EP0422192B1 - Process for coating a metallurgical container with a purifying layer and composition relating thereto, and protective coating thus obtained - Google Patents

Process for coating a metallurgical container with a purifying layer and composition relating thereto, and protective coating thus obtained Download PDF

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Publication number
EP0422192B1
EP0422192B1 EP90907138A EP90907138A EP0422192B1 EP 0422192 B1 EP0422192 B1 EP 0422192B1 EP 90907138 A EP90907138 A EP 90907138A EP 90907138 A EP90907138 A EP 90907138A EP 0422192 B1 EP0422192 B1 EP 0422192B1
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Prior art keywords
composition
use according
alkaline
lining
coating
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EP90907138A
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German (de)
French (fr)
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EP0422192A1 (en
Inventor
Jean-Charles Daussan
Gérard Daussan
André Daussan
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Daussan SAS
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Daussan SAS
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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D41/00—Casting melt-holding vessels, e.g. ladles, tundishes, cups or the like
    • B22D41/02—Linings

Definitions

  • the present invention relates to a process for coating a metallurgical container, such as a tundish or ladle, with a purifying coating.
  • the present invention also relates to a use, for the implementation of the above process, of a composition known per se.
  • purifying coating is meant a coating capable of reducing pollution of the liquid metal by impurities such as oxides.
  • means are currently used such as pouring tubes interposed between the ladle and the tundish and covering powders disposed on the surface of the molten metal.
  • DE-C-966 136 discloses a method for producing a basic insulating-refractory brick having a porosity greater than 45%, by compression and baking of a raw mass containing a natural carbonate.
  • a base mass comprising a large proportion of fine-grained constituents, such as chromite, magnesia, zirconia, etc., is mixed with a coarser particle size carbonate containing approximately 50% by weight of CO2, then , if necessary after forming, the base mass is cooked, until a sintering or a ceramic bond is obtained.
  • Such a brick is adapted to be placed between the metal frame of a furnace and the basic refractory lining of this furnace. It is not suitable for being brought into contact with molten metal.
  • JP-A- 86-33743 also discloses a refractory material in the form of plates comprising two layers, an interior purifying layer of limestone material containing at least 10% by weight of CaO or CO3 Ca or the mixture of two, and an outer layer in contact with the permanent coating and containing at least 80% MgO.
  • coatings for metallurgical vessels in particular pouring distributors, obtained by spraying a composition in the form of aqueous mud containing refractory particles, such as SiO2, Al2O3, MgO or a mixture thereof, and an organic or inorganic binder. These particles sinter under the effect of the heat of the liquid metal poured into the container, which ensures the cohesion of the coating.
  • refractory particles such as SiO2, Al2O3, MgO or a mixture thereof
  • organic or inorganic binder such as silicad silicates
  • Coatings obtained by applying raw dolomite or calcium carbonate are also known.
  • Such coatings have purifying properties with respect to liquid metal. These properties are mainly based on the greed of CaO for oxides which pollute the metal such as Al2O3, FeO, Fe2O3, giving compounds which are more fusible than the constituents and which migrate towards the slag.
  • aqueous mixture comprising approximately 98% of raw dolomite and 2% of sodium silicate as a binder.
  • the coating was fully baked to around 900 ° C, in order to release the CO2 from the dolomite.
  • the coating thus cooked had a porous structure whose mechanical strength was insufficient to resist the abrasion caused by the liquid metal.
  • the Applicant has continued its research in order to discover an industrially acceptable solution making it possible to produce a purifying coating from raw dolomite or calcite.
  • the object of the present invention is precisely to propose a process for producing such a purifying coating, and a use of a known composition for the implementation of this process.
  • the invention thus relates to a method for coating the interior wall of a metallurgical container for transferring liquid metal with a purifying coating based on at least one oxide of an alkaline earth metal.
  • a composition comprising at least one simple or multiple carbonate of alkaline earth metal added of a predetermined proportion of refractory grain, this composition being capable of setting and sintering in contact with the liquid metal.
  • the composition may also contain a certain proportion of either alkaline earth hydroxides or alkaline earth oxides capable of hydrating during wetting of the composition and of activating lime or magnesia sufficiently "in situ" during preheating said composition, again with the aim of imparting sufficient resistance to the coating.
  • the process according to the invention thus makes it possible to obtain an economical purifying coating since it uses as starting material one or more alkaline earth carbonates such as dolomite or calcite.
  • the coating obtained has good resistance to erosion caused by the metal poured into the metallurgical vessel.
  • the coating according to the invention has a double function, namely the purifying function and the function of wear coating, so that it can advantageously replace all the wear and protective coatings applied so far which do not have no purifying function.
  • the merit of the present invention lies in the fact that it has surprisingly discovered that the addition of a certain proportion of refractory material to one or more simple or multiple alkaline earth carbonates made it possible to obtain, after baking, that is to say after the elimination of CO2, a structure having an erosion resistance markedly greater than that obtained in the absence of this refractory material.
  • the coating obtained in addition to its purifying properties due to the alkaline earth oxide which is obtained after baking, has a structure which is sufficiently porous to give it thermal insulation properties making it possible to limit the cooling of the liquid metal contained in the pouring container.
  • the coating obtained according to the process according to the invention does not adhere strongly to the permanent refractory coating to which it is applied so that at the end of casting, it can be easily removed in order to apply a new coating .
  • composition can advantageously be sprayed in the form of aqueous mud, with approximately 15 to 20% by weight of water.
  • the composition can also be poured between the interior surface of the metallurgical container and a wall forming a mold.
  • the coating is heated to the core around 900 ° C, to release the CO2 of the alkaline earth carbonate and optionally the water of constitution and / or hydration.
  • This heating can be carried out by any means such as a burner, electric heating elements by Joule effect or with emission of infrared radiation.
  • the single or multiple alkaline earth carbonate used in the composition is preferably a carbonate chosen from the following compounds: raw dolomite, raw calcite and their mixtures, dolomite being however preferred because of its low cost in the raw state (not calcined).
  • the composition used preferably contains a binder chosen from mineral binders such as, for example: alkali metal silicate or phosphate, organic such as, for example, phenolic resin, hydraulic, such as, for example, cements, and mixtures thereof.
  • mineral binders such as, for example: alkali metal silicate or phosphate
  • organic such as, for example, phenolic resin
  • hydraulic such as, for example, cements, and mixtures thereof.
  • the refractory material added to the alkaline earth carbonate is preferably chosen from the following compounds: - calcined dolomite, lime, magnesia, chromium magnesia, chromium oxide, zirconium silicate, silica, silico-aluminous and / or mixtures thereof.
  • the presence of the binder is not compulsory, because a setting effect with water already exists in its absence.
  • the alkaline earth carbonate can be pure carbonate of calcium or associated with another carbonate, for example magnesium carbonate, in the form of dolomite.
  • alkaline earth oxides cited as examples of refractory material may be replaced in whole or in part by hydroxides and / or sulfates, the latter being transformed into oxides during cooking.
  • the grains of the refractory material have at least in part a dimension greater than that of the grains of carbonates and / or hydroxides and / or alkaline earth sulfates.
  • the particle size can be adjusted as a function of the desired result, namely the porosity which gives insulating and / or sintering properties which ensures cohesion and resistance to erosion.
  • composition according to the invention also preferably contains up to 20% by weight of organic and / or mineral fibers.
  • composition according to the invention may also contain a carbonaceous matter in grains.
  • the composition additionally contains up to 5% by weight of a surfactant.
  • the aforementioned composition can be applied to the bottom and the lateral faces of a tundish, by spraying or molding in one or more layers a few centimeters thick.
  • a flux which migrates towards the surface with water during drying such as boric acid, for example, to obtain a rapid sintering of the surface which comes into contact with liquid steel, and seek a slower or less active sintering in the mass of the purifying coating thanks to a flux which does not migrate such as, for example, colemanite.
  • composition and the grain size of the grains can vary from one layer to another depending on the desired properties.
  • the inner layer (the one intended to come into contact with the liquid metal) to have a high resistance to erosion, it will contain more refractory material, and will contain fine particles to promote sintering.
  • the outer layer adjacent to the permanent refractory lining may be sinter less than the inner layer, so that it can be easily detached from the permanent lining at the end of casting.
  • the basicity of the inner layer may be favored by a high calcium content in order to obtain optimal purifying properties.
  • first purifying inner layer a second layer which is little or very little sinterable or not sinterable, and a third outer sinterable layer or at least partially sinterable.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Ceramic Products (AREA)
  • Furnace Housings, Linings, Walls, And Ceilings (AREA)
  • Paints Or Removers (AREA)

Abstract

A composition containing an alkaline-earth metal carbonate together with a certain concentration of refractory grain material is applied to the inner wall of a metallurgical container. Said coating is then heated so as to eliminate the CO2 and obtain an oxide layer of said alkaline-earth metal with a porous structure. The concentration of refractory material is sufficient to ensure that the coating is able to withstand the erosion of the liquid metal cast in the container. Use: for obtaining a purifying coating with a high resistance to erosion.

Description

La présente invention concerne un procédé pour revêtir un récipient métallurgique, tel que répartiteur de coulée ou poche de coulée, par un revêtement épurant.The present invention relates to a process for coating a metallurgical container, such as a tundish or ladle, with a purifying coating.

La présente invention concerne également une utilisation, pour la mise en oeuvre du procédé ci-dessus, d'une composition connue par elle-même.The present invention also relates to a use, for the implementation of the above process, of a composition known per se.

Par revêtement épurant on entend un revêtement capable de réduire la pollution du métal liquide par des impuretés telles que des oxydes.By purifying coating is meant a coating capable of reducing pollution of the liquid metal by impurities such as oxides.

Pour limiter l'oxydation du métal liquide, on a actuellement recours à des moyens tels que des tubes de coulée intercalés entre la poche de coulée et le répartiteur de coulée et des poudres de couverture disposées à la surface du métal liquide.To limit the oxidation of the liquid metal, means are currently used such as pouring tubes interposed between the ladle and the tundish and covering powders disposed on the surface of the molten metal.

Ces moyens ne permettent toutefois pas de réduire complètement la pollution du bain de métal.However, these means do not make it possible to completely reduce the pollution of the metal bath.

On connaît, d'après le DE-C- 966 136, un procédé pour réaliser une brique isolante-réfractaire basique présentant une porosité supérieure à 45 %, par compression et cuisson d'une masse crue contenant un carbonate naturel. Selon ce procédé, on mélange une masse de base comprenant une proportion importante de constituants à grains fins, telle que chromite, magnésie, zircone, etc..., avec un carbonate de granulométrie plus grossière contenant environ 50 % en poids de CO₂, puis, le cas échéant après formage, on cuit la masse de base, jusqu'à obtenir un frittage ou une liaison céramique.DE-C-966 136 discloses a method for producing a basic insulating-refractory brick having a porosity greater than 45%, by compression and baking of a raw mass containing a natural carbonate. According to this method, a base mass comprising a large proportion of fine-grained constituents, such as chromite, magnesia, zirconia, etc., is mixed with a coarser particle size carbonate containing approximately 50% by weight of CO₂, then , if necessary after forming, the base mass is cooked, until a sintering or a ceramic bond is obtained.

Une telle brique est adaptée à être placée entre l'armature métallique d'un four et le revêtement réfractaire basique de ce four. Elle n'est pas adaptée à être mise en contact avec du métal fondu.Such a brick is adapted to be placed between the metal frame of a furnace and the basic refractory lining of this furnace. It is not suitable for being brought into contact with molten metal.

On connaît en outre, d'après le JP-A- 86-33743 un matériau réfractaire en forme de plaques comportant deux couches, une couche intérieure épurante en matériau calcaire contenant au moins 10 % en poids de CaO ou CO₃ Ca ou le mélange des deux, et une couche extérieure en contact avec le revêtement permanent et contenant au moins 80 % de MgO.JP-A- 86-33743 also discloses a refractory material in the form of plates comprising two layers, an interior purifying layer of limestone material containing at least 10% by weight of CaO or CO₃ Ca or the mixture of two, and an outer layer in contact with the permanent coating and containing at least 80% MgO.

On sait que la mise en place de ces plaques à l'intérieur d'un répartiteur chaud constitue un travail à la fois délicat et pénible étant donné les températures élevées rencontrées.It is known that the installation of these plates inside a hot distributor is both delicate and painful work given the high temperatures encountered.

On connaît de plus des revêtements pour récipients métallurgiques, en particulier de répartiteurs de coulée, obtenus par projection d'une composition sous forme de boue aqueuse renfermant des particules réfractaires, telles que SiO₂, Al₂O₃, MgO ou un mélange de celles-ci, et un liant organique ou inorganique. Ces particules frittent sous l'effet de la chaleur du métal liquide coulé dans le récipient, ce qui assure la cohésion du revêtement. Toutefois, de tels revêtements ne possèdent pas de fonction épurante à l'égard du métal liquide, certains étant même polluants.Also known are coatings for metallurgical vessels, in particular pouring distributors, obtained by spraying a composition in the form of aqueous mud containing refractory particles, such as SiO₂, Al₂O₃, MgO or a mixture thereof, and an organic or inorganic binder. These particles sinter under the effect of the heat of the liquid metal poured into the container, which ensures the cohesion of the coating. However, such coatings do not have a purifying function with respect to the liquid metal, some being even polluting.

On connaît par ailleurs, un revêtement obtenu par application de dolomie cuite, c'est-à-dire essentiellement de CaO et de MgO sous forme de grains mélangés avec un liant tel que par exemple une résine thermodurcissable.There is also known a coating obtained by applying baked dolomite, that is to say essentially CaO and MgO in the form of grains mixed with a binder such as for example a thermosetting resin.

On connaît également des revêtements obtenus par application de dolomie crue ou de carbonate de calcium.Coatings obtained by applying raw dolomite or calcium carbonate are also known.

Après application de ces revêtements, ceux-ci subissent un chauffage qui décompose le carbonate et/ou le liant. Il reste ainsi une couche poreuse constituée essentiellement de CaO et/ou de MgO ayant une densité inférieure à 1.After application of these coatings, they undergo heating which decomposes the carbonate and / or the binder. There thus remains a porous layer essentially consisting of CaO and / or MgO having a density of less than 1.

De tels revêtements possèdent des propriétés épurantes vis-à-vis du métal liquide. Ces propriétés sont principalement basées sur l'avidité de CaO pour des oxydes qui polluent le métal tels que Al₂O₃, FeO, Fe₂O₃, en donnant des composés qui sont plus fusibles que les constituants et qui migrent vers la scorie.Such coatings have purifying properties with respect to liquid metal. These properties are mainly based on the greed of CaO for oxides which pollute the metal such as Al₂O₃, FeO, Fe₂O₃, giving compounds which are more fusible than the constituents and which migrate towards the slag.

Toutefois ces revêtements présentent l'inconvénient d'avoir une très faible résistance mécanique, de sorte qu'ils ne résistent pas à l'abrasion causée par le métal liquide.However, these coatings have the drawback of having very low mechanical strength, so that they do not resist the abrasion caused by the liquid metal.

Pour remédier à ces inconvénients, la demanderesse a réalisé les deux essais suivants :To remedy these drawbacks, the applicant has carried out the following two tests:

Dans un premier essai, la demanderesse a appliqué dans un répartiteur de coulée un mélange aqueux comprenant environ 98% de dolomie crue et 2% de silicate de sodium en tant que liant.In a first test, the applicant applied in an pouring distributor an aqueous mixture comprising approximately 98% of raw dolomite and 2% of sodium silicate as a binder.

Après projection, le revêtement a été cuit à coeur jusqu'à environ 900°C, de façon à libérer le CO₂ de la dolomie.After spraying, the coating was fully baked to around 900 ° C, in order to release the CO₂ from the dolomite.

Le revêtement ainsi cuit présentait une structure poreuse dont la résistance mécanique était insuffisante pour résister à l'abrasion engendrée par le métal liquide.The coating thus cooked had a porous structure whose mechanical strength was insufficient to resist the abrasion caused by the liquid metal.

Dans un second essai, la demanderesse a coulé le mélange précité dans l'espace compris entre la paroi intérieure du répartiteur de coulée et une paroi formant moule.In a second test, the applicant poured the above mixture into the space between the inner wall of the tundish and a wall forming a mold.

Après séchage à 180°C, il a été constaté que le revêtement ne présentait aucune résistance mécanique interne et se détruisait lors du retrait de la paroi formant moule de sorte que ce mode opératoire ne présente aucun intérêt industriel.After drying at 180 ° C, it was found that the coating had no internal mechanical resistance and was destroyed when the wall was removed forming a mold so that this procedure is of no industrial interest.

La demanderesse a poursuivi ses recherches afin de découvrir une solution industriellement acceptable permettant de réaliser un revêtement épurant à partir de dolomie crue ou de calcite.The Applicant has continued its research in order to discover an industrially acceptable solution making it possible to produce a purifying coating from raw dolomite or calcite.

Le but de la présente invention est précisément de proposer un procédé pour la réalisation d'un tel revêtement épurant, et une utilisation d'une composition connue pour la mise en oeuvre de ce procédé.The object of the present invention is precisely to propose a process for producing such a purifying coating, and a use of a known composition for the implementation of this process.

L'invention vise ainsi un procédé pour revêtir la paroi intérieure d'un récipient métallurgique de transvasement de métal liquide par un revêtement épurant à base d'au moins un oxyde d'un métal alcalino-terreux.The invention thus relates to a method for coating the interior wall of a metallurgical container for transferring liquid metal with a purifying coating based on at least one oxide of an alkaline earth metal.

Suivant l'invention, ce procédé est caractérisé par les étapes suivantes :

  • on applique sur la paroi intérieure du récipient une composition renfermant au moins un carbonate simple ou multiple de métal alcalino-terreux additionné d'une proportion prédéterminée de matière réfractaire en grains, cette composition étant susceptible de faire prise, et
  • on chauffe ce revêtement pour éliminer le CO₂ et éventuellement l'eau de constitution et/ou d'hydratation et obtenir une couche de structure poreuse du ou des oxydes de métal alcalino-terreux et de matière réfractaire en grains, la proportion de matière réfractaire étant prédéterminée pour conférer au revêtement une résistance prédéterminée à l'érosion du métal liquide coulé dans le récipient par suite du frittage de ce revêtement au contact du métal liquide.
According to the invention, this process is characterized by the following stages:
  • a composition is applied to the inner wall of the container containing at least one simple or multiple carbonate of alkaline earth metal added with a predetermined proportion of refractory grains, this composition being capable of setting, and
  • this coating is heated to remove the CO₂ and possibly the water of constitution and / or hydration and to obtain a layer of porous structure of the oxide (s) of alkaline earth metal and of refractory material in grains, the proportion of refractory material being predetermined to give the coating a predetermined resistance to erosion of the liquid metal poured into the container as a result of the sintering of this coating on contact with the liquid metal.

Suivant un autre aspect de l'invention, celle-ci vise également l'utilisation, pour réaliser un revêtement épurant par la mise en oeuvre du procédé précité, d'une composition comprenant au moins un carbonate simple ou multiple de métal alcalino-terreux additionné d'une proportion prédéterminée de matière réfractaire en grains, cette composition étant susceptible de faire prise et de fritter au contact du métal liquide.According to another aspect of the invention, it also relates to the use, for producing a purifying coating by the implementation of the aforementioned process, of a composition comprising at least one simple or multiple carbonate of alkaline earth metal added of a predetermined proportion of refractory grain, this composition being capable of setting and sintering in contact with the liquid metal.

La composition peut contenir en outre une certaine proportion soit d'hydroxydes alcalino-terreux, soit d'oxydes alcalino-terreux susceptibles de s'hydrater lors du mouillage de la composition et d'activer suffisamment "in situ" la chaux ou la magnésie lors du préchauffage de ladite composition, toujours dans le but de conférer une résistance suffisante au revêtement.The composition may also contain a certain proportion of either alkaline earth hydroxides or alkaline earth oxides capable of hydrating during wetting of the composition and of activating lime or magnesia sufficiently "in situ" during preheating said composition, again with the aim of imparting sufficient resistance to the coating.

Le procédé selon l'invention permet ainsi d'obtenir un revêtement épurant économique puisqu'il utilise comme produit de départ un ou des carbonates alcalino-terreux tel que de la dolomie ou de la calcite.The process according to the invention thus makes it possible to obtain an economical purifying coating since it uses as starting material one or more alkaline earth carbonates such as dolomite or calcite.

De plus, le revêtement obtenu présente une bonne résistance à l'érosion provoquée par le métal coulé dans le récipient métallurgique.In addition, the coating obtained has good resistance to erosion caused by the metal poured into the metallurgical vessel.

Ainsi, le revêtement selon l'invention présente une double fonction à savoir la fonction épurante et la fonction de revêtement d'usure, de sorte qu'il peut avantageusement remplacer tous les revêtements d'usure et de protection appliqués jusqu'à présent qui ne présentent pas de fonction épurante.Thus, the coating according to the invention has a double function, namely the purifying function and the function of wear coating, so that it can advantageously replace all the wear and protective coatings applied so far which do not have no purifying function.

Le mérite de la présente invention réside dans le fait d'avoir découvert de façon surprenante que l'addition d'une certaine proportion de matière réfractaire à un ou plusieurs carbonates alcalino-terreux simples ou multiples permettait d'obtenir après cuisson, c'est-à-dire aprés l'élimination du CO₂, une structure présentant une résistance à l'érosion nettement supérieure à celle obtenue en l'absence de cette matiére réfractaire.The merit of the present invention lies in the fact that it has surprisingly discovered that the addition of a certain proportion of refractory material to one or more simple or multiple alkaline earth carbonates made it possible to obtain, after baking, that is to say after the elimination of CO₂, a structure having an erosion resistance markedly greater than that obtained in the absence of this refractory material.

De plus, le revêtement obtenu, outre ses propriétés épurantes dues à l'oxyde alcalino-terreux qui est obtenu après la cuisson, présente une structure suffisamment poreuse pour lui conférer des propriétés d'isolation thermique permettant de limiter le refroidissement du métal liquide contenu dans le récipient de coulée.In addition, the coating obtained, in addition to its purifying properties due to the alkaline earth oxide which is obtained after baking, has a structure which is sufficiently porous to give it thermal insulation properties making it possible to limit the cooling of the liquid metal contained in the pouring container.

Par ailleurs, le revêtement obtenu selon le procédé conforme à l'invention n'adhère pas fortement au revêtement réfractaire permanent sur lequel il est appliqué de sorte qu'en fin de coulée, il peut être facilement détaché en vue d'appliquer un revêtement neuf.Furthermore, the coating obtained according to the process according to the invention does not adhere strongly to the permanent refractory coating to which it is applied so that at the end of casting, it can be easily removed in order to apply a new coating .

La composition précitée peut être avantageusement projetée sous forme de boue aqueuse, avec 15 à 20% environ en poids d'eau.The aforementioned composition can advantageously be sprayed in the form of aqueous mud, with approximately 15 to 20% by weight of water.

La composition peut également être coulée entre la surface intérieure du récipient métallurgique et une paroi formant moule.The composition can also be poured between the interior surface of the metallurgical container and a wall forming a mold.

Après application, le revêtement est chauffé à coeur aux environs de 900°C, pour libérer le CO₂ du carbonate alcalino-terreux et éventuellement l'eau de constitution et/ou d'hydratation. Ce chauffage peut être réalisé par tout moyen tel que brûleur, éléments chauffants électriques par effet Joule ou à émission de rayonnement infra-rouge.After application, the coating is heated to the core around 900 ° C, to release the CO₂ of the alkaline earth carbonate and optionally the water of constitution and / or hydration. This heating can be carried out by any means such as a burner, electric heating elements by Joule effect or with emission of infrared radiation.

Le carbonate alcalino-terreux simple ou multiple utilisé dans la composition est de préférence un carbonate choisi parmi les composés suivants : dolomie crue, calcite crue et leurs mélanges, la dolomie étant cependant préférée en raison de son faible coût à l'état cru (non calciné).The single or multiple alkaline earth carbonate used in the composition is preferably a carbonate chosen from the following compounds: raw dolomite, raw calcite and their mixtures, dolomite being however preferred because of its low cost in the raw state (not calcined).

Pour faciliter son application la composition utilisée renferme de préférence un liant choisi parmi les liants minéraux tels que par exemple : silicate ou phosphate alcalin, organiques tels que par exemple résine phénolique, hydrauliques tels que, par exemple, ciments, et leurs mélanges.To facilitate its application, the composition used preferably contains a binder chosen from mineral binders such as, for example: alkali metal silicate or phosphate, organic such as, for example, phenolic resin, hydraulic, such as, for example, cements, and mixtures thereof.

La matière réfractaire ajoutée au carbonate alcalino-terreux est de préférence choisie parmi les composés suivants :
   - dolomie calcinée, chaux, magnésie, chrome magnésie, oxyde de chrome, silicate de zirconium, silice, silico-alumineux et/ou leurs mélanges.The refractory material added to the alkaline earth carbonate is preferably chosen from the following compounds:
- calcined dolomite, lime, magnesia, chromium magnesia, chromium oxide, zirconium silicate, silica, silico-aluminous and / or mixtures thereof.

La composition pondérale des constituants principaux est avantageusement la suivante :

  • . carbonate alcalino-terreux   : 30 à 95%
  • . matière réfractaire   : 70 à 5%
  • . liant   : 0 à 15%.
The weight composition of the main constituents is advantageously as follows:
  • . alkaline earth carbonate: 30 to 95%
  • . refractory material: 70 to 5%
  • . binder: 0 to 15%.

Les proportions optimales dépendront de l'effet recherché. Plus la proportion de carbonate alcalino-terreux est élevée, plus l'effet épurant sera important.The optimal proportions will depend on the desired effect. The higher the proportion of alkaline earth carbonate, the greater the purifying effect.

Inversement, plus la proportion de matière réfractaire est élevée, plus la résistance à l'érosion du revêtement sera importante.Conversely, the higher the proportion of refractory material, the greater the resistance to erosion of the coating.

Il y a cependant avantage à ce que la proportion de matiére réfractaire soit tout juste suffisante pour conférer au revêtement la résistance à l'érosion désirée de façon à préserver les propriétés épurantes dues à l'oxyde alcalino-terreux subsistant après libération du CO₂. Afin d'accroître les propriétés épurantes du revêtement, on privilégiera dans la composition les éléments contenant du calcium.There is however an advantage in that the proportion of refractory material is barely sufficient to give the coating the desired resistance to erosion so as to preserve the purifying properties due to the alkaline earth oxide remaining after release of CO₂. In order to increase the purifying properties of the coating, the elements containing calcium will be favored in the composition.

Dans certains cas, la présence du liant n'est pas obligatoire, car un effet de prise à l'eau existe déjà en son absence.In some cases, the presence of the binder is not compulsory, because a setting effect with water already exists in its absence.

Les meilleurs résultats sont obtenus avec la composition suivante :

  • . 60 à 80% de dolomie crue
  • . 10 à 40% de matière réfractaire ; et
  • . 1 à 5% de liant.
The best results are obtained with the following composition:
  • . 60 to 80% raw dolomite
  • . 10 to 40% of refractory material; and
  • . 1 to 5% of binder.

Le carbonate alcalino-terreux peut être du carbonate de calcium pur ou associé à un autre carbonate, par exemple du carbonate de magnésium, sous forme de dolomie.The alkaline earth carbonate can be pure carbonate of calcium or associated with another carbonate, for example magnesium carbonate, in the form of dolomite.

Par ailleurs, les oxydes alcalino-terreux cités à titre d'exemples de matière réfractaire peuvent être remplacés en tout ou partie par des hydroxydes et/ou des sulfates, ces derniers étant transformés en oxydes lors de la cuisson.Furthermore, the alkaline earth oxides cited as examples of refractory material may be replaced in whole or in part by hydroxides and / or sulfates, the latter being transformed into oxides during cooking.

De préférence, les grains de la matière réfractaire ont au moins en partie une dimension supérieure à celle des grains de carbonates et/ou d'hydroxydes et/ou de sulfates alcalino-terreux.Preferably, the grains of the refractory material have at least in part a dimension greater than that of the grains of carbonates and / or hydroxides and / or alkaline earth sulfates.

En effet, les grains de carbonates, d'hydroxydes et de sulfates se décomposent d'autant plus facilement et rapidement qu'ils sont plus petits.In fact, the grains of carbonates, hydroxides and sulfates decompose the more easily and quickly the smaller they are.

De façon générale, on peut régler la granulométrie en fonction du résultat recherché, à savoir la porosité qui confère des propriétés isolantes et/ou de frittage qui assure la cohésion et la résistance à l'érosion.In general, the particle size can be adjusted as a function of the desired result, namely the porosity which gives insulating and / or sintering properties which ensures cohesion and resistance to erosion.

La composition selon l'invention renferme en outre de préférence jusqu'à 20% en poids de fibres organiques et/ou minérales.The composition according to the invention also preferably contains up to 20% by weight of organic and / or mineral fibers.

La composition selon l'invention peut également renfermer une matière carbonée en grains.The composition according to the invention may also contain a carbonaceous matter in grains.

De préférence, la composition renferme en outre jusqu'à 5% en poids d'un agent tensio-actif.Preferably, the composition additionally contains up to 5% by weight of a surfactant.

La composition précitée peut être appliquée sur le fond et les faces latérales d'un répartiteur de coulée, par projection ou moulage en une ou plusieurs couches de quelques centimètres d'épaisseur.The aforementioned composition can be applied to the bottom and the lateral faces of a tundish, by spraying or molding in one or more layers a few centimeters thick.

Dans le cas où l'on veut accélérer l'apparition du frittage à la surface de la couche épurante lors de son premier contact avec l'acier liquide, on pourra utilement ajouter au mélange un ou plusieurs fondants tels que, par exemple : de l'olivine, de la colémanite, de la borocalcite (borate de calcium), de l'oxyde de fer, un fluorure, de l'acide borique et ses sels (borax) et leurs mélanges. On peut ainsi choisir un fondant qui migre vers la surface avec l'eau lors du séchage, tel que de l'acide borique, par exemple, pour obtenir un frittage rapide de la surface qui vient au contact de l'acier liquide, et rechercher un frittage moins rapide ou moins actif dans la masse du revêtement épurant grâce à un fondant qui ne migre pas tel que, par exemple, de la colémanite.In the case where it is desired to accelerate the appearance of sintering on the surface of the purifying layer during its first contact with the liquid steel, it is useful to add to the mixture one or more fluxes such as, for example: olivine, colemanite, borocalcite (calcium borate), iron oxide, fluoride, boric acid and its salts (borax) and their mixtures. We can thus choose a flux which migrates towards the surface with water during drying, such as boric acid, for example, to obtain a rapid sintering of the surface which comes into contact with liquid steel, and seek a slower or less active sintering in the mass of the purifying coating thanks to a flux which does not migrate such as, for example, colemanite.

La finesse des grains constituant le revêtement joue également un rôle dans le processus du frittage, et on peut avantageusement utiliser les formules suivantes, les pourcentages étant donnés en poids :
   Dolomie et/ou calcite et/ou hydroxydes et/ou
   sulfates : 30 à 95%, diamètre des grains < 3 mm, de préférence < 1 mm
   Matière réfractaire : 70 à 5%, diamètre des grains < 5 mm, de préférence < 2 mm

Liant
: 0 à 15%
Carbone
: 0 à 5%
Fondants
: 0 à 10%
The fineness of the grains constituting the coating also plays a role in the sintering process, and the following formulas can advantageously be used, the percentages being given by weight:
Dolomite and / or calcite and / or hydroxides and / or
sulfates: 30 to 95%, grain diameter <3 mm, preferably <1 mm
Refractory material: 70 to 5%, grain diameter <5 mm, preferably <2 mm
Binder
: 0 to 15%
Carbon
: 0 to 5%
Fondants
: 0 to 10%

On pourra choisir comme fondant, suivant le cas :

  • un fondant facilement soluble, susceptible de migrer vers la surface,
  • un fondant peu ou pas soluble,
  • un mélange des deux types de fondants dans une proportion prédéterminée permettant un certain frittage sélectif en surface et dans les différentes épaisseurs de la couche.
We can choose as fondant, as appropriate:
  • an easily soluble flux, capable of migrating to the surface,
  • a poorly or not soluble fondant,
  • a mixture of the two types of fluxes in a predetermined proportion allowing a certain selective sintering on the surface and in the different thicknesses of the layer.

On peut en outre obtenir une compacité maximale de la couche en optimisant les granulométries respectives des différents constituants de façon connue, par exemple grâce à l'application de la loi de Bolomey ou de la compacité Furnas ou encore grâce à la règle du triangle : on peut ainsi augmenter la résistance de la couche épurante à l'érosion par le métal liquide sans avoir à utiliser un procédé quelconque de compactage mécanique irréalisable en pratique à peu de frais.It is also possible to obtain a maximum compactness of the layer by optimizing the respective particle sizes of the various constituents in a known manner, for example by applying the Bolomey law or the Furnas compactness or else by means of the triangle rule: can thus increase the resistance of the purifying layer to erosion by liquid metal without having to use any mechanical compaction process which is impracticable in practice at low cost.

Dans le cas d'un revêtement en plusieurs couches, la composition et la granulométrie des grains peuvent varier d'une couche à l'autre en fonction des propriétés recherchées.In the case of a coating in several layers, the composition and the grain size of the grains can vary from one layer to another depending on the desired properties.

Ainsi, si l'on veut que la couche intérieure (celle destinée à venir en contact avec le métal liquide) ait une grande résistance à l'érosion, celle-ci renfermera davantage de matière réfractaire, et contiendra des particules fines pour favoriser le frittage.Thus, if we want the inner layer (the one intended to come into contact with the liquid metal) to have a high resistance to erosion, it will contain more refractory material, and will contain fine particles to promote sintering.

A l'inverse, on pourra préférer que la couche extérieure adjacente au revêtement réfractaire permanent fritte moins que la couche intérieure, de façon à pouvoir la détacher facilement du revêtement permanent en fin de coulée.Conversely, it may be preferable for the outer layer adjacent to the permanent refractory lining to sinter less than the inner layer, so that it can be easily detached from the permanent lining at the end of casting.

De même, on pourra privilégier la basicité de la couche intérieure par une forte teneur en calcium pour obtenir des propriétés épurantes optimales.Likewise, the basicity of the inner layer may be favored by a high calcium content in order to obtain optimal purifying properties.

Un revêtement en plusieurs couches pour protéger la paroi intérieure d'un récipient métallurgique peut ainsi comporter :

  • une couche intérieure épurante d'usure venant au contact de l'acier liquide, à base d'oxyde d'un métal alcalino-terreux (dolomie, hydroxydes, sulfates, calcite, carbonates),
  • une couche extérieure de sécurité, mise en place entre la couche épurante d'usure et le revêtement permanent ; cette couche peut être, soit une couche frittable aux températures en jeu, à base de grains d'oxydes réfractaires stables (par exemple à base de magnésie et/ou de silice et/ou d'alumine et/ou de zircon et/ou de zircone), soit en variante une couche extérieure peu ou très peu frittable de sécurité à base d'oxydes réfractaires stables additionnés de carbone (moins de 35% de carbone). Cette dernière couche peut également jouer le rôle de troisième couche peu ou très peu frittable mise en place entre la couche précitée de sécurité et le revêtement permanent pour éviter tout accrochage du revêtement permanent, comme toute autre couche partiellement, peu ou très peu frittable.
A coating in several layers to protect the interior wall of a metallurgical vessel can thus include:
  • a purifying inner layer of wear coming into contact with liquid steel, based on an oxide of an alkaline earth metal (dolomite, hydroxides, sulfates, calcite, carbonates),
  • an outer safety layer, placed between the purifying wear layer and the permanent coating; this layer may be either a sinterable layer at the temperatures in play, based on grains of stable refractory oxides (for example based on magnesia and / or silica and / or alumina and / or zircon and / or zirconia), or alternatively an outer layer with little or very little sinterability of security based on stable refractory oxides added with carbon (less than 35% carbon). This last layer can also play the role of third layer with little or very little sinterability placed between the aforementioned safety layer and the permanent coating to avoid any attachment of the permanent coating, like any other partially, little or very little sinterable layer.

On peut ainsi, par exemple, prendre pour la (ou les) couche(s) extérieure(s) de sécurité, les compositions indiquées respectivement dans les brevets français n° 2 393 637 et 2 585 273 au nom de la demanderesse.It is thus possible, for example, to take for the outer layer (s) of security, the compositions indicated respectively in the patents French No. 2,393,637 and 2,585,273 in the name of the plaintiff.

On peut également, dans le cas de trois couches, avoir une première couche intérieure épurante, une seconde couche peu ou très peu frittable ou pas frittable, et une troisième couche extérieure frittable ou au moins partiellement frittable.It is also possible, in the case of three layers, to have a first purifying inner layer, a second layer which is little or very little sinterable or not sinterable, and a third outer sinterable layer or at least partially sinterable.

Claims (22)

  1. A method of lining the inside wall of a metallurgical vessel for transferring liquid metal, with a purifying lining based on the oxide of an alkaline-earth metal, characterised by the following steps:
    - there is applied to the inside wall of the vessel a composition containing at least one single or multiple carbonate of an alkaline-earth metal plus a predetermined proportion of granular refractory material, this composition being adapted to set, and
    - this lining is heated to eliminate the CO₂ and any constitutional and/or hydration water, and to obtain a porous-structure layer of the or each oxide of alkaline-earth metal and granular refractory material, the proportion of refractory material being predetermined to give the lining a predetermined resistance to the erosion of the metal liquid poured into the vessel as a result of sintering of said lining in contact with the liquid metal.
  2. A method according to claim 1, characterised in that the composition is sprayed in the form of an aqueous slurry.
  3. A method according to claim 1, characterised in that the composition is poured between the inside surface of the vessel and a wall which forms a mould.
  4. A method according to any one of claims 1 to 3, characterised in that the lining is heated throughout to about 900°C.
  5. A method according to any one of claims 1 to 4, characterised in that there is applied, before the purifying lining, at least one first layer of a refractory material based on stable refractory oxides, said material being adapted to sinter at least partially at the temperatures involved.
  6. A method according to any one of claims 1 to 4, characterised in that there are applied, before the purifying lining, two layers of refractory materials based on stable refractory oxides, the material of one of the layers being little or very little adapted to sintering, the material of the other layer being at least partially adapted to sintering at the temperatures involved.
  7. The use, to produce a purifying lining by the practice of the method according to any one of claims 1 to 6, of a composition comprising at least one single or multiple carbonate of alkaline-earth metal plus a predetermined proportion of granular refractory material, said composition being adapted to set and sinter in contact with the liquid metal.
  8. The use according to claim 7, characterised in that the said alkaline-earth carbonate is selected from the following compounds: non-calcined dolomite, calcite and their mixtures.
  9. The use according to claim 7 or 8, characterised in that the composition used also contains a binder selected from the mineral, organic, and hydraulic binders, and their mixtures.
  10. The use according to any one of claims 7 to 9, characterised in that the refractory material is selected from the following compounds:
    - calcined dolomite, lime, magnesia, chromium-magnesia, chromium oxide, zirconium silicate, silica, silico-aluminous and their mixtures.
  11. The use according to any one of claims 7 to 10, characterised in that the composition contains by weight:
    . alkaline-earth carbonate:   30 to 95%
    . refractory material   70 to 5%
    . binder   0 to 15%.
  12. The use according to claim 11, characterised in that the composition contains by weight:
    . 60 to 80% of non-calcined dolomite
    . 10 to 40% of refractory material and
    . 1 to 5% of binder.
  13. The use according to any one of claims 7 to 12, characterised in that the grains of refractory material have at least partly a larger dimension than that of the grains of alkaline-earth carbonate.
  14. The use according to any one of claims 7 to 13, characterised in that the composition also contains up to 20% by weight of organic and/or mineral fibres.
  15. The use according to any one of claims 7 to 14, characterised in that the composition also contains up to 5% by weight of a surfactant.
  16. The use according to any one of claims 7 to 13, characterised in that the composition also contains a certain proportion of alkaline-earth hydroxide(s) and/or alkaline-earth oxide(s) adapted to hydrate when the composition is wetted, and/or alkaline-earth sulphates.
  17. The use according to any one of claims 7 to 16, characterised in that the composition also contains from 0 to 10% by weight of a flux.
  18. The use according to claim 17, characterised in that the flux is selected from olivine, colemanite, borocalcite (calcium borate), iron oxide, fluorides, boric acid and its salts (borax) and their mixtures.
  19. The use according to claim 17 or 18, characterised in that the composition contains a readily soluble flux.
  20. The use according to any one of claims 7 to 19, characterised in that the composition contains by weight:
    . dolomite and/or calcite and/or hydroxides and/or sulphates of alkaline-earth metals   30 to 95%
    . refractory grains:   70 to 5%
    . binder:   0 to 15%
    . carbon:   0 to 5%
    . flux:   0 to 10%.
  21. The use according to any one of claims 7 to 20, characterised in that the main constituents have the following particle sizes:
    - carbonates, hydroxides, oxides and sulphates of alkaline-earth metals: diameter less than 3 mm and preferably less than 1 mm;
    - refractory grains: diameter less than 5 mm and preferably less than 2 mm.
  22. The use according to any one of claims 7 to 21, characterised in that the respective grain sizes of the different constituents are selected to give the purifying lining maximum compactness.
EP90907138A 1989-04-12 1990-04-11 Process for coating a metallurgical container with a purifying layer and composition relating thereto, and protective coating thus obtained Expired - Lifetime EP0422192B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT90907138T ATE99199T1 (en) 1989-04-12 1990-04-11 PROCESS AND COMPOSITION FOR LINING A METALLURGICAL VESSEL BY MEANS OF A CLEANING LINING AND LINING THUS MANUFACTURED.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR8904822A FR2648066B1 (en) 1989-04-12 1989-04-12 PROCESS FOR COATING A METALLURGICAL CONTAINER WITH A PURIFYING COATING AND COMPOSITION RELATING THERETO
FR8904822 1989-04-12

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EP0422192A1 EP0422192A1 (en) 1991-04-17
EP0422192B1 true EP0422192B1 (en) 1993-12-29

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KR (1) KR960005886B1 (en)
AU (1) AU628557B2 (en)
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ES (1) ES2047930T3 (en)
FR (1) FR2648066B1 (en)
HU (1) HUT60173A (en)
WO (1) WO1990011853A1 (en)

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FR2683220B1 (en) * 1991-11-04 1994-05-20 Sollac PROCESS FOR COATING A CONTINUOUS CASTING DISTRIBUTOR WITH REFRACTORY MATERIAL, DISTRIBUTOR AND REFRACTORY MATERIAL RESULTING FROM THE IMPLEMENTATION OF THIS PROCESS.
US5314599A (en) * 1992-07-28 1994-05-24 Alcan International Limited Barrier layer against fluoride diffusion in linings of aluminum reduction cells
US5507474A (en) * 1994-01-13 1996-04-16 Minerals Technologies, Inc. Lining for molten metal handling vessles
US5643350A (en) * 1994-11-08 1997-07-01 Vectra Technologies, Inc. Waste vitrification melter
AUPS329202A0 (en) * 2002-07-01 2002-07-18 Cast Centre Pty Ltd Coatings for articles used with molten metal
WO2005087406A1 (en) * 2004-03-15 2005-09-22 Krosakiharima Corporation Nozzle for use in continuous casting
CN115448701B (en) * 2022-08-19 2023-04-14 山西太钢不锈钢股份有限公司 Magnesium-calcium refractory material for AOD smelting nickel-based alloy and preparation method thereof

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1239266B (en) * 1962-04-28 1967-04-27 Basf Ag Process for dyeing and / or printing textile goods

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB527024A (en) * 1939-03-28 1940-10-01 Pierre Imbert Improvements in or relating to basic refractory materials
DE966136C (en) * 1951-05-28 1957-07-11 Veitscher Magnesitwerke Ag Process for the production of highly refractory, basic insulating bricks
DE1218923B (en) * 1959-04-23 1966-06-08 Rheinische Kalksteinwerke Process for the production of highly porous, refractory, basic lightweight bricks
DE1239226B (en) * 1961-01-05 1967-04-20 Dolomitwerke Gmbh Process for the production of porous moldings from dolomite and / or magnesite
US4400335A (en) * 1981-12-15 1983-08-23 Hoganas Ab Process for repairing refractory linings
JPS6133743A (en) * 1984-07-25 1986-02-17 Kobe Steel Ltd Construction of plate-shaped refractories

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1239266B (en) * 1962-04-28 1967-04-27 Basf Ag Process for dyeing and / or printing textile goods

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AU5551790A (en) 1990-11-05
HU904442D0 (en) 1992-08-28
HUT60173A (en) 1992-08-28
CS179790A3 (en) 1992-09-16
WO1990011853A1 (en) 1990-10-18
KR960005886B1 (en) 1996-05-03
DE69005578T2 (en) 1994-04-28
US5188794A (en) 1993-02-23
ES2047930T3 (en) 1994-03-01
DE69005578D1 (en) 1994-02-10
EP0422192A1 (en) 1991-04-17
KR920700081A (en) 1992-02-19
BR9006411A (en) 1991-08-06
CA2030522A1 (en) 1990-10-13
FR2648066B1 (en) 1994-04-01
FR2648066A1 (en) 1990-12-14

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