US2950955A - Process for the preparation of finely divided ferromagnetic ferric oxide - Google Patents
Process for the preparation of finely divided ferromagnetic ferric oxide Download PDFInfo
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- US2950955A US2950955A US701708A US70170857A US2950955A US 2950955 A US2950955 A US 2950955A US 701708 A US701708 A US 701708A US 70170857 A US70170857 A US 70170857A US 2950955 A US2950955 A US 2950955A
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- flame
- oxide
- finely divided
- ferric
- hydrogen
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- 238000000034 method Methods 0.000 title claims description 21
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N iron oxide Inorganic materials [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 title claims description 15
- 230000005294 ferromagnetic effect Effects 0.000 title claims description 13
- 238000002360 preparation method Methods 0.000 title claims description 7
- NDLPOXTZKUMGOV-UHFFFAOYSA-N oxo(oxoferriooxy)iron hydrate Chemical compound O.O=[Fe]O[Fe]=O NDLPOXTZKUMGOV-UHFFFAOYSA-N 0.000 title description 12
- 239000007789 gas Substances 0.000 claims description 22
- 239000000203 mixture Substances 0.000 claims description 18
- 239000001257 hydrogen Substances 0.000 claims description 13
- 229910052739 hydrogen Inorganic materials 0.000 claims description 13
- 150000004820 halides Chemical class 0.000 claims description 11
- 229910052760 oxygen Inorganic materials 0.000 claims description 10
- 239000001301 oxygen Substances 0.000 claims description 10
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 9
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical class [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 claims description 8
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 8
- 238000002485 combustion reaction Methods 0.000 claims description 6
- 239000008246 gaseous mixture Substances 0.000 claims description 6
- 230000015572 biosynthetic process Effects 0.000 claims description 5
- 230000007062 hydrolysis Effects 0.000 claims description 5
- 238000006460 hydrolysis reaction Methods 0.000 claims description 5
- 238000002156 mixing Methods 0.000 claims description 4
- 238000000354 decomposition reaction Methods 0.000 claims description 2
- 239000007792 gaseous phase Substances 0.000 claims description 2
- 150000002506 iron compounds Chemical group 0.000 claims description 2
- LIKBJVNGSGBSGK-UHFFFAOYSA-N iron(3+);oxygen(2-) Chemical compound [O-2].[O-2].[O-2].[Fe+3].[Fe+3] LIKBJVNGSGBSGK-UHFFFAOYSA-N 0.000 claims description 2
- 230000003301 hydrolyzing effect Effects 0.000 claims 1
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 12
- 239000000047 product Substances 0.000 description 10
- 239000003570 air Substances 0.000 description 7
- 229910052757 nitrogen Inorganic materials 0.000 description 7
- 229910021578 Iron(III) chloride Inorganic materials 0.000 description 6
- RBTARNINKXHZNM-UHFFFAOYSA-K iron trichloride Chemical compound Cl[Fe](Cl)Cl RBTARNINKXHZNM-UHFFFAOYSA-K 0.000 description 6
- 239000002245 particle Substances 0.000 description 6
- 238000006243 chemical reaction Methods 0.000 description 5
- 238000005345 coagulation Methods 0.000 description 5
- 230000015271 coagulation Effects 0.000 description 5
- 150000002431 hydrogen Chemical class 0.000 description 5
- 238000000926 separation method Methods 0.000 description 5
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 4
- 230000005291 magnetic effect Effects 0.000 description 4
- 238000012423 maintenance Methods 0.000 description 4
- 239000000443 aerosol Substances 0.000 description 3
- 239000003795 chemical substances by application Substances 0.000 description 3
- 239000008240 homogeneous mixture Substances 0.000 description 3
- 239000007795 chemical reaction product Substances 0.000 description 2
- 230000008021 deposition Effects 0.000 description 2
- 238000011161 development Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 229910052742 iron Inorganic materials 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 2
- JTJMJGYZQZDUJJ-UHFFFAOYSA-N phencyclidine Chemical class C1CCCCN1C1(C=2C=CC=CC=2)CCCCC1 JTJMJGYZQZDUJJ-UHFFFAOYSA-N 0.000 description 2
- 239000007787 solid Substances 0.000 description 2
- MYMOFIZGZYHOMD-UHFFFAOYSA-N Dioxygen Chemical compound O=O MYMOFIZGZYHOMD-UHFFFAOYSA-N 0.000 description 1
- VTLYFUHAOXGGBS-UHFFFAOYSA-N Fe3+ Chemical compound [Fe+3] VTLYFUHAOXGGBS-UHFFFAOYSA-N 0.000 description 1
- 150000001728 carbonyl compounds Chemical class 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 238000009833 condensation Methods 0.000 description 1
- 230000005494 condensation Effects 0.000 description 1
- 230000006735 deficit Effects 0.000 description 1
- 238000007865 diluting Methods 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 239000000945 filler Substances 0.000 description 1
- 238000011010 flushing procedure Methods 0.000 description 1
- 239000012770 industrial material Substances 0.000 description 1
- 239000011261 inert gas Substances 0.000 description 1
- 229940087654 iron carbonyl Drugs 0.000 description 1
- JEIPFZHSYJVQDO-UHFFFAOYSA-N iron(III) oxide Inorganic materials O=[Fe]O[Fe]=O JEIPFZHSYJVQDO-UHFFFAOYSA-N 0.000 description 1
- 238000011068 loading method Methods 0.000 description 1
- 238000009659 non-destructive testing Methods 0.000 description 1
- 230000005298 paramagnetic effect Effects 0.000 description 1
- 239000012071 phase Substances 0.000 description 1
- 239000000049 pigment Substances 0.000 description 1
- 238000005498 polishing Methods 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
- 239000011164 primary particle Substances 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
- 239000006104 solid solution Substances 0.000 description 1
- 239000007858 starting material Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 239000000725 suspension Substances 0.000 description 1
- 230000007704 transition Effects 0.000 description 1
- 239000012808 vapor phase Substances 0.000 description 1
Classifications
-
- 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
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
- C01G49/00—Compounds of iron
- C01G49/02—Oxides; Hydroxides
- C01G49/06—Ferric oxide [Fe2O3]
-
- 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
Definitions
- the invention relates to a process for the direct production of finely divided ferromagnetic ferric oxide from ferric halides in the vapor phase.
- fern'c oxide can be obtained by hydrolysis of the corresponding halide in a hydrogen-oxygen flame. In this process in general an excess of oxygen is used and the ferric oxide obtained is paramagnetic.
- ferric oxide iron pentacarbonyl has also been already used as the starting material and this was burned alone or together with other combustible substances.
- the preparation of magnetic fenic oxide has also already been described by processing iron carbonyl compounds with a deficit of oxygen, relative to the composition of ferric oxides.
- the ferric oxide obtained according to the process of the invention, in contrast to the products of the processes previously known, is ferromagnetic even for almost stoichiometn'c composition, referred to Fe O Because of its finely divided nature it is pre-eminently suitable as magnetogram-carrier, further for the preparation of magnetic solid solutions by pressing or also as agent for nondestructive testing of industrial materials. Likewise, of course, due to its extremely finely divided state and its activity, it can also be incorporated for purposes of which the utilization of the magnetic properties is not itself or not primarily the object, and it can serve, for example, as filler or also as pigment or polishing agent.
- the process according to the application is not limited in the selection of water-forming gases for the flame to pure oxygen or pure hydrogen, although the latter is, however, preferably used, rather the production of the flame can take place through the utilization of hydrogencontaining and hydrogen-forming gases or gas mixtures such as illuminating gas, methane or the like, While air can be used advantageously as oxygen-carrier.
- the water-forming gases are mixed homogeneously together with the volatile ferric halides before bringing them to the flame, whereupon the reactive mixture is expediently led to the flame in laminar flow.
- the flame burns autark (self-sufficiently) in relation to all components required for the formation of Fe O by bydrolysis, so that there is no dependence on the uncontrolled entrance of oxygen from the environment of the flame.
- autark self-sufficiently in relation to all components required for the formation of Fe O by bydrolysis
- the particles at first separated from the aerosol state thus act, so to say, as an inoculating agent or condensation nucleus for the further separation of the portions not yet coagulated, inasmuch as they are kept in suspension in as long a path as possible.
- the coagulation is further favored by the fact that the particles are moved especially in relation to one another.
- the gas stream containing the aerosol is whirled up in chambers of large volume or moved through long, purposely bent tubes up to 60 m. and more in length, in such a way that a preferably turbulent flow is developed and the suspended particles remain for some time, for example longer than 3 seconds, preferably 5 seconds or more, in the coagulation space.
- the final separation of the solid from the gaseous react-ion products then takes place in auxiliary equipment, itself known, especially in cyclones.
- filters or electrical separators it is possible also to use filters or electrical separators.
- the advantage of the method of operation according to the invention lies primarily in the fact that it is possible to use even cyclones alone as the separation instrument, because, due to the previously described coagulation, the actual separation equipment is no longer burdened with the coagulation.
- a gas mixture containing hydrogen, air, and nitrogen in the volume relationship 2.2 to 2.2 to 4 is mixed with sufficient vaporized ferric chloride so that the charge comes to g. FeCl /m. gas mixture.
- This homogeneous mixture is led to a tubular burner 24 mm. in diameter of such a type that every hour 2.2 m. hydrogen, 2.2 m. air, and 4 111. nitrogen (all measured at standard condition of temperature and pressure) are passed through.
- a suthciently high rate of outflow e.g. 520 cm./sec. a flash back of the flame is prevented.
- the ferric chloride hydrolyzes practically quantitatively into Fe O which is separated from the reaction gases after coagulation.
- the finely divided product is colored light yellowish brown and is strongly ferromagnetic.
- the rate of outflow is given according to a temperature of 20 C.
- a gas mixture containing hydrogen. and air in the volume relationship 1.1 to 12.0 is mixed with vaporized ferric chloride to come to a charge of 120 g. FeCl /m gas mixture and burnt in the same burner as in the foregoing example.
- the rate of outflow was ca. 810 cm./sec.
- the finely divided product is colored light yellowish brown and is practically non-ferromagnetic.
- Process for the preparation of finely divided ferromagnetic ferric oxide by decomposition of iron compounds in the gaseous phase characterized by the steps of first homogeneously mixing a volatile ferric halide with waterforming gases, the gaseous mixture containing oxygen and hydrogen in at least sufllcient amount for the formation of water for the complete hydrolysis of said ferric halide and hydrogen in excess of that amount, burning said mixture in a self-sufficient flame thereby completely bydrolyzin g the halide to ferromagnetic oxide and thereafter separating the oxide from the products of combustion.
- the method of forming finely divided magnetic ferric oxide comprising mixing vapors of ferric chloride with hydrogen, oxygen and nitrogen in relative amounts such that upon burning Water vapor is formed, the amount of oxygen being at least the stoichiometric equivalent of the ferric iron, the amount of hydrogen being in excess of the stoichiometric equivalent of the oxygen and the amount of nitrogen being suflicient to maintain a flame temperature of less than 1000 C., to form a homogeneous gaseous mixture, causing said mixture to flow from a burner by laminar flow at a rate at the burner in excess of the rate of flame propagation through said mixture, burning said mixture as it flows from the burner in a self-sufficient flame, thereby forming a flame containing water vapor as a combustion product and causing said ferric chloride to be hydrolyzed to ferric oxide by reaction with said water vapor, flowing the combustion products formed by said burning with the ferric oxide suspended therein in turbulent flow for at least three seconds, and thereafter separating the ferric oxide from said combustion products
- the method of forming finely divided ferro-magnetic oxide comprising forming a gaseous mixture containing relatively by volume 2.2 parts of hydrogen, 2.2 parts of air and 4 parts of nitrogen, mixing ferric chloride vapors with said gaseous mixture in relative amount of grams per cubic meter and forming a homogeneous mixture, flowing said homogeneous mixture from a burner tube having an outlet diameter of 24 mm. at a volume rate per hour of 1008 grams of FeCl 2.2 m of H 2.2 m. of air and 4 m. of N and at a linear rate at the mouth of the burner of 520 cm./sec., burning said homogeneous gaseous mixture, and separating ferric oxide from the combustion products formed from said burning.
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- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Inorganic Chemistry (AREA)
- Health & Medical Sciences (AREA)
- Dermatology (AREA)
- General Health & Medical Sciences (AREA)
- Compounds Of Iron (AREA)
- Silicon Compounds (AREA)
Description
United States Tatent-O PROCESS FOR THE PREPARATION OF FINELY DIVIDED FERROMAGNETIC FERRIC OXIDE Ernst Wagner, Rheinfelden,
to Dentsche Goldfurt am Main,
Baden, Germany, assignor und Silber-Scheideanstalt, Frank- Germany, a corporation of Germany The invention relates to a process for the direct production of finely divided ferromagnetic ferric oxide from ferric halides in the vapor phase.
It is known that like other oxides fern'c oxide can be obtained by hydrolysis of the corresponding halide in a hydrogen-oxygen flame. In this process in general an excess of oxygen is used and the ferric oxide obtained is paramagnetic. For obtaining ferric oxide, iron pentacarbonyl has also been already used as the starting material and this was burned alone or together with other combustible substances. The preparation of magnetic fenic oxide has also already been described by processing iron carbonyl compounds with a deficit of oxygen, relative to the composition of ferric oxides.
It has now been found that finely divided ferromagnetic ferric oxide can be obtained directly in a simple way in the gas phase if volatile ferric halides are converted by hydrolysis within a flame of water-forming gases and in connection with this certain critical quantitative relationships with reference to the water-forming gases are maintained. According to the invention, the oxygen for the flame is proportioned so that the water formed is completely suflicient for practical purposes for the hydrolysis of the volatile ferric halide into an oxide of trivalent iron,
while the hydrogen is applied in excess, referred to the formation of water. The ferric oxide, obtained according to the process of the invention, in contrast to the products of the processes previously known, is ferromagnetic even for almost stoichiometn'c composition, referred to Fe O Because of its finely divided nature it is pre-eminently suitable as magnetogram-carrier, further for the preparation of magnetic solid solutions by pressing or also as agent for nondestructive testing of industrial materials. Likewise, of course, due to its extremely finely divided state and its activity, it can also be incorporated for purposes of which the utilization of the magnetic properties is not itself or not primarily the object, and it can serve, for example, as filler or also as pigment or polishing agent.
The process according to the application is not limited in the selection of water-forming gases for the flame to pure oxygen or pure hydrogen, although the latter is, however, preferably used, rather the production of the flame can take place through the utilization of hydrogencontaining and hydrogen-forming gases or gas mixtures such as illuminating gas, methane or the like, While air can be used advantageously as oxygen-carrier.
According to a particularly preferred form of procedure of the process according to the invention, the water-forming gases are mixed homogeneously together with the volatile ferric halides before bringing them to the flame, whereupon the reactive mixture is expediently led to the flame in laminar flow. In this form of procedure, the flame burns autark (self-sufficiently) in relation to all components required for the formation of Fe O by bydrolysis, so that there is no dependence on the uncontrolled entrance of oxygen from the environment of the flame. Here it is important to make sure that the rate of outflow of the gas mixture from the burner opening is Patented Aug. 30, 1960 a multiple of its rate of flame propagation, and that, for example, by means of mechanical stripping or by flush gases, flowing past the burner mouth in a thin layer, the burner is protected from the deposition of a tuft, consisting of finely divided oxide, that causes clogging or that could disturb the uniform course of the reaction. Products obtained in this way are distinguished in particular by a largely uniform particle size, that is by a narrow band of granular size division and by uniform development of the surface of the individual primary particles. This depends on the uniform and homogeneous distribution of the various reaction components practically in the total flame volume, by which the same reaction conditions are created for each flame element. In connection with this, disturbances of the homogeneous formation of the flame, for example by turbulences, vortices or the like, are undesirable, therefore it is advantageous to lead the gaseous or vaporous initial mixture on the way to the flame and into it largely in a laminar way.
For the preparation of especially high grade products, for which a restoration of the surface is to be prevented as much as possible with reference to the maintenance of disordered places of the lattice and a granular growth, it has been found to be advantageous to keep the temperature of the flame as low as possible and to operate at flame temperatures below 1000 0., preferably at those below 800 C. The maintenance of a low flame temperature can be achieved, according to the invention, for example by the method of introducing into the flame inert gases, such as nitrogen, having a diluting effect. The application of this measure also leads to a decrease in the loading of the gas mixture with the compound to be decomposed and thus to a decrease in particle size of the ferromagnetic oxides formed, desirable in such cases.
For the maintenance of the favorable properties of the oxide particles formed with reference to the fineness and the surface development up to the separation or final recovery of the solid reaction products, it has been found to be extraordinarily advantageous to permit as complete a transition as possible of theferric oxide produced in the process as aerosol, into the gel form, in the presence of the already coagulated portions, to take place. The particles at first separated from the aerosol state thus act, so to say, as an inoculating agent or condensation nucleus for the further separation of the portions not yet coagulated, inasmuch as they are kept in suspension in as long a path as possible. The coagulation is further favored by the fact that the particles are moved especially in relation to one another. According to the invention the gas stream containing the aerosol is whirled up in chambers of large volume or moved through long, purposely bent tubes up to 60 m. and more in length, in such a way that a preferably turbulent flow is developed and the suspended particles remain for some time, for example longer than 3 seconds, preferably 5 seconds or more, in the coagulation space. The final separation of the solid from the gaseous react-ion products then takes place in auxiliary equipment, itself known, especially in cyclones. However, it is possible also to use filters or electrical separators. The advantage of the method of operation according to the invention lies primarily in the fact that it is possible to use even cyclones alone as the separation instrument, because, due to the previously described coagulation, the actual separation equipment is no longer burdened with the coagulation.
The invention is further clarified by the following examples:
(1) A gas mixture containing hydrogen, air, and nitrogen in the volume relationship 2.2 to 2.2 to 4 is mixed with sufficient vaporized ferric chloride so that the charge comes to g. FeCl /m. gas mixture. This homogeneous mixture is led to a tubular burner 24 mm. in diameter of such a type that every hour 2.2 m. hydrogen, 2.2 m. air, and 4 111. nitrogen (all measured at standard condition of temperature and pressure) are passed through. By maintenance of a suthciently high rate of outflow, e.g. 520 cm./sec. a flash back of the flame is prevented. The ferric chloride hydrolyzes practically quantitatively into Fe O which is separated from the reaction gases after coagulation. The finely divided product is colored light yellowish brown and is strongly ferromagnetic. The rate of outflow is given according to a temperature of 20 C.
(2) A gas mixture containing hydrogen. and air in the volume relationship 1.1 to 12.0 is mixed with vaporized ferric chloride to come to a charge of 120 g. FeCl /m gas mixture and burnt in the same burner as in the foregoing example. The rate of outflow was ca. 810 cm./sec. The finely divided product is colored light yellowish brown and is practically non-ferromagnetic.
Having thus disclosed my invention and described in detail illustrative procedure, I claim as new and desire to secure by Letters Patent:
1. Process for the preparation of finely divided ferromagnetic ferric oxide by decomposition of iron compounds in the gaseous phase, characterized by the steps of first homogeneously mixing a volatile ferric halide with waterforming gases, the gaseous mixture containing oxygen and hydrogen in at least sufllcient amount for the formation of water for the complete hydrolysis of said ferric halide and hydrogen in excess of that amount, burning said mixture in a self-sufficient flame thereby completely bydrolyzin g the halide to ferromagnetic oxide and thereafter separating the oxide from the products of combustion.
2. Process, according to claim 1, characterized by the fact that the gas mixture led to the flame contains hydrogen and air in the relationship 1:1.
3. Process, according to claim 1, characterized by the fact that the rate of discharge of the initial mixture leaving the burner opening comes to a multiple of its rate of flame propagation and that the burner flange is protected from the deposition of a tuft of finely divided oxide, by decrease of the ignition rate of the exit gases in its direct vicinity by flushing gases that flow in a thin layer past the burner flange.
4. Process, according to claim 1, characterized by the fact that the flame temperature is kept below 1000 0., preferably below 800 C.
'5. The method of forming finely divided magnetic ferric oxide comprising mixing vapors of ferric chloride with hydrogen, oxygen and nitrogen in relative amounts such that upon burning Water vapor is formed, the amount of oxygen being at least the stoichiometric equivalent of the ferric iron, the amount of hydrogen being in excess of the stoichiometric equivalent of the oxygen and the amount of nitrogen being suflicient to maintain a flame temperature of less than 1000 C., to form a homogeneous gaseous mixture, causing said mixture to flow from a burner by laminar flow at a rate at the burner in excess of the rate of flame propagation through said mixture, burning said mixture as it flows from the burner in a self-sufficient flame, thereby forming a flame containing water vapor as a combustion product and causing said ferric chloride to be hydrolyzed to ferric oxide by reaction with said water vapor, flowing the combustion products formed by said burning with the ferric oxide suspended therein in turbulent flow for at least three seconds, and thereafter separating the ferric oxide from said combustion products.
6. The method of forming finely divided ferro-magnetic oxide comprising forming a gaseous mixture containing relatively by volume 2.2 parts of hydrogen, 2.2 parts of air and 4 parts of nitrogen, mixing ferric chloride vapors with said gaseous mixture in relative amount of grams per cubic meter and forming a homogeneous mixture, flowing said homogeneous mixture from a burner tube having an outlet diameter of 24 mm. at a volume rate per hour of 1008 grams of FeCl 2.2 m of H 2.2 m. of air and 4 m. of N and at a linear rate at the mouth of the burner of 520 cm./sec., burning said homogeneous gaseous mixture, and separating ferric oxide from the combustion products formed from said burning.
References Cited in the file of this patent UNITED STATES PATENTS 1,816,388 Mittasch et al. July 28, 1931 1,850,286 Mittasch et al. Mar. 22, 1932 1,992,685 Wescott Feb. 26, 1935 2,635,946 Weber et al Apr. 21, 1953 FOREIGN PATENTS 7 677,878 Great Britain Aug. 20, 1952 126,250 Great Britain Mar. 16, 1955
Claims (1)
1. PROCESS FOR THE PREPARATION OF FINELY DIVIDED FERROMAGNETIC FERRIC OXIDE BY DECOMPOSITION OF IRON COMPOUNDS IN THE GASEOUS PHASE, CHARACTERIZED BY THE STEPS OF FIRST HOMOGENEOUSLY MIXING A VOLATILE FERRIC HALIDE WITH WATER FORMING GASES, THE GASEOUS MIXTURE CONTAINING OXYGEN AND HYDROGEN IN AT LEAST SUFFICIENT AMOUNT FOR THE FORMATION OF WATER FOR THE COMPLETE HYDROLYSIS OF SAID FERRIC HALIDE AND HYDROGEN IN EXCESS OF THAT AMOUNT, BURNING SAID MIXTURE IN A SELF-SUFFICIENT FLAME THEREBY COMPLETELY HYDROLYZING THE HALIDE TO FERROMAGNETIC OXIDE AND THEREAFTER SEPARATING THE OXIDE FROM THE PRODUCTS OF COMBUSTION.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DED24600A DE1034163B (en) | 1956-12-31 | 1956-12-31 | Process for the production of finely divided, ferromagnetic iron oxide |
Publications (1)
Publication Number | Publication Date |
---|---|
US2950955A true US2950955A (en) | 1960-08-30 |
Family
ID=7038241
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US701708A Expired - Lifetime US2950955A (en) | 1956-12-31 | 1957-12-10 | Process for the preparation of finely divided ferromagnetic ferric oxide |
Country Status (5)
Country | Link |
---|---|
US (1) | US2950955A (en) |
CH (1) | CH372648A (en) |
DE (1) | DE1034163B (en) |
GB (1) | GB836275A (en) |
NL (1) | NL222078A (en) |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4765920A (en) * | 1986-07-14 | 1988-08-23 | Cabot Corporation | High temperature process for producing fine magnetic particles of M-phase structure |
US4777031A (en) * | 1986-07-14 | 1988-10-11 | Cadot Corporation | High temperature process for making fine magnetic particles |
US5277368A (en) * | 1987-11-30 | 1994-01-11 | Genesis Research Corporation | Coal cleaning process |
US5348160A (en) * | 1987-11-30 | 1994-09-20 | Genesis Research Corporation | Coal cleaning process |
US5794791A (en) * | 1987-11-30 | 1998-08-18 | Genesis Research Corporation | Coal cleaning process |
Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US1816388A (en) * | 1924-05-23 | 1931-07-28 | Ig Farbenindustrie Ag | Method of producing finely divided metal oxides |
US1850286A (en) * | 1925-05-20 | 1932-03-22 | Ig Farbenindustrie Ag | Process for making finely divided metal oxides |
US1992685A (en) * | 1928-06-22 | 1935-02-26 | Sulphur And Smelting Corp | Production of ferric oxide by burning ferric chloride |
GB677878A (en) * | 1949-12-29 | 1952-08-20 | Basf Ag | Improvements in the production of magnetic iron oxides |
US2635946A (en) * | 1951-06-04 | 1953-04-21 | Schweizerhall Saeurefab | Process and apparatus for the production of finely divided metallic oxides useful as pigments |
GB726250A (en) * | 1952-04-02 | 1955-03-16 | Degussa | Process for the production of finely divided oxides |
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1956
- 1956-12-31 DE DED24600A patent/DE1034163B/en active Granted
-
1957
- 1957-10-21 CH CH5178957A patent/CH372648A/en unknown
- 1957-11-01 NL NL222078A patent/NL222078A/xx unknown
- 1957-12-10 US US701708A patent/US2950955A/en not_active Expired - Lifetime
- 1957-12-30 GB GB40290/57A patent/GB836275A/en not_active Expired
Patent Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US1816388A (en) * | 1924-05-23 | 1931-07-28 | Ig Farbenindustrie Ag | Method of producing finely divided metal oxides |
US1850286A (en) * | 1925-05-20 | 1932-03-22 | Ig Farbenindustrie Ag | Process for making finely divided metal oxides |
US1992685A (en) * | 1928-06-22 | 1935-02-26 | Sulphur And Smelting Corp | Production of ferric oxide by burning ferric chloride |
GB677878A (en) * | 1949-12-29 | 1952-08-20 | Basf Ag | Improvements in the production of magnetic iron oxides |
US2635946A (en) * | 1951-06-04 | 1953-04-21 | Schweizerhall Saeurefab | Process and apparatus for the production of finely divided metallic oxides useful as pigments |
GB726250A (en) * | 1952-04-02 | 1955-03-16 | Degussa | Process for the production of finely divided oxides |
Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4765920A (en) * | 1986-07-14 | 1988-08-23 | Cabot Corporation | High temperature process for producing fine magnetic particles of M-phase structure |
US4777031A (en) * | 1986-07-14 | 1988-10-11 | Cadot Corporation | High temperature process for making fine magnetic particles |
US5277368A (en) * | 1987-11-30 | 1994-01-11 | Genesis Research Corporation | Coal cleaning process |
US5314124A (en) * | 1987-11-30 | 1994-05-24 | Genesis Research Corporation | Coal cleaning process |
US5348160A (en) * | 1987-11-30 | 1994-09-20 | Genesis Research Corporation | Coal cleaning process |
US5794791A (en) * | 1987-11-30 | 1998-08-18 | Genesis Research Corporation | Coal cleaning process |
Also Published As
Publication number | Publication date |
---|---|
DE1034163C2 (en) | 1958-12-24 |
GB836275A (en) | 1960-06-01 |
NL222078A (en) | 1963-03-15 |
DE1034163B (en) | 1958-07-17 |
CH372648A (en) | 1963-10-31 |
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