DE2028536A1 - Iron powder produced by reduction in a fluidized bed - Google Patents
Iron powder produced by reduction in a fluidized bedInfo
- Publication number
- DE2028536A1 DE2028536A1 DE19702028536 DE2028536A DE2028536A1 DE 2028536 A1 DE2028536 A1 DE 2028536A1 DE 19702028536 DE19702028536 DE 19702028536 DE 2028536 A DE2028536 A DE 2028536A DE 2028536 A1 DE2028536 A1 DE 2028536A1
- Authority
- DE
- Germany
- Prior art keywords
- fluidized bed
- reduction
- particles
- iron
- powder
- 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.)
- Pending
Links
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 title claims description 28
- 239000002245 particle Substances 0.000 claims description 32
- 239000000843 powder Substances 0.000 claims description 18
- 239000007789 gas Substances 0.000 claims description 15
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical compound [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 claims description 13
- 230000005291 magnetic effect Effects 0.000 claims description 13
- 238000000034 method Methods 0.000 claims description 7
- 239000000203 mixture Substances 0.000 claims description 7
- 229910052742 iron Inorganic materials 0.000 claims description 6
- 239000000463 material Substances 0.000 claims description 6
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 5
- 239000001257 hydrogen Substances 0.000 claims description 5
- 229910052739 hydrogen Inorganic materials 0.000 claims description 5
- 239000001301 oxygen Substances 0.000 claims description 5
- 229910052760 oxygen Inorganic materials 0.000 claims description 5
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 claims description 4
- 230000001590 oxidative effect Effects 0.000 claims description 4
- UBUHAZKODAUXCP-UHFFFAOYSA-N iron(2+);oxygen(2-);hydrate Chemical compound O.[O-2].[Fe+2] UBUHAZKODAUXCP-UHFFFAOYSA-N 0.000 claims description 3
- 239000000126 substance Substances 0.000 claims description 3
- 238000006243 chemical reaction Methods 0.000 description 11
- 230000005294 ferromagnetic effect Effects 0.000 description 9
- 235000013980 iron oxide Nutrition 0.000 description 8
- 229910002588 FeOOH Inorganic materials 0.000 description 5
- VBMVTYDPPZVILR-UHFFFAOYSA-N iron(2+);oxygen(2-) Chemical class [O-2].[Fe+2] VBMVTYDPPZVILR-UHFFFAOYSA-N 0.000 description 5
- 230000005415 magnetization Effects 0.000 description 5
- 239000007787 solid Substances 0.000 description 5
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 4
- 238000004519 manufacturing process Methods 0.000 description 3
- RYHBNJHYFVUHQT-UHFFFAOYSA-N 1,4-Dioxane Chemical compound C1COCCO1 RYHBNJHYFVUHQT-UHFFFAOYSA-N 0.000 description 2
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 2
- 239000003054 catalyst Substances 0.000 description 2
- 239000013078 crystal Substances 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- 229910052757 nitrogen Inorganic materials 0.000 description 2
- 230000000630 rising effect Effects 0.000 description 2
- 235000008331 Pinus X rigitaeda Nutrition 0.000 description 1
- 235000011613 Pinus brutia Nutrition 0.000 description 1
- 241000018646 Pinus brutia Species 0.000 description 1
- 229910052786 argon Inorganic materials 0.000 description 1
- 238000009835 boiling Methods 0.000 description 1
- 239000006227 byproduct Substances 0.000 description 1
- 229910010293 ceramic material Inorganic materials 0.000 description 1
- 239000007795 chemical reaction product Substances 0.000 description 1
- 235000013312 flour Nutrition 0.000 description 1
- 150000002431 hydrogen Chemical class 0.000 description 1
- 238000007654 immersion Methods 0.000 description 1
- 239000011261 inert gas Substances 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- NDLPOXTZKUMGOV-UHFFFAOYSA-N oxo(oxoferriooxy)iron hydrate Chemical compound O.O=[Fe]O[Fe]=O NDLPOXTZKUMGOV-UHFFFAOYSA-N 0.000 description 1
- 238000012797 qualification Methods 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 238000005245 sintering Methods 0.000 description 1
- 230000006641 stabilisation Effects 0.000 description 1
- 238000011105 stabilization Methods 0.000 description 1
- 230000000087 stabilizing effect Effects 0.000 description 1
- 239000007858 starting material Substances 0.000 description 1
Classifications
-
- 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
- B22F9/16—Making metallic powder or suspensions thereof using chemical processes
- B22F9/18—Making metallic powder or suspensions thereof using chemical processes with reduction of metal compounds
- B22F9/20—Making metallic powder or suspensions thereof using chemical processes with reduction of metal compounds starting from solid metal compounds
- B22F9/22—Making metallic powder or suspensions thereof using chemical processes with reduction of metal compounds starting from solid metal compounds using gaseous reductors
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
- G11B5/62—Record carriers characterised by the selection of the material
- G11B5/68—Record carriers characterised by the selection of the material comprising one or more layers of magnetisable material homogeneously mixed with a bonding agent
- G11B5/70—Record carriers characterised by the selection of the material comprising one or more layers of magnetisable material homogeneously mixed with a bonding agent on a base layer
- G11B5/706—Record carriers characterised by the selection of the material comprising one or more layers of magnetisable material homogeneously mixed with a bonding agent on a base layer characterised by the composition of the magnetic material
- G11B5/70605—Record carriers characterised by the selection of the material comprising one or more layers of magnetisable material homogeneously mixed with a bonding agent on a base layer characterised by the composition of the magnetic material metals or alloys
- G11B5/70615—Record carriers characterised by the selection of the material comprising one or more layers of magnetisable material homogeneously mixed with a bonding agent on a base layer characterised by the composition of the magnetic material metals or alloys containing Fe metal or alloys
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
- G11B5/62—Record carriers characterised by the selection of the material
- G11B5/68—Record carriers characterised by the selection of the material comprising one or more layers of magnetisable material homogeneously mixed with a bonding agent
- G11B5/70—Record carriers characterised by the selection of the material comprising one or more layers of magnetisable material homogeneously mixed with a bonding agent on a base layer
- G11B5/706—Record carriers characterised by the selection of the material comprising one or more layers of magnetisable material homogeneously mixed with a bonding agent on a base layer characterised by the composition of the magnetic material
- G11B5/70626—Record carriers characterised by the selection of the material comprising one or more layers of magnetisable material homogeneously mixed with a bonding agent on a base layer characterised by the composition of the magnetic material containing non-metallic substances
- G11B5/70642—Record carriers characterised by the selection of the material comprising one or more layers of magnetisable material homogeneously mixed with a bonding agent on a base layer characterised by the composition of the magnetic material containing non-metallic substances iron oxides
- G11B5/70647—Record carriers characterised by the selection of the material comprising one or more layers of magnetisable material homogeneously mixed with a bonding agent on a base layer characterised by the composition of the magnetic material containing non-metallic substances iron oxides with a skin
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
- G11B5/62—Record carriers characterised by the selection of the material
- G11B5/68—Record carriers characterised by the selection of the material comprising one or more layers of magnetisable material homogeneously mixed with a bonding agent
- G11B5/70—Record carriers characterised by the selection of the material comprising one or more layers of magnetisable material homogeneously mixed with a bonding agent on a base layer
- G11B5/706—Record carriers characterised by the selection of the material comprising one or more layers of magnetisable material homogeneously mixed with a bonding agent on a base layer characterised by the composition of the magnetic material
- G11B5/70626—Record carriers characterised by the selection of the material comprising one or more layers of magnetisable material homogeneously mixed with a bonding agent on a base layer characterised by the composition of the magnetic material containing non-metallic substances
- G11B5/70642—Record carriers characterised by the selection of the material comprising one or more layers of magnetisable material homogeneously mixed with a bonding agent on a base layer characterised by the composition of the magnetic material containing non-metallic substances iron oxides
- G11B5/70652—Record carriers characterised by the selection of the material comprising one or more layers of magnetisable material homogeneously mixed with a bonding agent on a base layer characterised by the composition of the magnetic material containing non-metallic substances iron oxides gamma - Fe2 O3
Landscapes
- Engineering & Computer Science (AREA)
- Metallurgy (AREA)
- Health & Medical Sciences (AREA)
- Dermatology (AREA)
- General Health & Medical Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Chemical & Material Sciences (AREA)
- Hard Magnetic Materials (AREA)
- Magnetic Record Carriers (AREA)
- Paints Or Removers (AREA)
Description
PHN. 4170PHN. 4170
Dipl.-Ing. HORSTAUERDipl.-Ing. HORSTAUER
Anmelder: N.V. PiLLU2S' G.0eiLAMPEi^FABRIEKEN Applicant: NV PiLLU 2 S 'G.0eiLAMPEi ^ FABRIEKEN
Akte= PHN- 417ΌFile = PHN- 417Ό
Anmeldung vomt 9. tTuni I97ORegistration from June 9th, 1997
"Durch Reduktion in einer Wirbelschicht hergestelltes Eisenpulver"."Iron powder produced by reduction in a fluidized bed".
Die Erfindung bezieht sich auf ein Verfahren zur Herstellung eines für magnetische Aufzeichnung verwendbaren Eisenpulvers.The invention relates to a method of making one useful for magnetic recording Iron powder.
Fein-pulver aus stabförmigen Teilchen ferromagne ti scher Eisenoxide (Fe„Oj, und ^-Fe'O,,) sind als Materialien für magnetische Aufzeichnung bereits lange bekannt. Die beiden betreffenden Eisenoxide haben eine kubische Kristallstruktur und aus se rd em eine nur geringe magnetische ,Kristallanisotropie. Dadurch sind befriedigende Werte der remanenten Magnetisierung, O , und der Koerzitivkraft, H , mit Pulvern dieserFine powder from rod-shaped particles of ferromagnetic iron oxides (Fe "Oj, and ^ -Fe'O") have long been known as materials for magnetic recording. The two iron oxides in question have a cubic crystal structure and therefore only a low magnetic, crystal anisotropy. As a result, satisfactory values of the remanent magnetization, O , and the coercive force, H, with powders are these
I* CI * C
Stoffe nur dadurch erreichbar, dass den Pulverteilchen eine hohe magnetische Formanisotropie erteilt wird. Dies erfolgt dadurch, dass den Teilchen eine Stabform gegeben wird, undSubstances can only be reached by giving the powder particles a high magnetic shape anisotropy is granted. this happens by giving the particles a rod shape, and
009852/1566009852/1566
zwar am liebsten derart, dass die Länge jedes Teilchens mehr als das Fünffache des grössten Durchmessers irgendeiner Fläche senkrecht zur Längsachse des Teilchens beträgt (nachfolgend kurz als "Durchmesser" des betrachteten Teilchens bezeichnet). Die gemeinten Feinpulver aus ferromagnetischen Eisenoxiden können (siehe U.S. Patentschrift 2.69^.656) durch pseudomorphe Umwandlung mit einem Reduktionsgas aus ebenfalls aus stabförmigen Teilchen bestehenden nicht ferromagnetischen Eisenoxiden, beispielsweise <^ -FepO_, oder nicht-ferromagnetischen Eisenoxidhydraten, beispielsweisepreferably in such a way that the length of each particle is more than five times the largest diameter of any surface perpendicular to the longitudinal axis of the particle (hereinafter briefly referred to as the "diameter" of the particle under consideration). The meant fine powder from ferromagnetic Iron oxides can (see U.S. Patent 2.69 ^ .656) by pseudomorphic conversion with a reducing gas from non-ferromagnetic particles also consisting of rod-shaped particles Iron oxides, for example <^ -FepO_, or non-ferromagnetic iron oxide hydrates, for example
ö\ -FeOOH bis Fe„04, gegebenenfalls mit nachfolgender topochemischer Umwandlung dieses letzteren mit einem Oxydationsgas, zu y-Fe2O- erhalten werden. Zur Erläuterung diene, dass unter "pseudomorpher" Umwandlung eine Umwandlung verstanden wird, wobei die Teilchen des Ausgangsmaterials und die des Reaktionsproduktes im wesentlichen dieselbe Form und Abmessungen haben, also wobei jedes Teilchen des Feststoffes einzeln mit dem Gas reagiert und dabei seine Form und Abmessungen im wesentlichen beibehält. Eine Bedingung dazu ist daher, dass die Teilchen bei der Temperatur, bei der die Reaktion erfolgt, und die meistens einige Hunderte 0C beträgt, nicht zusammensintern. Deswegen hat man bereits vorgeschlagen (siehe die französische Patentschrift 1.422.638), die obengenannte Umwandlung eines nicht-ferromagnetischen Eisenoxidhydrats in ein ferromagnetisch.es Eisenoxid in einer sogenannten "Wirbelschicht" erfolgen zu lassen. In einem Wirbelschichtofen bilden die Teilchen des Feststoffes unterö \ -FeOOH to Fe „04, optionally with subsequent topochemical conversion of this latter with an oxidizing gas, to y-Fe 2 O- can be obtained. To illustrate, the term "pseudomorphic" conversion is understood to mean a conversion in which the particles of the starting material and those of the reaction product have essentially the same shape and dimensions, i.e. each particle of the solid reacts individually with the gas and its shape and dimensions in the process essential retains. A condition for this is thus that the particles at the temperature at which the reaction takes place and the usually several hundreds is 0 C, not sinter together. It has therefore already been proposed (see French patent specification 1.422.638) that the aforementioned conversion of a non-ferromagnetic iron oxide hydrate into a ferromagnetic iron oxide should take place in a so-called "fluidized bed". In a fluidized bed furnace, the particles form the solid under
009852/1566009852/1566
'COPY'COPY
dom Einfluss nines durch eine horizontal im Ofen liegende ■poröse Platte hochsteigenden Stromes heissen Gases, mit dem man sie wünscht reagieren zu lassen, auf dieser Platte pine Wirbelschicht, die wie eine heftig siedende Flüssigkeit aussieht. Die Vorteile des Wirbelschichtverfahrens /um feinverteilte Feststoffe mit Gasen reagieren zu lassen ■sintl vielerlei. Gasförmige Nebenerzeugnisse der Reaktion worden schnell durch das hochsteigende Gas mitgeführt und auf diese Weise aus der reagierenden Masse entfernt. Weiter, woiL eine sohl- zweckdienliche Wärmeübertragung stattfindet, ist die gewünschte Umwandlung bei einer verhältnismässig niedrigen Temperatur durchführbar, so dass es in vielen VIi I1 en möglich ist, das Zusammensintern der Feststoffteilchen völlig zu vermeiden, bzw. wenigstens auf ein Minimum zu beschränken.The influence of hot gas rising upwards through a porous plate lying horizontally in the furnace, with which it is desired to react, on this plate pine fluidized bed, which looks like a violently boiling liquid. The advantages of the fluidized bed process / to allow finely divided solids to react with gases ■ are many. Gaseous by-products of the reaction were quickly carried along by the rising gas and thus removed from the reacting mass. Furthermore, where a heat transfer that is useful for the sole purpose takes place, the desired conversion can be carried out at a relatively low temperature, so that in many cases it is possible to completely avoid the solid particles from sintering together, or at least to limit it to a minimum.
Wenn am Wirbel schichtverfahren auch ferromagnetische Stoffe mit einem Curiepunkt über der Reaktionstemperatur beteiligt sind, besteht bekanntlich noch die Gefahr, dass zwei oder mehrere Teilchen des Feststoffes infolge magnetischer Anziehungskräfte einander so dicht nähern, dass sie dennoch wieder mehr oder weniger zusammensintern.If the fluidized bed process is also ferromagnetic Substances with a Curie point above the reaction temperature are involved, as is well known, there is still the risk that two or more particles of the solid due to magnetic forces of attraction approach one another so closely that they still more or less sinter together again.
Als Materialien für magnetische Aufzeichnung sind ausser den bereits genannten ferromagnetischen Eisenoxiden auch aus stabförmigen Teilchen bestehende Eisenpulver bekannt, die durch pseudomorphe Reduktion eines aus stabförmigen Oxidteilchen bestehenden .Pulvers (siehe die britische Patentschrift 796.^+6^) hergestellt sind. Die Sättigungsmagnetisierung, pro Volumeneinheit, derartiger Eisenpulver beträgtAs materials for magnetic recording are except the already mentioned ferromagnetic iron oxides as well Known iron powder consisting of rod-shaped particles, which is produced by pseudomorphic reduction of a rod-shaped Oxide particles (see British Patent 796. ^ + 6 ^) are made. The saturation magnetization, per unit volume, such iron powder is
009857/1566009857/1566
-k--k-
etwa das Fünffache von der der obengenannten Pulver aus Fe Ο· und </ -Fe„0„. Dies ist der Grund, weshalb bisher nicht vorgeschlagen wurde, die betreffenden Eisenpulver in einem Wirbelschichtverfahren herzustellen. Die im Vergleich zu den Fe„CK - und ^-Fe O„ - Pulvern viel grössere Sättigungsmagnetisierung, pro Volumeneinheit, der betreffenden Eisenpulver Hess nämlich fürchten, dass je nachdem die Reaktion in der Wirbelschicht fortschreitet und sich also mehr ferromagnetische Teilchen bilden, die stärkeren magnetischen Anziehungskräfte zwischen den Teilchen untereinander diese Teilchen auch in viel höherem Masse zum Zusammenballen und folglich auch zum Zusammensintern führen sollten, wodurch die Stabform der Teilchen während der Reaktion und damit selbstverständlich auch die Brauchbarkeit der Pulver dieser Teilchen als Material für magnetische Aufzeichnung, verlorengehen sollte.about five times that of the above powders Fe Ο · and </ -Fe "0". This is why so far it has not been proposed to produce the iron powders in question in a fluidized bed process. The in Much compared to the Fe "CK and ^ -Fe O" powders greater saturation magnetization, per unit volume, of the iron powder in question caused people to fear that depending on the progress of the reaction in the fluidized bed and so more ferromagnetic particles are formed, which stronger magnetic forces of attraction between the particles among each other these particles also to a much greater extent to agglomerate and consequently also to sinter together should lead, whereby the rod shape of the particles during the reaction and thus of course also the Usefulness of the powders of these particles as a material for magnetic recording, should be lost.
Nach der Erfindung hat sich nun auf überraschende Weise gezeigt, dass auch bei der Herstellung von aus Eisenteilchen mit der gewünschten Stabform bestehenden und dadurch als Material für magnetische Aufzeichnung geeigneten Pulvern, das Wirbelschichtverfahren durchaus anwendbar ist.According to the invention, it has now been shown, in a surprising way, that even in the production of iron particles with the desired rod shape and thus suitable as a material for magnetic recording powders, the fluidized bed process can be used.
Die Erfindung schafft ein Verfahren zur Herstellung eines für magnetische Aufzeichnung geeigneten Eisenpulvers, das aus stabförmigen Teilchen mit einer Länge von 0.5 bis 2 -um besteht, und wobei die Längsachse mindestens das fünffache des Durchmessers ist, durch pseudomorphe Reduktion eines aus stabförmigen Teilchen bestehenden PulversThe invention provides a method for producing an iron powder suitable for magnetic recording, that of rod-shaped particles with a length of 0.5 to 2 -um, and where the longitudinal axis is at least five times the diameter, by pseudomorphic reduction a powder consisting of rod-shaped particles
009852/1566009852/1566
aus Eisenoxid (-hydrat), und ist dadurch gekennzeichnet, dass die Reduktion dadurch ausgeführt wird, dass das Eisenoxid (-hydrat) in einer Wirbelschicht bei einer Temperatur zwischen 200°C und 4OO°C mit einem Reduktionsgas, das mindestens im wesentlichen aus Wasserstoff besteht, zum Reagieren gebracht wird.from iron oxide (hydrate), and is characterized in that the reduction is carried out by placing the iron oxide (hydrate) in a fluidized bed at a temperature between 200 ° C and 400 ° C with a reducing gas that is at least im consists essentially of hydrogen, is made to react.
Auf die obenstehend beschriebene Weise erhaltene Eisenpulver sind oft in hohem Masse pyrophor, d.h. dass sie, sobald sie mit Luft in Kontakt treten, unter starkem Aufglühen zu Eisenoxid oxydiert werden. Nach einer vorzugsweiseIron powders obtained in the manner described above are often highly pyrophoric, i.e. they, as soon as they come into contact with air, they glow strongly oxidized to iron oxide. After one preferably
angewandten Ausführungsform der vorliegenden Erfindung ersetzt man, nachdem die Reduktion in der Wirbelschicht beendet ist, das fortströmende Reduktionsgas, das die Wirbelschicht trägt, bei einer Temperatur zwischen 20 C und 50 C allmählich durch ein schwach oxydierendes Gas, beispielsweise ein Gemisch aus einem inerten Gas, wie Stickstoff oder Argon, mit etwas Sauerstoff. Durch Regelung des Sauerstoff gehaltes des schwach-oxydierenden Gasgemisches, das nun die Wirbelschicht trägt, werden die durch die vorhergehende Reduktion gebildeten Eisenteilchen mit einer stabilisierenden Oxidschicht bedeckt, wodurch sie nicht mehr pyrophor sind.applied embodiment of the present invention replaced after the reduction in the fluidized bed has ended, the reducing gas flowing away, which carries the fluidized bed, is at a temperature between 20 ° C. and 50 ° C. gradually by a weakly oxidizing gas, for example a mixture of an inert gas such as nitrogen or argon, with a little oxygen. By regulating the oxygen content of the weakly oxidizing gas mixture that now the fluidized bed carries, those are carried by the previous one Reduction formed iron particles covered with a stabilizing oxide layer, making them no longer pyrophoric are.
Es sei bemerkt, dass das Stabilisieren feinverteilter pyrophorer metallhaltiger Katalysatoren in einer Wirbelschicht, dadurch, dass> die Oberflächen der Katalysatorteilchen mit Oxidhäutchen bedeckt werden, aus der U.S. Patentschrift 2.265.347 bekannt ist.It should be noted that the stabilization is finely divided Pyrophoric metal-containing catalysts in a fluidized bed, in that> the surfaces of the catalyst particles become covered with oxide skins, from U.S. Pat. Patent 2,265,347 is known.
0098500985
■6" 2G2-3536■ 6 "2G2-3536
Die Erfindung wird an Hand einiger Ausf'ührungsbeispielo1 näher
erläutert.
BEISPIEL I The invention is explained in more detail with the aid of some exemplary embodiments 1.
EXAMPLE I
In einem zylinderförmigen Ofen (Querschnitt ca. 30 mm), dessen Unterseite durch eine horizontal im Ofen liegende poröse Platte aus keramischem Material abgeschlossen ist, gibt man 20 g eines Pulvers aus v* -FeOOH, das zuvor durch Erwärmung bei einer Temperatur von 180 C während 8 Stunden getrocknet ist. Das (j\ -FeOOH-Pulver besteht aus stabförmigen Teilchen mit einer Länge von 1 /um und einem Durchmesser von 0,1 /um. Zwei Stunden lang führt man bei einer Temperatur von ca. 370 C mit einer Geschwindigkeit von ca. 3 l/min Wasserstoff in vertikaler Aufwärtsrichtung durch die poröse Platte. In der über der Platte gebildeten Wirbelschicht wird das o( -FeOOH pseudomorph zu Eisenteilchen mit ungefähr derselben Form und denselben Abmessungen wie die der <λ -FeOOH-Teilchen, von denen ausgegangen wurde, reduziert. Nachdem diese Reduktion beendet ist, taucht man das gebildete Eisenpulver unter Abschluss der Luft in Dioxan. Nach einiger Zeit entfernt man das Pulver aus der Flüssigkeit und entfernt die noch anhaftenden Reste. Die für magnetische Aufzeichnung qualitätsbestimmenden Eigenschaften des Pulvers waren: Sättigungsmagnetisierung, (f 2,3x10~ V.s.m/kgIn a cylindrical oven (cross-section approx. 30 mm), the underside of which is closed by a porous plate made of ceramic material lying horizontally in the oven, 20 g of a powder of v * -FeOOH, which was previously heated at a temperature of 180 ° C., are added dried for 8 hours. The (j \ -FeOOH powder consists of rod-shaped particles with a length of 1 μm and a diameter of 0.1 μm. For two hours, the mixture is passed at a temperature of about 370 ° C. at a rate of about 3 liters / min hydrogen in vertical upward direction through the porous plate In the fluidized bed formed above the plate, the o (-FeOOH is pseudomorphically reduced to iron particles with approximately the same shape and dimensions as the <λ -FeOOH particles that were assumed After this reduction is complete, the iron powder formed is immersed in dioxane in the absence of air. After some time, the powder is removed from the liquid and the residues still adhering are removed. The properties of the powder that determine the quality of magnetic recording were: saturation magnetization, (f 2.3x10 ~ Vsm / kg
' ■ (in der 0 die remanente Magnetisierung darstellt) . ös r '■ (in which 0 represents the remanent magnetization). ös r
2 Koezitivkraft, H 8OO Oe. V. see/m2 coezitive force, H 8OO Oe. V. see / m
009852/1566 e.NAL ,MSPECTED009852/1566 e. N AL, MSPECTED
202 6 5 36202 6 5 36
IiKISPIKl. IlIiKISPIKl. Il
Auf ähnliche Weise wie im Beispiel I beschrieben wurde, wird durch Reduktion mit Wasserstoff in einer Wirbelschicht e in Kispnpulver hergestellt. Nachdem die Reduktion beendet ist", ersetzt man den durch die poröse Platte in Aufwärts— richtung strömenden Wasserstoff, der die Wirbelschicht trägt, durch ein ebenfalls in Aufwärt si'ichtung strömendes aus 99 VoI Λ Sticktoff und 1 Vol.^j Sauerstoff bestellendes Gasgemisch. Die Temperatur dieses Gasgemisches, das nun die .Wirbelschicht trägt, beträgt 2O 0. Nachdem man das obengenannte Gasgemisch 5 min lang hindurchgeführt hat, ersetzt man es allmählich -durch Sauerstoff. Man sorgt dafür, dass die Temperatur der Wirbelschicht dabei 50 C nicht überschroi t e t.In a manner similar to that described in Example I, is produced by reduction with hydrogen in a fluidized bed in Kispnpulver. After the reduction has ended is ", one replaces the hydrogen flowing upwards through the porous plate, which carries the fluidized bed, by a gas mixture which also flows upwards and consists of 99 vol. nitrogen and 1 vol. oxygen. The temperature of this gas mixture, which now carries the fluidized bed, is 2O 0. After the above Has passed gas mixture for 5 minutes, replaced you do it gradually - through oxygen. It is ensured that the temperature of the fluidized bed does not exceed 50 ° C t e t.
■Das nun erhaltene Eisenpulver ist nicht pyrophor und braucht also nicht mehl" durch Eintauchen in Dioxan stabilisiert vu werden. Die Qualifikationen dieses Pulvers waren dieselben wie die des Pulvers, das auf die Art und Weise wie in Beispiel 1 beschrieben wurde, hergestellt war.■ The iron powder now obtained is not pyrophoric and So does not need flour "stabilized by immersion in dioxane vu become. The qualifications of this powder were the same as that of the powder prepared in the manner as described in Example 1.
BAD ORIGINAL 009857/1F66BATH ORIGINAL 009857 / 1F66
Claims (3)
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| NL6909443A NL6909443A (en) | 1969-06-20 | 1969-06-20 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| DE2028536A1 true DE2028536A1 (en) | 1970-12-23 |
Family
ID=19807253
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| DE19702028536 Pending DE2028536A1 (en) | 1969-06-20 | 1970-06-10 | Iron powder produced by reduction in a fluidized bed |
Country Status (7)
| Country | Link |
|---|---|
| AT (1) | AT298823B (en) |
| BE (1) | BE752202A (en) |
| CH (1) | CH531904A (en) |
| DE (1) | DE2028536A1 (en) |
| FR (1) | FR2046957B1 (en) |
| GB (1) | GB1265768A (en) |
| NL (1) | NL6909443A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE2361539A1 (en) * | 1973-12-11 | 1975-06-12 | Philips Patentverwaltung | METHOD OF MANUFACTURING FERROMAGNETIC MATERIAL |
| EP0041142A1 (en) * | 1980-06-04 | 1981-12-09 | BASF Aktiengesellschaft | Process for preparing acicular ferromagnetic particles mainly consisting of iron |
| WO1993009900A1 (en) * | 1991-11-22 | 1993-05-27 | Ampex Media Corporation | Storage of metal particles |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| IT1026663B (en) * | 1974-11-29 | 1978-10-20 | Montedison Spa | PROCEDURE FOR PREPARING IRON-BASED METALLIC POWDERS FOR HAGNETIC REGISTRATION |
| DE3116489A1 (en) | 1981-04-25 | 1982-11-11 | Basf Ag, 6700 Ludwigshafen | METHOD FOR STABILIZING PYROPHORES, SUBSTANTIALLY IRON, FERROMAGNETIC, NEEDLE-SHAPED METAL PARTICLES |
| DE4115426A1 (en) * | 1991-05-10 | 1992-11-12 | Basf Magnetics Gmbh | METHOD FOR THE STABILIZATION OF NEEDLE-SHAPED, FERROMAGNETIC METAL POWDERS, CONSISTENTLY OF IRON |
-
1969
- 1969-06-20 NL NL6909443A patent/NL6909443A/xx unknown
-
1970
- 1970-06-10 DE DE19702028536 patent/DE2028536A1/en active Pending
- 1970-06-17 GB GB1265768D patent/GB1265768A/en not_active Expired
- 1970-06-17 AT AT544470A patent/AT298823B/en not_active IP Right Cessation
- 1970-06-17 CH CH921270A patent/CH531904A/en not_active IP Right Cessation
- 1970-06-18 BE BE752202D patent/BE752202A/en unknown
- 1970-06-19 FR FR7022689A patent/FR2046957B1/fr not_active Expired
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE2361539A1 (en) * | 1973-12-11 | 1975-06-12 | Philips Patentverwaltung | METHOD OF MANUFACTURING FERROMAGNETIC MATERIAL |
| EP0041142A1 (en) * | 1980-06-04 | 1981-12-09 | BASF Aktiengesellschaft | Process for preparing acicular ferromagnetic particles mainly consisting of iron |
| US4378240A (en) | 1980-06-04 | 1983-03-29 | Basf Aktiengesellschaft | Preparation of acicular ferromagnetic metal particles consisting essentially of iron |
| WO1993009900A1 (en) * | 1991-11-22 | 1993-05-27 | Ampex Media Corporation | Storage of metal particles |
Also Published As
| Publication number | Publication date |
|---|---|
| FR2046957A1 (en) | 1971-03-12 |
| NL6909443A (en) | 1970-12-22 |
| BE752202A (en) | 1970-12-18 |
| FR2046957B1 (en) | 1973-01-12 |
| AT298823B (en) | 1972-05-25 |
| CH531904A (en) | 1972-12-31 |
| GB1265768A (en) | 1972-03-08 |
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