EP0272250A1 - Process for the production of neodym alloys - Google Patents
Process for the production of neodym alloys Download PDFInfo
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- EP0272250A1 EP0272250A1 EP88100014A EP88100014A EP0272250A1 EP 0272250 A1 EP0272250 A1 EP 0272250A1 EP 88100014 A EP88100014 A EP 88100014A EP 88100014 A EP88100014 A EP 88100014A EP 0272250 A1 EP0272250 A1 EP 0272250A1
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- Prior art keywords
- neodymium
- iron
- calcium
- alloys
- calcium chloride
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
- C22B5/00—General methods of reducing to metals
- C22B5/02—Dry methods smelting of sulfides or formation of mattes
- C22B5/04—Dry methods smelting of sulfides or formation of mattes by aluminium, other metals or silicon
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C28/00—Alloys based on a metal not provided for in groups C22C5/00 - C22C27/00
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
- C22B59/00—Obtaining rare earth metals
Definitions
- the present invention relates to neodymium alloys and their manufacturing process.
- ceric rare earth metals a designation which includes lanthanum, cerium, praseodymium and neodymium, the latter is the only metal that cannot be manufactured industrially by electrolysis of these salts. Indeed, it is mentioned in the article by T. KURITA (Denki Kagaku, 1967, 35 (7) p.496-501) that yields of 6 to 20% of pure neodymium are obtained by electrolysis in a molten bath - neodymium chloride, potassium chloride -.
- neodymium alloys more particularly neodymium and magnesium alloys, which consists of using neodymium chloride, an alkali metal and magnesium, all the reagents being introduced and kept in the molten state throughout the duration of the reaction.
- the objective of the present invention is to have new neodymium alloys obtained according to an industrial manufacturing process.
- One of the objects of the present invention resides in a process for the manufacture of neodymium and iron alloys characterized in that it consists in reducing a neodymium fluoride using calcium, in the presence of iron; the quantity of iron being defined so that the neodymium-iron alloy has an iron content of 5 to 30%.
- Another object of the present invention are the alloys obtained according to the method of the invention.
- neodymium fluoride is used.
- Neodymium fluoride is available in the anhydrous state because it is a low hygroscopic product.
- the drying time can vary between 2 and 24 hours.
- drying conditions are not critical and are given on a preferential basis.
- the particle size of neodymium fluoride can vary. It is commercially available in the form of a powder, the particle size of which varies from 40 to 150 ⁇ m. The size of the particles influencing the reduction speed, it is recommended that the powder is fine which can lead to a grinding operation so that the average diameter of the neodymium fluoride particles is less than 100 ⁇ m. There is no lower diameter limit.
- the reducing metal used in the process of the invention is calcium.
- the reducing metal is used in the form in which it is sold, whether it is in the solid state or in the form of pellets or balls.
- a preferred variant of the process of the invention consists in adding to the reaction medium, calcium chloride in order to lower the melting point and the density of the slag formed in the reaction so that the alloy formed neodymium-iron separates easier.
- the method of the invention consists in mixing a neodymium fluoride, calcium. iron and calcium chloride in the proportions given below.
- the amount of calcium can vary within wide limits. However, it is advantageous to use an amount sufficient to reduce the neodymium fluoride but it should not be too large if one does not wish to find it, in an important way, in the final alloy.
- the amount of reducing metal is at least equal to the stoichiometric amount or even in slight excess, up to 20% of the stoichiometric amount.
- the amount of iron is adjusted according to the desired composition of the alloy. It is such that a fusible alloy with neodymium is obtained at the reaction temperature. It is calculated so that the iron represents from 5 to 30% of the weight of the alloy obtained.
- the amount of calcium chloride added is adjusted in order to obtain a slag containing from 30 to 70% by weight of calcium chloride and preferably 60 to 70%.
- the different neodymium and calcium halides and iron constitute "a filler" having the desired weight composition.
- the constituents of this charge can be reacted in any order: by simultaneous mixing of all the constituents or by making premixes, on the one hand, the neodymium and calcium halides and on the other hand the calcium and iron.
- the reaction is carried out at a temperature between 800 ° C and 1100 ° C.
- the upper temperature limit is not critical and can reach a value as high as 1400 ° C.
- a temperature between 900 ° C and 1100 ° C is chosen.
- the reaction is carried out under atmospheric pressure but in an inert gas atmosphere.
- the air is excluded by lowering ment of the pressure up to a non-critical value, for example between 1 mm and 100 mm of mercury, then a scanning of inert gases is carried out: rare gases, in particular argon.
- rare gases in particular argon. It is desirable to subject the rare gas to a dehydration and deoxygenation treatment carried out according to the usual techniques, for example by passage through a molecular sieve.
- the inert atmosphere is maintained throughout the reduction.
- the duration of the reaction depends on the capacity of the apparatus and its ability to rapidly rise in temperature. Generally once the desired temperature has been reached, it is maintained for a variable duration of approximately 30 minutes to 3 hours.
- a metallic phase consisting of the neodymium-iron alloy on which floats a slag consisting of CaF2-CaCl2 having a density lower than that of the alloy.
- the alloy can be immediately separated from the slag by hot casting or allowed to cool under an inert gas atmosphere at room temperature (15 to 25 ° C) so that the alloy solidifies and can then be demolded.
- the yield of neodymium in the alloy expressed relative to the neodymium contained in the halide varies from 80 to 96%.
- the method of the invention as described, can be implemented in an apparatus of conventional type, used in metallurgy.
- the reduction is carried out in a crucible placed in a reactor made of a material resistant to hydrofluoric and hydrochloric vapors. It can be chosen from refractory steel, for example, steel containing 25% chromium and 20% nickel but preferably inconel which is an alloy containing nickel, chromium (20%), iron (5%), molybdenum (8-10%).
- Said reactor is equipped with a temperature control device (eg thermocouple), an inlet and outlet of inert gases. It is provided in its upper part with a double envelope in which circulates a coolant.
- a temperature control device eg thermocouple
- This reactor is placed in an induction furnace or in an furnace heated by electrical resistances.
- a crucible in which the temperature control device is immersed is placed at the bottom of the reactor. It must be made of a material resistant to neodymium fluoride or have a coating resistant to them. Preferably, a tantalum crucible is used.
- the molten alloy can be cast in molds, for example, cast iron.
- the alloys obtained according to the present invention have the following weight composition: - from 70 to 95% of neodymium - 5 to 30% iron - less than 3% of reducing metal
- compositions of the neodymium-iron alloys used . 83 to 91% neodymium . 9 to 16% iron . less than 1% calcium
- the alloys obtained according to the present invention are very rich in neodymium since they can contain up to 95%.
- They can be used as master alloys in particular in the manufacture of permanent magnets.
- the methods for assaying the various constituents of the alloy will be explained briefly by the following techniques: - the neodymium is dosed, according to the chemical method described below and consists of: . dissolving the alloy sample in an acid medium, . bring the solution obtained to a boil, . precipitating the reducing metal, iron and neodymium in the form of their hydroxide at pH 9, by treatment with ammonia, then filtering and washing the precipitates obtained, . redissolving the precipitate of neodymium hydroxide in an acid medium, . adding ammonium oxalate to the solution obtained in boiling to obtain neodymium oxalate, .
- neodymium oxalate calcining the neodymium oxalate at 900 ° C for 1 hour to transform it into oxide, . weighing the quantity of oxide obtained, thus making it possible to calculate the quantity of neodymium contained in the alloy.
- the other metals, reducing metal and iron are titrated by atomic absorption.
- a premix containing 382.2 g of calcium chloride in the dry state and 281.4 g of neodymium fluoride having an average particle diameter of 60 ⁇ m is then made.
- the previously defined load is then ready for use.
- the calciothermic reduction reaction of neodymium fluoride is carried out in a tantalum crucible of about 1 liter placed at the bottom of an inconel reactor which is equipped with an inlet and an argon outlet and a thermocouple introduced into a thermometric sheath which is immersed in the reaction medium contained in the crucible: the upper part of the reactor is provided with a double jacket in which cold water circulates (about 10 ° C).
- the proportion of the constituents of the charge is defined so that the conditions set out below are met: - that we obtain an alloy containing 12% iron - that there is an excess of calcium of 20% compared to the required stoichiometric weight - that a slag containing 70% calcium chloride is formed.
- a temperature rise is carried out at the same time until the temperature fixed at 1100 ° C. is obtained; this temperature being kept constant for another 30 minutes.
- neodymium-iron alloy 562 g are collected and 188 g of a neodymium-iron alloy are recovered by hot casting in a cast iron ingot mold.
- the neodymium yield in the alloy expressed relative to the neodymium contained in the neodymium fluoride is 81%.
- the analysis of the alloy obtained is as follows: - 87.4% neodymium - 12% iron - 0.6% calcium.
Abstract
La présente invention a pour objet un procédé de fabrication d'alliages de néodyme et de fer. Le procédé de l'invention est caractérisé par le fait qu'il consiste à réduire un fluorure de néodyme à l'aide de calcium, en présence de fer ; la quantité de fer étant définie de telle sorte que l'alliage néodyme-fer ait une teneur en fer de 5 à 30 %.The present invention relates to a process for the manufacture of neodymium and iron alloys. The method of the invention is characterized in that it consists in reducing a neodymium fluoride using calcium, in the presence of iron; the quantity of iron being defined so that the neodymium-iron alloy has an iron content of 5 to 30%.
Description
La presente invention a trait à des alliages de néodyme et leur procédé de fabrication.The present invention relates to neodymium alloys and their manufacturing process.
Parmi les métaux des terres rares cériques, appellation qui regroupe le lanthane, le cérium, le praséodyme et le néodyme, ce dernier est le seul metal qui ne puisse ëtre fabrique industriellement par électrolyse de ces sels. En effet, il est mentionné dans l'article de T. KURITA (Denki Kagaku, 1967, 35 (7) p.496-501) que l'on obtient des rendements de 6 à 20 & de néodyme pur par électrolyse en bain fondu - chlorure de néodyme, chlorure de potassium -.Among the ceric rare earth metals, a designation which includes lanthanum, cerium, praseodymium and neodymium, the latter is the only metal that cannot be manufactured industrially by electrolysis of these salts. Indeed, it is mentioned in the article by T. KURITA (Denki Kagaku, 1967, 35 (7) p.496-501) that yields of 6 to 20% of pure neodymium are obtained by electrolysis in a molten bath - neodymium chloride, potassium chloride -.
Par conséquent, l'obtention d'alliages de néodyme a partir de neodyme métallique n'apparait pas comme une voie valable industriellement.Consequently, obtaining neodymium alloys from metallic neodymium does not appear to be an industrially valid route.
Un procéde de ce type a éte utilise pour l'élaboration du diagramme fer-néodyme [cf. "Iron-Binary Phase Diagrams" O. Kubaschewski (1982) p. 101 et 102].A procedure of this type was used for the elaboration of the iron-neodymium diagram [cf. "Iron-Binary Phase Diagrams" O. Kubaschewski (1982) p. 101 and 102].
Il est également connu, selon AT-328 884, un procédé de fabrication d'alliages de neodyme, plus particuliérement d'alliages de néodyme et de magnésium, qui consiste mettre en oeuvre un chlorure de néodyme, un métal alcalin et du magnésium, tous les réactifs étant introduits et maintenus à l'état fondu pendant toute la durée de la réaction.It is also known, according to AT-328 884, a process for manufacturing neodymium alloys, more particularly neodymium and magnesium alloys, which consists of using neodymium chloride, an alkali metal and magnesium, all the reagents being introduced and kept in the molten state throughout the duration of the reaction.
L'objectif de la présente invention est de disposer de nouveaux alliages de néodyme obtenus selon un procédé industriel de fabrication.The objective of the present invention is to have new neodymium alloys obtained according to an industrial manufacturing process.
L'un des objets de la présente invention réside dans un procédé de fabrication d'alliages de néodyme et de fer caractérisé par le fait qu'il consiste à réduire un fluorure de néodyme à l'aide de calcium, en présence de fer ; la quantité de fer étant définie de telle sorte que l'alliage néodyme-fer ait une teneur en fer de 5 à 30 %.One of the objects of the present invention resides in a process for the manufacture of neodymium and iron alloys characterized in that it consists in reducing a neodymium fluoride using calcium, in the presence of iron; the quantity of iron being defined so that the neodymium-iron alloy has an iron content of 5 to 30%.
Un autre objet de la présente invention sont les alliages obtenus selon le procédé de l'invention.Another object of the present invention are the alloys obtained according to the method of the invention.
Conformément à l'invention, on fait appel au fluorure de néodyme.In accordance with the invention, neodymium fluoride is used.
Il est souhaitable qu'il soit d'une grande pureté c'est-àdire exempt d'oxyde résiduaire et d'oxyhalogénure et qu'il soit sec : sa teneur en eau doit être inférieure à 5 % et de préférence inférieure à 2 %.It is desirable that it be of high purity, that is to say free of residual oxide and of oxyhalide and that it be dry: its water content must be less than 5% and preferably less than 2%. .
Le fluorure de néodyme est disponible à l'ëtat anhydre car c'est un produit peu hygroscopique.Neodymium fluoride is available in the anhydrous state because it is a low hygroscopic product.
Il est également possible, si nécessaire, de soumettre le fluorure à une étape de séchage à une température comprise entre 100°C et 500°C mais de préférence entre 200°C et 250°C. Cette opération peut être faite à l'air ou sous pression réduite comprise par exemple entre 1 mm de mercure (= 133,322 Pa) et 100 mm de mercure (= 13 332,2 Pa).It is also possible, if necessary, to subject the fluoride to a drying step at a temperature between 100 ° C and 500 ° C but preferably between 200 ° C and 250 ° C. This operation can be done in air or under reduced pressure, for example between 1 mm of mercury (= 133,322 Pa) and 100 mm of mercury (= 13,332.2 Pa).
La durée de séchage peut varier entre 2 et 24 heures.The drying time can vary between 2 and 24 hours.
Les conditions énoncées ci-dessus de séchage ne présentent aucun caractère critique et sont données à titre préférentiel.The above-mentioned drying conditions are not critical and are given on a preferential basis.
La taille des particules du fluorure de néodyme peut varier. On le trouve dans le commerce sous forme de poudre dont la taille des particules varie de 40 à 150 µm.
La taille des particules influençant la vitesse de réduction, il est recommandé que la poudre soit fine ce qui peut entraîner une opération de broyage afin que le diamètre moyen des particules de fluorure de néodyme soit inférieur à 100 µm. Il n'y a aucune limite inférieure de diamètre.The particle size of neodymium fluoride can vary. It is commercially available in the form of a powder, the particle size of which varies from 40 to 150 µm.
The size of the particles influencing the reduction speed, it is recommended that the powder is fine which can lead to a grinding operation so that the average diameter of the neodymium fluoride particles is less than 100 µm. There is no lower diameter limit.
Le métal réducteur utilisé dans le procédé de l'invention est le calcium.The reducing metal used in the process of the invention is calcium.
Le métal réducteur est mis en oeuvre sous la forme sous laquelle il est commercialisé, qu'il soit a l'état massif ou sous forme de grenailles ou billes.The reducing metal is used in the form in which it is sold, whether it is in the solid state or in the form of pellets or balls.
En ce qui concerne le fer qui intervient dans l'alliage avec le néodyme, il donne un alliage fusible à basse température ce qui rend le procédé industriellement avantageux.As regards the iron which intervenes in the alloy with neodymium, it gives a fusible alloy at low temperature which makes the process industrially advantageous.
On le met en oeuvre sous sa forme telle que commercialisée, poudre ou écailles.It is used in its form as sold, powder or flakes.
Une variante préférée du procédé de l'invention consiste à ajouter au milieu réactionnel, du chlorure de calcium afin d'abaisser le point de fusion et la densité de la scorie formée dans la reaction de sorte que l'alliage formé néodyme-fer se sépare plus facilement.A preferred variant of the process of the invention consists in adding to the reaction medium, calcium chloride in order to lower the melting point and the density of the slag formed in the reaction so that the alloy formed neodymium-iron separates easier.
On peut utiliser, selon l'invention, les halogénures de calcium disponibles sur le marché : chlorure de calcium anhydre, chlorure de calcium dihydraté qui doit être seché entre 300°C et 400°C sous pression réduite de l'ordre de 1 mm de mercure (= 133,322 Pa) à 100 mm de mercure (= 13 332,2 Pa).Can be used, according to the invention, the calcium halides available on the market: anhydrous calcium chloride, calcium chloride dihydrate which must be dried between 300 ° C and 400 ° C under reduced pressure of the order of 1 mm mercury (= 133,322 Pa) to 100 mm of mercury (= 13,332.2 Pa).
La procédé de l'invention consiste à mélanger un fluorure de néodyme, le calcium. le fer et un chlorure de calcium dans les proportions données ci-dessous.
La quantité de calcium peut varier dans de larges limites. Cependant, il y a intérêt à mettre en oeuvre une quantité suffisante pour reduire le fluorure de néodyme mais elle ne doit pas être trop grande si l'on ne souhaite pas en retrouver, d'une manière importante, dans l'alliage final. La quantité de metal reducteur est au moins égale à la quantité stoechiométrique voire-même en léger excès, pouvant atteindre 20 % de la quantité stoechiomètrique.
La quantité de fer est réglée suivant la composition désirée de l'alliage. Elle est telle que l'on obtienne un alliage fusible avec le néodyme à la température de réaction. Elle est calculée de sorte que le fer represente de 5 à 30 % du poids de l'alliage obtenu. La quantité de chlorure de calcium ajoutée est ajustée afin d'obtenir une scorie contenant de 30 à 70 % en poids de chlorure de calcium et de préférence 60 à 70 %.The method of the invention consists in mixing a neodymium fluoride, calcium. iron and calcium chloride in the proportions given below.
The amount of calcium can vary within wide limits. However, it is advantageous to use an amount sufficient to reduce the neodymium fluoride but it should not be too large if one does not wish to find it, in an important way, in the final alloy. The amount of reducing metal is at least equal to the stoichiometric amount or even in slight excess, up to 20% of the stoichiometric amount.
The amount of iron is adjusted according to the desired composition of the alloy. It is such that a fusible alloy with neodymium is obtained at the reaction temperature. It is calculated so that the iron represents from 5 to 30% of the weight of the alloy obtained. The amount of calcium chloride added is adjusted in order to obtain a slag containing from 30 to 70% by weight of calcium chloride and preferably 60 to 70%.
Les differents halogénures de néodyme et de calcium et le fer constituent "une charge" ayant la composition pondérale souhaitée. Les constituants de cette charge peuvent être mis à réagir dans n'importe quel ordre : par mélange simultané de tous les constituants ou en faisant des pré-mélanges, d'une part, les halogénures de néodyme et de calcium et d'autre part le calcium et le fer.The different neodymium and calcium halides and iron constitute "a filler" having the desired weight composition. The constituents of this charge can be reacted in any order: by simultaneous mixing of all the constituents or by making premixes, on the one hand, the neodymium and calcium halides and on the other hand the calcium and iron.
La réaction est effectuée à une température comprise entre 800°C et 1100°C. La borne supérieure de température n'a aucun caractére critique et peut atteindre une valeur aussi élevée que 1400°C. D'une manière préférentielle, on choisit une température comprise entre 900°C et 1100°C.The reaction is carried out at a temperature between 800 ° C and 1100 ° C. The upper temperature limit is not critical and can reach a value as high as 1400 ° C. Preferably, a temperature between 900 ° C and 1100 ° C is chosen.
On effectue la réaction sous pression atmosphérique mais en atmosphére de gaz inerte. A cet effet, on exclut l'air par abaisse ment de la pression jusqu'à une valeur non critique, par exemp1e comprise entre 1 mm et 100 mm de mercure puis on assure un balayage de gaz inertes : gaz rares notamment l'argon. Il est souhaitable de soumettre le gaz rare à un traitement de déshydratation et de désoxygénation réalisé selon les techniques usuelles par exemple par passage au travers d'un tamis moléculaire.The reaction is carried out under atmospheric pressure but in an inert gas atmosphere. For this purpose, the air is excluded by lowering ment of the pressure up to a non-critical value, for example between 1 mm and 100 mm of mercury, then a scanning of inert gases is carried out: rare gases, in particular argon. It is desirable to subject the rare gas to a dehydration and deoxygenation treatment carried out according to the usual techniques, for example by passage through a molecular sieve.
On maintient l'atmosphère inerte tout au cours de la réduction.The inert atmosphere is maintained throughout the reduction.
La duree de la réaction est fonction de la capacité de l'appareillage et de son aptitude à monter rapidement en température. Généralement une fois la température souhaitée atteinte, on la maintient pendant une durée variable d'environ 30 minutes à 3 heures.The duration of the reaction depends on the capacity of the apparatus and its ability to rapidly rise in temperature. Generally once the desired temperature has been reached, it is maintained for a variable duration of approximately 30 minutes to 3 hours.
Au cours du chauffage, il se forme deux phases dans le milieu réactionnel : une phase métallique constituée par l'alliage néodyme-fer sur laquelle surnage une scorie constituée de CaF₂-CaCl₂ ayant une densité inférieure à celle de l'alliage.During heating, two phases are formed in the reaction medium: a metallic phase consisting of the neodymium-iron alloy on which floats a slag consisting of CaF₂-CaCl₂ having a density lower than that of the alloy.
Au bout du temps de chauffage précité, on arrête le chauffage.At the end of the above heating time, the heating is stopped.
On peut immédiatement separer l'alliage de la scorie par coulée à chaud ou le laisser refroidir sous atmosphère de gaz inerte à température ambiante (de 15 à 25°C) de sorte que l'alliage se solidifie et peut être alors demoulé.The alloy can be immediately separated from the slag by hot casting or allowed to cool under an inert gas atmosphere at room temperature (15 to 25 ° C) so that the alloy solidifies and can then be demolded.
On constate que le rendement en néodyme dans l'alliage exprimé par rapport au néodyme contenu dans l'halogénure varie de 80 à 96 %.It can be seen that the yield of neodymium in the alloy expressed relative to the neodymium contained in the halide varies from 80 to 96%.
Le procédé de l'invention tel que décrit, peut être mis en oeuvre dans un appareillage de type classique, utilisé en métallurgie.The method of the invention as described, can be implemented in an apparatus of conventional type, used in metallurgy.
La réduction est conduite dans un creuset placé dans un réacteur constitué par un matériau résistant aux vapeurs fluorhydrique et chlorhydrique.
Il peut être choisi en acier réfractaire, par exemple, en acier contenant 25 % de chrome et 20 % de nickel mais de préférence en inconel qui est un alliage contenant du nickel, du chrome (20 %), du fer (5 %), du molybdène (8-10 %).The reduction is carried out in a crucible placed in a reactor made of a material resistant to hydrofluoric and hydrochloric vapors.
It can be chosen from refractory steel, for example, steel containing 25% chromium and 20% nickel but preferably inconel which is an alloy containing nickel, chromium (20%), iron (5%), molybdenum (8-10%).
Ledit réacteur est equipé d'un dispositif de contrôle de température (par exemple thermocouple), d'une arrivée et d'une sortie de gaz inertes. Il est muni dans sa partie supérieure d'une double enveloppe dans laquelle circule un liquide de refroidissement.
Ce réacteur est placé dans un four à induction ou dans un four chauffé par résistances électriques.
Un creuset dans lequel plonge le dispositif de contrôle de température est placé au fond du réacteur. Il doit être constitué d'un matériau résistant au fluorure de néodyme ou posséder un revêtement leur résistant. D'une manière préférentielle, on utilise un creuset en tantale.Said reactor is equipped with a temperature control device (eg thermocouple), an inlet and outlet of inert gases. It is provided in its upper part with a double envelope in which circulates a coolant.
This reactor is placed in an induction furnace or in an furnace heated by electrical resistances.
A crucible in which the temperature control device is immersed is placed at the bottom of the reactor. It must be made of a material resistant to neodymium fluoride or have a coating resistant to them. Preferably, a tantalum crucible is used.
Une fois la réaction effectuée, l'alliage fondu peut être coulé en lingotières, par exemple, en fonte.Once the reaction is complete, the molten alloy can be cast in molds, for example, cast iron.
Les alliages obtenus selon la présente invention ont la composition pondérale suivante :
- de 70 à 95 % de néodyme
- de 5 à 30 % de fer
- moins de 3 % de métal réducteurThe alloys obtained according to the present invention have the following weight composition:
- from 70 to 95% of neodymium
- 5 to 30% iron
- less than 3% of reducing metal
On donne, ci-aprés, à titre illustratif et non limitatif, des compositions préférées des alliages nèodyme-fer abtenus :
. de 83 à 91 % de nèodyme
. de 9 à 16 % de fer
. moins de 1 % de calciumThe following are given, by way of illustration and without limitation, preferred compositions of the neodymium-iron alloys used:
. 83 to 91% neodymium
. 9 to 16% iron
. less than 1% calcium
Les alliages obtenus selon la présente invention sont très riches en néodyme puisqu'ils peuvent en contenir jusqu'a 95%.The alloys obtained according to the present invention are very rich in neodymium since they can contain up to 95%.
Ils peuvent être utilisés comme alliages-mères notamment dans la fabrication d'aimants permanents.They can be used as master alloys in particular in the manufacture of permanent magnets.
Avant de détailler les exemples concrétisant la réalisation pratique de l'invention, on exposera succinctement les méthodes de dosage des différents constituants de l'alliage par les techniques suivantes :
- le néodyme est dosé, selon la méthode chimique exposée ci-après et consiste :
. à dissoudre l'échantillon d'alliage en milieu acide,
. à porter à ébullition la solution obtenue,
. à précipiter le métal réducteur, le fer et le néodyme sous la forme de leur hydroxyde à pH 9, par traitement à l'ammoniaque, puis à filtrer et laver les précipités obtenus,
. à redissoudre le précipité d'hydroxyde de néodyme en milieu acide,
. à ajouter à ébullition à la solution obtenue, de l'oxalate d'ammonium afin d'obtenir l'oxalate de néodyme,
. à calciner l'oxalate de néodyme à 900°C pendant 1 heure pour le transformer en oxyde,
. à peser la quantité d'oxyde obtenu permettant ainsi de calculer la quantité de néodyme contenu dans l'alliage.
- les autres métaux, métal réducteur et fer sont titrés par absorption atomique.Before detailing the examples embodying the practical implementation of the invention, the methods for assaying the various constituents of the alloy will be explained briefly by the following techniques:
- the neodymium is dosed, according to the chemical method described below and consists of:
. dissolving the alloy sample in an acid medium,
. bring the solution obtained to a boil,
. precipitating the reducing metal, iron and neodymium in the form of their hydroxide at pH 9, by treatment with ammonia, then filtering and washing the precipitates obtained,
. redissolving the precipitate of neodymium hydroxide in an acid medium,
. adding ammonium oxalate to the solution obtained in boiling to obtain neodymium oxalate,
. calcining the neodymium oxalate at 900 ° C for 1 hour to transform it into oxide,
. weighing the quantity of oxide obtained, thus making it possible to calculate the quantity of neodymium contained in the alloy.
- the other metals, reducing metal and iron are titrated by atomic absorption.
On donne, ci-après, un exemple de réalisation de l'invention.An exemplary embodiment of the invention is given below.
Les pourcentages mentionnés dans les exemples sont exprimés en poids.The percentages mentioned in the examples are expressed by weight.
On commence par broyer, grossièrement, 382,2 g de chlorure de calcium puis on le séche pendant 3 heures, à une température de 350°C-400°C et sous pression réduite de 1 mm de mercure (= 133,322 Pa).We begin by grinding, roughly, 382.2 g of calcium chloride and then drying it for 3 hours, at a temperature of 350 ° C-400 ° C and under reduced pressure of 1 mm of mercury (= 133.322 Pa).
On fait ensuite un prémélange contenant 382,2 g de chlorure de calcium a l'état sec et 281,4 g de fluorure de néodyme ayant un diamètre moyen de particules de 60 µm. On réalise le séchage dudit mélange pendant 24 heures dans une étuve à vide à une température de 225°C et sous pression réduite de 1 mm de mercure (= 133,322 Pa). La charge précédemment définie est alors prête à l'emploi.A premix containing 382.2 g of calcium chloride in the dry state and 281.4 g of neodymium fluoride having an average particle diameter of 60 μm is then made. The drying of the said mixture is carried out for 24 hours in a vacuum oven at a temperature of 225 ° C. and under a pressure reduced by 1 mm of mercury (= 133.322 Pa). The previously defined load is then ready for use.
La réaction de réduction calciothermique du fluorure de néodyme est réalisée dans un creuset en tantale de 1 litre environ placé au fond d'un réacteur en inconel qui est équipé d'une arrivée et d'une sortie d'argon et d'un thermocouple introduit dans une gaîne thermomètrique qui est plongée dans le milieu réactionnel contenu dans le creuset : la partie supérieure du réacteur est munie d'une double enveloppe dans laquelle circule de l'eau froide (environ 10°C).The calciothermic reduction reaction of neodymium fluoride is carried out in a tantalum crucible of about 1 liter placed at the bottom of an inconel reactor which is equipped with an inlet and an argon outlet and a thermocouple introduced into a thermometric sheath which is immersed in the reaction medium contained in the crucible: the upper part of the reactor is provided with a double jacket in which cold water circulates (about 10 ° C).
On définit la proportion des constituants de la charge de telle sorte que les conditions énoncées, ci-aprés, soient remplies:
- que l'on obtienne un alliage contenant 12 % de fer
- que l'on ait un excès de calcium de 20 % par rapport au poids stoechiométrique requis
- que l'on forme une scorie contenant 70 % de chlorure de calcium.The proportion of the constituents of the charge is defined so that the conditions set out below are met:
- that we obtain an alloy containing 12% iron
- that there is an excess of calcium of 20% compared to the required stoichiometric weight
- that a slag containing 70% calcium chloride is formed.
On introduit successivement au fond du creuset 27,5 g de fer sous forme d'écailles, 101 g de calcium sous forme de grenailles et la charge precitée contenant 382,2 g de chlorure de calcium et 281,4 g de fluorure de néodyme.27.5 g of iron in the form of scales, 101 g of calcium in the form of pellets and the abovementioned charge containing 382.2 g of calcium chloride and 281.4 g of neodymium fluoride are successively introduced at the bottom of the crucible.
Une fois le creuset replacé dans le réacteur que l'on ferme, on abaisse la pression aux environs de 100 mm de mercure (= 13 332,2 Pa) pour chasser l'air puis on établit un balayage à l'argon sec qui sera maintenu tout au long de la réaction.Once the crucible has been replaced in the closed reactor, the pressure is lowered to around 100 mm of mercury (= 13,332.2 Pa) to expel the air, then a dry argon sweep is established, which will be maintained throughout the reaction.
On effectue en même temps une montée en température jusqu'à obtention de la température fixée à 1100°C ; cette température êtant tenue constante encore 30 minutes.A temperature rise is carried out at the same time until the temperature fixed at 1100 ° C. is obtained; this temperature being kept constant for another 30 minutes.
On recueille 562 g de scorie et on récupère 188 g d'un alliage neodyme-fer par coulage à chaud dans une lingotière en fonte. Le rendement en néodyme dans l'alliage exprimé par rapport au néodyme contenu dans le fluorure de néodyme est de 81 %.562 g of slag are collected and 188 g of a neodymium-iron alloy are recovered by hot casting in a cast iron ingot mold. The neodymium yield in the alloy expressed relative to the neodymium contained in the neodymium fluoride is 81%.
L'analyse de l'alliage obtenu est la suivante :
- 87,4 % de néodyme
- 12 % de fer
- 0,6 % de calcium.The analysis of the alloy obtained is as follows:
- 87.4% neodymium
- 12% iron
- 0.6% calcium.
Claims (16)
- de 70 à 95 % de nèodyme
- de 5 à 30 % de fer
- moins de 3 % de calcium15- Neodymium alloys according to claim 14, characterized in that they contain:
- from 70 to 95% of neodymium
- 5 to 30% iron
- less than 3% calcium
- de 83 à 91 % de nèodyme
- de 9 à 16 % de fer
- moins de 1 % de calcium.16 - Neodymium and iron alloys according to claim 15, characterized in that they contain:
- from 83 to 91% of neodymium
- from 9 to 16% iron
- less than 1% calcium.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| AT88100014T ATE81156T1 (en) | 1983-07-05 | 1984-06-22 | PROCESS FOR THE PRODUCTION OF NEODYMIUM ALLOYS. |
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FR8311139A FR2548687B1 (en) | 1983-07-05 | 1983-07-05 | NEODYM ALLOYS AND THEIR MANUFACTURING METHOD |
| FR8311139 | 1983-07-05 | ||
| FR838314392A FR2551769B2 (en) | 1983-07-05 | 1983-09-09 | NEODYM ALLOYS AND THEIR MANUFACTURING METHOD |
| FR8314392 | 1983-09-09 |
Related Parent Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| EP84401307.8 Division | 1984-06-22 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| EP0272250A1 true EP0272250A1 (en) | 1988-06-22 |
| EP0272250B1 EP0272250B1 (en) | 1992-09-30 |
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Family Applications (2)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| EP88100014A Expired - Lifetime EP0272250B1 (en) | 1983-07-05 | 1984-06-22 | Process for the production of neodym alloys |
| EP84401307A Expired EP0134162B1 (en) | 1983-07-05 | 1984-06-22 | Alloys of neodymium and process for their production |
Family Applications After (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| EP84401307A Expired EP0134162B1 (en) | 1983-07-05 | 1984-06-22 | Alloys of neodymium and process for their production |
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| Country | Link |
|---|---|
| US (1) | US4636353A (en) |
| EP (2) | EP0272250B1 (en) |
| JP (1) | JPS6046346A (en) |
| KR (1) | KR920006603B1 (en) |
| AU (1) | AU579579B2 (en) |
| BR (1) | BR8403289A (en) |
| CA (1) | CA1253721A (en) |
| DE (2) | DE3485950T2 (en) |
| FR (1) | FR2551769B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0364089A1 (en) * | 1988-10-11 | 1990-04-18 | General Motors Corporation | Method of de-calcifying rare-earth metals formed by a reduction-diffusion process |
Families Citing this family (31)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4612047A (en) * | 1985-10-28 | 1986-09-16 | The United States Of America As Represented By The United States Department Of Energy | Preparations of rare earth-iron alloys by thermite reduction |
| US4837109A (en) * | 1986-07-21 | 1989-06-06 | Hitachi Metals, Ltd. | Method of producing neodymium-iron-boron permanent magnet |
| FR2607520B1 (en) * | 1986-11-27 | 1992-06-19 | Comurhex | PROCESS FOR THE PRODUCTION BY METALLOTHERMY OF PURE ALLOYS BASED ON RARE EARTHS AND TRANSITION METALS |
| US4992096A (en) * | 1989-06-09 | 1991-02-12 | The Dow Chemical Company | Metallothermic reduction or rare earth metals |
| US5073337A (en) * | 1990-07-17 | 1991-12-17 | Iowa State University Research Foundation, Inc. | Rare earth/iron fluoride and methods for making and using same |
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| US5240513A (en) * | 1990-10-09 | 1993-08-31 | Iowa State University Research Foundation, Inc. | Method of making bonded or sintered permanent magnets |
| US5242508A (en) * | 1990-10-09 | 1993-09-07 | Iowa State University Research Foundation, Inc. | Method of making permanent magnets |
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| US5314526A (en) * | 1990-12-06 | 1994-05-24 | General Motors Corporation | Metallothermic reduction of rare earth fluorides |
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| RU2596563C1 (en) * | 2015-04-23 | 2016-09-10 | Федеральное государственное унитарное предприятие "Всероссийский научно-исследовательский институт авиационных материалов" (ФГУП "ВИАМ") | Method for production of hard-magnetic material |
| CN114891953B (en) * | 2022-03-31 | 2024-03-08 | 包头市英思特稀磁新材料股份有限公司 | Method for improving sintering NdFeB material yield |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR489155A (en) * | 1917-04-19 | 1918-12-28 | Maurice Duburguet | Preparation of rare earth metals |
| US1648954A (en) * | 1921-09-29 | 1927-11-15 | Westinghouse Lamp Co | Production of rare metals and alloys thereof |
| FR986924A (en) * | 1943-12-11 | 1951-08-07 | Process for preparing rare earth metals | |
| US3186834A (en) * | 1961-03-02 | 1965-06-01 | Dow Chemical Co | Preparation of rare earth metal sponge |
| US3295963A (en) * | 1962-07-27 | 1967-01-03 | Pechiney Prod Chimiques Sa | Alloys containing rare earth metals |
| AT329884B (en) * | 1973-07-19 | 1976-06-10 | Treibacher Chemische Werke Ag | PROCESS FOR MANUFACTURING LANTHAN, CER, PRASEODYME AND NEODYME METALS AND ALLOYS OF THE SAME AND MIXED METALS |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5696834A (en) * | 1979-12-28 | 1981-08-05 | Mitsubishi Monsanto Chem Co | Compound semiconductor epitaxial wafer and manufacture thereof |
| US4496395A (en) * | 1981-06-16 | 1985-01-29 | General Motors Corporation | High coercivity rare earth-iron magnets |
| JPS5976A (en) * | 1982-06-22 | 1984-01-05 | 日本電気株式会社 | High energy ct for radiation treatment |
| DE3379131D1 (en) * | 1982-09-03 | 1989-03-09 | Gen Motors Corp | Re-tm-b alloys, method for their production and permanent magnets containing such alloys |
| JPS6263642A (en) * | 1986-09-12 | 1987-03-20 | Sumitomo Special Metals Co Ltd | Rare earth alloy for magnet stock and its production |
-
1983
- 1983-09-09 FR FR838314392A patent/FR2551769B2/en not_active Expired - Lifetime
-
1984
- 1984-06-22 EP EP88100014A patent/EP0272250B1/en not_active Expired - Lifetime
- 1984-06-22 DE DE8888100014T patent/DE3485950T2/en not_active Expired - Fee Related
- 1984-06-22 EP EP84401307A patent/EP0134162B1/en not_active Expired
- 1984-06-22 DE DE8484401307T patent/DE3479595D1/en not_active Expired
- 1984-07-02 AU AU30081/84A patent/AU579579B2/en not_active Ceased
- 1984-07-03 BR BR8403289A patent/BR8403289A/en not_active IP Right Cessation
- 1984-07-04 CA CA000458064A patent/CA1253721A/en not_active Expired
- 1984-07-05 JP JP59138065A patent/JPS6046346A/en active Granted
- 1984-07-05 KR KR1019840003886A patent/KR920006603B1/en not_active IP Right Cessation
-
1985
- 1985-06-18 US US06/745,828 patent/US4636353A/en not_active Expired - Fee Related
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR489155A (en) * | 1917-04-19 | 1918-12-28 | Maurice Duburguet | Preparation of rare earth metals |
| US1648954A (en) * | 1921-09-29 | 1927-11-15 | Westinghouse Lamp Co | Production of rare metals and alloys thereof |
| FR986924A (en) * | 1943-12-11 | 1951-08-07 | Process for preparing rare earth metals | |
| US3186834A (en) * | 1961-03-02 | 1965-06-01 | Dow Chemical Co | Preparation of rare earth metal sponge |
| US3295963A (en) * | 1962-07-27 | 1967-01-03 | Pechiney Prod Chimiques Sa | Alloys containing rare earth metals |
| AT329884B (en) * | 1973-07-19 | 1976-06-10 | Treibacher Chemische Werke Ag | PROCESS FOR MANUFACTURING LANTHAN, CER, PRASEODYME AND NEODYME METALS AND ALLOYS OF THE SAME AND MIXED METALS |
Non-Patent Citations (6)
| Title |
|---|
| CHEMICAL ABSTRACTS, vol. 93, 1980, page 379, résumé no. 226435c, Columbus, Ohio, US; V.D. SAVIN et al.: "Kinetics of the reduction of cerium and neodymium from chlorides by calcium", & ZH. FIZ. KHIM. 1980, 54(9), 2241-5 * |
| CHEMICAL ABSTRACTS, vol. 94, 1981, page 213, résumé no. 195573k, Columbus, Ohio, US; G.N. ZVIADADZE et al.: "Kinetics of aluminothermal reduction of neodymium from fluoride", & IZV. AKAD. NAUK SSSR, Met. 1981 (1), 14-17 * |
| CHEMICAL ABSTRACTS, vol. 95, 1981, page 463, résumé no. 157685m, Columbus, Ohio, US; G.N. ZVIADADZE et al.: "Thermodynamics of the aluminothermal reduction of scandium, yttrium, and neodymium from fluorides", & DEPOSITED DOC. 1980, VINITI, 1804-80, 19pp. * |
| CHIMIE ET INDUSTRIE, vol. 77, no. 2, février 1957, pages 277-288, Société de productions documentaires, Rueil-Malmaison, FR; F. TROMBE: "Préparation et propriétés des métaux des terres rares" * |
| GMELIN HANDBUCH DER ANORGANISCHEN CHEMIE, partie B2, système no. 39, pages 214-215, Springer Verlag, Berlin, DE * |
| M. BOUISSIERES et al.: "Nouveau traité de chimie minérale", tome VII, 1959, pages 488-525, Masson Editeurs * |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0364089A1 (en) * | 1988-10-11 | 1990-04-18 | General Motors Corporation | Method of de-calcifying rare-earth metals formed by a reduction-diffusion process |
Also Published As
| Publication number | Publication date |
|---|---|
| EP0272250B1 (en) | 1992-09-30 |
| BR8403289A (en) | 1985-06-18 |
| DE3485950T2 (en) | 1993-02-25 |
| KR850001297A (en) | 1985-03-18 |
| JPH0224902B2 (en) | 1990-05-31 |
| EP0134162B1 (en) | 1989-08-30 |
| CA1253721A (en) | 1989-05-09 |
| US4636353A (en) | 1987-01-13 |
| FR2551769B2 (en) | 1990-02-02 |
| JPS6046346A (en) | 1985-03-13 |
| EP0134162A1 (en) | 1985-03-13 |
| DE3485950D1 (en) | 1992-11-05 |
| FR2551769A2 (en) | 1985-03-15 |
| KR920006603B1 (en) | 1992-08-10 |
| AU579579B2 (en) | 1988-12-01 |
| DE3479595D1 (en) | 1989-10-05 |
| AU3008184A (en) | 1985-01-10 |
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