EP0088701B1 - Process and device for casting a molten non ferrous metal - Google Patents

Process and device for casting a molten non ferrous metal Download PDF

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Publication number
EP0088701B1
EP0088701B1 EP83400479A EP83400479A EP0088701B1 EP 0088701 B1 EP0088701 B1 EP 0088701B1 EP 83400479 A EP83400479 A EP 83400479A EP 83400479 A EP83400479 A EP 83400479A EP 0088701 B1 EP0088701 B1 EP 0088701B1
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EP
European Patent Office
Prior art keywords
casting
metal
inert gas
insulation
jet
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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
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EP83400479A
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German (de)
French (fr)
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EP0088701A1 (en
Inventor
Jean Francis Rimbert
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Noranda Inc
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Noranda Inc
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D5/00—Machines or plants for pig or like casting
    • B22D5/04—Machines or plants for pig or like casting with endless casting conveyors
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D1/00—Treatment of fused masses in the ladle or the supply runners before casting
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D27/00—Treating the metal in the mould while it is molten or ductile ; Pressure or vacuum casting
    • B22D27/003—Treating the metal in the mould while it is molten or ductile ; Pressure or vacuum casting by using inert gases

Definitions

  • the subject of the invention is a method and an installation for casting in the form of a free jet of a non-ferrous metal capable of presenting the problem of the formation of a solid metal foam at the foot of the casting jet. It applies more particularly to the casting of zinc in an ingot mold.
  • This problem of the protection of the casting jet arises in a particular way during the casting of non-ferrous metals capable of causing the formation of a solid metallic foam at the foot of the casting jet, and more especially during the casting of zinc in an ingot mold.
  • the subject of the present invention is a method of casting a non-ferrous metal in the liquid state, which makes it possible to avoid the formation of solid metallic foam, in falling casting installations of the usual type.
  • the invention provides a casting method in the form of a free jet of a non-ferrous metal, which presents the problem of the formation of a solid metallic foam at the foot of the casting jet, of a reserve of said metal.
  • liquid to at least one receptacle for said metal in which at least one of the receptacles is covered by isolation means so as to form a zone of isolation from the environment, and said zone is previously inerted isolation by means of supply and distribution of an inert gas inside said isolation zone, the oxygen content therein being less than 1% preferably 0.1%, characterized in that the 'a direct passage of the liquid metal is established between said reserve and the receiving container placed below the pouring jet, so that the pouring jet of the liquid metal remains entirely inside the isolation zone, while maintaining the injection of inert gas in the upper part of said isolation zone at a rate such that the atmosphere in the vicinity of the jet of liquid metal has an oxygen content lower than the above values.
  • the receiving container is preferably an ingot mold, the reserve of liquid metal preferably a distributor tray with pouring orifice at its bottom.
  • the isolation means can consist of metal covers or metal walls, possibly connected by connecting means.
  • a set of ingot molds is made to pass, arranged transversely side by side, under said reserve of liquid metal, and each of the ingot molds is inerted beforehand before passing under the jet of liquid metal.
  • at least two adjacent molds of said set are covered by the isolation wall.
  • the invention also relates to a casting installation in the form of a free jet of a non-ferrous metal which presents the problem of the formation of a solid metal foam at the foot of the casting jet, of a reserve of said liquid metal to at least one receptacle for receiving said metal, comprising isolation means covering at least one of the receptacles so as to form a zone of isolation from the environment and means for supplying and distributing a gas inert inside said isolation zone, the oxygen content therein being less than 1%, preferably less than 0.1%, characterized in that it comprises means allowing the direct passage of the liquid metal between said reserve and the receiving container placed below the pouring jet inside the isolation zone, and in that the inert gas supply and distribution means maintain the injection of inert gas in the upper part of said zone isolation at a flow rate such that the atmosphere in the vicinity of the metal jet itself has an oxygen content lower than the above values.
  • the creation of the isolation zone with respect to the atmosphere and the introduction into this zone of a liquefied inert gas prevents any oxidation of the liquid metal, and therefore the formation of solid metallic foam. Indeed, there is no stabilization or solidification of the bubbles formed which therefore remain liquid and are eliminated in the metal bath. Thus, thanks to the process of the invention, any loss of metal is avoided during casting and ingots free of foam are obtained at the end of the process.
  • a zinc casting installation comprises a metal distributor tray 1 in the shape of a rectangular parallelepiped, having a bottom 2 and four side walls 3a, 3b and 4a, 4b.
  • the bottom 2 of the tank 1 has a slot 5.
  • a chute 6 for supplying liquid zinc connected to a holding furnace (not shown in the figure) and slightly inclined, opens at the upper part of the wall 3a of the distribution tank 1.
  • Metal ingot molds L placed transversely side by side and integral with two endless transmission chains 8 via pivot axes 16, travel in the direction of arrow F under the distribution bin 1 and successively take positions 7A , 7B, 7C, 7D.
  • These ingot molds L are in the form of a trough comprising a rectangular bottom 9 and four side walls 10a, 10b and 11a, 11b slightly inclined.
  • a metal cover 12 in the shape of a rectangular parallelepiped has a horizontal upper plate 13 and four vertical side walls 14a, 14b and 15a, 15b.
  • the upper plate 13 is pierced with a rectangular opening having the dimensions just necessary to embed the lower part of the distribution tank 1.
  • the plate 13 of the cover 12 is fixed by means of four metal connection plates 18 using of bolts 19 to the walls 3a, 3b and 4a, 4b of the distribution box 1.
  • the cover 12 completely overhangs the two ingot molds 7B and 7C, and its side walls 14a, 14b and 15a, 15b arrive just flush with the upper edges of these ingot molds. More specifically, the lower edge 20 of the walls 14a, 14b stops just above the upper edges 21 of the walls 10a, 10b of the molds 7B and 7C and the lower edge 22 of the walls 15a, 15b stops just at the above the upper edges 28 of the walls 11a, 11b of the molds 7B and 7C.
  • the cover 12 forms a quasi-hermetic protective cover for the internal cavity of the molds 7B and 7C while not preventing them from scrolling.
  • a ramp 23 for supplying and distributing a liquefied inert gas is fixed under the upper plate 13 parallel to the wall 14a, in the upstream part of the cover 12 relative to the direction of movement F of the molds L.
  • This ramp 23 is of the conventional phase separator type, comprising a degassing slot 29 at its upper part and provided, at its lower part and at regular intervals, with injection nozzles 24 for liquid inert gas oriented downwards.
  • the ramp 23 is connected to a tank of liquefied inert gas 25 via a conduit 26 and a dip tube 27.
  • the supply and distribution ramp 23 is preferably located in the upstream part of the cover 12 relative to the direction of movement F, as shown in the figures, but it can also be placed in the downstream part of the cover 12; there may also be two supply and distribution ramps for liquefied inert gas, one in the upstream part and the other in the downstream part of the cover.
  • a vertical conduit 30 crosses the downstream part of the upper plate 13 relative to the direction of movement F and opens slightly below said plate 13.
  • This conduit 30, fitted with a pump 32, is connected to an oxygen analyzer 31.
  • a preheating ramp 33 arranged parallel to the wall 14a of the cover 12 and above the ingot mold 7A, is fixed to the wall 14a by means of metal rods 34 provided with metal rings 35.
  • This preheating ramp 33 is consisting of a pipe 36 connected to fuel gas and oxidizing gas supply sources (not shown in the figures) and provided, at regular intervals, with burners 37 oriented towards the internal cavity of the mold 7A.
  • the distribution tank 1 contains a bath of liquid zinc 40 which flows through the slot 5 in the form of a jet J to form a bath of liquid zinc 41 in the mold 7C.
  • the operation of the installation according to the invention is as follows.
  • the distributor tank 1 is continuously supplied with liquid zinc, coming from a holding oven, using the chute 6; the impurities, in particular the oxides formed during transport in air in the chute 6, remain on the surface of the bath of liquid metal 40 thus formed in the distributor 1 and the pure liquid zinc settles at the bottom of the distributor 1 and flows by the slot 5 in the mold which is in position 7C.
  • each mold L in position 7A, is preheated to a temperature above 100 ° C by means of the preheating ramp 33.
  • this ingot mold L arrives in position 7B, it receives the jets of a liquefied inert gas, such as argon or nitrogen, injected by the nozzles 24 of the supply rail 23.
  • a liquefied inert gas such as argon or nitrogen
  • the oxygen content of the atmosphere in the vicinity of the pouring jet J and of the surface of the metal bath 41 is continuously monitored using the oxygen analyzer 31, and the injection rate of the liquefied inert gas into the supply rail 23 so that this oxygen content is less than 1%, preferably 0.1%.
  • each mold in position 7A is intended, in certain cases, to avoid excessive cooling of the latter when it is in position 7B as well as of the bath of liquid metal which it will contain when it is in position 7C, cooling which comes from the frigories brought by liquefied inert gas.
  • a zinc casting installation comprises a distribution tank 50 in the form of a rectangular parallelepiped comprising a bottom 51 and four side walls 52.
  • the bottom 51 of the tank 50 has a slot 53.
  • a chute 54 d the liquid zinc inlet opens into the upper part of the distribution tank 50.
  • Metal ingot molds 53 placed transversely side by side, pass in the direction of arrow G, following a slightly ascending slope by means of a transport ramp (not shown in the figures), and successively assume positions 55A, 55B, 55C , 55D.
  • These ingot molds 55 are in the shape of a trough comprising a rectangular bottom 56 and four side walls 57 slightly inclined.
  • a metal cover 59 bearing on the protection plates of the transport ramp (not shown in the figures) and overhanging at least one ingot mold 55 is equipped with a ramp 60 for supplying inert gas.
  • This ramp 60 is, on the other hand, connected to a wall 52 of a distribution tank 50 by a skirt 61, made of refractory fabric for example.
  • An injection pipe for a liquefied inert gas 62 opens out above the internal cavity of one of the ingot molds 55.
  • a skirt 63 fixed to the bottom 51 of the distributor 50, descends vertically into the internal cavity of the ingot mold next.
  • a metal cover 64 bearing on three of the side walls 52 of the tank 1 is equipped with a ramp 65 for supplying inert gas.
  • a skirt 67 connects the ramp 65 to a metal cover 68 which overhangs the chute 54.
  • a vertical partition 58 which stops at a distance from the bottom of the chute 54, stops the zinc foam formed on the surface of the liquid zinc during its transport in the open air to the chute and forces the pure zinc to pass through the bottom.
  • a skirt 69 connects a side wall 52 of the tank 50 and the bottom of the chute 54.
  • FIG. 3 represents the respective position of the elements of the installation when filling an ingot mold 55C with liquid zinc
  • FIG. 4 represents the respective position of the elements of the installation during the passage from an ingot mold filled with liquid zinc 55C to the next empty ingot mold 55B.
  • the distributor 50 When filling the mold 55C (fig. 3), the distributor 50 is in a horizontal position. It is supplied with liquid zinc by the chute 54; thanks to the protection zone constituted by the cover 68, the skirt 67 and the cover 64, and the inerting of said protection zone by an inert gas (ramp 65) the surface of the bath of liquid zinc 70 contained in the chute 54 , the jet of liquid zinc 71 flowing from the chute 54 into the tank 50 and the surface of the bath of liquid zinc 72 contained in the tank 50, are perfectly clean, that is to say free from dross and foam due to possible oxidation of zinc.
  • the jet of liquid zinc 73 and the surface of the bath of liquid zinc 74 contained in the mold 55C are protected against any oxidation by virtue of the confinement zone constituted by the cover 59, the bottom 51 and the inerting from said containment zone by an inert gas (ramp 60) and a liquefied inert gas (cane 62).
  • the set of molds is scrolled so as to bring the following mold 55B under the distribution tray 50.
  • the tray 50 is placed in the tilted position by tilting about an axis 66 so that the level of the liquid zinc bath 72 is such that the zinc cannot flow through the slot 53.
  • the inerting of the protection zone (hood 68, skirt 67 and hood 64) and of the confinement zone (hood 59, bottom 51 is maintained) and skirt 63), as described above.
  • the confinement zone overhanging at least one ingot mold is inert, whether in the filling position of one ingot mold or in the position for passing from one ingot mold to another, both by injection of an inert gas liquefied upstream, relative to the direction of movement G, of the casting slot 53 and injection of an inert gas downstream of said slot 53; in this case, the amount of liquefied inert gas. injected is 75% to 100% of the total amount of gas used.
  • the confinement zone is inerted by injection of an inert liquefied gas only upstream of the casting slot 53.
  • the confinement zone is inerted by injection of a gas inert liquefied both upstream and downstream of the casting slot 53.
  • the inert gas used can be, for example, nitrogen or argon.
  • the invention applies more particularly to the continuous casting of zinc in an ingot mold, but it could also be applied to the casting of any non-ferrous metal in free fall liable to present the problem of the formation of solid metallic foam at the foot of the casting jet, such as lead or lead and calcium alloys, or zinc alloys.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Continuous Casting (AREA)
  • Manufacture And Refinement Of Metals (AREA)

Description

L'invention a pour objet un procédé et une installation de coulée sous forme d'un jet libre d'un métal non ferreux susceptible de présenter le problème de la formation d'une mousse métallique solide au pied du jet de coulée. Elle s'applique plus particulièrement à la coulée de zinc en lingotière.The subject of the invention is a method and an installation for casting in the form of a free jet of a non-ferrous metal capable of presenting the problem of the formation of a solid metal foam at the foot of the casting jet. It applies more particularly to the casting of zinc in an ingot mold.

Comme on le sait, lors de la coulée de métaux sous forme d'un jet libre, on tente de protéger le jet de coulée contre l'oxydation par l'air ambiant. Parmi les nombreuses méthodes de protection de jets de coulée mises en oeuvre jusqu'à ce jour, on peut citer le procédé de coulée de métal dans des moules, décrit dans le brevet français n° 2165769, selon lequel on assure, d'une part, l'inertage de la surface du métal en fusion lors de son chauffage par injection d'un gaz inerte liquéfié au moyen d'une lance traversant le couvercle du creuset de chauffage dudit métal, et, d'autre part, l'inertage préalable du moule dans lequel va s'effectuer la coulée. Ce procédé présente l'inconvénient qu'il y a risque d'oxydation lors du transfert à l'air libre du moule de son poste d'inertage à son poste de coulée, et également pendant la coulée proprement dite.As is known, during the casting of metals in the form of a free jet, an attempt is made to protect the casting jet against oxidation by ambient air. Among the numerous methods for protecting casting jets used to date, mention may be made of the method of casting metal into molds, described in French patent n ° 2165769, according to which, on the one hand, , the inerting of the surface of the molten metal during its heating by injection of an inert liquefied gas by means of a lance passing through the cover of the crucible for heating said metal, and, on the other hand, the preliminary inerting of the mold in which the casting will take place. This process has the disadvantage that there is a risk of oxidation during the transfer to the open air of the mold from its inerting station to its casting station, and also during the actual casting.

Ce problème de la protection du jet de coulée se pose d'une façon particulière lors de la coulée de métaux non ferreux susceptibles de provoquer la formation d'une mousse métallique solide au pied du jet de coulée, et plus spécialement lors de la coulée de zinc en lingotière.This problem of the protection of the casting jet arises in a particular way during the casting of non-ferrous metals capable of causing the formation of a solid metallic foam at the foot of the casting jet, and more especially during the casting of zinc in an ingot mold.

En effet, d'une façon générale, il est bien connu qu'à tout endroit où il y a chute de zinc liquide en jet libre, notamment lors de la coulée de zinc en lingotière, il se forme une mousse métallique solide au pied du jet de coulée qui se répand ensuite sur la surface du bain liquide contenu dans la lingotière.In general, it is well known that at any place where there is a fall of liquid zinc in free jet, in particular during the casting of zinc in an ingot mold, a solid metallic foam is formed at the foot of the casting jet which then spreads over the surface of the liquid bath contained in the mold.

Comme on le sait, la formation de cette mousse provient de l'oxydation du zinc. En effet, au point d'impact du jet de coulée, il y a création de bulles du fait de la tension superficielle élevée du zinc (≃780 dynes/cm). Or, l'air entraîné par le jet provoque une oxydation superficielle rapide de ces bulles. Comme l'oxyde de zinc (température de fusion du Zn0 = 1950°C) est solide à la température de coulée (470°C à 520°C) et que, de plus, sa capacité calorifique est nettement supérieure à celle du zinc (ZnO:Cp =12 cal.mole-1 T-1; Zn:=Cp=7,5cal.mole-' T-'), il y a stabilisation et solidification immédiate des bulles. La mousse métallique solide ainsi formée se présente sous la forme d'un feuilleté très fin qui comprend environ 98% de métal et représente 1 à 1,5% du métal coulé.As is known, the formation of this foam comes from the oxidation of zinc. Indeed, at the point of impact of the casting jet, bubbles are created due to the high surface tension of the zinc (≃780 dynes / cm). However, the air entrained by the jet causes rapid surface oxidation of these bubbles. As zinc oxide (melting temperature of Zn0 = 1950 ° C) is solid at the casting temperature (470 ° C to 520 ° C) and, moreover, its heat capacity is significantly higher than that of zinc ( ZnO: Cp = 12 cal.mole -1 T- 1 ; Zn: = Cp = 7,5cal.mole- 'T-'), there is immediate stabilization and solidification of the bubbles. The solid metal foam thus formed is in the form of a very thin laminate which comprises approximately 98% of metal and represents 1 to 1.5% of the cast metal.

Pour éviter les défauts constitués par les oxydes provenant de cette mousse dans les lingots de zinc ultérieurement obtenus, on est obligé d'éliminer-la couche superficielle de mousse de la surface du bain par écrémage manuel, en général avec une raclette, avant la solidification complète du métal dans la lingotière. Ainsi, outre l'inconvénient d'une perte non négligeable en métal de départ, la formation de mousse de zinc représente des investissements en main d'oeuvre et en temps qui nuisent à la rentabilité de l'ensemble du procédé.To avoid the defects formed by the oxides coming from this foam in the zinc ingots subsequently obtained, it is necessary to remove the surface layer of foam from the surface of the bath by manual skimming, generally with a squeegee, before solidification. full of metal in the mold. Thus, in addition to the disadvantage of a non-negligible loss of starting metal, the formation of zinc foam represents investments in manpower and time which harm the profitability of the whole process.

Il est connu, pour éviter la formation de mousse de zinc, d'effectuer la coulée avec des installations de conception différente par exemple des installations dans lesquelles la coulée s'effectue en source. Mais, comme on le sait, la coulée en source est plus onéreuse et difficile à mettre en oeuvre que la coulée en chute.It is known, in order to avoid the formation of zinc foam, to carry out the casting with installations of different design, for example installations in which the casting takes place at the source. But, as we know, source casting is more expensive and difficult to carry out than falling casting.

La présente invention a pour objet un procédé de coulée d'un métal non ferreux à l'état liquide, qui permet d'éviter la formation de mousse métallique solide, dans des installations de coulée en chute de type habituel.The subject of the present invention is a method of casting a non-ferrous metal in the liquid state, which makes it possible to avoid the formation of solid metallic foam, in falling casting installations of the usual type.

Ainsi, l'invention propose un procédé de coulée sous forme d'un jet libre d'un métal non ferreux, qui présente le problème de la formation d'une mousse métallique solide au pied du jet de coulée, d'une réserve dudit métal liquide vers au moins un récipient récepteur dudit métal, dans lequel on recouvre au moins un des récipients récepteurs par des moyens d'isolement de façon à former une zone d'isolement par rapport à l'ambiance, et on inerte préalablement ladite zone d'isolement grâce à des moyens d'alimentation et de distribution d'un gaz inerte à l'intérieur de ladite zone d'isolement, la teneur en oxygène y étant inférieure à 1% de préférence à 0,1%, caractérisé en ce que l'on établit un passage direct du métal liquide entre ladite réserve et le récipient récepteur placé en dessous du jet de coulée, de façon à ce que le jet de coulée du métal liquide demeure entièrement à l'intérieur de la zone d'isolement, tout en maintenant l'injection de gaz inerte dans la partie haute de ladite zone d'isolement à un débit tel que l'atmosphère au voisinage du jet de métal liquide ait une teneur en oxygène inférieure aux valeurs précitées.Thus, the invention provides a casting method in the form of a free jet of a non-ferrous metal, which presents the problem of the formation of a solid metallic foam at the foot of the casting jet, of a reserve of said metal. liquid to at least one receptacle for said metal, in which at least one of the receptacles is covered by isolation means so as to form a zone of isolation from the environment, and said zone is previously inerted isolation by means of supply and distribution of an inert gas inside said isolation zone, the oxygen content therein being less than 1% preferably 0.1%, characterized in that the 'a direct passage of the liquid metal is established between said reserve and the receiving container placed below the pouring jet, so that the pouring jet of the liquid metal remains entirely inside the isolation zone, while maintaining the injection of inert gas in the upper part of said isolation zone at a rate such that the atmosphere in the vicinity of the jet of liquid metal has an oxygen content lower than the above values.

Selon l'invention, le récipient récepteur est de préférence une lingotière, la réserve de métal liquide de préférence un bac répartiteur à orifice de coulée en son fond. Les moyens d'isolement peuvent être constitués de capots métalliques ou de parois métalliques, éventuellement reliés par des moyens de liaison.According to the invention, the receiving container is preferably an ingot mold, the reserve of liquid metal preferably a distributor tray with pouring orifice at its bottom. The isolation means can consist of metal covers or metal walls, possibly connected by connecting means.

Selon une variante de l'invention, on fait défiler un jeu de lingotières, disposées transversalement côte à côte, sous ladite réserve de métal liquide, et on inerte préalablement chacune des lingotières avant son passage sous le jet du métal liquide. Selon un mode de réalisation, on recouvre par la paroi d'isolement au moins deux lingotières adjacentes dudit jeu.According to a variant of the invention, a set of ingot molds is made to pass, arranged transversely side by side, under said reserve of liquid metal, and each of the ingot molds is inerted beforehand before passing under the jet of liquid metal. According to one embodiment, at least two adjacent molds of said set are covered by the isolation wall.

L'invention a également pour objet une installation de coulée sous forme d'un jet libre d'un métal non-ferreux qui présente le problème de la formation d'une mousse métallique solide au pied du jet de coulée, d'une réserve dudit métal liquide vers au moins un récipient récepteur dudit métal, comportant des moyens d'isolement recouvrant au moins un des récipients de façon à former une zone d'isolement par rapport à l'ambiance et des moyens d'alimentation et de distribution d'un gaz inerte à l'intérieur de ladite zone d'isolement, la teneur en oxygène y étant inférieure à 1% de préférence à 0,1%, caractérisée en ce qu'elle comporte des moyens permettant le passage direct du métal liquide entre ladite réserve et le récipient récepteur placé en dessous du jet de coulée à l'intérieur de la zone d'isolement, et en ce que les moyens d'alimentation et de distribution de gaz inerte maintiennent l'injection de gaz inerte dans la partie haute de ladite zone d'isolement à un débit tel que l'atmosphère au voisinage du jet de métal luiqide ait une teneur en oxygène inférieure aux valeurs précitées.The invention also relates to a casting installation in the form of a free jet of a non-ferrous metal which presents the problem of the formation of a solid metal foam at the foot of the casting jet, of a reserve of said liquid metal to at least one receptacle for receiving said metal, comprising isolation means covering at least one of the receptacles so as to form a zone of isolation from the environment and means for supplying and distributing a gas inert inside said isolation zone, the oxygen content therein being less than 1%, preferably less than 0.1%, characterized in that it comprises means allowing the direct passage of the liquid metal between said reserve and the receiving container placed below the pouring jet inside the isolation zone, and in that the inert gas supply and distribution means maintain the injection of inert gas in the upper part of said zone isolation at a flow rate such that the atmosphere in the vicinity of the metal jet itself has an oxygen content lower than the above values.

Comme on le comprend, la création de la zone d'isolement par rapport à l'ambiance et l'introduction dans cette zone d'un gaz inerte liquéfié empêche toute oxydation du métal liquide, et donc la formation de mousse métallique solide. En effet, il n'y a pas stabilisation ni solidification des bulles formées qui restent donc liquides et s'éliminent dans le bain de métal. Ainsi, grâce au procédé de l'invention, on évite toute perte en métal lors de la coulée et on obtient des lingots exempts de mousse en fin de procédé.As will be understood, the creation of the isolation zone with respect to the atmosphere and the introduction into this zone of a liquefied inert gas prevents any oxidation of the liquid metal, and therefore the formation of solid metallic foam. Indeed, there is no stabilization or solidification of the bubbles formed which therefore remain liquid and are eliminated in the metal bath. Thus, thanks to the process of the invention, any loss of metal is avoided during casting and ingots free of foam are obtained at the end of the process.

Les caractéristiques et avantages de l'invention apparaîtront dans la description qui suit, donnés à titre non limitatif, en référence aux dessins annexés dans lesquels:

  • - la figure 1 est une vue en perspective d'une installation de coulée d'un métal non ferreux;
  • - la figure 2 est une vue en coupe transversale partielle et agrandie selon II/II de la figure 1.
The characteristics and advantages of the invention will appear in the description which follows, given without limitation, with reference to the appended drawings in which:
  • - Figure 1 is a perspective view of an installation for casting a non-ferrous metal;
  • - Figure 2 is a partial and enlarged cross-sectional view along II / II of Figure 1.

En se référant aux figures 1 et 2, une installation de coulée de zinc comporte un bac répartiteur métallique 1 en forme de parallélépipède rectangle, comportant un fond 2 et quatre parois latérales 3a, 3b et 4a, 4b. Le fond 2 du bac 1 comporte une fente 5. Une goulotte 6 d'amenée de zinc liquide, reliée à un four de maintien (non représenté sur la figure) et légèrement inclinée, débouche à la partie supérieure de la paroi 3a du bac répartiteur 1.Referring to Figures 1 and 2, a zinc casting installation comprises a metal distributor tray 1 in the shape of a rectangular parallelepiped, having a bottom 2 and four side walls 3a, 3b and 4a, 4b. The bottom 2 of the tank 1 has a slot 5. A chute 6 for supplying liquid zinc, connected to a holding furnace (not shown in the figure) and slightly inclined, opens at the upper part of the wall 3a of the distribution tank 1.

Des lingotières métalliques L, placées transversalement côte à côte et solidaires de deux chaînes de transmission sans fin 8 par l'intermédiaire d'axes de pivotement 16, défilent dans le sens de la flèche F sous le bac répartiteur 1 et prennent successivement les positions 7A, 7B, 7C, 7D. Ces lingotières L sont en forme d'auge comportant un fond rectangulaire 9 et quatre parois latérales 10a, 10b et 11a, 11b légèrement inclinées.Metal ingot molds L, placed transversely side by side and integral with two endless transmission chains 8 via pivot axes 16, travel in the direction of arrow F under the distribution bin 1 and successively take positions 7A , 7B, 7C, 7D. These ingot molds L are in the form of a trough comprising a rectangular bottom 9 and four side walls 10a, 10b and 11a, 11b slightly inclined.

Un capot métallique 12, en forme de parallélépipède rectangle comporte une plaque supérieure horizontale 13 et quatre parois latérales verticales 14a, 14b et 15a, 15b. La plaque supérieure 13 est percée d'une ouverture rectangulaire ayant les dimensions juste nécessaires pour y encastrer la partie inférieure du bac répartiteur 1. La plaque 13 du capot 12 est fixée par l'intermédiaire de quatre plaques de liaison métalliques 18 à l'aide de boulons 19 aux parois 3a, 3b et 4a, 4b du bac répartiteur 1.A metal cover 12, in the shape of a rectangular parallelepiped has a horizontal upper plate 13 and four vertical side walls 14a, 14b and 15a, 15b. The upper plate 13 is pierced with a rectangular opening having the dimensions just necessary to embed the lower part of the distribution tank 1. The plate 13 of the cover 12 is fixed by means of four metal connection plates 18 using of bolts 19 to the walls 3a, 3b and 4a, 4b of the distribution box 1.

Le capot 12 surplombe entièrement les deux lingotières 7B et 7C, et ses parois latérales 14a, 14b et 15a, 15b arrivent juste au ras des bords supérieurs de ces lingotières. De façon plus précise, le bord inférieur 20 des parois 14a, 14b s'arrête juste au-dessus des bords supérieurs 21 des parois 10a, 10b des lingotières 7B et 7C et le bord inférieur 22 des parois 15a, 15b s'arrête juste au-dessus des bords supérieurs 28 des parois 11a, 11b des lingotières 7B et 7C. Ainsi, le capot 12 forme un couvercle de protection quasi-hermétique pour la cavité interne des lingotières 7B et 7C tout en ne les empêchant pas de défiler.The cover 12 completely overhangs the two ingot molds 7B and 7C, and its side walls 14a, 14b and 15a, 15b arrive just flush with the upper edges of these ingot molds. More specifically, the lower edge 20 of the walls 14a, 14b stops just above the upper edges 21 of the walls 10a, 10b of the molds 7B and 7C and the lower edge 22 of the walls 15a, 15b stops just at the above the upper edges 28 of the walls 11a, 11b of the molds 7B and 7C. Thus, the cover 12 forms a quasi-hermetic protective cover for the internal cavity of the molds 7B and 7C while not preventing them from scrolling.

Une rampe 23 d'alimentation et de distribution d'un gaz inerte liquéfié est fixée sous la plaque supérieure 13 parallèlement à la paroi 14a, dans la partie amont du capot 12 par rapport au sens de déplacement F des lingotières L. Cette rampe 23 est du type séparateur de phases classique, comportant une fente 29 de dégazage à sa partie supérieure et munie, à sa partie inférieure et à espacements réguliers, de buses d'injection 24 de gaz inerte liquide orientées vers le bas. La rampe 23 est reliée à un réservoir de gaz inerte liquéfié 25 par l'intermédiaire d'un conduit 26 et d'un tube plongeur 27. La rampe d'alimentation et de distribution 23 est située de préférence dans la partie amont du capot 12 par rapport au sens de déplacement F, comme représenté sur les figures, mais elle peut être également placée dans la partie aval du capot 12; il peut également y avoir deux rampes d'alimentation et de distribution de gaz inerte liquéfié, l'une dans la partie amont et l'autre dans la partie aval du capot.A ramp 23 for supplying and distributing a liquefied inert gas is fixed under the upper plate 13 parallel to the wall 14a, in the upstream part of the cover 12 relative to the direction of movement F of the molds L. This ramp 23 is of the conventional phase separator type, comprising a degassing slot 29 at its upper part and provided, at its lower part and at regular intervals, with injection nozzles 24 for liquid inert gas oriented downwards. The ramp 23 is connected to a tank of liquefied inert gas 25 via a conduit 26 and a dip tube 27. The supply and distribution ramp 23 is preferably located in the upstream part of the cover 12 relative to the direction of movement F, as shown in the figures, but it can also be placed in the downstream part of the cover 12; there may also be two supply and distribution ramps for liquefied inert gas, one in the upstream part and the other in the downstream part of the cover.

Un conduit vertical 30 traverse la partie aval de la plaque supérieure 13 par rapport au sens de déplacement F et débouche légèrement en-dessous de ladite plaque 13. Ce conduit 30, muni d'une pompe 32, est relié à un analyseur d'oxygène 31.A vertical conduit 30 crosses the downstream part of the upper plate 13 relative to the direction of movement F and opens slightly below said plate 13. This conduit 30, fitted with a pump 32, is connected to an oxygen analyzer 31.

Une rampe de préchauffage 33, disposée parallèlement à la paroi 14a du capot 12 et au-dessus de la lingotière 7A, est fixée à la paroi 14a par l'intermédiaire de tiges métalliques 34 munies de bagues métalliques 35. Cette rampe de préchauffage 33 est constituée d'un tuyau 36 relié à des sources d'alimentation en gaz combustible et en gaz comburant (non représentées sur les figures) et muni, à espacements réguliers, de brûleurs 37 orientés vers la cavité interne de la lingotière 7A.A preheating ramp 33, arranged parallel to the wall 14a of the cover 12 and above the ingot mold 7A, is fixed to the wall 14a by means of metal rods 34 provided with metal rings 35. This preheating ramp 33 is consisting of a pipe 36 connected to fuel gas and oxidizing gas supply sources (not shown in the figures) and provided, at regular intervals, with burners 37 oriented towards the internal cavity of the mold 7A.

Le bac répartiteur 1 contient un bain de zinc liquide 40 qui s'écoule par la fente 5 sous forme d'un jet J pour former un bain de zinc liquide 41 dans la lingotière 7C.The distribution tank 1 contains a bath of liquid zinc 40 which flows through the slot 5 in the form of a jet J to form a bath of liquid zinc 41 in the mold 7C.

Le fonctionnement de l'installation selon l'invention est le suivant. On alimente en continu le bac répartiteur 1 en zinc liquide, provenant d'un four de maintien, à l'aide de la goulotte 6; les impuretés, notamment les oxydes formés lors du transport à l'air dans la goulotte 6, restent à la surface du bain de métal liquide 40 ainsi formé dans le répartiteur 1 et le zinc liquide pur décante au fond du répartiteur 1 et s'écoule par la fente 5 dans la lingotière qui est en position 7C.The operation of the installation according to the invention is as follows. The distributor tank 1 is continuously supplied with liquid zinc, coming from a holding oven, using the chute 6; the impurities, in particular the oxides formed during transport in air in the chute 6, remain on the surface of the bath of liquid metal 40 thus formed in the distributor 1 and the pure liquid zinc settles at the bottom of the distributor 1 and flows by the slot 5 in the mold which is in position 7C.

On fait défiler, à l'aide des chaînes 8, les lingotières L sous le capot 12 dans le sens de la flèche F. Avant de passer sous le capot 12, chaque lingotière L, en position 7A, est préchauffée à une température supérieure à 100°C au moyen de la rampe de préchauffage 33. Quand cette lingotière L arrive ensuite en position 7B, elle reçoit les jets d'un gaz inerte liquéfié, tel que de l'argon ou de l'azote, injectés par les buses 24 de la rampe d'alimentation 23. Une partie de ce gaz inerte liquéfié se vaporise et se répand dans l'espace défini par le capot 12 et les lingotières en position 7B et 7C; l'autre partie reste liquide et forme une couche liquide 42 sur le fond de la lingotière 7B qui se retrouvera à la surface du bain métallique 41 quand la lingotière sera en position 7C. Ainsi, il se crée une atmosphère gazeuse inerte dans la cavité interne de la lingotière L en position 7B ainsi qu'au-dessus de la surface du bain 41 et autour du jetJ dans la lingotière suivante (position 7C). Ensuite, la lingotière L arrive en position 7C où elle reçoit le jet J de zinc liquide et se remplit peu à peu tout en étant maintenue en atmosphère gazeuse inerte comme on vient de l'expliquer précédemment. Quand la lingotière L arrive en position 7D, elle contient un bain de zinc liquide dont la surface est exempte de mousse métallique solide.The molds L are scrolled using the chains 8 under the cover 12 in the direction of the arrow F. Before passing under the cover 12, each mold L, in position 7A, is preheated to a temperature above 100 ° C by means of the preheating ramp 33. When this ingot mold L then arrives in position 7B, it receives the jets of a liquefied inert gas, such as argon or nitrogen, injected by the nozzles 24 of the supply rail 23. A portion of this liquefied inert gas vaporizes and spreads in the space defined by the cover 12 and the molds in position 7B and 7C; the other part remains liquid and forms a liquid layer 42 on the bottom of the mold 7B which will be found on the surface of the metal bath 41 when the mold is in position 7C. Thus, an inert gas atmosphere is created in the internal cavity of the ingot mold L in position 7B as well as above the surface of the bath 41 and around the jet J in the following ingot mold (position 7C). Then, the ingot mold L arrives in position 7C where it receives the jet J of liquid zinc and gradually fills while being maintained in an inert gas atmosphere as just explained above. When ingot mold L arrives in position 7D, it contains a bath of liquid zinc, the surface of which is free of solid metal foam.

Tout au long du procédé, on surveille en permanence la teneur en oxygène de l'atmosphère au voisinage du jet de coulée J et de la surface du bain métallique 41 à l'aide de l'analyseur d'oxygène 31, et on règle le débit d'injection du gaz inerte liquéfié dans la rampe d'alimentation 23 de façon à ce que cette teneur en oxygène soit inférieure à 1% de préférence à 0,1%.Throughout the process, the oxygen content of the atmosphere in the vicinity of the pouring jet J and of the surface of the metal bath 41 is continuously monitored using the oxygen analyzer 31, and the injection rate of the liquefied inert gas into the supply rail 23 so that this oxygen content is less than 1%, preferably 0.1%.

Le préchauffage éventuel de chaque lingotière en position 7A est destiné, dans certains cas, à éviter un refroidissement trop important de cette dernière quand elle sera en position 7B ainsi que du bain de métal liquide qu'elle contiendra quand elle sera en position 7C, refroidissement qui provient des frigories apportées par le gaz inerte liquéfié.The possible preheating of each mold in position 7A is intended, in certain cases, to avoid excessive cooling of the latter when it is in position 7B as well as of the bath of liquid metal which it will contain when it is in position 7C, cooling which comes from the frigories brought by liquefied inert gas.

On a représenté, sur les figures 3 et 4 jointes, deux vues en coupe transversale d'un autre mode de réalisation d'une installation de coulée d'un métal non ferreux mettant en oeuvre le procédé conforme à l'invention.There is shown in Figures 3 and 4 attached, two cross-sectional views of another embodiment of an installation for casting a non-ferrous metal implementing the method according to the invention.

En se référant aux figures 3 et 4, une installation de coulée de zinc comporte un bac répartiteur 50 en forme de parallélépipède rectangle comportant un fond 51 et quatre parois latérales 52. Le fond 51 du bac 50 comporte une fente 53. Une goulotte 54 d'amenée de zinc liquide débouche dans la partie supérieure du bac répartiteur 50.With reference to FIGS. 3 and 4, a zinc casting installation comprises a distribution tank 50 in the form of a rectangular parallelepiped comprising a bottom 51 and four side walls 52. The bottom 51 of the tank 50 has a slot 53. A chute 54 d the liquid zinc inlet opens into the upper part of the distribution tank 50.

Des lingotières métalliques 53, placées transversalement côte à côte, défilent dans le sens de la flèche G, en suivant une pente légèrement ascendante grâce à une rampe de transport (non représentée sur les figures), et prennent successivement les positions 55A, 55B, 55C, 55D. Ces lingotières 55 sont en forme d'auge comportant un fond rectangulaire 56 et quatre parois latérales 57 légèrement inclinées.Metal ingot molds 53, placed transversely side by side, pass in the direction of arrow G, following a slightly ascending slope by means of a transport ramp (not shown in the figures), and successively assume positions 55A, 55B, 55C , 55D. These ingot molds 55 are in the shape of a trough comprising a rectangular bottom 56 and four side walls 57 slightly inclined.

Un capot métallique 59 prenant appui sur des plaques de protection de la rampe de transport (non représentées sur les figures) et surplombant au moins une lingotière 55 est équipé d'une rampe 60 d'alimentation en gaz inerte. Cette rampe 60 est, d'autre part, reliée à une paroi 52 d'un bac répartiteur 50 par une jupe 61, en tissu réfractaire par exemple. Une canne d'injection d'un gaz inerte liquéfié 62 débouche au-dessus de la cavité interne d'une des lingotières 55. Une jupe 63, fixée au fond 51 du bac répartiteur 50, descend verticalement jusque dans la cavité interne de la lingotière suivante.A metal cover 59 bearing on the protection plates of the transport ramp (not shown in the figures) and overhanging at least one ingot mold 55 is equipped with a ramp 60 for supplying inert gas. This ramp 60 is, on the other hand, connected to a wall 52 of a distribution tank 50 by a skirt 61, made of refractory fabric for example. An injection pipe for a liquefied inert gas 62 opens out above the internal cavity of one of the ingot molds 55. A skirt 63, fixed to the bottom 51 of the distributor 50, descends vertically into the internal cavity of the ingot mold next.

Un capot métallique 64 prenant appui sur trois des parois latérales 52 du bac 1 est équipé d'une rampe 65 d'alimentation en gaz inerte. Une jupe 67 relie la rampe 65 à un capot métallique 68 qui surplombe la goulotte 54. Une cloison verticale 58, qui s'arrête à distance du fond de la goulotte 54, arrête la mousse de zinc formée à la surface du zinc liquide lors de son transport à l'air libre vers la goulotte et oblige le zinc pur à passer par le bas. Une jupe 69 relie une paroi latérale 52 du bac 50 et le fond de la goulotte 54.A metal cover 64 bearing on three of the side walls 52 of the tank 1 is equipped with a ramp 65 for supplying inert gas. A skirt 67 connects the ramp 65 to a metal cover 68 which overhangs the chute 54. A vertical partition 58, which stops at a distance from the bottom of the chute 54, stops the zinc foam formed on the surface of the liquid zinc during its transport in the open air to the chute and forces the pure zinc to pass through the bottom. A skirt 69 connects a side wall 52 of the tank 50 and the bottom of the chute 54.

Le fonctionnement de l'installation représentée aux figures 3 et 4 est le suivant. La figure 3 représente la position respective des éléments de l'installation lors du remplissage d'une lingotière 55C par du zinc liquide; la figure 4 représente la position respective des éléments de l'installation lors du passage d'une lingotière remplie de zinc liquide 55C à la lingotière vide suivante 55B.The operation of the installation shown in Figures 3 and 4 is as follows. FIG. 3 represents the respective position of the elements of the installation when filling an ingot mold 55C with liquid zinc; FIG. 4 represents the respective position of the elements of the installation during the passage from an ingot mold filled with liquid zinc 55C to the next empty ingot mold 55B.

Lors du remplissage de la lingotière 55C (fig. 3), le bac répartiteur 50 est en position horizontale. Il est alimenté en zinc liquide par la goulotte 54; grâce à la zone de protection constituée par le capot 68, la jupe 67 et le capot 64, et l'inertage de ladite zone de protection par un gaz inerte (rampe 65) la surface du bain de zinc liquide 70 contenu dans la goulotte 54, le jet de zinc liquide 71 s'écoulant de la goulotte 54 dans le bac 50 et la surface du bain de zinc liquide 72 contenu dans le bac 50, sont parfaitement propres, c'est-à-dire exempts de crasses et de mousses dues à une oxydation éventuelle du zinc. D'autre part, le jet de zinc liquide 73 et la surface du bain de zinc liquide 74 contenu dans la lingotière 55C, sont protégés contre toute oxydation grâce à la zone de confinement constituée par le capot 59, le fond 51 et l'inertage de ladite zone de confinement par un gaz inerte (rampe 60) et un gaz inerte liquéfié (canne 62).When filling the mold 55C (fig. 3), the distributor 50 is in a horizontal position. It is supplied with liquid zinc by the chute 54; thanks to the protection zone constituted by the cover 68, the skirt 67 and the cover 64, and the inerting of said protection zone by an inert gas (ramp 65) the surface of the bath of liquid zinc 70 contained in the chute 54 , the jet of liquid zinc 71 flowing from the chute 54 into the tank 50 and the surface of the bath of liquid zinc 72 contained in the tank 50, are perfectly clean, that is to say free from dross and foam due to possible oxidation of zinc. On the other hand, the jet of liquid zinc 73 and the surface of the bath of liquid zinc 74 contained in the mold 55C, are protected against any oxidation by virtue of the confinement zone constituted by the cover 59, the bottom 51 and the inerting from said containment zone by an inert gas (ramp 60) and a liquefied inert gas (cane 62).

Une fois la lingotière 55C remplie, on fait défiler le jeu de lingotières de façon à amener la lingotière suivante 55B sous le bac répartiteur 50. Lors du passage de la lingotière 55C à la lingotière 55B (voir figure 4), on met le bac 50 en position inclinée par basculement autour d'un axe 66 de façon à ce que le niveau du bain de zinc liquide 72 soit tel que le zinc ne puisse pas s'écouler par la fente 53. Pendant toute l'opération de déplacement des lingotières jusqu'à ce que la lingotière 55B ait pris la position occupée précédemment par la lingotière 55C, on maintient l'inertage de la zone de protection (capot 68, jupe 67 et capot 64) et de la zone de confinement (capot 59, fond 51 et jupe 63), comme décrit ci-dessus. Grâce à la souplesse conférée à l'ensemble par la présence des jupes 61, 67, 69, 63, l'isolement de la zone de protection et de la zone de confinement est maintenu sans problème lors du passage d'une lingotière à une autre. Ainsi, grâce au procédé de l'invention, on obtient du zinc liquide propre en tout point entre la goulotte 54, le bac répartiteur 50 et le jet 73; et, lors du remplissage d'une lingotière à partir de ce zinc liquide propre, on le protège contre toute oxydation par inertage de la zone de confinement. On est ainsi certain de supprimer complètement la formation de mousse de zinc à la surface du bain contenu dans les lingotières une fois remplies.Once the mold 55C is filled, the set of molds is scrolled so as to bring the following mold 55B under the distribution tray 50. When passing from the mold 55C to the mold 55B (see FIG. 4), the tray 50 is placed in the tilted position by tilting about an axis 66 so that the level of the liquid zinc bath 72 is such that the zinc cannot flow through the slot 53. During the entire operation of moving the molds up to '' until the ingot mold 55B has taken the position previously occupied by the ingot mold 55C, the inerting of the protection zone (hood 68, skirt 67 and hood 64) and of the confinement zone (hood 59, bottom 51 is maintained) and skirt 63), as described above. Thanks to the flexibility given to the assembly by the presence of skirts 61, 67, 69, 63, the isolation of the protection zone and of the confinement zone is maintained without problem when switching from one mold to another. Thus, thanks to the process of the invention, clean liquid zinc is obtained at all points between the chute 54, the distribution tank 50 and the jet 73; and, when filling an ingot mold with this clean liquid zinc, it is protected against any oxidation by inerting of the confinement zone. It is thus certain to completely eliminate the formation of zinc foam on the surface of the bath contained in the molds once filled.

Selon une première variante de réalisation, on inerte la zone de confinement surplombant au moins une lingotière, que ce soit en position de remplissage d'une lingotière ou en position de passage d'une lingotière à une autre, à la fois par injection d'un gaz inerte liquéfié en amont, par rapport au sens de déplacement G, de la fente de coulée 53 et injection d'un gaz inerte en aval de ladite fente 53; dans ce cas, la quantité de gaz inerte liquéfié. injecté est de 75% à 100% de la quantité totale de gaz utilisé. Selon une deuxième variante de réalisation, on inerte la zone de confinement par injection d'un gaz inerte liquéfié uniquement en amont de la fente de coulée 53. Selon une troisième variante de réalisation, on inerte la zone de confinement par injection d'un gaz inerte liquéfié à la fois en amont et en aval de la fente de coulée 53.According to a first alternative embodiment, the confinement zone overhanging at least one ingot mold is inert, whether in the filling position of one ingot mold or in the position for passing from one ingot mold to another, both by injection of an inert gas liquefied upstream, relative to the direction of movement G, of the casting slot 53 and injection of an inert gas downstream of said slot 53; in this case, the amount of liquefied inert gas. injected is 75% to 100% of the total amount of gas used. According to a second alternative embodiment, the confinement zone is inerted by injection of an inert liquefied gas only upstream of the casting slot 53. According to a third alternative embodiment, the confinement zone is inerted by injection of a gas inert liquefied both upstream and downstream of the casting slot 53.

Le gaz inerte utilisé peut être, par exemple, de l'azote ou de l'argon.The inert gas used can be, for example, nitrogen or argon.

L'invention s'applique plus particulièrement à la coulée continue du zinc en lingotière, mais elle pourrait également s'appliquer à la coulée de tout métal non ferreux en chute libre susceptible de présenter le problème de la formation de mousse métallique solide au pied du jet de coulée, tel que du plomb ou des alliages de plomb et de calcium, ou des alliages de zinc.The invention applies more particularly to the continuous casting of zinc in an ingot mold, but it could also be applied to the casting of any non-ferrous metal in free fall liable to present the problem of the formation of solid metallic foam at the foot of the casting jet, such as lead or lead and calcium alloys, or zinc alloys.

Claims (16)

1. Process for casting in the form of a free jet a nonferrous metal which presents the problem of forming a solid metal foam at the bottom of the casting jet, from a reserve of the said liquid metal (1) towards at least one receiving receptacle (L) for the said metal, in which at least one of the receiving receptacles is covered by insulating means (12, 51, 59, 61, 63) so as to form a zone of insulation with respect to the surroundings, and the said insulation zone is made inert beforehand by virtue of means for supplying and distributing an inert gas (23, 60, 62) within the said insulation zone, the content of oxygen therein being less than 1 %, preferably less than 0.1 %, characterized in that a direct passage for the liquid metal is established between the said reserve and the receiving receptacle placed below the casting jet, so that the casting jet of the liquid metal remains entirely within the insulation zone, while injection of inert gas into the top part of the said insulation zone is maintained at a rate such that the atmosphere in the vicinity of the jet of liquid metal has an oxygen content which is lower than the abovementioned values.
2. Process according to Claim 1, according to which a set of receiving receptacles (L) arranged transversely side by side is made to travel in succession under the said reserve of liquid metal (1), characterized in that each of the receiving receptacles (L) is first made inert before it passes under the jet of liquid metal.
3. Process according to either of Claims 1 and 2, characterized in that at least two adjacent receiving receptacles of the said set are covered by insulating means.
4. Process according to one of Claims 1 to 3, characterized in that each of the receiving receptacles (L) is preheated before its passage in the insulation zone.
5. Process according to one of Claims 1 to 4, characterized in that the inert gas is nitrogen or argon.
6. Plant for casting in the form of a free jet a non-ferrous metal which presents the problem of forming a solid metal film at the bottom of the casting jet, from a reserve of the said liquid metal (1) towards at least one receiving receptacle (L) for the said metal, comprising means of insulation (12, 51, 59, 61, 63) covering at least one of the receiving receptacles (L) so as to form a zone of insulation with respect to the surroundings and means for supplying and distributing an inert gas (23, 60, 62) within the said insulation zone, the content of oxygen therein being less than 1%, preferably less than 0.1%, characterized in that it comprises means permitting the liquid metal to pass directly between the said reserve and the receiving receptacle placed below the casting jet inside the insulation zone, and in that the means for supplying and distributing inert gas (23, 60, 62) maintains the injection of inert gas into the top part of the said insulation zone at a rate such that the atmosphere in the vicinity of the jet of liquid metal has an oxygen content which is lower than the abovementioned values.
7. Plant according to Claim 6, characterized in that the means for a direct passage of the liquid metal between the said reserve and the receiving receptacle comprise a distribution tank (1, 50) with a casting orifice (5, 53) in the bottom, the means for insulating with respect to the surrounding being integrally connected to the said distribution tank around the said casting orifice and extending downwards so as to cover at least one receiving receptacle.
8. Plant according to either of Claims 6 and 7, characterized in that it comprises means for driving and guiding (8) for a set of receiving receptacles (L) arranged transversely side by side as a train capable of travelling in succession under the said means of insulation (12).
9. Plant according to one of Claims 6 to 8, characterized in that it comprises preheating means (33) upstream of the reserve of liquid metal (1) relative to the direction of travel of the said train.
10. Plant according to one of Claims 6 to 9, characterized in that it comprises means for measuring the oxygen content (31) within the means of insulation (12), in the vicinity of the casting orifice of the distribution tank (1).
11. Plant according to one of Claims 6 to 10, characterized in that the means of insulation (12) consist of a metal hood in the shape of a rectangular parallelepiped whose upper horizontal plate (13) comprises a rectangular opening whose dimensions are just those necessary to fit therein the lower part of the distribution tank (1) and whose four plates (14a, 14b, 15a, 15b) come just flush with the upper edges of at least one receiving receptacle (L).
12. Plant according to Claim 11, characterized in that the means for supplying and distributing an inert gas are connected to a storage tank (25) for liquefied inert gas and consist of a supply and distribution manifold (23) of the type forming a phase-separator with orifices for liquid discharge (24) in the lower region and orifices for gas discharge (29) in an upper region, placed within the said means of insulation (12).
13. Plant according to one of Claims 6 to 10, characterized in that the means of insulation comprise a metal hood (59) overhanging at least one receiving receptacle, the bottom (51) of the distribution tank (50), and means for connecting (61) the said hood (59) to the said distribution tank (50) and for a connection (63) between the bottom (51) of the said distribution tank (50) and the internal cavity of a receiving receptacle.
14. Plant according to Claim 13, characterized in that the distribution tank (50) is mounted rockingly around a horizontal axis.
15. Plant according to either of Claims 13 and 14, characterized in that the connecting means (61) and (63) consist of skirts.
16. Plant according to one of Claims 13 to 15, characterized in that the means for supplying and distributing an inert gas consist of a pipe (62) for injecting liquefied inert gas, opening above the internal cavity of a receiving receptacle and of a supply manifold (60) for inert gas.
EP83400479A 1982-03-08 1983-03-08 Process and device for casting a molten non ferrous metal Expired EP0088701B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR8203817A FR2523005A1 (en) 1982-03-08 1982-03-08 PROCESS AND INSTALLATION FOR CASTING A NON-FERROUS LINGOTIERE METAL
FR8203817 1982-03-08

Publications (2)

Publication Number Publication Date
EP0088701A1 EP0088701A1 (en) 1983-09-14
EP0088701B1 true EP0088701B1 (en) 1986-12-10

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EP83400479A Expired EP0088701B1 (en) 1982-03-08 1983-03-08 Process and device for casting a molten non ferrous metal

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US (1) US4565234A (en)
EP (1) EP0088701B1 (en)
JP (1) JPS58167056A (en)
AU (1) AU555738B2 (en)
BE (1) BE896099A (en)
CA (1) CA1257067A (en)
DE (1) DE3368215D1 (en)
ES (1) ES520367A0 (en)
FR (1) FR2523005A1 (en)
IT (1) IT1161582B (en)
ZA (1) ZA831233B (en)

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US4549598A (en) * 1981-12-17 1985-10-29 Noranda Inc. Process for minimizing foam formation during free falling of molten metal into moulds, launders or other containers
AU560253B2 (en) * 1983-12-23 1987-04-02 Noranda Mines Ltd. Process and apparatus for minimizing foam formation during free falling of molten metal into moulds, launders or other containers
US4576220A (en) * 1983-12-23 1986-03-18 Noranda Inc. Method and apparatus for maintaining an atmosphere around a predetermined portion of an endless discrete object conveyor
JPS61158025A (en) * 1984-12-28 1986-07-17 Canon Inc Magnetic recording medium
FR2607039B1 (en) * 1986-11-26 1989-03-31 Air Liquide STEEL CASTING PROCESS INCLUDING INERING OF THE STEEL BATH WITH CARBONIC ANHYDRIDE IN THE FORM OF SNOW
US4933005A (en) * 1989-08-21 1990-06-12 Mulcahy Joseph A Magnetic control of molten metal systems
US5404929A (en) * 1993-05-18 1995-04-11 Liquid Air Corporation Casting of high oxygen-affinity metals and their alloys
AUPN716195A0 (en) * 1995-12-14 1996-01-18 Australian Magnesium Corporation Pty Ltd Ingot mould system
AU723278B2 (en) * 1995-12-14 2000-08-24 Australian Magnesium Operations Pty Ltd Ingot mould system
FR2809643B1 (en) * 2000-05-31 2002-10-25 Brochot Sa METHOD AND DEVICE FOR PROTECTING NON-FERROUS MOLTEN METAL
KR20030085642A (en) * 2002-04-29 2003-11-07 김학배 A moulding method for nonferrous metal plate
US20080184848A1 (en) 2006-08-23 2008-08-07 La Sorda Terence D Vapor-Reinforced Expanding Volume of Gas to Minimize the Contamination of Products Treated in a Melting Furnace
US20090064821A1 (en) * 2006-08-23 2009-03-12 Air Liquide Industrial U.S. Lp Vapor-Reinforced Expanding Volume of Gas to Minimize the Contamination of Products Treated in a Melting Furnace
US8403187B2 (en) * 2006-09-27 2013-03-26 Air Liquide Industrial U.S. Lp Production of an inert blanket in a furnace

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US1978222A (en) * 1932-09-24 1934-10-23 Allegheny Steel Co Method of and apparatus for treating metallic materials
FR1262890A (en) * 1960-07-12 1961-06-05 Method and device for casting and stacking metal parts, in particular plates
GB956865A (en) * 1959-07-15 1964-04-29 Heinrich Josef Baggeler Improvements in or relating to methods and apparatus for casting and stacking metal pieces
FR1319216A (en) * 1962-04-06 1963-02-22 Verwaltungs Ges Moeller & Neum Casting plant for metals, in particular for zinc slabs
JPS4830627A (en) * 1971-08-26 1973-04-23
BE793567A (en) * 1971-12-30 1973-06-29 Air Liquide METAL CASTING PROCESS
US3991813A (en) * 1973-08-23 1976-11-16 Allmanna Svenska Elektriska Aktiebolaget Melt casting apparatus
JPS5332829A (en) * 1976-09-09 1978-03-28 Tokyo Shibaura Electric Co Continuous casting device
JPS53137830A (en) * 1977-05-09 1978-12-01 Nippon Chiyuutankou Kk Degassing casting method and apparatus for molten steel
FR2403849A1 (en) * 1977-09-23 1979-04-20 Siderurgie Fse Inst Rech NEW ELECTROMAGNETIC CENTRIFUGAL CONTINUOUS CASTING PROCESS OF FUSION METALS
JPS626804Y2 (en) * 1980-05-29 1987-02-17

Also Published As

Publication number Publication date
AU555738B2 (en) 1986-10-09
ZA831233B (en) 1983-11-30
JPS58167056A (en) 1983-10-03
BE896099A (en) 1983-09-07
CA1257067A (en) 1989-07-11
IT8319809A0 (en) 1983-02-25
EP0088701A1 (en) 1983-09-14
ES8404216A1 (en) 1984-04-16
AU1186383A (en) 1983-09-15
FR2523005A1 (en) 1983-09-16
US4565234A (en) 1986-01-21
IT1161582B (en) 1987-03-18
FR2523005B1 (en) 1984-12-07
DE3368215D1 (en) 1987-01-22
ES520367A0 (en) 1984-04-16

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