EP0166646B1 - Installation for the production of steel by preliminary refining of pig iron - Google Patents

Installation for the production of steel by preliminary refining of pig iron Download PDF

Info

Publication number
EP0166646B1
EP0166646B1 EP85401122A EP85401122A EP0166646B1 EP 0166646 B1 EP0166646 B1 EP 0166646B1 EP 85401122 A EP85401122 A EP 85401122A EP 85401122 A EP85401122 A EP 85401122A EP 0166646 B1 EP0166646 B1 EP 0166646B1
Authority
EP
European Patent Office
Prior art keywords
reactor
level
decanter
dephosphorizing
desiliconizing
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
EP85401122A
Other languages
German (de)
French (fr)
Other versions
EP0166646A1 (en
Inventor
Aristide Berthet
Guy Denier
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
Original Assignee
Institut de Recherches de la Siderurgie Francaise IRSID
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
Application filed by Institut de Recherches de la Siderurgie Francaise IRSID filed Critical Institut de Recherches de la Siderurgie Francaise IRSID
Priority to AT85401122T priority Critical patent/ATE36007T1/en
Publication of EP0166646A1 publication Critical patent/EP0166646A1/en
Application granted granted Critical
Publication of EP0166646B1 publication Critical patent/EP0166646B1/en
Expired legal-status Critical Current

Links

Images

Classifications

    • 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
    • C21C5/56—Manufacture of steel by other methods
    • C21C5/567—Manufacture of steel by other methods operating in a continuous way
    • 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
    • C21C1/00—Refining of pig-iron; Cast iron
    • 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
    • C21C1/00—Refining of pig-iron; Cast iron
    • C21C1/04—Removing impurities other than carbon, phosphorus or sulfur

Definitions

  • the present invention relates to the production of steel by pre-refining cast iron.
  • the oxygen refining converter is a reactor which, in principle, makes it possible to remove oxidizable elements from cast iron to very low contents, the main ones being carbon, phosphorus and silicon .
  • the main ones being carbon, phosphorus and silicon .
  • oxygen blowing from the bottom, or mixed blowing from the bottom and from the top it still seems difficult to obtain well reproducible results from one refining installation to another. .
  • the desiliconization and dephosphorization operations carried out under these conditions characterize what is now called, the pre-treatment, or more precisely the pre-refining of the cast iron.
  • the known pre-refining installations all proceed by sequential operations (desiliconization, then dephosphorization, then decarburization) on discrete and repetitive quantities of pig iron (see example GB-A-2,072,221).
  • Part of the mass of liquid pig iron to be pretreated is in fact transferred successively into several independent metallurgical vessels, more or less specialized each for the treatment phase assigned to it, or else placed in a single vessel, generally a straight pocket, which it is brought to fixed stations of successive treatments distributed in the workshop. (French patent application No. 2,439,821 to NSC).
  • the desiliconization and dephosphorization stage comprises a closed desiliconization unit and a closed dephosphorization unit each comprising a reactor separated from a settling tank by a partition comprising a communication opening below the predetermined level and the upper end of which is situated above this level and forms an overflow threshold for the slag,
  • the desiliconization reactor comprising means for introducing the pre-refining iron, means for introducing the desiliciants, and means for stirring the metal bath;
  • the dephosphorization reactor comprising means for introducing the dephosphorizing agents, means for creating an oxidizing atmosphere, and means for stirring the metal bath;
  • desiliconization and dephosphorization decanters comprising means for continuously evacuating the slag which they contain; the desiliconization decanter being connected to the dephosphorization reactor by a natural iron transfer duct while the dephosphorization decanter is connected to a submerged connecting duct communicating with the decarburization stage.
  • the installation shown in FIGS. 1 to 3 comprises a stage of desiliconization and dephosphorization constituted by a closed enclosure A in which the cast iron to be pre-refined is intended to form a molten bath AR reaching a predetermined level N, substantially constant, a stage decarburization also formed by a closed enclosure B communicating with the outlet of stage A, and a metallurgical container C provided where appropriate for nuancing the steel leaving stage B.
  • the desiliconization and dephosphorization stage A comprises a first reactor 1 and a contiguous first decanter 2 separated from each other by a first partition 3 comprising a communication opening 4 below the Ni level and the end of which upper is above it.
  • the first reactor comprises a chute 5 for introducing the liquid cast iron to be pre-refined, a pipe 6 for introducing agents for desiliconization and dephosphorization in the divided solid state, a door 7 for introducing possibly cooling additions such as scrap, pre-reduced or ore, etc ..., and a lance 8 blowing gaseous oxygen preferably technically pure to create an oxidizing atmosphere above the iron bath.
  • a chute 5 for introducing the liquid cast iron to be pre-refined
  • a pipe 6 for introducing agents for desiliconization and dephosphorization in the divided solid state
  • a door 7 for introducing possibly cooling additions such as scrap, pre-reduced or ore, etc ...
  • a lance 8 blowing gaseous oxygen preferably technically pure to create an oxidizing atmosphere above the iron bath.
  • the desiliconing agents are generally natural metal oxides such as iron or manganese ore, and the dephosphorizing agents, basic compounds such as sodium carbonate, lime or calcium carbonate, which can, if necessary, be in the form of agglomerates specially prepared and the basicity of which is adjusted to the desired value.
  • the first reactor 1 further comprises means for stirring 9 of the metal bath, these means may for example be constituted by injectors of stirring fluid such as permeable refractory elements, connected to a supply (not shown) of pressurized gas, such as nitrogen or argon for example.
  • these means may for example be constituted by injectors of stirring fluid such as permeable refractory elements, connected to a supply (not shown) of pressurized gas, such as nitrogen or argon for example.
  • the permeable refractory elements can advantageously be of the type described in European patent No. 0 021 861.
  • the first decanter 2 comprises an outlet opening 10 located below the level Ni and connected to a connecting duct 11, such as a siphon intended for naturally and continuously transferring the desiliciated and dephosphorized iron AD from the decanter to the decarburization stage B. It also comprises, above the level N ′′ and preferably in a position remote from the reactor, a scouring weir 12 for continuously discharging the slag of desiliconization and dephosphorization supplied in the reactor 1 and then passed in the calm enclosure of the decanter by overflowing above the threshold which constitutes the free upper end of the separating partition 3. A chimney 13 for extracting the fumes is also provided at the end of the decanter remote from the reactor.
  • the decarburization stage B comprises a second reactor 14 in which the bath of the decarburization iron BR is intended for forming a molten bath reaching a predetermined level N 2 , and a second decanter 15 separated from the second reactor 14 by a watertight partition 16 whose upper end is above the level N 2 .
  • the second reactor 14 comprises, in its part located below the level N 2 , an inlet opening 17 communicating with the siphon 11, and means 18 for pneumatic stirring of the bath, which may be of the type provided in the bottom of the first reactor 1. It further comprises means 19 for blowing an oxidizing gas above the iron bath which it contains, these means being for example an oxygen lance, as well as a door 21 for possibly introducing cooling materials, such as as scrap.
  • the levels N and N 2 are at the same height since the reactor 1, the decanter 2 and the reactor 14 communicate with each other according to the principle of communicating vessels. It goes without saying, however, that the level N 2 could be at a height lower than that of the level N "for example if the siphon 11 was replaced by a pipe with adjustable flow rate.
  • the second settling tank 15 As for the second settling tank 15, it comprises a weir 20 for discharging the decarburization slag, a chimney 22 for extracting the fumes, and an outlet orifice 23 intended for discharging the refined cast iron towards the shade C.
  • the silicon and phosphorus of the cast iron contained in the first reactor 1 oxidize on contact with the oxygen supplied by the ore, and the oxides produced are fixed in the slag formed by the agents of desiliconization and dephosphorization and of which the major part floating on the free surface of the molten bath.
  • This slag being produced continuously, it constantly overflows above the partition-3 3 and arrives in the first settling tank 2 to go towards the weir 12 which ensures its continuous evacuation.
  • the iron which is largely desiliconized and dephosphorized in the first reactor 1, passes continuously through the communication opening 4 of the partition 3 and thus reaches the first settling tank 2 in which the desiliconization and the dephosphorization calmly end, at the same time as the separation of the metal and the slag which were passably mixed in the reactor takes place under the combined influence of the oxidation reactions and the pneumatic stirring of the bath.
  • the siliceous and dephosphorized cast iron then flows out of the decanter 2 through the passage 10 and passes through the siphon 11 to reach the second reactor 14.
  • the metal-slag emulsion is divided slowly by gravity into two superposed phases: the refined metal which flows continuously through the outlet orifice 23 and the slag supernatant on the bath of metal and which is continuously discharged through the weir 20.
  • Figures 4 and 5 show an installation in which the desiliconization and dephosphorization stage A is divided into two adjacent and contiguous units: a desiliconization unit D and a dephosphorization unit E downstream of the desiliconization unit.
  • the desiliconization unit D comprises a reactor 24 separated from a decanter 25 by a partition 26 comprising a communication opening 27 below the level N 3 defined by the free surface of the cast iron to be refined and the upper end of which is above this level.
  • the dephosphorization unit E comprises a reactor 28 separated from a reactor 29 by a partition 30 having an opening 31 below the level N 3 and the upper end of which is above this level.
  • the desiliconization reactor 24 comprises, in its part located above the level N 3 , means 32 for introducing the pre-refined cast iron, means 33 for introducing oxidation materials of the silicon, (such as iron ore) and the agents for forming a desilicon slag and means 34 for introducing coolants if necessary, and in its part located below level N 3 , stirring means 35 such as those provided in reactors 1 and 14 of the installation shown in Figures 1 to 3.
  • the desiliconization decanter 25 comprises a weir 36 provided above the level N 3 to eliminate the slag of desiliconization, and an opening 37 located below the level N 3 and communicating with the dephosphorization reactor 28.
  • the dephosphorization reactor 28 in its part located above the level N 3 , means 38 for introducing the dephosphorization agents and means 39 to create an oxidizing atmosphere, urie door 34 'for the possible introduction of cooling materials, such as scrap metal, and in its part located below level N 3 , stirring means 40 of the metal bath.
  • the dephosphorization settling tank 29 in turn comprises a weir 41 provided above the level N 3 to eliminate the slag of dephosphorization, and an opening 42 provided below the level N 3 and communicating with a conduit 43 terminating in the reactor 14 decarburization stage B.
  • FIGS. 4 and 5 therefore differs from the previous one by its stage A in which the desiliconization and the dephosphorization are carried out one after the other in separate reactive chambers instead of being carried out at the same time in the same container.
  • the cast iron poured into the installations in accordance with the invention may be raw blast furnace cast iron or cast iron with a substantially constant silicon content coming from a mixer.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Manufacturing & Machinery (AREA)
  • Refinement Of Pig-Iron, Manufacture Of Cast Iron, And Steel Manufacture Other Than In Revolving Furnaces (AREA)
  • Steroid Compounds (AREA)
  • Transition And Organic Metals Composition Catalysts For Addition Polymerization (AREA)
  • Fertilizers (AREA)
  • Treatment Of Steel In Its Molten State (AREA)
  • Carbon Steel Or Casting Steel Manufacturing (AREA)

Abstract

Installation according to the invention comprising a desilication and dephosphorization stage (A), followed by a decarburization stage and in which the pig iron to be pre-smelted is intended to form a bath whose free surface is maintained at a predetermined level (N1). The dephosphorization comprises a reactor (1) comprising means (5, 6, 8) respectively for introducing the pig iron to be pre-smelted, for adding desilication and dephosphorization agents, and for creating an oxidizing atmosphere, as well as rabbling means (9). It also comprises a decanter (2) separated from the reactor (1) by a partition (3) having an opening (4) below the level (N1) and whose upper end is above the latter. The decanter comprises an immersed outlet opening (10) connected to the decarburization stage and an overflow (12) for evacuating the slag. The slag formed in the reactor (1) flows out in the decanter (2), overflows above the partition (3), and moves toward the overflow (12) which evacuated it.

Description

La présente invention se rapporte à l'élaboration de l'acier par préaffinage de la fonte.The present invention relates to the production of steel by pre-refining cast iron.

On sait que le convertisseur d'affinage à l'oxygène est un réacteur qui permet, en principe, d'éliminer jusqu'à des teneurs très faibles les éléments oxydables de la fonte, dont les principaux sont le carbone, le phosphore et le silicium. Cependant, malgré des progrès importants (soufflage d'oxygène par le fond, ou soufflage mixte, par le fond et par le haut), il semble toujours difficile d'obtenir des résultats bien reproductibles, d'une installation d'affinage à une autre.We know that the oxygen refining converter is a reactor which, in principle, makes it possible to remove oxidizable elements from cast iron to very low contents, the main ones being carbon, phosphorus and silicon . However, despite significant progress (oxygen blowing from the bottom, or mixed blowing from the bottom and from the top), it still seems difficult to obtain well reproducible results from one refining installation to another. .

Par ailleurs, la tendance du marché vers des nuances d'acier de plus en plus pures implique un accroissement sensible du prix de revient pour ces nuances élaborées au convertisseur, ou même, parfois, une impossibilité de pouvoir réaliser au convertisseur seul toutes les spécifications demandées.Furthermore, the market trend towards increasingly pure steel grades implies a significant increase in the cost price for these grades produced with the converter, or even, sometimes, an impossibility of being able to produce all the required specifications in the converter alone. .

On sait qu'une réponse à ces problèmes consiste à séparer dans le temps et dans l'espace les diverses opérations d'oxydation qui permettent de passer de la fonte à l'acier (désiliciation, déphosphoration, décarburation) de façon à les optimiser séparément.We know that an answer to these problems consists in separating in time and space the various oxidation operations which make it possible to pass from cast iron to steel (desiliconization, dephosphorization, decarburization) so as to optimize them separately. .

Les opérations de désiliciation et de déphosphoration menées dans ces conditions caractérisent ce que l'on dénomme désormais, le prétraite- ment, ou plus précisément le préaffinage de la fonte.The desiliconization and dephosphorization operations carried out under these conditions characterize what is now called, the pre-treatment, or more precisely the pre-refining of the cast iron.

Les installations connues de préaffinage procèdent toutes par des opérations séquentielles (désiliciation, puis déphosphoration, puis décarburation) sur des quantités de fonte discrètes et répétitives (voir exemple GB-A-2 072 221).The known pre-refining installations all proceed by sequential operations (desiliconization, then dephosphorization, then decarburization) on discrete and repetitive quantities of pig iron (see example GB-A-2,072,221).

Une partie de la masse de fonte liquide à prétraiter est en effet transvasée successivement dans plusieurs récipients métallurgiques indépendants, plus ou moins spécialisés chacun pour la phase de traitement qui lui est dévolue, ou bien placée dans un récipient unique, généralement une poche droite, que l'on amène auprès de postes fixes de traitements successifs répartis dans l'atelier. (Demande de brevet français n° 2 439 821 de NSC).Part of the mass of liquid pig iron to be pretreated is in fact transferred successively into several independent metallurgical vessels, more or less specialized each for the treatment phase assigned to it, or else placed in a single vessel, generally a straight pocket, which it is brought to fixed stations of successive treatments distributed in the workshop. (French patent application No. 2,439,821 to NSC).

Quel que soit leur type, ces installations ne donnent pas encore entière satisfaction. En particulier, les transferts de la fonte dans les différents récipients, ou d'un poste de traitement au suivant, occasionnent des temps d'attente, donc également des pertes thermiques, et bien souvent même une détérioration de la « mise au mille métal en raison des opérations de décrassages intermédiaires des laitiers d'épuration formés dans chaque phase opératoire de préaffinage. De plus, comme le fonctionnement est discontinu, chacune de ces phases est cyclique et présente de ce fait des périodes de régime transitoire qui sont malaisés à bien maîtriser et qui pénalisent l'efficacité du traitement global, et ceci même à supposer que l'ensemble des phases successives puisse être correctement coordonné dans le temps.Whatever their type, these installations are not yet entirely satisfactory. In particular, the transfers of the cast iron into the various containers, or from one treatment station to the next, cause waiting times, therefore also heat losses, and very often even a deterioration of the “setting to the thousand metal in due to the intermediate descaling operations of the slag treatment plants formed in each pre-refining operating phase. In addition, as the operation is discontinuous, each of these phases is cyclical and therefore has transient periods which are difficult to control well and which penalize the effectiveness of the overall treatment, even assuming that all successive phases can be correctly coordinated over time.

La présente invention se propose de remédier à ces inconvénients. Pour ce faire, elle a pour objet une installation pour l'élaboration de l'acier par préaffinage de la fonte, comprenant un étage de désiliciation et de déphosphoration, suivi d'un étage de décarburation, caractérisé en ce que l'étage de désiliciation et de déphosphoration est constitué par au moins une unité close formant :

  • - un réacteur dans lequel la fonte à préaffiner est destinée à former un bain dont la surface est maintenue à un niveau prédéterminé N" ledit réacteur présentant, d'une part, une partie supérieure, au-dessus du niveau N, pourvu de moyens pour introduire la fonte à préaffiner, de moyens pour introduire des agents d'oxydation du silicium et du phosphore, ainsi que des agents de formation d'un laitier de désiliciation et de déphosphoration, et de moyens pour créer une atmosphère oxydante au-dessus du bain et, d'autre part, une partie inférieure, en dessous du niveau N1, pourvue de moyens de brassage du bain métallique ;
  • - et un décanteur séparé du réacteur par une cloison comportant une ouverture de communication en dessous du niveau du bain Ni et dont l'extrémité supérieure libre, dépassant au-dessus dudit niveau N1, constitue un seuil de débordement du laitier formé dans le réacteur, ce décanteur comportant, d'une part, une ouverture de sortie située en dessous du niveau Ni et communiquant avec un conduit de liaison destiné à permettre la circulation d'un courant de fonte désiliciée et déphosphorée vers l'étage de décarburation et, d'autre part, un déversoir situé au-dessus du niveau Ni pour évacuer à l'extérieur le laitier de désiliciation et de déphosphoration décanté provenant du réacteur.
The present invention proposes to remedy these drawbacks. To do this, it relates to an installation for the production of steel by pre-refining cast iron, comprising a stage of desiliconization and dephosphorization, followed by a stage of decarburization, characterized in that the stage of desiliconization and dephosphorization consists of at least one closed unit forming:
  • a reactor in which the cast iron to be pre-refined is intended to form a bath, the surface of which is maintained at a predetermined level N ", said reactor having, on the one hand, an upper part, above the level N, provided with means for introducing the pre-refining pig iron, means for introducing oxidizing agents for silicon and phosphorus, as well as agents for forming a slag for de-siliciding and dephosphorization, and means for creating an oxidizing atmosphere above the bath and, on the other hand, a lower part, below level N 1 , provided with means for stirring the metal bath;
  • - And a decanter separated from the reactor by a partition comprising a communication opening below the level of the Ni bath and whose free upper end, protruding above said level N 1 , constitutes an overflow threshold of the slag formed in the reactor , this decanter comprising, on the one hand, an outlet opening situated below the level Ni and communicating with a connecting duct intended to allow the circulation of a stream of desiliciated and dephosphorized pig iron towards the decarburization stage and, d 'on the other hand, a spillway located above the Ni level to evacuate outside the slag desiliconization and decanted dephosphorization from the reactor.

De préférence, l'étage de décarburation est constitué par une enceinte close formant :

  • - un second réacteur dans lequel la fonte à décarburer provenant du conduit de liaison avec le décanteur est destinée à former un bain dont la surface libre est maintenue à un niveau prédéterminé N2, ce réacteur comportant une ouverture d'entrée située en dessous du niveau N2 et communiquant avec ledit conduit de liaison ainsi que des moyens situés au-dessus du niveau N2 pour insuffler un gaz oxydant de décarburation de la fonte ;
  • - et un second décanteur séparé du réacteur par une cloison étanche dont l'extrémité supérieure libre, dépassant au-dessus du niveau N2, constitue un seuil de débordement d'une émulsion métal-laitier formée dans le réacteur sous l'action de l'insufflation dudit gaz oxydant, ledit décanteur présentant un déversoir pour évacuer à l'extérieur le laitier décanté sur le bain métallique et une ouverture sous le niveau du bain métallique dans le décanteur pour la sortie d'un courant d'acier liquide.
  • . L'installation conforme à l'invention est conçue pour fonctionner en continu et peut donc avoir un rendement nettement supérieur à celui des installations actuelles. Par ailleurs, comme la fonte peut circuler librement de l'étage de désiliciation et de déphosphoration à l'étage de décarburation, les dispositifs de transfert utilisés jusqu'ici peuvent être purement et simplement supprimés, ce qui permet par conséquent une réduction appréciable des investissements.
Preferably, the decarburization stage consists of a closed enclosure forming:
  • a second reactor in which the iron to be decarburized coming from the connection pipe with the decanter is intended to form a bath the free surface of which is maintained at a predetermined level N 2 , this reactor comprising an inlet opening situated below the level N 2 and communicating with said connecting conduit as well as means situated above the level N 2 for injecting an oxidizing gas for decarburization of the cast iron;
  • - And a second decanter separated from the reactor by a watertight bulkhead whose free upper end, protruding above the level N 2 , constitutes an overflow threshold of a metal-slag emulsion formed in the reactor under the action of l insufflation of said oxidizing gas, said decanter having a weir for discharging outside the slag decanted on the metal bath and an opening below the level of the metal bath in the decanter for the exit of a stream of liquid steel.
  • . The installation according to the invention is designed to operate continuously and can therefore have a significantly higher efficiency than current installations. Furthermore, since the pig iron can circulate freely from the desiliconization and dephosphorization stage to the decarburization stage, the transfer devices used up to now can be purely and simply eliminated, which consequently allows an appreciable reduction in investments. .

Selon un mode de réalisation particulier de l'invention, l'étage de désiliciation et de déphosphoration comprend une unité close de désiliciation et une unité close de déphosphoration comportant chacune un réacteur séparé d'un décanteur par une cloison comportant une ouverture de communication au-dessous du niveau prédéterminé et dont l'extrémité supérieure est située au-dessus de ce niveau et forme un seuil de débordement du laitier, le réacteur de désiliciation comportant des moyens pour introduire la fonte à préaffiner, des moyens pour introduire les agents de désiliciation, et des moyens de brassage du bain métallique ; le réacteur de déphosphoration comportant des moyens pour introduire les agents de déphosphoration, des moyens pour créer une atmosphère oxydante, et des moyens de brassage du bain métallique ; les décanteurs de désiliciation et de déphosphoration comportant des moyens pour évacuer continûment le laitier qu'ils renferment ; le décanteur de désiliciation étant relié au réacteur de déphosphoration par un conduit de transfert naturel de la fonte tandis que le décanteur de déphosphoration est relié à un conduit de liaison immergé communiquant avec l'étage de décarburation.According to a particular embodiment of the invention, the desiliconization and dephosphorization stage comprises a closed desiliconization unit and a closed dephosphorization unit each comprising a reactor separated from a settling tank by a partition comprising a communication opening below the predetermined level and the upper end of which is situated above this level and forms an overflow threshold for the slag, the desiliconization reactor comprising means for introducing the pre-refining iron, means for introducing the desiliciants, and means for stirring the metal bath; the dephosphorization reactor comprising means for introducing the dephosphorizing agents, means for creating an oxidizing atmosphere, and means for stirring the metal bath; desiliconization and dephosphorization decanters comprising means for continuously evacuating the slag which they contain; the desiliconization decanter being connected to the dephosphorization reactor by a natural iron transfer duct while the dephosphorization decanter is connected to a submerged connecting duct communicating with the decarburization stage.

D'autres caractéristiques et avantages de la présente invention ressortiront de la description qui sera donnée ci-après à titre d'exemple nullement limitatif en référence aux dessins annexés dans lesquels :

  • - la figure 1 est une vue en plan schématique d'une installation conforme à l'invention ;
  • - la figure 2 est une vue en coupe schématique effectuée selon la ligne II-II de la figure 1 ;
  • - la figure 3 est une vue en coupe schématique effectuée selon la ligne III-III de la figure 1 ;
  • - la figure 4 est une vue en plan schématique d'une variante de l'installation représentée sur la figure 1 ;
  • - et la figure 5 est une vue en coupe schématique effectuée selon la ligne IV-IV de la figure 4.
Other characteristics and advantages of the present invention will emerge from the description which will be given below by way of nonlimiting example with reference to the appended drawings in which:
  • - Figure 1 is a schematic plan view of an installation according to the invention;
  • - Figure 2 is a schematic sectional view taken along the line II-II of Figure 1;
  • - Figure 3 is a schematic sectional view taken along the line III-III of Figure 1;
  • - Figure 4 is a schematic plan view of a variant of the installation shown in Figure 1;
  • - and Figure 5 is a schematic sectional view taken along line IV-IV of Figure 4.

L'installation représentée sur les figures 1 à 3 comprend un étage de désiliciation et de déphosphoration constituée par une enceinte close A dans laquelle la fonte à préaffiner est destinée à former un bain en fusion AR atteignant un niveau prédéterminé N, sensiblement constant, un étage de décarburation formé également par une enceinte close B communiquant avec la sortie de l'étage A, et un récipient métallurgique C prévu le cas échéant pour mettre à la nuance l'acier sortant de l'étage B.The installation shown in FIGS. 1 to 3 comprises a stage of desiliconization and dephosphorization constituted by a closed enclosure A in which the cast iron to be pre-refined is intended to form a molten bath AR reaching a predetermined level N, substantially constant, a stage decarburization also formed by a closed enclosure B communicating with the outlet of stage A, and a metallurgical container C provided where appropriate for nuancing the steel leaving stage B.

L'étage de désiliciation et de déphosphoration A comprend un premier réacteur 1 et un premier décanteur 2 contigu séparés l'un de l'autre par une première cloison 3 comportant une ouverture de communication 4 au-dessous du niveau Ni et dont l'extrémité supérieure est au-dessus de celui-ci.The desiliconization and dephosphorization stage A comprises a first reactor 1 and a contiguous first decanter 2 separated from each other by a first partition 3 comprising a communication opening 4 below the Ni level and the end of which upper is above it.

Dans sa partie supérieure au-dessus du bain métallique, le premier réacteur comporte une goulotte 5 pour introduire la fonte liquide à préaffiner, une conduite 6 pour introduire des agents de désiliciation et de déphosphoration à l'état solide divisé, une porte 7 pour introduire éventuellement des additions refroidissantes telles que des ferrailles, des pré-réduits ou du minerai, etc..., et une lance 8 soufflant de l'oxygène gazeux de préférence techniquement pur pour créer une atmosphère oxydante au-dessus du bain de fonte. Ces différents moyens étant de conception classique, on ne décrira pas leur structure. On précisera toutefois que la lance 8 pourrait fort bien être remplacée par une tuyère fixe en paroi, puisque si le bain est bien maintenu à un niveau constant Ni, la mobilité de l'injecteur d'oxygène n'est plus souhaitable.In its upper part above the metal bath, the first reactor comprises a chute 5 for introducing the liquid cast iron to be pre-refined, a pipe 6 for introducing agents for desiliconization and dephosphorization in the divided solid state, a door 7 for introducing possibly cooling additions such as scrap, pre-reduced or ore, etc ..., and a lance 8 blowing gaseous oxygen preferably technically pure to create an oxidizing atmosphere above the iron bath. These different means being of conventional design, we will not describe their structure. However, it should be noted that the lance 8 could very well be replaced by a fixed nozzle on the wall, since if the bath is well maintained at a constant level Ni, the mobility of the oxygen injector is no longer desirable.

On précisera par ailleurs à toutes fins utiles que les agents de désiliciation sont généralement des oxydes métalliques naturels tels que du minerai de fer ou de manganèse, et les agents de déphosphoration, des composés basiques tels que du carbonate de sodium, de la chaux ou du carbonate de calcium, qui peuvent, le cas échéant, se présenter sous la forme d'agglomérés préparés spécialement et dont la basicité est ajustée à la valeur souhaitée.It will also be specified for all practical purposes that the desiliconing agents are generally natural metal oxides such as iron or manganese ore, and the dephosphorizing agents, basic compounds such as sodium carbonate, lime or calcium carbonate, which can, if necessary, be in the form of agglomerates specially prepared and the basicity of which is adjusted to the desired value.

Dans sa partie située au-dessous du niveau Ni, et plus précisément dans son fond, le premier réacteur 1 comporte en outre des moyens de brassage 9 du bain métallique, ces moyens pouvant par exemple être constitués par des injecteurs de fluide de brassage tels que des éléments réfractaires perméables, reliés à une alimentation (non représentée) en gaz sous pression, tel que de l'azote ou de l'argon par exemple.In its part located below the Ni level, and more precisely in its bottom, the first reactor 1 further comprises means for stirring 9 of the metal bath, these means may for example be constituted by injectors of stirring fluid such as permeable refractory elements, connected to a supply (not shown) of pressurized gas, such as nitrogen or argon for example.

Les éléments réfractaires perméables peuvent avantageusement être du type décrit dans le brevet européen n° 0 021 861.The permeable refractory elements can advantageously be of the type described in European patent No. 0 021 861.

Le premier décanteur 2 comprend quant à lui une ouverture de sortie 10 située au-dessous du niveau Ni et reliée à un conduit de liaison 11, tel qu'un siphon destiné à transférer naturellement et en continu la fonte désiliciée et déphosphorée AD du décanteur vers l'étage de décarburation B. Il comprend également, au-dessus du niveau N" et de préférence en position éloignée du réacteur, un déversoir de décrassage 12 pour évacuer en continu le laitier de désiliciation et de déphosphoration fourni dans le réacteur 1 puis passé dans l'enceinte calme du décanteur par débordement au-dessus du seuil que constitue l'extrémité supérieure libre de la cloison séparatrice 3. Une cheminée 13 pour extraire les fumées est également prévue à l'extrémité du décanteur éloignée du réacteur.The first decanter 2 comprises an outlet opening 10 located below the level Ni and connected to a connecting duct 11, such as a siphon intended for naturally and continuously transferring the desiliciated and dephosphorized iron AD from the decanter to the decarburization stage B. It also comprises, above the level N ″ and preferably in a position remote from the reactor, a scouring weir 12 for continuously discharging the slag of desiliconization and dephosphorization supplied in the reactor 1 and then passed in the calm enclosure of the decanter by overflowing above the threshold which constitutes the free upper end of the separating partition 3. A chimney 13 for extracting the fumes is also provided at the end of the decanter remote from the reactor.

De son côté, l'étage de décarburation B comprend un second réacteur 14 dans lequel le bain de la fonte à décarburer BR est destiné à former un bain en fusion atteignant un niveau prédéterminé N2, et un second décanteur 15 séparé du second réacteur 14 par une cloison étanche 16 dont l'extrémité supérieure est au-dessus du niveau N2.For its part, the decarburization stage B comprises a second reactor 14 in which the bath of the decarburization iron BR is intended for forming a molten bath reaching a predetermined level N 2 , and a second decanter 15 separated from the second reactor 14 by a watertight partition 16 whose upper end is above the level N 2 .

Le second réacteur 14 comporte, dans sa partie située sous le niveau N2, une ouverture d'entrée 17 communiquant avec le siphon 11, et des moyens 18 de brassage pneumatique du bain pouvant être du type de ceux prévus dans le fond du premier réacteur 1. Il comporte en outre des moyens 19 pour insuffler un gaz oxydant au-dessus du bain de fonte qu'il contient, ces moyens étant par exemple une lance à oxygène, ainsi qu'une porte 21 pour introduire éventuellement des matières refroidissantes, telles que des ferrailles.The second reactor 14 comprises, in its part located below the level N 2 , an inlet opening 17 communicating with the siphon 11, and means 18 for pneumatic stirring of the bath, which may be of the type provided in the bottom of the first reactor 1. It further comprises means 19 for blowing an oxidizing gas above the iron bath which it contains, these means being for example an oxygen lance, as well as a door 21 for possibly introducing cooling materials, such as as scrap.

Dans l'exemple de réalisation représenté, les niveaux N, et N2 sont à la même hauteur puisque le réacteur 1, le décanteur 2 et le réacteur 14 communiquent entre eux selon le principe des vases communicants. Il va de soi cependant que le niveau N2 pourrait être à une hauteur inférieure à celle du niveau N" par exemple si le siphon 11 était remplacé par une conduite à débit réglable.In the embodiment shown, the levels N and N 2 are at the same height since the reactor 1, the decanter 2 and the reactor 14 communicate with each other according to the principle of communicating vessels. It goes without saying, however, that the level N 2 could be at a height lower than that of the level N "for example if the siphon 11 was replaced by a pipe with adjustable flow rate.

Quant au second décanteur 15, il comporte un déversoir 20 pour évacuer le laitier de décarburation, une cheminée 22 pour extraire les fumées, et un orifice de sortie 23 destiné à évacuer la fonte affinée vers le nuanceur C.As for the second settling tank 15, it comprises a weir 20 for discharging the decarburization slag, a chimney 22 for extracting the fumes, and an outlet orifice 23 intended for discharging the refined cast iron towards the shade C.

Pour produire de l'acier avec l'installation représentée sur les figures 1 à 3, on procède de la manière suivante :

  • - on introduit en continu dans le premier réacteur 1, de la fonte à préaffiner et des agents de désiliciation et de déphosphoration. par la goulotte 5 et la conduite 6 respectivement ;
  • - on crée une atmosphère oxydante au-dessus de ce bain en actionnant les moyens 8, et au besoin on ajoute par la porte 7 des matières refroidissantes dans le premier réacteur pour maintenir le bain métallique à la température d'élaboration voulue ;
  • - on actionne les moyens de brassage 9 et 18 des étages A et B;
  • - on insuffle par la lance 19 un débit d'02 déterminé pour assurer la décarburation de la fonte dans le second réacteur 15 ;
  • - et, le cas échéant, on ajoute des matières refroidissantes à la fonte par la porte 21 pour le réglage thermique.
To produce steel with the installation shown in Figures 1 to 3, the procedure is as follows:
  • - Is continuously introduced into the first reactor 1, the pre-refining pig iron and desiliconization and dephosphorization agents. via chute 5 and line 6 respectively;
  • - An oxidizing atmosphere is created above this bath by actuating the means 8, and if necessary, coolants are added through the door 7 to the first reactor to maintain the metal bath at the desired production temperature;
  • - the mixing means 9 and 18 of stages A and B are actuated;
  • - Is injected by the lance 19 a flow of 0 2 determined to ensure decarburization of the cast iron in the second reactor 15;
  • - And, if necessary, coolants are added to the cast iron through door 21 for thermal adjustment.

Le silicium et le phosphore de la fonte contenue dans le premier réacteur 1 s'oxydent au contact de l'oxygène apporté par le minerai, et les oxydes produits sont fixés dans le laitier formé par les agents de désiliciation et de déphosphoration et dont la majeure partie surnage à la surface libre du bain en fusion. Ce laitier étant produit en continu, il déborde constamment au-dessus de la cloison-3 3 et parvient dans le premier décanteur 2 pour se diriger vers le déversoir 12 qui assure son évacuation en continu.The silicon and phosphorus of the cast iron contained in the first reactor 1 oxidize on contact with the oxygen supplied by the ore, and the oxides produced are fixed in the slag formed by the agents of desiliconization and dephosphorization and of which the major part floating on the free surface of the molten bath. This slag being produced continuously, it constantly overflows above the partition-3 3 and arrives in the first settling tank 2 to go towards the weir 12 which ensures its continuous evacuation.

La fonte, en grande partie désiliciée et déphosphorée dans le premier réacteur 1, passe en continu par l'ouverture de communication 4 de la cloison 3 et parvient ainsi dans le premier décanteur 2 dans lequel s'achèvent calmement la désiliciation et la déphosphoration, en même temps que s'opère la séparation du métal et du laitier qui étaient passablement mélangés dans le réacteur sous l'influence conjuguée des réactions d'oxydation et du brassage pneumatique du bain.The iron, which is largely desiliconized and dephosphorized in the first reactor 1, passes continuously through the communication opening 4 of the partition 3 and thus reaches the first settling tank 2 in which the desiliconization and the dephosphorization calmly end, at the same time as the separation of the metal and the slag which were passably mixed in the reactor takes place under the combined influence of the oxidation reactions and the pneumatic stirring of the bath.

La fonte désiliciée et déphosphorée s'écoule ensuite hors du décanteur 2 par le passage 10 et traverse le siphon 11 pour parvenir dans le second réacteur 14.The siliceous and dephosphorized cast iron then flows out of the decanter 2 through the passage 10 and passes through the siphon 11 to reach the second reactor 14.

Dans celui-ci, le carbone en excès de la fonte, tout comme le silicium et le phosphore que celle-ci pourrait encore contenir, sont éliminés du bain métallique grâce à l'oxygène insufflé par la lance 19. De ce fait, le laitier de décarburation résultant et la fonte forment une émulsion qui déborde au-dessus de la seconde paroi 16 et se répand dans le second décanteur 15.In this one, the excess carbon of the pig iron, like the silicon and the phosphorus which it could still contain, are eliminated from the metal bath thanks to the oxygen blown in by the lance 19. As a result, the slag resulting decarburization and the cast iron form an emulsion which overflows above the second wall 16 and spreads into the second decanter 15.

Une fois parvenue au repos dans le second décanteur, l'émulsion métal-laitier se partage lentement par gravité en deux phases superposées : le métal affiné qui s'écoule en continu par l'orifice de sortie 23 et le laitier surnageant sur le bain de métal et qui est évacué en continu par le déversoir 20.Once at rest in the second settling tank, the metal-slag emulsion is divided slowly by gravity into two superposed phases: the refined metal which flows continuously through the outlet orifice 23 and the slag supernatant on the bath of metal and which is continuously discharged through the weir 20.

Les figures 4 et 5 représentent une installation dans laquelle l'étage de désiliciation et de déphosphoration A est divisé en deux unités adjacentes et contiguës : une unité de désiliciation D et une unité de déphosphoration E en aval de l'unité de désiliciation.Figures 4 and 5 show an installation in which the desiliconization and dephosphorization stage A is divided into two adjacent and contiguous units: a desiliconization unit D and a dephosphorization unit E downstream of the desiliconization unit.

L'unité de désiliciation D comporte un réacteur 24 séparé d'un décanteur 25 par une cloison 26 comportant une ouverture de communication 27 au-dessous du niveau N3 défini par la surface libre de la fonte à affiner et dont l'extrémité supérieure est au-dessus de ce niveau.The desiliconization unit D comprises a reactor 24 separated from a decanter 25 by a partition 26 comprising a communication opening 27 below the level N 3 defined by the free surface of the cast iron to be refined and the upper end of which is above this level.

De même, l'unité de déphosphoration E comporte un réacteur 28 séparé d'un réacteur 29 par une cloison 30 comportant une ouverture 31 au-dessous du niveau N3 et dont l'extrémité supérieure est au-dessus de ce niveau.Likewise, the dephosphorization unit E comprises a reactor 28 separated from a reactor 29 by a partition 30 having an opening 31 below the level N 3 and the upper end of which is above this level.

Le réacteur de désiliciation 24 comporte, dans sa partie située au-dessus du niveau N3, des moyens 32 pour introduire la fonte à préaffiner, des moyens 33 pour introduire des matières d'oxydation du silicium, (tel que du minerai de fer) et les agents de formation d'un laitier de désiliciation et des moyens 34 pour introduire le cas échéant des matières refroidissantes, et dans sa partie située sous le niveau N3, des moyens de brassage 35 tels que ceux prévus dans les réacteurs 1 et 14 de l'installation représentée sur les figures 1 à 3.The desiliconization reactor 24 comprises, in its part located above the level N 3 , means 32 for introducing the pre-refined cast iron, means 33 for introducing oxidation materials of the silicon, (such as iron ore) and the agents for forming a desilicon slag and means 34 for introducing coolants if necessary, and in its part located below level N 3 , stirring means 35 such as those provided in reactors 1 and 14 of the installation shown in Figures 1 to 3.

De son côté, le décanteur de désiliciation 25 comporte un déversoir 36 prévu au-dessus du niveau N3 pour éliminer le laitier de désiliciation, et une ouverture 37 située au-dessous du niveau N3 et communiquant avec le réacteur de déphosphoration 28.For its part, the desiliconization decanter 25 comprises a weir 36 provided above the level N 3 to eliminate the slag of desiliconization, and an opening 37 located below the level N 3 and communicating with the dephosphorization reactor 28.

Le réacteur de déphosphoration 28 comporte, quant à lui, dans sa partie située au-dessus du niveau N3, des moyens 38 pour introduire les agents de déphosphoration et des moyens 39 pour créer une atmosphère oxydante, urie porte 34' pour l'introduction éventuelle de matières refroidissantes, telles que des ferrailles, et dans sa partie située sous le niveau N3, des moyens de brassage 40 du bain métallique.The dephosphorization reactor 28, meanwhile, in its part located above the level N 3 , means 38 for introducing the dephosphorization agents and means 39 to create an oxidizing atmosphere, urie door 34 'for the possible introduction of cooling materials, such as scrap metal, and in its part located below level N 3 , stirring means 40 of the metal bath.

Le décanteur de déphosphoration 29 comporte à son tour un déversoir 41 prévu au-dessus du niveau N3 pour éliminer le laitier de déphosphoration, et une ouverture 42 prévue au-dessous du niveau N3 et communiquant avec un conduit 43 aboutissant dans le réacteur 14 de l'étage de décarburation B.The dephosphorization settling tank 29 in turn comprises a weir 41 provided above the level N 3 to eliminate the slag of dephosphorization, and an opening 42 provided below the level N 3 and communicating with a conduit 43 terminating in the reactor 14 decarburization stage B.

L'installation représentée sur les figures 4 et 5 se différencie donc de la précédente par son étage A dans lequel la désiliciation et la déphosphoration sont conduites l'une après l'autre dans des enceintes réactives séparées au lieu d'être réalisées en même temps dans le même récipient.The installation shown in FIGS. 4 and 5 therefore differs from the previous one by its stage A in which the desiliconization and the dephosphorization are carried out one after the other in separate reactive chambers instead of being carried out at the same time in the same container.

Bien que le fonctionnement de cette installation paraîtra évident pour l'homme de l'art, on précisera que :

  • - le laitier de désiliciation formé dans le réacteur 24 s'écoule dans le décanteur 25 en débordant au-dessus de la cloison 26 et en est évacué continûment par le déversoir 36 ;
  • - le laitier de déphosphoration formé dans le réacteur 28 s'écoule dans le décanteur 29 en débordant au-dessus de la cloison 30 et en est évacué continûment par le déversoir 41 ;
  • - le décanteur 25 contient de la fonte désiliciée qui circule en continu vers le réacteur 28 en empruntant le passage de communication 37 ;
  • - le décanteur 29 contient de la fonte désiliciée et déphosphorée qui circule en continu vers l'étage de décarburation B en empruntant le passage de communication 43.
Although the operation of this installation will appear obvious to those skilled in the art, it will be noted that:
  • - The desilicon slag formed in the reactor 24 flows into the decanter 25 overflowing above the partition 26 and is continuously discharged therefrom through the weir 36;
  • - The dephosphorization slag formed in the reactor 28 flows into the decanter 29 overflowing above the partition 30 and is continuously discharged therefrom by the weir 41;
  • - the settling tank 25 contains desiliconized iron which circulates continuously towards the reactor 28 via the communication passage 37;
  • the decanter 29 contains siliceous and dephosphorized cast iron which circulates continuously towards the decarburization stage B by taking the communication passage 43.

Quant à l'étage de décarburation B, ses caractéristiques techniques et fonctionnelles sont bien entendu les mêmes que celles décrites en référence aux figures 1, 2 et 3.As for the decarburization stage B, its technical and functional characteristics are of course the same as those described with reference to Figures 1, 2 and 3.

Il peut être prévu, pour réduire les pertes en fer par les laitiers, de recycler le laitier de déphosphoration, ou du moins une partie, dans le réacteur de désiliciation.Provision may be made, in order to reduce the losses of iron by the slags, to recycle the dephosphorization slag, or at least a part, in the desiliconization reactor.

Pour être complet, on précisera que la fonte déversée dans les installations conformes à l'invention peut être de la fonte brute de haut fourneau ou de la fonte à teneur en silicium sensiblement constante provenant d'un mélangeur.To be complete, it will be specified that the cast iron poured into the installations in accordance with the invention may be raw blast furnace cast iron or cast iron with a substantially constant silicon content coming from a mixer.

Claims (8)

1. An installation for the production of steel by preliminary refining of pig iron comprising a desiliconizing and dephosphorizing stage followed by a decarburization stage, characterized in that the desiliconizing and dephosphorizing stage is constituted by at least one closed unit (A) forming :
- a reactor (1) in which the pig iron to be preliminarly refined is intended to form a bath whose surface is maintained at a predetermined level N1. said reactor having, on the one hand, an upper portion, above level N" provided with means (5) for introducing the pig iron to be preliminarily refined, means (6) for introducing silicon and phosphorus oxidizing agents, and agents for forming a desiliconizing and dephosphorizing slag, and means (8) for creating an oxidizing atmosphere above the bath and, on the other hand, a lower portion, below level N1, provided with means (9) for stirring the molten metal bath ;
- and a decanter (2) separated from the reactor (1) by a partition (3) comprising a communication opening (4) below the bath level N, and whose free upper end, protruding above said level N1, constitutes an overflow threshold for the slag formed in the reactor (1), said decanter comprising, on the one hand, a discharge opening (10) located below level N, and communicating with a connecting pipe (11) intended to permit circulation of a current of desiliconized and dephosphorized pig iron toward the decarburization stage and, on the other hand, an outlet (12) located above level N, for evacuating to the outside the decanted desiliconizing and dephosphorizing slag coming from the reactor (1).
2. An installation according to claim 1, characterized in that the decarburization stage is constituted by an enclosure (B) forming :
- a second reactor (14) in which the pig iron to be decarburized coming from the pipe (11) connecting the decanter (2) is intended to form a bath whose free surface is maintained at a predetermined level N2, said reactor comprising an intake opening (17) located below level N2 and communicating with said connecting pipe (11) as well as means (19) located above level N2 for top-blowing an oxidizing gas for decarburizing the pig iron ;
- and a second decanter (15) separated from the reactor (14) by an impervious partition (16) whose free upper end, protruding above level N2, constitutes an overflow threshold for a metal-slag emulsion formed in the reactor (14) by the action of the top-blowing of said oxidizing gas, said decanter (15) having an outlet (20) for evacuating to the outside the slag decanted on the molten metal bath and an opening (23) below the level of the molten metal bath in the decanter for discharging a current of liquid steel.
3. An installation according to claim 2, characterized in that the decarburization reactor (14) comprises means (18) for stirring the molten metal bath.
4. An installation according to claim 1 or 3, characterized in that the stirring means (9) of the reactor (1) of the desiliconizing and dephosphorizing stage and/or the stirring means (18) of the reactor (14) of the decarburization stage are constituted by permeable refractory elements housed in the bottoms of said reactors and connected to a supply of stirring gas.
5. An installation according to claim 1, characterized in that the desiliconizing and decarburization stage is constituted by a closed desiliconizing unit (D) and by a closed dephosphorizing unit (E), each unit comprising a reactor (24, 28) separated from a decanter (25, 29) by a partition (26, 30) comprising a communication opening (27, 31) below the predetermined level (N2) and whose upper end is located above this level and forms an overflow threshold ; in that the desiliconizing reactor (24) comprises means (32) for introducing the pig iron to be refined, means (33) for introducing desiliconizing agents, and stirring means (35), in that the dephosphorizing reactor (28) comprises means (38) for introducing dephosphorizing agents, means (39) for creating an oxidizing atmosphere, and means (40) for stirring the molten metal bath ; in that the desiliconizing and dephosphorizing decanters (25, 29) comprise means (36, 41) for evacuating the slag they obtain ; and in that the desiliconizing decanter (25) is connected to the dephosphorizing reactor (28) by a natural transfer pipe (37) while the dephosphorizing decanter (29) is connected to an immersed connecting pipe (42) communicating with the decarburization stage (B).
6. An installation according to any of the above claims, characterized in that the desiliconizing and dephosphorizing stage (A) and/or the decarburization stage (B) are provided with means (7, 21 ; 34, 21) for introducing into their respective reactors cooling additions ; in particular in the form of scrap.
7. An installation according to any of the above claims, characterized in that the means (5, 32) for introducing the pig iron into the desiliconizing and dephosphorizing stage (A) are connected to the outlet of a mixer delivering pig iron with a substantially constant silicon content.
8. An installation according to any of the above claims, characterized in that it also comprises a metallurgical vessel (C) for grading the produced steel, connected to the outlet of the decarburization stage (B).
EP85401122A 1984-06-22 1985-06-07 Installation for the production of steel by preliminary refining of pig iron Expired EP0166646B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT85401122T ATE36007T1 (en) 1984-06-22 1985-06-07 DEVICE FOR MAKING STEEL BY PRE-REFILLING PIG IRON.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR8409819A FR2566427B1 (en) 1984-06-22 1984-06-22 PLANT FOR THE PREPARATION OF STEEL BY CAST IRON
FR8409819 1984-06-22

Publications (2)

Publication Number Publication Date
EP0166646A1 EP0166646A1 (en) 1986-01-02
EP0166646B1 true EP0166646B1 (en) 1988-07-27

Family

ID=9305314

Family Applications (1)

Application Number Title Priority Date Filing Date
EP85401122A Expired EP0166646B1 (en) 1984-06-22 1985-06-07 Installation for the production of steel by preliminary refining of pig iron

Country Status (7)

Country Link
US (1) US4627601A (en)
EP (1) EP0166646B1 (en)
JP (1) JPS6176607A (en)
AT (1) ATE36007T1 (en)
BR (1) BR8502988A (en)
DE (1) DE3563982D1 (en)
FR (1) FR2566427B1 (en)

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
IT1201815B (en) * 1986-09-25 1989-02-02 Danieli Off Mecc TRANSFORMATION PLANT OF A METAL CHARGE IN SEMIPRODUCTS AND RELATED MELTING AND CASTING PROCESS
US5301620A (en) * 1993-04-01 1994-04-12 Molten Metal Technology, Inc. Reactor and method for disassociating waste
US5555822A (en) * 1994-09-06 1996-09-17 Molten Metal Technology, Inc. Apparatus for dissociating bulk waste in a molten metal bath
US5733358A (en) * 1994-12-20 1998-03-31 Usx Corporation And Praxair Technology, Inc. Process and apparatus for the manufacture of steel from iron carbide
WO2021176024A1 (en) * 2020-03-05 2021-09-10 Saint-Gobain Centre De Recherches Et D'etudes Europeen Dephosphorization slag
KR102546043B1 (en) * 2022-12-07 2023-06-22 주식회사 부력에너지 Line illumination structure for easy converter replacement

Family Cites Families (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1027601A (en) * 1962-04-16 1966-04-27 Loire Atel Forges Method and apparatus for producing steel from pig iron
FR1430784A (en) * 1964-05-04 1966-03-04 Centre Nat Rech Metall Process and device for refining cast iron, as well as steels, metals and slag obtained by said process or similar process
US3809379A (en) * 1970-04-21 1974-05-07 Alsacienne Atom Installation for the treatment and movement of liquid metals
JPS5147135B2 (en) * 1972-10-11 1976-12-13
US4140521A (en) * 1973-01-22 1979-02-20 Galnbek Arnold A Method of continuously converting metallurgical melts
US4084959A (en) * 1976-12-15 1978-04-18 Nippon Steel Corporation Method for continuous refining of a molten iron base metal
US4295882A (en) * 1978-10-24 1981-10-20 Nippon Steel Corporation Steel making process
AU6823981A (en) * 1980-03-21 1981-10-15 Nippon Steel Corporation Multi-stage steel making
AU532932B2 (en) * 1981-03-30 1983-10-20 Nippon Steel Corporation Post-refining of basic oxygen steel
US4457777A (en) * 1981-09-07 1984-07-03 British Steel Corporation Steelmaking
JPS5913008A (en) * 1982-07-13 1984-01-23 Nippon Steel Corp Method for extremely reducing phosphorus in low silicon molten iron

Also Published As

Publication number Publication date
US4627601A (en) 1986-12-09
DE3563982D1 (en) 1988-09-01
JPS6176607A (en) 1986-04-19
FR2566427A1 (en) 1985-12-27
FR2566427B1 (en) 1989-10-13
ATE36007T1 (en) 1988-08-15
EP0166646A1 (en) 1986-01-02
BR8502988A (en) 1986-03-04

Similar Documents

Publication Publication Date Title
KR100417503B1 (en) Operation method and device of double container arc
EP0166646B1 (en) Installation for the production of steel by preliminary refining of pig iron
RU2152437C1 (en) Process of metallurgical treatment of iron-carrying material and steel melting furnace
EP0110809B1 (en) Process and installation for the treatment of steel in the ladle
US2862810A (en) Process and apparatus for reducing the silicon content and increasing the temperature of molten pig iron
UA41448C2 (en) Iron smelting process and plant according smelting process
US4093452A (en) Refining liquid metal
US4052197A (en) Process for making steel from pig iron
PL184546B1 (en) Method of and smelting tank for obtaining steel of high cr content and/or ferroalloys
JPH086131B2 (en) Metal melt processing method and apparatus for carrying out the method
US4094495A (en) Method and apparatus for the production of quality steels
LU84213A1 (en) DEVICE FOR DRAINING METALLURGICAL CONTAINERS
US4199350A (en) Method for the production of quality steels
KR100887132B1 (en) Method for Tapping Molten Steel in Converter
RU2156811C1 (en) Method for preparing iron-carbon melt at making steel
JP3278071B2 (en) Molten metal processing method
RU2289630C2 (en) Melt metal bath metallurgical processing method
FR2671563A1 (en) Process for metallurgical treatments
JPH0741875A (en) Method and apparatus for refining molten metal
FR2463188A1 (en) PROCESS AND CUBILOT FOR THE INTRODUCTION OF TREATMENT PRODUCTS IN CAST IRON LIQUID
BE543585A (en)
JPH0435522B2 (en)
JPS60138389A (en) Method of simultaneously supplying cast iron molten metal ofdifferent kind
Pulvermacher et al. Production of high-chrome steel using vacuum metallurgical technology
BE834767A (en) PROCESS FOR ENRICHING FERRO-ALLOYS WITH NON-FERROUS ELEMENTS SUCH AS NICKEL AND / OR COBALT

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Designated state(s): AT BE DE GB IT LU NL SE

17P Request for examination filed

Effective date: 19860616

17Q First examination report despatched

Effective date: 19871110

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): AT BE DE GB IT LU NL SE

REF Corresponds to:

Ref document number: 36007

Country of ref document: AT

Date of ref document: 19880815

Kind code of ref document: T

REF Corresponds to:

Ref document number: 3563982

Country of ref document: DE

Date of ref document: 19880901

ITF It: translation for a ep patent filed

Owner name: ING. DR. LAZZARO MARTINI S.R.L.

GBT Gb: translation of ep patent filed (gb section 77(6)(a)/1977)
PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed
PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 19910424

Year of fee payment: 7

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: SE

Payment date: 19910521

Year of fee payment: 7

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: BE

Payment date: 19910605

Year of fee payment: 7

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: LU

Payment date: 19910607

Year of fee payment: 7

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 19910612

Year of fee payment: 7

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: AT

Payment date: 19910614

Year of fee payment: 7

ITTA It: last paid annual fee
PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: NL

Payment date: 19910630

Year of fee payment: 7

EPTA Lu: last paid annual fee
PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LU

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 19920607

Ref country code: GB

Effective date: 19920607

Ref country code: AT

Effective date: 19920607

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: SE

Effective date: 19920608

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: BE

Effective date: 19920630

BERE Be: lapsed

Owner name: INSTITUT DE RECHERCHES DE LA SIDERURGIE FRANCAISE

Effective date: 19920630

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: NL

Effective date: 19930101

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 19920607

NLV4 Nl: lapsed or anulled due to non-payment of the annual fee
PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Effective date: 19930302

EUG Se: european patent has lapsed

Ref document number: 85401122.8

Effective date: 19930109