International License.
Application filed by Dolomitwerke GmbH, 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 additives.
  • the basic lining of converters usually consists of tempered, less often green tar or pitch-bound dolomite stones, magnesite stones or dolomite / magnesite mixed stones. These linings are subject to heavy wear while the pig iron is being freshed, 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 Freshen up.
  • the iron oxide content of the slag is to 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.
  • signs of wear are derived from the composition of the final slags.
  • an acidic slag is formed which can be obtained by adding basic additives, e.g. tries to neutralize it with Ca0.
  • the basic slag has a considerable ability to dissolve Mg0, which the slag takes from the lining.
  • This Mg0 solubility of the slag is greatest at the start of freshening and decreases at the end of the blowing. It follows that the slag attack on the converter lining is greatest at the start of freshening and that the composition of the final slag cannot be used as a yardstick for assessing feed wear.
  • 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.
  • the present invention is based on the object of extending 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 fluxes, and also maintaining the Mg0 saturation of the slag throughout Fresh process, so that there is no hindrance to the dephosphorization and desulphurization by too viscous final slag and finally further avoidance of excess basic additives.
  • the Mg0 or the Mg0-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 procedures, for example in the so-called LDAC method, in the AOD method and also in the OBM method.
  • LDAC method in the so-called LDAC method
  • OBM method in the OBM method.
  • 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 game by using pre-formed slag and blowing in calcined fine-grained dolomite with the help of a separate lance with oxygen as the carrier gas or by adding a lime additive before the start of freshening, then calcareous magnesite using an inert gas via a separate lance or as part of the OBM Procedure or the AOD procedure.
  • These variations are only intended to serve as examples of possible variants of the method according to the invention.
  • the required amount of lime depends on the metallurgical 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 end 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. In the case of high silicon contents, however, the MgO injection should be stopped before adding the remaining lime.
  • the amounts of MgO and lime are such that there is a percentage in the slag Ca0 / 11g0 and a percentage CaO / SiO 2 ratio that functionally belong together according to Figure 1 and lie between curves A and B.
  • the curves can be expressed as
  • the amount of 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, their MgO or Ca0 content must be taken into account, of course also when using MgO-containing substances or pre-formed slag.
  • the amounts of CaO and MgO used are calculated from this: 265o kg of dolomite are blown in.
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 true EP0011779A1 (fr) 1980-06-11
EP0011779B1 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

Country Status (3)

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
AT394055B (de) * 1990-04-12 1992-01-27 Veitscher Magnesitwerke Ag Metallurgisches gefaess und verfahren zur herstellung der feuerfesten auskleidung solcher gefaesse
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
RU2545874C2 (ru) * 2012-04-27 2015-04-10 Закрытое Акционерное Общество "МагнийПром" Способ получения магнезиального флюса для выплавки стали

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
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
FR2371512A1 (fr) * 1976-11-17 1978-06-16 Kyoei Steel Ltd Procede de production d'acier au four electrique
LU77946A1 (fr) * 1977-08-09 1979-05-23 Icm Holding Sa Procede permettant de proteger les revetements refractaires des melangeurs a fonte

Family Cites Families (2)

* 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
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

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
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
FR2371512A1 (fr) * 1976-11-17 1978-06-16 Kyoei Steel Ltd Procede de production d'acier au four electrique
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
ATE884T1 (de) 1982-05-15
DE2962590D1 (en) 1982-06-03
EP0011779B1 (fr) 1982-04-21
DE2852248C3 (de) 1982-02-11
DE2852248A1 (de) 1980-06-04
DE2852248B2 (de) 1981-06-04

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