EP0170372B1 - Metallothermische Reduktion seltener Erdoxide mittels Kalzium - Google Patents

Metallothermische Reduktion seltener Erdoxide mittels Kalzium Download PDF

Info

Publication number
EP0170372B1
EP0170372B1 EP85304046A EP85304046A EP0170372B1 EP 0170372 B1 EP0170372 B1 EP 0170372B1 EP 85304046 A EP85304046 A EP 85304046A EP 85304046 A EP85304046 A EP 85304046A EP 0170372 B1 EP0170372 B1 EP 0170372B1
Authority
EP
European Patent Office
Prior art keywords
rare earth
bath
oxide
metal
metallothermic
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
EP85304046A
Other languages
English (en)
French (fr)
Other versions
EP0170372A1 (de
Inventor
Ram Autar Sharma
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.)
Motors Liquidation Co
Original Assignee
Motors Liquidation Co
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Motors Liquidation Co filed Critical Motors Liquidation Co
Priority to AT85304046T priority Critical patent/ATE36560T1/de
Publication of EP0170372A1 publication Critical patent/EP0170372A1/de
Application granted granted Critical
Publication of EP0170372B1 publication Critical patent/EP0170372B1/de
Expired legal-status Critical Current

Links

Images

Classifications

    • 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
    • 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
    • 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

Definitions

  • This inveniton relates to a novel metallothermic process for the direct reduction of rare earth oxide, particularly neodymium oxide, to rare earth metal.
  • the method has particular application to low cost production of neodymium metal for use in neodymium-iron-boron magnets.
  • Sources of the rare earth (RE) elements are bastnaesite and monazite ores. Mixtures of the rear earths can be extracted from the ores by several well known beneficiating techniques. The rear earths can then be separated from one another by such conventional processes as elution and liquid-liquid extraction.
  • RE rare earth
  • the electrolytic processes include (1) decomposition of anhydrous rare earth chlorides dissolved in molten alkali or alkaline earth salts, and (2) decomposition of rare earth oxides dissolved in molten rare earth fluoride salts.
  • Electrolytic processes include the use of expensive electrodes which are eventually consumed, the use of anhydrous chloride or fluoride salts to prevent the formation of undesirable RE-oxy salts (NdOCI, e.g.), high temperature cell operation (generally greater than 1000°C), low current efficiences resulting in high power costs, and low yield of metal from the salt (40% or less of the metal can be recovered).
  • the RE-chloride reduction process release corrosive chlorine gas while the fluoride process requires careful control of a temperature gradient in the electrolytic salt cell to cause solidification of rare earth metal nodules.
  • An advantage of electrolytic processes is that they can be made to run continuously if provision is made to tap the reduced metal and to refortify the salt bath.
  • the metallothermic (non-electrolytic) processes include (1) reduction of RE-fluorides with calcium metal powder (the calciothermic process), and (2) reduction-diffusion of RE-oxide with calcium hydride (CaH 2 ) or calcium metal (Ca).
  • both are batch processes, they must be conducted in a non-oxidizing atmosphere, they are energy intensive and the product in the case of reduction-diffusion is a powder which must be hydrated to purify it before use. Both processes involve many steps.
  • One advantage of the metallothermic reduction processes is that the yield of metal from the oxide or fluoride is generally better than ninety percent.
  • a metallothermic, non-electrolytic method of reducing rare earth oxide to rare earth metal according to the present invention consists in that the reduction takes place in a molten salt bath comprised predominantly of calcium chloride, a volume of rare earth oxide that is less than the salt bath volume is dispersed in the bath, a stoichiometric excess of calcium metal with respect to the amount of rare earth metal ion present is added to the bath, and said bath is agitated so that the oxide is reduced to rare earth metal in accordance with the formula where RE represents one or more rare earth elements having a valency of 2,3 or 4,0 represents oxygen, Ca represents calcium, CaO represents calcium oxide, and n and m are integers such that the valency of the rare earth element multiplied by n equals the valency of oxygen multiplied by m.
  • a reaction vessel is provided which can be heated to desired temperatures by electrical resistance heaters or some other heating means.
  • the vessel body is preferably made of a metal or refractory material that is either substantially inert or innocuous to the reaction constituents.
  • a predetermined amount of RE-oxide is charged into the reaction vessel containing a salt mixture of about 70 weight percent calcium chloride or greater and about 5 to 30 weight percent sodium chloride (NaCI).
  • the salt serves as a medium for the reduction reaction.
  • a stoichiometric excess of calcium metal, based on the amount of rear earth oxide, is added. It may be advantageous to add an amount of another metal such as iron or zinc to form a eutectic alloy with the reduced rare earth metal to enable the reaction to be carried out at lower temperatures and to obtain the RE metal product in a liquid state.
  • the vessel is heated to a temperature above the melting point of the constituents (about 675°C).
  • the molten constituents are rapidly stirred in the vessel to keep them in contact with one another as the reaction progresses.
  • the bath is replenished with calcium chloride (CaCl 2 ) as necessary to maintain a weight percent of 70% of the combined weights of CaC1 2 and NaCI. While the reaction runs at CaCI 2 concentrations lower than 70%, the yield falls of rapidly.
  • n and m are the number of moles of constituent and where the relation of n and m is determined by the oxidation state of the rare earth element.
  • the reduced metal has a density of about 7 grams/cc while that of the salt bath is about 1.9 grams/cc.
  • the reduced metal forms a clean layer at the bottom of the reaction vessel. This layer may be tapped while molten or separated from the salt layer after it solidifies.
  • the method of the invention provides many advantages over prior art methods. It is carried out at a relatively low temperature of about 700°C, particularly where the rare earth metal is recovered as a zinc or iron eutectic alloy. It uses relatively inexpensive RE-oxide, CaCl 2 , NaCI and Ca metal reactants. It does not require pretransformation of RE-oxide to chloride or fluoride, nor the use of expensive pure Ca or CaH 2 reducing agent. Energy consumption is low because the method is not electrolytic and it is preferably carried out at atmospheric pressure at temperatures at about 700°C. The method can be practiced as either a batch or a continuous process, and the by-products of CaC1 2 , NaCI and calcium oxide (CaO) are easily disposed of. Moreover, the rare earth metals may be alloyed with additional iron in the reaction vessel if they are made as a RE-Fe eutectic alloy or may be alloyed later for use in RE-Fe magnets without further expensive purification treatments.
  • the rare earth metals include elements 57 to 71 of the periodic table (lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium) and atomic number 39, yttrium.
  • the oxides of the rare earths are generally coloured powders produced in the metals separation process.
  • the term "light rare earth” refers to the elements lanthanum (La), cerium (ce), praseodymium (Pr) and neodymium (Nd).
  • the RE-oxides can generally be used as received from the separator but may be calcined to remove excess absorbed moisture or carbon dioxide.
  • the RE-oxides were oven-dried for about two hours at 1000°C prior to use.
  • the CaCI 2 and NaCI for the salt baths were reagent grade and dried for about two hours at 500°C prior to use.
  • RE-oxychloride is formed by the reaction
  • both RE-oxides and RE-oxychlorides are readily reduced by calcuim metal.
  • the formation of RE-oxychlorides is advantageous because they float on molten layers of reduced RE metals.
  • RE-oxides on the other hand, have densities close to the reduced RE metals so they may be retained as contaminants in the molten layers of reduced RE metals, and may make the RE metals unsuited for use in magnets.
  • the RE metals reduced by the method according to the present invention have been substantially oxide-free.
  • Unalloyed Nd metal has a melting temperature of about 1025°C.
  • the other rare earth metals also have high melting points. If one wanted to run the subject reaction at such temperatures, it would be possible to do so and obtain pure metal at high yields.
  • iron forms a low melting eutectic alloy with neodymium (11.5 weight percent Fe; m.p. about 640°C) as does zinc (11.9 weight percent Zn, m.p. about 630°C).
  • a Nd-Fe eutectic alloy may be directly alloyed with additional iron and boron to make magnets having the optimum Nd 2 Fe 14 B magnetic phase described in the aforementioned European patent applications.
  • a metal with a boiling point much lower than the boiling point of the recovered rare earth can be added to the reaction vessel.
  • the low-melting metal can then be readily separated from the rare earth metal by simple distillation.
  • Yttria-lined alumina and boron nitride are non-reactive, refractory materials generally acceptable. It is also possible to use a refractory liner made of a substantially inert metal such as tantalum or a consumable but innocuous metal such as iron. An iron liner could be used to contain.reduced RE metal and then be alloyed with the RE for use in magnets.
  • a new method has been discovered of using calcium metal to reduce rare earth oxides.
  • the method entails bringing together molten calcium and RE-oxide to cause the reaction Unless the reaction vessel is pressurized, it is desirable to keep the temperature at below 910°C to avoid the excessive loss of Na formed by the reaction of Ca with NaCI. It is preferred to run the reactions at atmospheric pressure.
  • the most preferred range of operating temperatures is between about 650°C and 750°C. At such temperatures wear on the reaction vessel is not excessive. This temperature range is suitable for reducing Nd 2 0 3 to Nd metal because the Nd-Re and Nd-Zn eutectic melting-point temperatures are below 700°C.
  • the solubility of Ca metal in the salt bath is about 1.3 molecular percent. This is sufficient to rapidly reduce RE-oxide to RE metal.
  • the reaction temperature must be above the melting point of the reduced RE metal or the melting point of the reduced RE metal alloyed or co-reduced with another metal.
  • These relatively dense RE metals and alloys collect at the bottom of the reaction vessel when allowed to settle. There they can be tapped while molten or removed after solidification.
  • Table I shows the molecular weight (m.w.), density (p) at 25°C, melting point (m.p.) and boiling point (b.p.) for elements and compounds used in the present invention.
  • FIG 1 shows an apparatus suitable for the practice of the invention in which the experiments set out in the several examples were conducted.
  • the furnace was heated by means of three tubular, electric, clamshell heating elements 8, 10 and 12 having an inside diameter of 13.3 cm and a total length of 45.7 cm.
  • the side and bottom of the furnace well were surrounded with refractory insulation 14.
  • Thermocouples 15 were mounted on an outer wall 16 of furnace wall 20 at various locations along its length.
  • One of the centrally located thermocouples was used in conjunction with a proportional band temperature controller (not shown) to automatically control centre clamshell heater 10.
  • the other three thermocouples were monitored with a digital temperature readout system and top and bottom clamshell heaters 8 and 12 were manually controlled with transformers to maintain a fairly uniform temperature throughout the furnace.
  • reaction vessel 22 was carried out in a reaction vessel 22 retained in a stainless steel crucible 18 having a 10.2 cm outer diameter, 12.7 cm deep and 0.15 cm thick retained in stainless steel furnace well 20.
  • Reaction vessel 22 was made of tantalum metal unless otherwise noted in the examples.
  • a tantalum stirrer 24 was used to agitate the melt during the reduction process. It had a shaft 48.32 cm long and a welded blade 26.
  • the stirrer was powered by a 100 W variable speed motor 28 capable of operating at speeds up to 700 revolutions per minute.
  • the motor was mounted on a bracket 30 so that the depth of stirrer blade 26 in reaction vessel 22 could be adjusted.
  • the shaft was journalled in a bushing 32 carried in an annular support bracket 34. The bracket is retained by collar 35 to which furnace well 20 is fastened by bolts 37.
  • Chill water coils 36 were located near the top of well 20 to promote condensation and prevent escape of volatile reaction constituents.
  • Cone-shaped stainless steel baffles 38 were used to reflux Na vapors. Reflux products drop through tube 40 on bottom baffle 42.
  • Figure 2 is an idealized flow chart for the reduction of Nd 2 0 3 to Nd metal in accordance with this invention.
  • the Nd 2 0 3 is added to the reaction vessel along with calcium chloride and sodium chloride in suitable proportions. Calcium metal and enough of a eutectic forming metal such as iron or zinc to form a near eutectic Nd alloy are added.
  • the reaction is run, with rapid stirring at about 300-700 revolutions per minute at a temperature of about 700°C for at least one hour.
  • a blanket of an inert gas such as helium is maintained over the reaction vessel.
  • Nd 2 0 3 After the Nd 2 0 3 has been reduced, stirring is continued at a lower speed of 100 revolutions per minute for one hour and then stirring is stopped to allow the various liquids in the vessel to stratify.
  • the reduced Nd eutectic alloy collects at the bottom because it has the highest density.
  • the remaining salts and any unreacted Ca collect above the Nd alloy and can be readily broken away after the vessel has cooled and the constituents have solidified.
  • Nd-Fe alloys so produced can be alloyed with additional elements to produce permanent magnet compositions. These magnet alloys may be processed by melt-spinning or they can be ground and processed by powder metallurgy to make magnets.
  • the furnace temperature was lowered to about 720°C.
  • 150 grams of NaCl and 350 grams of CaC1 2 were added to create a salt bath of 70 weight percent CaCl 2 .
  • 234 grams (0.7 moles) Nd 2 0 3 were added.
  • 104 grams of Ca (2.6 moles) metal were added to the crucible and it was stirred at a rate of 300 revolutions per minute for about two hours and then for another hour at a stirring rate of 60 revolutions per minute.
  • the crucible was removed from the furnace and cooled on the floor of the drybox.
  • Nd metal of purity greater than 99% was recovered (not including the 265 grams of Nd metal from the original seed pool) by distilling the Nd-Zn alloy collected at the bottom of the vessel.
  • the yield of Nd metal from the oxide was about 94%.
  • the furnace temperature was lowered to about 720°C.
  • 300 grams of NaCl and 700 grams of CaCI 2 were added to create a salt bath of 70 weight percent CaCl 2 .
  • 117 grams (0.35 moles) of Nd 2 0 3 were added.
  • 46 grams (1.15 moles) of Ca metal and 10.8 grams (0.47 moles) of Na were added to the crucible and they were stirred at a rate of 300 revolutions per minute for about 135 minutes.
  • an additional 117 grams (0.35 moles) of Nd 2 0 3 46 grams (1.15 moles) of Ca metal and 10.8 grams (0.47 moles) of Na were added.
  • the reactants were stirred for another 114 minutes at 300 rpm and then for another hour at a stirring rate of 60 rpm.
  • the reaction vessel was removed from the furnace and cooled on the floor of the drybox. A layer of unreacted Ca-Na alloy formed on top of the salt layer.
  • Nd-Fe alloy 594 grams of 97% purity Nd-Fe alloy were recovered. Such alloy could be combined directly as recovered with additional iron and boron to make the ideal Nd-Fe-B alloy for permanent magnet manufacture. 180 grams of Nd metal of purity greater than 99% was recovered as Nd-Fe alloy. This example shows that a calcium and sodium melt is capable of reducing a rare earth oxide in a CaCl 2 -NaCl flux bath.
  • Table II sets out the amounts of various constituents used in the metallothermic reduction of about 234 grams Nd 2 O 3 with Ca metal using the process set out in Example except that the reactants were stirred for four hours at 300 revolutions per minute followed by an additional hour of stirring at 60 rpm.
  • FIG. 3 is a plot of Nd metal yield from Nd 2 0 3 as a function of the weight percent CaC1 2 in a two component NaCI-CaCI 2 starting salt bath with a Ca metal reductant. Referring to Table II and Figure 3, it has been found that, to obtain high yields, it is necessary to maintain the amount of CaC1 2 in the salt bath above about 70 weight percent.
  • the CaC1 2 -containing bath is a significant feature of this invention.
  • the resultant alloy was analyzed and was found to be of greater than 99% purity with 0.4% aluminium, 0.1 % silicon, 0.01 % calcium and traces of zinc, magnesium and iron contamination.
  • the Nd metal so produced was melted in a vacuum furnace with electrolytic iron and ferroboron to produce an alloy having the nominal composition Nd 0.15 B 0.05 Fe 0.80 .
  • the alloy was melt-spun, as described in European patent application No. 0108474 cited above, to produce very finely crystalline ribbon with an as-quenched coercivity of about 10 megaGaussOersteds.

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Mechanical Engineering (AREA)
  • Materials Engineering (AREA)
  • Organic Chemistry (AREA)
  • Manufacturing & Machinery (AREA)
  • Metallurgy (AREA)
  • Environmental & Geological Engineering (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Geology (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Manufacture And Refinement Of Metals (AREA)
  • Electrolytic Production Of Metals (AREA)
  • Compounds Of Alkaline-Earth Elements, Aluminum Or Rare-Earth Metals (AREA)
  • Hard Magnetic Materials (AREA)
  • Manufacturing Cores, Coils, And Magnets (AREA)
  • Electrical Discharge Machining, Electrochemical Machining, And Combined Machining (AREA)

Claims (11)

1. Metallothermisches, nicht-elektrolytisches Verfahren zur Reduktion von Seltenerdoxiden zur den Saltenerdmetallen, das darin besteht, daß die Reduktion in einem geschmolzenen Salzbad (44) stattfindet, das überwiegend Calciumchlorid enthält, ein Volumen des Seltenerdoxids, das kleiner ist als das Salzbadvolumen, in dem Bad dispergiert wird, ein gegenüber der anwesenden Menge des Seltenerdmetallions stöchiometrischer Überschuß von Calciummetall zu dem Bad zugesetzt wird, und dieses Bad so bewegt wird, daß das Oxid zum Seltenerdmetall entsprechend der Gleichung
Figure imgb0010
reduziert wird, in der RE ein oder mehrere Seltenerdelemente mit einer Wertigkeit von 2, 3 oder 4, 0 Sauerstoff, Ca Calcium, CaO Calciumoxid sowie n und m solche ganzen Zahlen bedeuten, daß die Wertigkeit des Seltenerdelements multipliziert mit n gleich der Wertigkeit von Sauerstoff multipliziert mit m ist.
2. Metallothermisches, nicht-elektrolytisches Reduktionsverfahren nach Anspruch 1, dadurch gekenzeichnet, daß Neodymoxid zu Neodymmetall in Übereinstimmung mit der Reaktionsgleichung
Figure imgb0011
reduziert wird.
3. Metallothermisches, nicht-elektrolytisches Reduktionsverfahren nach Anspruch 1, dadurch gekennzeichnet, daß das geschmolzene Salzbad (44) wenigstens 70 Gew.-% Calciumchlorid enthält, das Bad (44) im geschmolzenen Zustand gehalten und bewegt wird, bis das Calciummetall das Seltenerdoxid zum Seltenerdmetall reduziet, und dann mit dem Bewegen aufgehört wird, so daß eine getrennte Schicht (43), die das Seitenerdmetall enthält, in dem Bad (44) gebildet wird.
4. Metallothermisches, nicht-elektrolytisches Reduktionsverfahren nach Anspruch 3, dadurch gekennzeichnet, daß das Seltenerdoxid ein oder mehrere Seitenerdoxide aus der Gruppe Lathanoxid, Ceroxid, Praseodymoxid und Neodymoxid ist.
5. Metallothermisches, nicht-elektrolytisches Reduktionsverfahren nach Anspruch 3, dadurch gekennzeichnet, daß das geschmolzene Bad (44) wenigstens 70 Gew.-% Calciumchlorid und Rest Natriumchlorid enthält, ein Volumen von Neodymoxid Nd203, das kleiner als 50% des Volumens des geschmolzenen Bades (44) ist, zu dem Bad (44) gegeben wird, das Bad (44) so gerührt wird, daß die Bestandteile miteinander gemischt werden und bis ein wesentlicher Teil des Neodymoxids zu Neodymmetall reduziert ist, dann mit den Rühren aufgehört wird, während die Bestandteile in geschmolzenem Zustand gehalten werden, so daß die getrennte Schicht (43), die das reduzierte Neodymmetall im wesentlichen frei von Einschlüssen an Neodymoxid enthält, in dem Bad (44) gebildet wird.
6. Metallothermisches, nicht-elektrolytisches Reduktionsverfahren nach Anspruch 1, dadurch gekennzeichnet, daß die geschmolzene Bad (44) wenigstens 70 Gew.-% Calciumchlorid und Rest Natriumchlorid enthält, ein Volumen von Seltenerdoxid, das kleiner als 50% des Volumens des geschmolzenen Bades (44) ist, zu dem Bad (44) gegeben wird, das Bad (44) so gerührt wird, daß die Bestandteile miteinander gemischt werden und bis ein wesentlicher Teil des Seltenerdoxids zum Seltenerdmetall reduziert ist, dann mit dem Rühren aufgehört wird, während die Bestandteile im geschmolzenen Zustand gehalten werden, so daß eine getrennte Schicht (43), die das reduzierte Seltenerdmetall enthält, in dem Bad (44) gebildet wird.
7. Metallothermisches, nicht-elektrolytisches Reduktionsverfahren nach Anspruch 1, dadurch gekennzeichnet, daß das geschmolzene Bad (44) wenigstens 70 Gew.-% Calciumchlorid und 0 bis 30 Gew.-% Natriumchlorid enthält, eine Menge an Nicht-Seltenerd-Metall zu dem Bad (44) gegeben wird, die ausreicht, um eine Seitenerd/Nicht-Seltenerd-Metallegierung mit einer wesentlich niedrigeren Schmelztemperatur als die Schmelztemperatur des Seltenerdmetalls zu bilden, und dann mit der Bewegung aufgehört wird, so daß sich die Seltenerd/Nicht-Seltenerd-Metallegierung in einer getrennten Schicht (43) in dem Bad (44) sammelt.
8. Metallothermisches, nicht-elektrolytisches Reduktionsverfahren nach Anspruch 7, dadurch gekennzeichnet, daß das Seitenerdoxid ein oder mehrere Seltenerdoxide aus der Gruppe Lanthanoxid, Ceroxid, Praseodymoxid und Neodymoxid ist.
9. Metallothermisches, nicht-elektrolytisches Reduktionsverfahren nach Anspruch 7, dadurch gekennzeichnet, daß das Seltenerdoxid Neodymoxid ist.
10. Metallothermisches, nicht-elektrolytisches Reduktionsverfahren nach einem der Ansprüche 7 bis 9, dadurch gekennzeichnet, daß das Nicht-Seltenerd-Metall Eisen ist.
11. Metallothermisches, nicht-elektrolytisches Reduktionsverfahren nach einem der Ansprüche 7 bis 9, dadurch gekennzeichnet, daß das Nicht-Seltenerd-Metall Zink ist.
EP85304046A 1984-07-03 1985-06-07 Metallothermische Reduktion seltener Erdoxide mittels Kalzium Expired EP0170372B1 (de)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT85304046T ATE36560T1 (de) 1984-07-03 1985-06-07 Metallothermische reduktion seltener erdoxide mittels kalzium.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US62773684A 1984-07-03 1984-07-03
US627736 1984-07-03

Publications (2)

Publication Number Publication Date
EP0170372A1 EP0170372A1 (de) 1986-02-05
EP0170372B1 true EP0170372B1 (de) 1988-08-17

Family

ID=24515917

Family Applications (1)

Application Number Title Priority Date Filing Date
EP85304046A Expired EP0170372B1 (de) 1984-07-03 1985-06-07 Metallothermische Reduktion seltener Erdoxide mittels Kalzium

Country Status (10)

Country Link
EP (1) EP0170372B1 (de)
JP (1) JPS6130639A (de)
KR (1) KR910001581B1 (de)
AT (1) ATE36560T1 (de)
AU (1) AU575965B2 (de)
BR (1) BR8503140A (de)
DE (1) DE3564451D1 (de)
ES (1) ES8702508A1 (de)
MX (1) MX173880B (de)
ZA (1) ZA854474B (de)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2009139667A1 (ru) * 2008-05-12 2009-11-19 Volkov Anatoly Evgenievich Способ и устройство автоклавного производства химически активных металлов
US11607734B2 (en) 2018-05-30 2023-03-21 Hela Novel Metals Llc Methods for the production of fine metal powders from metal compounds

Families Citing this family (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4578242A (en) * 1984-07-03 1986-03-25 General Motors Corporation Metallothermic reduction of rare earth oxides
US4680055A (en) * 1986-03-18 1987-07-14 General Motors Corporation Metallothermic reduction of rare earth chlorides
US4837109A (en) * 1986-07-21 1989-06-06 Hitachi Metals, Ltd. Method of producing neodymium-iron-boron permanent magnet
AT389899B (de) * 1986-08-19 1990-02-12 Treibacher Chemische Werke Ag Verfahren zur herstellung von se-metallen und se-haltigen legierungen
JPH01138119A (ja) * 1987-11-24 1989-05-31 Mitsubishi Metal Corp 希土類電解スラグからサマリウムとユーロピウムを回収する方法
DE3817553A1 (de) * 1988-05-24 1989-11-30 Leybold Ag Verfahren zum herstellen von titan und zirkonium
US4917724A (en) * 1988-10-11 1990-04-17 General Motors Corporation Method of decalcifying rare earth metals formed by the reduction-diffusion process
KR100373109B1 (ko) * 1999-09-30 2003-02-25 해 남 현 토양의 치환성 칼리 침출방법 및 이를 이용하여 침출된 토양 치환성 칼리의 정량방법
JP2004052003A (ja) * 2002-07-16 2004-02-19 Cabot Supermetal Kk ニオブ粉末またはタンタル粉末の製造方法および製造装置
JP2013517451A (ja) * 2010-01-12 2013-05-16 シルバン ソース， インコーポレイテッド 熱伝達インターフェース
CN103436718B (zh) * 2013-08-16 2015-06-17 宁夏东方钽业股份有限公司 一种高纯金属镧的制取方法
KR102153737B1 (ko) * 2019-12-12 2020-09-09 한국지질자원연구원 철-희토류계 영구자석으로부터 선택염화법에 의한 희토류 원소의 회수 방법
CN111139366B (zh) * 2020-01-17 2024-05-31 鹰潭市宇钠科技中心(有限合伙) 一种钠冷快堆中核纯级冷却材料制备提纯方法及其设备

Family Cites Families (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB190923215A (en) * 1909-10-11 1910-09-29 Hans Kuzel Process for the Production of Zirconium and other Rare Metals.
US2950962A (en) * 1957-03-28 1960-08-30 Carlson Oscar Norman Reduction of fluoride to metal
GB1040468A (en) * 1964-10-26 1966-08-24 Dow Chemical Co Preparation of rare earth metal, yttrium, or scandium
GB1579978A (en) * 1977-07-05 1980-11-26 Johnson Matthey Co Ltd Production of yttrium
SU1027232A1 (ru) * 1982-01-15 1983-07-07 Научно-исследовательский институт металлургии Способ получени лигатуры
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
JPS59177346A (ja) * 1983-03-25 1984-10-08 Sumitomo Special Metals Co Ltd 希土類磁石素材用配合合金
JPS6077943A (ja) * 1983-10-03 1985-05-02 Sumitomo Special Metals Co Ltd 希土類磁石用原料合金の製造方法
US4578242A (en) * 1984-07-03 1986-03-25 General Motors Corporation Metallothermic reduction of rare earth oxides

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2009139667A1 (ru) * 2008-05-12 2009-11-19 Volkov Anatoly Evgenievich Способ и устройство автоклавного производства химически активных металлов
US11607734B2 (en) 2018-05-30 2023-03-21 Hela Novel Metals Llc Methods for the production of fine metal powders from metal compounds

Also Published As

Publication number Publication date
ES8702508A1 (es) 1987-01-01
ATE36560T1 (de) 1988-09-15
ES544799A0 (es) 1987-01-01
ZA854474B (en) 1986-03-26
KR910001581B1 (ko) 1991-03-16
DE3564451D1 (en) 1988-09-22
MX173880B (es) 1994-04-07
BR8503140A (pt) 1986-03-18
JPS6137341B2 (de) 1986-08-23
EP0170372A1 (de) 1986-02-05
AU4448885A (en) 1986-01-09
AU575965B2 (en) 1988-08-11
JPS6130639A (ja) 1986-02-12
KR860001203A (ko) 1986-02-24

Similar Documents

Publication Publication Date Title
EP0170373B1 (de) Metallothermische Reduktion seltener Erdoxide
EP0238185B1 (de) Metallothermische Reduktion der Chloride der seltenen Erden
EP0170372B1 (de) Metallothermische Reduktion seltener Erdoxide mittels Kalzium
US6309441B1 (en) Reduction-melting process to form rare earth-transition metal alloys and the alloys
US4786319A (en) Proces for the production of rare earth metals and alloys
US4767455A (en) Process for the preparation of pure alloys based on rare earths and transition metals by metallothermy
Sharma Neodymium production processes
US5314526A (en) Metallothermic reduction of rare earth fluorides
Sharma et al. Metallothermic Reduction of Nd2 O 3 with Ca in CaCl2‐NaCl Melts
CN85100813A (zh) 稀土氧化物的金属热还原
US4308245A (en) Method of purifying metallurgical-grade silicon
JPS6311628A (ja) 希土類金属の製造法
KR920007932B1 (ko) 희토류-철 합금의 제조방법
AU2021382943A1 (en) Reduction system and method for high-melting point metal oxides, using liquid metal crucible
Sharma et al. Metallothermic Reduction of Nd2O3 with Ca in CaCl2-NaCl Melts
JPS61157646A (ja) 希土類合金の製造方法
US3951764A (en) Aluminum-manganese alloy
US20240191321A1 (en) Semi-continuous rare earth metal production
US3951647A (en) Reduction method for producing manganese metal
Mehra et al. Extractive metallurgy of rare earths-developmental work at the Bhabha Atomic Research Centre
WO1994009168A1 (en) Methods for producing high purity magnesium alloys
RU1791462C (ru) Шихта дл внепечного получени магнитных сплавов с редкоземельными металлами
PL161378B1 (pl) Sposób wytwarzania stopu neodym - żelazo
JPH02228433A (ja) 希土類金属又は希土類金属―遷移金属合金の製造方法

Legal Events

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

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 19850617

AK Designated contracting states

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

17Q First examination report despatched

Effective date: 19870506

ITF It: translation for a ep patent filed
GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

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

REF Corresponds to:

Ref document number: 36560

Country of ref document: AT

Date of ref document: 19880915

Kind code of ref document: T

REF Corresponds to:

Ref document number: 3564451

Country of ref document: DE

Date of ref document: 19880922

ET Fr: translation filed
PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

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

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

26N No opposition filed
ITTA It: last paid annual fee
EAL Se: european patent in force in sweden

Ref document number: 85304046.7

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

Ref country code: AT

Payment date: 19990610

Year of fee payment: 15

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

Ref country code: FR

Payment date: 19990617

Year of fee payment: 15

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

Ref country code: SE

Payment date: 19990630

Year of fee payment: 15

Ref country code: NL

Payment date: 19990630

Year of fee payment: 15

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

Ref country code: DE

Payment date: 19990726

Year of fee payment: 15

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

Ref country code: AT

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

Effective date: 20000607

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

Ref country code: SE

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

Effective date: 20000608

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

Ref country code: NL

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

Effective date: 20010101

EUG Se: european patent has lapsed

Ref document number: 85304046.7

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

Ref country code: FR

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

Effective date: 20010228

NLV4 Nl: lapsed or anulled due to non-payment of the annual fee

Effective date: 20010101

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

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

Ref country code: DE

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

Effective date: 20010403

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

Ref country code: GB

Payment date: 20010604

Year of fee payment: 17

REG Reference to a national code

Ref country code: GB

Ref legal event code: IF02

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

Ref country code: GB

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

Effective date: 20020607

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

Effective date: 20020607