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EP0125161A1 - Process for producing metal powder starting from a molten metal - Google Patents

Process for producing metal powder starting from a molten metal Download PDF

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Publication number
EP0125161A1
EP0125161A1 EP84400733A EP84400733A EP0125161A1 EP 0125161 A1 EP0125161 A1 EP 0125161A1 EP 84400733 A EP84400733 A EP 84400733A EP 84400733 A EP84400733 A EP 84400733A EP 0125161 A1 EP0125161 A1 EP 0125161A1
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EP
European Patent Office
Prior art keywords
liquid
cryogenic fluid
metallic material
fluid
metal
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
EP84400733A
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German (de)
French (fr)
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EP0125161B1 (en
Inventor
Albert-Gilbert Goursat
Gilles Vernet
Jean-Francis Rimbert
Jean Foulard
Thierry Darle
Jean Bigot
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Air Liquide SA
LAir Liquide SA pour lEtude et lExploitation des Procedes Georges Claude
Original Assignee
Air Liquide SA
LAir Liquide SA pour lEtude et lExploitation des Procedes Georges Claude
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Application filed by Air Liquide SA, LAir Liquide SA pour lEtude et lExploitation des Procedes Georges Claude filed Critical Air Liquide SA
Priority to AT84400733T priority Critical patent/ATE27780T1/en
Publication of EP0125161A1 publication Critical patent/EP0125161A1/en
Application granted granted Critical
Publication of EP0125161B1 publication Critical patent/EP0125161B1/en
Expired legal-status Critical Current

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F9/00—Making metallic powder or suspensions thereof
    • B22F9/02—Making metallic powder or suspensions thereof using physical processes
    • B22F9/12—Making metallic powder or suspensions thereof using physical processes starting from gaseous material

Definitions

  • the present invention relates to a method for manufacturing metallic powders, in particular ultra-fine powders, from a molten metallic material.
  • metal powders powders constituted by solid particles either of a single metal such as iron, zinc, magnesium, etc., or of a metal alloy for example a magnesium-zinc alloy , or even a metallic compound, for example zinc oxide, magnesium nitride, etc.
  • metal material is meant either a pure metal or an alloy of two or more metals.
  • a cryogenic fluid in the liquid phase it consists in pouring onto the metal bath, brought to a temperature such that its vapor pressure is at least 1 mm of mercury, a cryogenic fluid in the liquid phase, to evacuate outside the enclosure the cryogenic fluid which contains, in suspension, the solid particles formed, to separate the latter from said fluid and to collect them to obtain the abovementioned powder.
  • a cryogenic fluid in the liquid phase allows very rapid cooling of the metallic vapors coming from the bath and their direct passage from the gaseous state to the solid state.
  • the method described in patent No. 78.26.648, has the advantage of making it possible to obtain, either from a pure metal or from alloys, solid particles having a regular shape and a small particle size. (from 100A to 2000A).
  • this method has the disadvantage of being usable only for obtaining metal powders whose vapor pressure corresponds to medium temperatures.
  • volatile metals such as lead, zinc, magnesium
  • less volatile metals such as iron, nickel, cobalt
  • the materials generally constituting metal melting crucibles do not have sufficient mechanical strength to withstand temperatures above 2000 ° C.
  • the subject of the invention is precisely a process which overcomes the drawbacks mentioned above and makes it possible to obtain powders of elements whose vapor pressure corresponds to very high temperatures.
  • the method for manufacturing metallic powder according to the invention consists in bringing into contact with a cryogenic fluid in the liquid phase, in a closed treatment enclosure, a metallic material, heated to a temperature such that its vapor pressure is at least minus 1mm of mercury, to evacuate from the enclosure the cryogenic fluid which contains, in suspension, the solid particles formed, to separate the latter from said fluid, and to collect them to obtain the aforementioned metallic powder. It is characterized in that, by induction of high frequency current, said metallic material is heated and levitated in the cryogenic liquid.
  • the principle of levitation fusion is to place a metal part in an inductor of suitable shape traversed by high frequency currents.
  • the interaction between the magnetic field and the currents induced in the metal part allows this one to float, to levitate, without any contact with a material support.
  • the metallic material is heated by levitation fusion makes it possible to be able to bring it without problem to temperatures above 2000 ° C. and to obtain, thanks to the bringing into contact with the liquid cryogenic, solid particles from metals that are only volatile at very high temperatures.
  • the metallic material in fusion is maintained in the cryogenic liquid
  • the latter separated from said material by a gaseous layer due to the heat-up phenomenon, heats up in the vicinity of the molten metallic material; the cold vapors thus formed condense the metallic vapors coming from the material and immediately transform them into solid particles which are entrained upwards by the remaining vapors of the cryogenic liquid.
  • This results in a shift in the liquid metal - metal vapor equilibrium which entails the suction of other metal vapors which are immediately condensed in the form of solid particles and carried upwards.
  • the treatment enclosure is maintained either at atmospheric pressure or at a pressure higher than atmospheric pressure.
  • the fact of working at a pressure higher than atmospheric pressure makes it possible to increase the speed of production of metallic powders.
  • the gaseous layer, surrounding and separating the molten metallic material from the cryogenic liquid is less thick: thus, the cold vapors of the cryogenic liquid cool the metallic vapors more quickly and, as a result, the suction phenomenon described above is faster.
  • the metal is heated in levitation, it is subjected to stirring caused by the circulation currents due to the interaction between magnetic field and currents induced within said metal; this increases and renews the heat exchanges with the cryogenic liquid.
  • the cryogenic fluid used is a chemically active fluid chosen as a function of the desired compound.
  • the installation shown in the attached figure includes a quartz treatment enclosure 1, closed, therefore isolated from the ambient atmosphere, provided with a pipe 2 for supplying cryogenic liquid and provided at its upper part with a pipe d 'evacuation 3 which opens into a recovery container 4.
  • a levitation melting device of which only the turns 5 of the inductor are shown, is placed in the vicinity of the lower part of the enclosure 3; the inductor used is an inductor of known type, consisting of a conical winding of a few turns (copper tubes cooled by a stream of water) surmounted by one or two turns developing in opposite directions.
  • Liquid argon is introduced via line 2 at a rate sufficient for the liquid argon bath 6 to permanently fill approximately half of the enclosure 1 so that the metallic material 7, heated in levitation, is constantly immersed in said bath 6.
  • the level of the liquid argon bath 6 is controlled by a level detector 8.
  • the container 4 contains an organic liquid 9, chemically inert with respect to the metal constituting the particles, such as a hydrocarbon, for example hexane, and the pipe 3 dips in said liquid 9. There is bubbling of the argon gas containing the particles in hexane; the argon gas is evacuated through a conduit 10 opening into the upper part of the container 4 and the metal particles remain in suspension in hexane which then plays the role of conditioning liquid.
  • an organic liquid 9 chemically inert with respect to the metal constituting the particles, such as a hydrocarbon, for example hexane
  • the pipe 3 dips in said liquid 9.
  • a strip 11 comprising heating resistors supplied by an electric generator 12, is wound on a part of the pipe 3.
  • an alumina crucible 13 is placed in the bottom of the latter.
  • the invention advantageously applies to the manufacture of ultra-fine metal powders from low volatile metals, these powders can be made up either of a single metal, or of a metal alloy, or of a metal compound; it can also be applied to the selective elimination of one or more metals in powder form from a mixture of molten metals.

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  • Manufacture Of Metal Powder And Suspensions Thereof (AREA)
  • Physical Or Chemical Processes And Apparatus (AREA)

Abstract

A cryogenic fluid in the liquid phase is put in contact with a metal material maintained in a closed treating vessel, the cryogenic fluid which contains the solid particles formed is exhausted from the vessel, and the solid particles are separated from the cryogenic fluid and collected. The metal material is heated by induction heating with a high-frequency current and maintained in levitation in the cryogenic liquid. The process is applicable to the production of ultra-fine powders from metals which are only slightly volatile.

Description

La présente invention a pour objet un procédé de fabrication de poudres métalliques, notamment de poudres ultra-fines, à partir d'un matériau métallique en fusion.The present invention relates to a method for manufacturing metallic powders, in particular ultra-fine powders, from a molten metallic material.

Par "poudres métalliques", on entend des poudres constituées par des particules solides soit d'un métal unique tel que le fer, le zinc, le magnésium, etc..., soit d'un alliage métallique par exemple un alliage magnésium-zinc, soit encore d'un composé métallique, par exemple oxyde de zinc, nitrure de magnésium, etc...By "metal powders" is meant powders constituted by solid particles either of a single metal such as iron, zinc, magnesium, etc., or of a metal alloy for example a magnesium-zinc alloy , or even a metallic compound, for example zinc oxide, magnesium nitride, etc.

Par "matériau nétallique" on entend, soit un métal pur, soit un alliage de deux ou plusieurs métaux.By "metallic material" is meant either a pure metal or an alloy of two or more metals.

Parmi les procédés connus jusqu'à présent selon lesquels on cherche, soit à obtenir des poudres métalliques ultra-fines à partir d'un bain métallique (métal pur ou alliage), soit à éliminer sélectivement un ou plusieurs métaux sous forme de particules solides à partir d'un mélange de métaux en fusion, on peut citer le procédé décrit dans le brevet français n° 78.26.648 du 18 septembre 1978, au nom du demandeur. Ce procédé met en oeuvre le principe de la transformation en particules solides de la vapeur d'un matériau métallique en fusion par abaissement de la température de ladite vapeur. Il consiste à déverser sur le bain métallique, porté à une température telle que sa tension de vapeur soit d'au moins 1 mm de mercure, un fluide cryogénique en phase liquide, à évacuer hors de l'enceinte le fluide cryogénique qui contient, en suspension, les particules solides formées, à séparer ces dernières dudit fluide et à les collecter pour obtenir la poudre précitée. Selon ce procédé, l'emploi d'un fluide cryogénique en phase liquide permet un refroidissement très rapide des vapeurs métalliques provenant du bain et leur passage direct de l'état gazeux à l'état solide.Among the processes known so far according to which it is sought either to obtain ultra-fine metal powders from a metal bath (pure metal or alloy), or to selectively remove one or more metals in the form of solid particles to starting from a mixture of molten metals, one can quote the process described in the French patent n ° 78.26.648 of September 18th, 1978, in the name of the applicant. This process implements the principle of transforming into solid particles the vapor of a molten metallic material by lowering the temperature of said vapor. It consists in pouring onto the metal bath, brought to a temperature such that its vapor pressure is at least 1 mm of mercury, a cryogenic fluid in the liquid phase, to evacuate outside the enclosure the cryogenic fluid which contains, in suspension, the solid particles formed, to separate the latter from said fluid and to collect them to obtain the abovementioned powder. According to this process, the use of a cryogenic fluid in the liquid phase allows very rapid cooling of the metallic vapors coming from the bath and their direct passage from the gaseous state to the solid state.

Le procédé, décrit dans le brevet n° 78.26.648, présente l'avantage de permettre d'obtenir, soit à partir d'un métal pur, soit à partir d'alliages, des particules solides ayant une forme régulière et une granulométrie faible (de 100A à 2000A). Toutefois, ce procédé présente l'inconvénient de n'être utilisable que pour l'obtention de poudres de métaux dont la tension de vapeur correspond à des températures de moyenne importance. Par exemple, avec des métaux volatils tels que le plomb, le zinc, le magnésium, il suffit de fondre le métal à des températures inférieures à 1000° C. Par contre, avec des métaux moins volatils tels que le fer, le nickel, le cobalt, il est nécessaire d'atteindre des températures de fusion supérieures à 2300° C. Or, les matériaux constituant généralement les creusets de fusion de métaux n'ont pas une tenue mécanique suffisante pour résister à des températures supérieures à 2000°C.The method, described in patent No. 78.26.648, has the advantage of making it possible to obtain, either from a pure metal or from alloys, solid particles having a regular shape and a small particle size. (from 100A to 2000A). However, this method has the disadvantage of being usable only for obtaining metal powders whose vapor pressure corresponds to medium temperatures. For example, with volatile metals such as lead, zinc, magnesium, it is sufficient to melt the metal at temperatures below 1000 ° C. On the other hand, with less volatile metals such as iron, nickel, cobalt, it is necessary to reach melting temperatures above 2300 ° C. However, the materials generally constituting metal melting crucibles do not have sufficient mechanical strength to withstand temperatures above 2000 ° C.

L'invention a justement pour objet un procédé qui pallie les inconvénients rappelés ci-dessus et permet d'obtenir des poudres d'éléments dont la tension de vapeur correspond à des températures très importantes.The subject of the invention is precisely a process which overcomes the drawbacks mentioned above and makes it possible to obtain powders of elements whose vapor pressure corresponds to very high temperatures.

Le procédé de fabrication de poudre métallique conforme à l'invention consiste à mettre en contact avec un fluide cryogénique en phase liquide, dans une enceinte de traitement fermée, un matériau métallique, chauffé à une température telle que sa tension de vapeur soit d'au moins 1mm de mercure, à évacuer hors de l'enceinte le fluide cryogénique qui contient, en suspension, les particules solides formées, à séparer ces dernières dudit fluide, et à les collecter pour obtenir la poudre métallique précitée. Il se caractérise en ce que, par induction de courant de haute fréquence, on chauffe et on maintient en lévitation dans le liquide cryogénique ledit matériau métallique.The method for manufacturing metallic powder according to the invention consists in bringing into contact with a cryogenic fluid in the liquid phase, in a closed treatment enclosure, a metallic material, heated to a temperature such that its vapor pressure is at least minus 1mm of mercury, to evacuate from the enclosure the cryogenic fluid which contains, in suspension, the solid particles formed, to separate the latter from said fluid, and to collect them to obtain the aforementioned metallic powder. It is characterized in that, by induction of high frequency current, said metallic material is heated and levitated in the cryogenic liquid.

Comme on le sait, le principe de la fusion en lévitation est de placer une pièce métallique dans un inducteur de forme convenable parcouru par des courants de haute fréquence. Selon le principe de la fusion en lévitation, l'interaction entre le champ magnétique et les courants induits dans la pièce métallique permet à celle-ci de flotter, de léviter, sans aucun contact avec un support matériel. Ainsi, le fait que, conformément à l'invention, on chauffe le matériau métallique par fusion en lévitation permet de pouvoir le porter sans problème à des températures supérieures à 2000° C et d'obtenir, grâce à la mise en contact avec le liquide cryogénique, des particules solides à partir de métaux qui ne sont volatils qu'à des températures très élevées.As we know, the principle of levitation fusion is to place a metal part in an inductor of suitable shape traversed by high frequency currents. According to the principle of fusion in levitation, the interaction between the magnetic field and the currents induced in the metal part allows this one to float, to levitate, without any contact with a material support. Thus, the fact that, in accordance with the invention, the metallic material is heated by levitation fusion makes it possible to be able to bring it without problem to temperatures above 2000 ° C. and to obtain, thanks to the bringing into contact with the liquid cryogenic, solid particles from metals that are only volatile at very high temperatures.

D'autre part, lorsqu'on maintient, selon l'invention, le matériau métallique en fusion dans le liquide cryogénique, ce dernier, séparé dudit matériau par une couche gazeuse en raison du phénomène de caléfaction, se réchauffe au voisinage du matériau métallique en fusion ; les vapeurs froides ainsi formées condensent les vapeurs métalliques provenant du matériau et les transforment immédiatement en particules solides qui sont entraînées vers le haut par les vapeurs restantes du liquide cryogénique. Il en résulte un déplacement de l'équilibre métal liquide - métal vapeur qui entraîne l'aspiration d'autres vapeurs métalliques qui sont immédiatement condensées sous forme de particules solides et entraînées vers le haut.On the other hand, when, according to the invention, the metallic material in fusion is maintained in the cryogenic liquid, the latter, separated from said material by a gaseous layer due to the heat-up phenomenon, heats up in the vicinity of the molten metallic material; the cold vapors thus formed condense the metallic vapors coming from the material and immediately transform them into solid particles which are entrained upwards by the remaining vapors of the cryogenic liquid. This results in a shift in the liquid metal - metal vapor equilibrium which entails the suction of other metal vapors which are immediately condensed in the form of solid particles and carried upwards.

Selon l'invention, on maintient l'enceinte de traitement, soit à la pression atmosphérique, soit à une pression supérieure à la pression atmosphérique. Le fait de travailler à une pression supérieure à la pression atmosphérique permet d'augmenter la vitesse de production des poudres métalliques. En effet, lorsqu'on utilise une pression de travail plus grande, la couche gazeuse, entourant et séparant le matériau métallique en fusion du liquide cryogénique, est moins épaisse : ainsi, les vapeurs froides du liquide cryogénique refroidissent plus rapidement les vapeurs métalliques et, en conséquence, le phénomène d'aspiration décrit ci-dessus est plus rapide.According to the invention, the treatment enclosure is maintained either at atmospheric pressure or at a pressure higher than atmospheric pressure. The fact of working at a pressure higher than atmospheric pressure makes it possible to increase the speed of production of metallic powders. In fact, when a higher working pressure is used, the gaseous layer, surrounding and separating the molten metallic material from the cryogenic liquid, is less thick: thus, the cold vapors of the cryogenic liquid cool the metallic vapors more quickly and, as a result, the suction phenomenon described above is faster.

De plus, comme, conformément à l'invention, le métal est chauffé en lévitation, il est soumis à un brassage provoqué par les courants de circulation dus à l'interaction entre champ magnétique et courants induits au sein dudit métal ; ceci accroît et renouvelle les échanges thermiques avec le liquide cryogénique.In addition, as, in accordance with the invention, the metal is heated in levitation, it is subjected to stirring caused by the circulation currents due to the interaction between magnetic field and currents induced within said metal; this increases and renews the heat exchanges with the cryogenic liquid.

Selon une caractéristique de l'invention, dans le cas où l'en désire fabriquer des poudres d'un métal unique ou des poudres d'alliage métallique, le fluide cryogénique utilisé est un fluide inerte chimiquement vis-à-vis du matériau métallique, tel que l'azote, l'argon, l'hélium. Pour fabriquer des poudres d'alliage métallique, le matériau métallique de départ peut :

  • - soit être constitué par un mélange de métaux qui ont sensiblement la même tension de vapeur (par exemple un mélange fer-nickel),
  • - soit être constitué par un mélange de métaux dont la composition est telle qu'elle compense la différence entre les tensions de vapeur des métaux purs le constituant (par exemple, en partant d'un mélange fer-manganèse à faible concentration en manganèse, on
peut obtenir une poudre fer-manganèse à 20 % de manganèse du fait que le manganèse est beaucoup plus volatil que le fer).According to a characteristic of the invention, in the case where it is desired to manufacture powders of a single metal or powders of metallic alloy, the cryogenic fluid used is a fluid chemically inert with respect to the metallic material, such as nitrogen, argon, helium. To make metal alloy powders, the starting metal material can:
  • - either consist of a mixture of metals which have substantially the same vapor pressure (for example an iron-nickel mixture),
  • - or be made up of a mixture of metals whose composition is such that it compensates for the difference between the vapor pressures of the pure metals constituting it (for example, starting from an iron-manganese mixture with a low manganese concentration,
can get an iron-manganese powder with 20% manganese because manganese is much more volatile than iron).

Selon une autre caractéristique de l'invention, dans le cas où l'on désire fabriquer des poudres de composés métalliques tels que oxydes, nitrures, hydrures, le fluide cryogénique utilisé est un fluide chimiquement actif choisi en fonction du composé désiré.According to another characteristic of the invention, in the case where it is desired to manufacture powders of metallic compounds such as oxides, nitrides, hydrides, the cryogenic fluid used is a chemically active fluid chosen as a function of the desired compound.

Les caractéristiques et avantages de l'invention apparaîtront à la lecture de la description qui suit en référence à la figure jointe qui représente schématiquenent, à titre d'exemple, une installation de mise en oeuvre d'un mode de réalisation du procédé considéré.The characteristics and advantages of the invention will appear on reading the description which follows with reference to the attached figure which schematically represents, by way of example, an installation for implementing an embodiment of the process considered.

L'installation représentée à la figure jointe comporte une enceinte de traitement 1 en quartz, fermée, donc isolée de l'atmosphère ambiante, munie d'un conduit 2 d'alimentation en liquide cryogénique et munie à sa partie supérieure d'une conduite d'évacuation 3 qui débouche dans un récipient de récupération 4. Un dispositif de fusion en lévitation, dont seules les spires 5 de l'inducteur sont représentées, est placé au voisinage de la partie inférieure de l'enceinte 3 ; l'inducteur utilisé est un inducteur de type connu, constitué d'un enroulement conique de quelques spires (tubes de cuivre refroidis par un courant d'eau) surmonté d'une ou deux spires se développant en sens inverse.The installation shown in the attached figure includes a quartz treatment enclosure 1, closed, therefore isolated from the ambient atmosphere, provided with a pipe 2 for supplying cryogenic liquid and provided at its upper part with a pipe d 'evacuation 3 which opens into a recovery container 4. A levitation melting device, of which only the turns 5 of the inductor are shown, is placed in the vicinity of the lower part of the enclosure 3; the inductor used is an inductor of known type, consisting of a conical winding of a few turns (copper tubes cooled by a stream of water) surmounted by one or two turns developing in opposite directions.

On introduit de l'argon liquide par le conduit 2 à un débit suffisant pour qu'en permanence le bain d'argon liquide 6 remplisse à peu près la moitié de l'enceinte 1 afin que le matériau métallique 7, chauffé en lévitation, soit constamment immergé dans ledit bain 6. On contrôle le niveau du bain d'argon liquide 6 grâce à un détecteur de niveau 8.Liquid argon is introduced via line 2 at a rate sufficient for the liquid argon bath 6 to permanently fill approximately half of the enclosure 1 so that the metallic material 7, heated in levitation, is constantly immersed in said bath 6. The level of the liquid argon bath 6 is controlled by a level detector 8.

Lorsque le matériau métallique 7 atteint une température supérieure à 2000° C, il se forme dans le bain d'argon 6 une suspension de particules métalliques. Les vapeurs d'argon qui se forment entraînent ces particules métalliques dans la conduite d'évacuation 3 et les amènent dans le récipient de récupération 4.When the metallic material 7 reaches a temperature higher than 2000 ° C., a suspension of metallic particles is formed in the argon bath 6. The argon vapors which form entrain these metallic particles in the evacuation pipe 3 and bring them into the recovery container 4.

Le récipient 4 contient un liquide organique 9, inerte chimiquement vis-à-vis du métal constituant les particules, tel qu'un hydrocarbure, par exemple l'hexane, et la conduite 3 plonge dans ledit liquide 9. Il y a barbotage de l'argon gazeux contenant les particules dans l'hexane ; l'argon gazeux est évacué par un conduit 10 débouchant dans la partie supérieure du récipient 4 et les particules métalliques restent en suspension dans l'hexane qui joue ensuite le rôle de liquide de conditionnement.The container 4 contains an organic liquid 9, chemically inert with respect to the metal constituting the particles, such as a hydrocarbon, for example hexane, and the pipe 3 dips in said liquid 9. There is bubbling of the argon gas containing the particles in hexane; the argon gas is evacuated through a conduit 10 opening into the upper part of the container 4 and the metal particles remain in suspension in hexane which then plays the role of conditioning liquid.

Pour éviter un problème de congélation éventuelle de l'hexane, un ruban 11, comportant des résistances chauffantes alimentées par un générateur électrique 12, est enroulé sur une partie de la conduite 3.To avoid a problem of possible freezing of hexane, a strip 11, comprising heating resistors supplied by an electric generator 12, is wound on a part of the pipe 3.

Lorsque l'on souhaite interrompre la production de poudres, on arrête le chauffage par induction, ce qui supprime le phénomène de lévitation. C'est pourquoi, pour éviter que le matériau 7 surchauffé n'endommage l'enceinte en quartz 1, on place dans le fond de cette dernière un creuset 13 en alumine.When it is desired to interrupt the production of powders, the induction heating is stopped, which eliminates the phenomenon of levitation. This is why, to prevent the overheated material 7 from damaging the quartz enclosure 1, an alumina crucible 13 is placed in the bottom of the latter.

Bien entendu, on peut disposer plusieurs récipients de récupération contenant de l'hexane, soit en parallèle si on a un fort débit d'argon gazeux qui risque de nuire à la régularité du barbotage, soit en série si on désire éliminer complètement les poudres de l'argon gazeux.Of course, it is possible to have several recovery containers containing hexane, either in parallel if there is a high flow of argon gas which is liable to affect the regularity of the bubbling, or in series if it is desired to completely eliminate the powders. argon gas.

D'autre part, on a décrit ci-dessus un mode de récupération des poudres formées par barbotage dans un liquide organique, ledit liquide organique remplissant ensuite le rôle d'une réserve desdites poudres les contenant en suspension. On peut tout aussi bien collecter les poudres par filtrage, gravité, etc...On the other hand, a method of recovering powders formed by bubbling in an organic liquid has been described above, said organic liquid then fulfilling the role of a reserve of said powders containing them in suspension. We can just as easily collect the powders by filtering, gravity, etc ...

L'invention s'applique avantageusement à la fabrication de poudres métalliques ultra-fines à partir de métaux peu volatils, ces poudres pouvant être constituées soit d'un métal unique, soit d'un alliage métallique, soit d'un composé métallique ; elle peut également s'appliquer à l'élimination sélective d'un ou plusieurs métaux sous forme de poudre à partir d'un mélange de métaux en fusion.The invention advantageously applies to the manufacture of ultra-fine metal powders from low volatile metals, these powders can be made up either of a single metal, or of a metal alloy, or of a metal compound; it can also be applied to the selective elimination of one or more metals in powder form from a mixture of molten metals.

Claims (15)

1. - Procédé de fabrication d'une poudre métallique par abaissement de la température de la vapeur d'un matériau métallique en fusion entraînant la transformation de ladite vapeur en particules solides, selon lequel on met en contact avec un fluide cryogénique en phase liquide, dans une enceinte de traitement fermée, un matériau métallique chauffé à une température telle que sa tension de vapeur soit d'au moins 1mm de mercure, on évacue hors de l'enceinte le fluide cryogénique qui contient, en suspension, les particules solides formées, on sépare ces dernières dudit fluide, et on les collecte pour obtenir la poudre métallique précitée, caractérisé en ce que, par induction de courant de haute fréquence, on chauffe et en maintient en lévitation dans le liquide cryogénique ledit matériau métallique.1. - Method for manufacturing a metallic powder by lowering the temperature of the vapor of a molten metallic material resulting in the transformation of said vapor into solid particles, according to which contact is made with a cryogenic fluid in the liquid phase, in a closed treatment enclosure, a metallic material heated to a temperature such that its vapor pressure is at least 1mm of mercury, the cryogenic fluid is removed from the enclosure which contains, in suspension, the solid particles formed, these are separated from said fluid, and they are collected to obtain the aforementioned metallic powder, characterized in that, by induction of high frequency current, said metallic material is heated and levitated in the cryogenic liquid. 2. - Procédé selon la revendication 1, caractérisé en ce qu'on introduit le fluide cryogénique et on l'évacue de ladite enceinte de façon continue.2. - Method according to claim 1, characterized in that the cryogenic fluid is introduced and it is removed from said enclosure continuously. 3. - Procédé selon l'une des revendications 1 ou 2, caractérisé en ce qu'on évacue le fluide cryogénique de ladite enceinte en phase gazeuse.3. - Method according to one of claims 1 or 2, characterized in that the cryogenic fluid is removed from said enclosure in the gas phase. 4. - Procédé selon l'une des revendications 1 à 3, caractérisé en ce qu'on sépare les particules solides du fluide cryogénique et on les collecte par barbotage dans un liquide.4. - Method according to one of claims 1 to 3, characterized in that the solid particles are separated from the cryogenic fluid and they are collected by bubbling in a liquid. 5. - Procédé selon la revendication 4, caractérisé en ce que le liquide de barbotage est un liquide inerte chimiquement vis-à-vis du métal constituant lesdites particules.5. - Method according to claim 4, characterized in that the bubbling liquid is a liquid chemically inert vis-à-vis the metal constituting said particles. 6. - Procédé selon la revendication 5, caractérisé en ce que le liquide de barbotage est un liquide organique, tel que l'hexane.6. - Method according to claim 5, characterized in that the bubbling liquid is an organic liquid, such as hexane. 7. - Procédé selon l'une des revendications 1 à 6, caractérisé en ce que le matériau métallique est un métal pur ou sensiblement pur.7. - Method according to one of claims 1 to 6, characterized in that the metallic material is a pure or substantially pure metal. 8. - Procédé selon l'une des revendications 1 à 6, caractérisé en ce que le matériau métallique est un alliage de deux ou plusieurs métaux.8. - Method according to one of claims 1 to 6, characterized in that the metallic material is an alloy of two or more metals. 9. - Procédé selon l'une des revendications 1 à 6, caractérisé en ce que le fluide cryogénique est un fluide inerte chimiquement vis-à-vis du matériau métallique tel que l'azote, l'argon, l'hélium.9. - Method according to one of claims 1 to 6, characterized in that the cryogenic fluid is an inert fluid chemically vis-à-vis metallic material such as nitrogen, argon, helium. 10. - Procédé selon l'une des revendications 1 à 8, caractérisé en ce que le fluide cryogénique est un fluide chimiquement actif.10. - Method according to one of claims 1 to 8, characterized in that the cryogenic fluid is a chemically active fluid. 11. - Procédé selon l'une des revendications 1 à 10, caractérisé en ce que l'on maintient l'enceinte de traitement à une pression égale à la pression atmosphérique.11. - Method according to one of claims 1 to 10, characterized in that the treatment enclosure is maintained at a pressure equal to atmospheric pressure. 12. - Procédé selon l'une des revendications 1 à 10, caractérisé en ce que l'on maintient l'enceinte de traitement à une pression supérieure à la pression atmosphérique.12. - Method according to one of claims 1 to 10, characterized in that the treatment enclosure is maintained at a pressure higher than atmospheric pressure. 13. - Réserve de poudre métallique, de granulométrie d'environ 100 A à environ 2000 A, caractérisée en ce qu'elle est constituée par une suspension desdites poudres dans un liquide organique.13. - Reserve of metallic powder, with a particle size of approximately 100 A to approximately 2000 A, characterized in that it consists of a suspension of said powders in an organic liquid. 14. - Réserve de poudre métallique selon la revendication 13, caractérisée en ce que ledit liquide est un hydrocarbure liquide.14. - Metallic powder reserve according to claim 13, characterized in that said liquid is a liquid hydrocarbon. 15. - Réserve de poudre métallique selon la revendication 14, caractérisée en ce que ledit hydrocarbure est constitué par de l'hexane.15. - A metal powder reserve according to claim 14, characterized in that said hydrocarbon consists of hexane.
EP84400733A 1983-05-04 1984-04-12 Process for producing metal powder starting from a molten metal Expired EP0125161B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT84400733T ATE27780T1 (en) 1983-05-04 1984-04-12 PROCESS FOR THE PRODUCTION OF METAL POWDER FROM METAL METAL.

Applications Claiming Priority (2)

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FR8307414A FR2545394B1 (en) 1983-05-04 1983-05-04 PROCESS FOR THE MANUFACTURE OF METAL POWDERS FROM A FUSED METAL MATERIAL
FR8307414 1983-05-04

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EP0125161A1 true EP0125161A1 (en) 1984-11-14
EP0125161B1 EP0125161B1 (en) 1987-06-16

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US (1) US4521244A (en)
EP (1) EP0125161B1 (en)
JP (1) JPS59208003A (en)
AT (1) ATE27780T1 (en)
DE (1) DE3464214D1 (en)
FR (1) FR2545394B1 (en)

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Publication number Priority date Publication date Assignee Title
US5922403A (en) * 1996-03-12 1999-07-13 Tecle; Berhan Method for isolating ultrafine and fine particles
CN103508489B (en) * 2012-06-21 2016-08-10 深圳富泰宏精密工业有限公司 Nano titanium oxide preparation facilities and apply the method that this device prepares nano titanium oxide
CN116219326A (en) * 2023-03-16 2023-06-06 浙江大学 Supercooling solidification method for preparing amorphous nanocrystalline magnetically soft alloy with high Fe content

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE903777C (en) * 1944-07-01 1954-02-11 Eisenwerke Muelheim Meiderich Process for producing metal powder, such as steel or iron powder in particular, by means of a granulation process
FR2299932A1 (en) * 1975-02-07 1976-09-03 Anvar VERY FINE DIVIDED LITHIUM AND ITS MANUFACTURING PROCESS
EP0009433A1 (en) * 1978-09-18 1980-04-02 L'air Liquide, Societe Anonyme Pour L'etude Et L'exploitation Des Procedes Georges Claude Process and apparatus for producing metallic powder starting from a molten metal or alloy

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4124377A (en) * 1977-07-20 1978-11-07 Rutger Larson Konsult Ab Method and apparatus for producing atomized metal powder

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE903777C (en) * 1944-07-01 1954-02-11 Eisenwerke Muelheim Meiderich Process for producing metal powder, such as steel or iron powder in particular, by means of a granulation process
FR2299932A1 (en) * 1975-02-07 1976-09-03 Anvar VERY FINE DIVIDED LITHIUM AND ITS MANUFACTURING PROCESS
EP0009433A1 (en) * 1978-09-18 1980-04-02 L'air Liquide, Societe Anonyme Pour L'etude Et L'exploitation Des Procedes Georges Claude Process and apparatus for producing metallic powder starting from a molten metal or alloy

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EP0125161B1 (en) 1987-06-16
FR2545394B1 (en) 1985-09-06
FR2545394A1 (en) 1984-11-09
US4521244A (en) 1985-06-04
ATE27780T1 (en) 1987-07-15
JPS59208003A (en) 1984-11-26
DE3464214D1 (en) 1987-07-23

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