EP0032350A2 - Verfahren zum Frischen einer Metallschmelze in einem Tiegel unter Aufblasen von Sauerstoff und dabei verwendeter Tiegel - Google Patents

Verfahren zum Frischen einer Metallschmelze in einem Tiegel unter Aufblasen von Sauerstoff und dabei verwendeter Tiegel Download PDF

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Publication number
EP0032350A2
EP0032350A2 EP80401900A EP80401900A EP0032350A2 EP 0032350 A2 EP0032350 A2 EP 0032350A2 EP 80401900 A EP80401900 A EP 80401900A EP 80401900 A EP80401900 A EP 80401900A EP 0032350 A2 EP0032350 A2 EP 0032350A2
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EP
European Patent Office
Prior art keywords
crucible
bath
injectors
gas
refining
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
EP80401900A
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English (en)
French (fr)
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EP0032350B1 (de
EP0032350A3 (en
Inventor
Jean-Claude Grosjean
Guy Denier
Claude Bauler
Paul Metz
Francois Schleimer
Lucien Lorang
Ferdinand Goedert
Romain Henrion
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.)
Institut de Recherches de la Siderurgie Francaise IRSID
Arcelor Luxembourg SA
Original Assignee
Institut de Recherches de la Siderurgie Francaise IRSID
Arbed SA
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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Application filed by Institut de Recherches de la Siderurgie Francaise IRSID, Arbed SA filed Critical Institut de Recherches de la Siderurgie Francaise IRSID
Priority to AT80401900T priority Critical patent/ATE14144T1/de
Publication of EP0032350A2 publication Critical patent/EP0032350A2/de
Publication of EP0032350A3 publication Critical patent/EP0032350A3/fr
Application granted granted Critical
Publication of EP0032350B1 publication Critical patent/EP0032350B1/de
Expired legal-status Critical Current

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    • 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
    • C22B9/00—General processes of refining or remelting of metals; Apparatus for electroslag or arc remelting of metals
    • C22B9/05—Refining by treating with gases, e.g. gas flushing also refining by means of a material generating gas in situ
    • 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
    • C21C5/30—Regulating or controlling the blowing
    • C21C5/35—Blowing from above and through the bath

Definitions

  • the present invention relates to the production of metals, in particular steel. It relates more particularly to the pneumatic refining of a cast iron bath contained in a crucible with oxygen blown from above.
  • a top blown oxygen refining crucible is a metal container lined with a thick refractory lining.
  • the container essentially consists of a vertical cylindrical part (called side wall) which is on the one hand closed at its lower end by a recessed circular bottom and on the other hand extended at its upper end by a frustoconical part forming the spout. Through this penetrates a vertical lance for blowing one or more refining oxygen jets towards the surface of the metal bath contained in the crucible.
  • One of the main technological characteristics of the process is the incorporation into the bottom of the crucible of injectors enabling the mixing gas to be blown into the bath at any time during and / or after the top blowing of oxygen. refining.
  • the injectors used which must ensure a selective passage of the stirring gas to avoid infiltration of molten metal in the opposite direction, can be nozzles with a small passage section (of a few mm 2 ) or, preferably, air-tight refractory elements. Elements of this type now exist, whose lifespan is equal to that of the bottom of the crucible and which have been the subject of several patent applications formulated by the inventors.
  • the inventors have now discovered that the LBE process makes it possible to greatly expand the possibilities of refining with oxygen from above, not only thanks to the flexibility already mentioned in the choice of the time, the duration and the intensity of gas mixing, but also - and quite surprisingly - by a judicious choice of the geometrical conditions which such mixing must meet.
  • this choice can be implemented in a very simple manner from considerations relating only to the location of the injectors in the bottom of the crucible.
  • the subject of the invention is a process for refining a metal bath, in particular of cast iron, in a crucible with oxygen blowing from above and according to which a stirring gas is blown from below. , a method characterized in that the mixing gas is blown at least partially at the periphery of the bottom of the crucible, in the immediate vicinity of the side wall of the latter.
  • the subject of the invention is also a particular crucible for implementing the method, characterized in that it has, incorporated into its refractory lining, injectors for blowing the stirring gas located in the bottom of the crucible, along a circle located in the immediate vicinity of the side wall of the latter.
  • the invention therefore has in particular the advantage of being able to use in all circumstances and throughout the refining operation a brewing gas by nature soluble in the liquid metal under certain conditions, for example nitrogen , without risk of excessive dissolution.
  • a brewing gas by nature soluble in the liquid metal under certain conditions, for example nitrogen , without risk of excessive dissolution.
  • nitrogen is undoubtedly the most economical, in particular as a sub -product of the manufacture of oxygen from atmospheric air.
  • the parameters indicative of the tendency to nitriding the bath are essentially the temperature of the latter as well as the progress of the refining reactions over time and more practically the progress of the reaction. decarburization.
  • the injectors are not distributed circularly but located in places such that, during the tilting of the crucible, they are no longer in contact with the bath of molten metal.
  • the advantage of such an arrangement is in particular to be able to stop the blowing of the stirring gas when it is not or no longer necessary, without risking infiltration in return of molten metal in the injectors.
  • the advantage can easily be understood when the injectors are nozzles, but the benefit obtained is not negligible in the case of air-tight refractory elements, at least for some of them, whose good behavior is conditioned by maintaining a gas flow, which is light but necessary at all times, even outside brewing periods to establish a pressure in the elements counterbalancing the ferro-static pressure.
  • the injectors are located symmetrically on either side of the tilting plane vertical to the tilting axis (axis of the pins equipping the crucible), the crucible being assumed itself in the vertical position.
  • the crucible shown consists mainly of a metal breastplate 1 of axial symmetry covered internally with a thick refractory lining 2.
  • the assembly thus formed consists of a cylindrical part 3 forming the side wall of the crucible and extended at its upper end by a frusto-conical part, or spout, 4, and closed in line with its lower part by a recessed bottom 5 by means of an annular seal made of refractory rammed earth represented in 6.
  • the cylindrical part has, approximately halfway up the assembly, a usual reinforcement belt 7 provided with two diametrically opposite pins 8 and 8 ′ ensuring the support of the crucible and allowing its tilting around the axis of tilting symbolized in 9. Furthermore, a vertical lance 10 for blowing oxygen from above penetrates axially into the crucible through the opening of the spout.
  • the bottom 5 of the crucible is equipped with mixing gas injectors 15 and 18 which, in this case, are air-tight refractory elements incorporated in the refractory masonry of the bottom.
  • these elements which are not part of the specific object of the invention, usually consist of a metal receptacle II inside which is placed an air-tight refractory mass 12 designed so that it can be crossed by gas under pressure.
  • the gas arrives through a supply pipe 13 provided at the base of the element and enters the bath through the opposite face 14 intended to be brought into contact with the latter.
  • these elements replace ordinary bricks constituting the bottom and that in this respect, they advantageously have an identi and an identical format, or very slightly smaller, respectively to the shape and format of the bricks they replace.
  • peripheral elements 15 are essential; the elements 18 being provided only incidentally as complementary elements, give the process greater flexibility as to the range of total flow rates of stirring gas that can be injected and as to a possible modulation of the flow rates according to different zones d injection on the bottom 5.
  • peripheral elements 15 are not distributed regularly along the circumference 16, but are concentrated in line with the axis 9 of the pins.
  • FIG. 2 Such an arrangement is well represented in FIG. 2, where it can be seen that the elements 18 have been placed in the vicinity of the tilting plane 27, in orientations substantially perpendicular to those of the primary elements 15.
  • the metal after refining and before casting fairly regularly has a nitrogen content very close to 20 ppm (parts per million) - 1st row of the table -.
  • the bottom of the crucible was initially equipped with twelve air-tight refractory elements arranged according to the prior art, that is to say regularly distributed in a circle approximately halfway between the center of the bottom and the side refractory wall.
  • a system of this type has been schematically represented on the right-hand side of FIG. 1. It comprises, between the single source 24 of nitrogen under pressure and the two main supply lines 22 and 23, an electropneumatic group composed, from the output from the source, from a general volumetric counter 28 debiting in two circuits in parallel, each equipped with a solenoid valve 29 (29 ') with "all or nothing" control, followed by a sub-assembly 30 (30') grouping together classic components to adjust the flow rate from a fixed or variable setpoint.
  • the whole is connected to the conduits 22 and 23 by a sealed circular connection 31 with two concentric passages at the level of the pin 8 and allowing the immobilization of the supply system despite the movements of the crucible on its tilting axis.
  • the invention lends itself perfectly to its integration into an automatic control system assisted by a computer, as symbolized at 32 and controlling the solenoid valves 29 and 29 'from a sensor 33 measuring the parameters representative of the 'state of progress of the refining operation, therefore of the tendency to nitriding the bath, such as for example the temperature of the reaction gases and their composition, in particular carbon monoxide.
  • the invention applies not only to the case of nitrogen, but to any other stirring gas capable of dissolving in the molten metal contained in the crucible and the final quality of which is not insensitive to its concentration of this gas.
  • the invention in its variant embodiment with two categories of geometrically differentiated injectors, appears, not only as a technique for reducing the nitriding of a steel bath stirred with nitrogen, but also, and much more generally, as a technique for controlling the rate of dissolution of a stirring gas in a molten bath, whatever the respective natures of this gas and of this bath.
  • the invention is not limited either to two categories of injectors but extends to a higher number, knowing that the tendency to dissolve increases when the injectors are activated near the center of the bottom and decreases when approaching the side refractory wall.
  • injectors are not necessarily preformed functional entities (airtight nozzles or refractory elements), but may very well have no individual individuality as such and appear during the actual construction of the bottom of the crucible, for example at by means of refractory bricks specially shaped so as to form between them, once juxtaposed, interstices reserved for blowing gas, as described in particular in US Patent No. 2,456,798 (SLICK).
  • the source of pressurized stirring gas is not necessarily unique, but can be increased tenfold at will, and in particular as many times as the number of categories of injectors.

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Manufacturing & Machinery (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Mechanical Engineering (AREA)
  • Carbon Steel Or Casting Steel Manufacturing (AREA)
  • Treatment Of Steel In Its Molten State (AREA)
  • Crucibles And Fluidized-Bed Furnaces (AREA)
  • Manufacture And Refinement Of Metals (AREA)
  • Crystals, And After-Treatments Of Crystals (AREA)
  • Cleaning And De-Greasing Of Metallic Materials By Chemical Methods (AREA)
  • Percussion Or Vibration Massage (AREA)
EP80401900A 1980-01-09 1980-12-31 Verfahren zum Frischen einer Metallschmelze in einem Tiegel unter Aufblasen von Sauerstoff und dabei verwendeter Tiegel Expired EP0032350B1 (de)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT80401900T ATE14144T1 (de) 1980-01-09 1980-12-31 Verfahren zum frischen einer metallschmelze in einem tiegel unter aufblasen von sauerstoff und dabei verwendeter tiegel.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
LU82069A LU82069A1 (fr) 1980-01-09 1980-01-09 Procede d'affinage d'un bain de metal
LU82069 1980-01-09

Publications (3)

Publication Number Publication Date
EP0032350A2 true EP0032350A2 (de) 1981-07-22
EP0032350A3 EP0032350A3 (en) 1981-08-26
EP0032350B1 EP0032350B1 (de) 1985-07-03

Family

ID=19729324

Family Applications (1)

Application Number Title Priority Date Filing Date
EP80401900A Expired EP0032350B1 (de) 1980-01-09 1980-12-31 Verfahren zum Frischen einer Metallschmelze in einem Tiegel unter Aufblasen von Sauerstoff und dabei verwendeter Tiegel

Country Status (17)

Country Link
US (1) US4369060A (de)
EP (1) EP0032350B1 (de)
JP (1) JPS56102508A (de)
AT (1) ATE14144T1 (de)
AU (1) AU540800B2 (de)
BR (1) BR8100113A (de)
CA (1) CA1172048A (de)
CS (1) CS242866B2 (de)
DE (1) DE3070844D1 (de)
ES (1) ES498382A0 (de)
IN (1) IN154540B (de)
LU (1) LU82069A1 (de)
PL (1) PL229121A1 (de)
PT (1) PT72324B (de)
RO (1) RO81955A (de)
SU (1) SU1190993A3 (de)
ZA (1) ZA8177B (de)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4565355A (en) * 1984-03-15 1986-01-21 Voest-Alpine Aktiengesellschaft Flushing arrangement for a metallurgical vessel
US4744546A (en) * 1986-02-03 1988-05-17 Voest-Alpine Aktiengesellschaft Flushing arrangement for a metallurgical vessel
EP0347351A1 (de) * 1988-06-17 1989-12-20 Vallourec Industries Verfahren zur Behandlung von flüssigen Stählen durch Einblasen von Gas durch den Pfannenboden

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2501722B1 (fr) * 1981-03-11 1986-08-14 Siderurgie Fse Inst Rech Procede de brassage pneumatique d'un bain metallique
US4428564A (en) 1982-01-26 1984-01-31 Pennsylvania Engineering Corporation Metallurgical vessel
US4488903A (en) * 1984-03-14 1984-12-18 Union Carbide Corporation Rapid decarburization steelmaking process
US4529442A (en) * 1984-04-26 1985-07-16 Allegheny Ludlum Steel Corporation Method for producing steel in a top oxygen blown vessel
US4599107A (en) * 1985-05-20 1986-07-08 Union Carbide Corporation Method for controlling secondary top-blown oxygen in subsurface pneumatic steel refining
LU92813B1 (en) * 2015-09-02 2017-03-20 Wurth Paul Sa Enhanced pressurising of bulk material in lock hoppers
CN116007370B (zh) * 2022-12-29 2025-09-26 湖南宏拓铝业有限公司 一种废旧铝熔炼装置及其熔炼方法

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR1210459A (fr) * 1957-12-02 1960-03-09 A R B E D Procédé de fabrication d'acier et convertisseur pour ce procédé ou procédés similaires
BE609232A (fr) * 1961-10-16 1962-04-16 Centre Nat Rech Metall Perfectionnements aux procédés d'affinage de la fonte
US3854932A (en) * 1973-06-18 1974-12-17 Allegheny Ludlum Ind Inc Process for production of stainless steel
FR2322202A1 (fr) * 1975-08-29 1977-03-25 Siderurgie Fse Inst Rech Procede d'elaboration d'acier par soufflage d'oxygene
US4198230A (en) * 1977-05-04 1980-04-15 Eisenwerk-Gesellschaft Maximilianshutte Mbh Steelmaking process
US4195985A (en) * 1977-12-10 1980-04-01 Eisenwerk-Gesellschaft Maximilianshutte Mbh. Method of improvement of the heat-balance in the refining of steel
US4280838A (en) * 1979-05-24 1981-07-28 Sumitomo Metal Industries, Ltd. Production of carbon steel and low-alloy steel with bottom blowing basic oxygen furnace

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4565355A (en) * 1984-03-15 1986-01-21 Voest-Alpine Aktiengesellschaft Flushing arrangement for a metallurgical vessel
US4744546A (en) * 1986-02-03 1988-05-17 Voest-Alpine Aktiengesellschaft Flushing arrangement for a metallurgical vessel
EP0347351A1 (de) * 1988-06-17 1989-12-20 Vallourec Industries Verfahren zur Behandlung von flüssigen Stählen durch Einblasen von Gas durch den Pfannenboden
FR2632971A1 (fr) * 1988-06-17 1989-12-22 Vallourec Procede de traitement des aciers liquides par injection de gaz a travers le fond de poche
US4957542A (en) * 1988-06-17 1990-09-18 Vallourec Industries Process for treating liquid steels by injecting gas through the ladle bottom

Also Published As

Publication number Publication date
CA1172048A (fr) 1984-08-07
EP0032350B1 (de) 1985-07-03
BR8100113A (pt) 1981-07-21
ES8203973A1 (es) 1982-04-01
RO81955B (ro) 1983-06-30
AU6604681A (en) 1981-07-16
ZA8177B (en) 1982-01-27
LU82069A1 (fr) 1981-09-10
PT72324B (en) 1981-12-18
AU540800B2 (en) 1984-12-06
RO81955A (ro) 1983-07-07
CS242866B2 (en) 1986-05-15
US4369060A (en) 1983-01-18
EP0032350A3 (en) 1981-08-26
JPS56102508A (en) 1981-08-17
SU1190993A3 (ru) 1985-11-07
IN154540B (de) 1984-11-10
PT72324A (en) 1981-02-01
PL229121A1 (de) 1981-09-18
ATE14144T1 (de) 1985-07-15
ES498382A0 (es) 1982-04-01
DE3070844D1 (en) 1985-08-08

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