Ferric Oxide Patents (Class 423/633)
  • Patent number: 5032367
    Abstract: A method for producing a powdered iron oxide comprises the steps of adjusting the pH of a crude iron chloride solution to 2.5-4.5; reducing the P content of the solution by mechanical stirring or air bubbling and filtering; and oxidizing the solution into a powdered iron oxide having a maximum P content of 0.005 wt. %. The P content of the solution may also be reduced by ultrafilter treatment. The soft ferrite made by using the powdered iron oxide by this process shows excellent magnetic properties.
    Type: Grant
    Filed: December 16, 1988
    Date of Patent: July 16, 1991
    Assignees: Chemirite, Ltd., TDK Corporation
    Inventors: Naoe Hirai, Tohoru Murase, Katsunobu Okutani, Teruo Mori
  • Patent number: 5032180
    Abstract: A process for the production of iron oxide yellow pigments by the Penniman-Zoph process from the raw materials iron (II) sulfate, sodium hydroxide and metallic iron, is disclosed in which iron (II) is oxidized to iron (III) by gassing with air in the presence of goethite nuclei, the iron (III) sulfate is dissolved to form iron (II) and the goethite nuclei are built up to iron oxide yellow pigments, characterized in that the gassing with air and dissolving of the metal are carried out in separate vessels.
    Type: Grant
    Filed: May 25, 1990
    Date of Patent: July 16, 1991
    Assignee: Bayer Aktiengesellschaft
    Inventors: Bernd Krockert, Helmut Printzen, Karl-Werner Ganter, Gunter Buxbaum
  • Patent number: 5004504
    Abstract: In accordance with the instant invention red transparent iron oxide pigment is prepared from yellow transparent iron oxide pigment filter cake by drying and calcining in a single operation using a spray dryer employing a nozzle of the two fluid design.
    Type: Grant
    Filed: February 26, 1990
    Date of Patent: April 2, 1991
    Assignee: BASF
    Inventors: Rodney G. Schroeder, Anand S. G. Sharangpani
  • Patent number: 4994255
    Abstract: A process for recovering elemental chlorine from ferrous chloride produced during chlorination of a titaniferous ore or ore beneficiate by oxidizing ferrous chloride in a fluidized bed of particulate material which is inert, e.g., sand, continuously oxidizing first to ferric chloride and then to ferric oxide as one stage.
    Type: Grant
    Filed: April 28, 1989
    Date of Patent: February 19, 1991
    Assignee: SCM Chemicals, Inc.
    Inventor: Charles K. Hsu
  • Patent number: 4960583
    Abstract: Oxides having the spinel structure of .gamma.-Fe.sub.2 O.sub.3 /Fe.sub.3 O.sub.4 type, substituted by trivalent and monovalent metals, or doped with non-spinel derivatives thereof, more particularly iron/aluminum/potassium oxides well suited as dehydrogenation catalysts, e.g., for dehydrogenating ethylbenzene into styrene, are prepared by thermally decomposing mixed iron, aluminum and potassium salts, notably the oxalates thereof, in the presence of air, then reducing the product of thermal decomposition at a temperature of less than 400.degree. C., advantageously in the presence of steam and hydrogen, and optionally oxidizing the product of reduction; oxides of .beta.-alumina structure are also produced.
    Type: Grant
    Filed: December 16, 1988
    Date of Patent: October 2, 1990
    Assignee: Atochem
    Inventors: Abel Rousset, Belaid Maachi, Bernard Gilot, Michel Gougeon
  • Patent number: 4940572
    Abstract: A process is disclosed for the production of micaceous iron oxide using metallic iron, for example scrap iron, as a feed stock for the preparation of an iron chloride and the resulting iron chloride is oxidized at an elevated temperature in the presence of a salt of an alkali metal or alkaline earth metal, preferably sodium chloride. A reaction may be effected in a packed tower reactor comprising a refractory tube 7 containing an inert packing material e.g. aluminosilcate ceramic balls. The reaction charge including packing material, metallic iron and the salt is introduced via hopper 13. A tube 7 is externally heated by electrical resistance elements 10 and chlorine and an oxidizing gas are introduced at inlet 8 and the off-gas removed at outlet 9. The micaceous iron reaction product is obtained as a coating on the inert packing material. Micaceous iron oxide is used as a pigment for the formulation of metal protective paints.
    Type: Grant
    Filed: July 5, 1989
    Date of Patent: July 10, 1990
    Assignee: Cookson Laminox Limited
    Inventors: Roy D. Laundon, Anthony J. Wickens, John H. W. Turner
  • Patent number: 4935219
    Abstract: The process of the invention is carried out in gaseous phase by the action of ammonia on the aqueous solutions of iron salts in an appropriate reacting vessels.
    Type: Grant
    Filed: December 15, 1987
    Date of Patent: June 19, 1990
    Inventors: Luis Escolar, Helio Nupieri
  • Patent number: 4913890
    Abstract: Finely divided acicular and pore-free .alpha.-Fe.sub.2 O.sub.3 is prepared from an iron(III) salt in the presence of one or more organic substances which form complexes with iron(III) ions, in alkaline supension at from 80.degree. to 250.degree. C., and is used for the preparation of magnetic materials suitable for magnetic recording media.
    Type: Grant
    Filed: February 24, 1989
    Date of Patent: April 3, 1990
    Assignee: BASF Aktiengesellschaft
    Inventors: Volker Arndt, Helmut Auweter, Rainer Feser, Ekkehard Schwab
  • Patent number: 4898619
    Abstract: A pigment which comprises crystallites of iron oxide having an average particle size of less than 100 nanometers doped with from 10% to 80% by weight of aluminium as Al.sup.3+ based on the weight of iron, having the general formula (Al.sub.x Fe.sub.2-x)O.sub.3, where x=0.34 to 1.24 and having an orange color with the following color measurements:L (Lightness)>45.degree.C (Strength)>40.degree.H (Hue) 50.degree. to 60.degree.A pigment precursor composition is also provided which, on firing, produces the pigment as defined above.
    Type: Grant
    Filed: December 19, 1988
    Date of Patent: February 6, 1990
    Assignee: Cookson Group PLC
    Inventors: John F. Clifford, Fiona C. R. Morrison
  • Patent number: 4889697
    Abstract: According to the subject method of refining a ferrous ion-containing acid solution, a metal selected from a group including Al, Cr, V, B, and Zn or an acid solution of that metal is added to a ferrous ion-containing acid solution, such as an acid solution which remains after steel is washed with an acid. The pH value of the acid solution is controlled to be within the range of 3.5 to 6 by adding an alkali liquid to the acid solution, whereby a hydroxide salt of the added metal is produced in the acid solution and the impurities in the acid solution are captured by the produced hydroxide salt. As a result, the impurities can be eliminated from the acid solution such that the Si component (e.g., SiO.sub.2) content in the acid solution is within the range of 2 to 3 ppm or less. Since the content of the other impurities such as Al, Ti, and Cr can also be reduced, a high-purity iron oxide can be obtained from the resultant acid solution.
    Type: Grant
    Filed: December 5, 1988
    Date of Patent: December 26, 1989
    Assignees: NKK Corporation, Kokan Mining Co., Ltd.
    Inventors: Tsutomu Fukushima, Tsugio Nakao, Kasane Yamashita, Takao Komuro, Katsuhiro Nishi
  • Patent number: 4869735
    Abstract: Here is provided an adsorbent for adsorbing and removing an arsenic compound which becomes a catalyst poison in a selective contact reduction process for removing nitrogen oxides (NOx) from a combustion exhaust gas by the use of an ammonia as a reducing agent and a denitrating catalyst.The adsorbent of the present invention comprises a material in which the total volume of pores is 0.2 to 0.7 cc/g and the volume of the pores having a pore diameter of 300 .ANG. or more is 10% or more with respect to the total pore volume, and the material is a specific element, its oxide, an ion-exchanged zeolite or the like.In addition, the present invention is directed to a method for removing the arsenic compound from the combustion exhaust gas by injecting the adsorbent into the flow of the gas on the upstream side of the denitrating catalyst.
    Type: Grant
    Filed: April 28, 1988
    Date of Patent: September 26, 1989
    Assignees: Mitsubishi Jukogyo K.K., Chemical Ind. Sakai, Mitsubishi Petrochemical Co., Ltd., Petrochemical Engineering Co., Ltd. Mitsubishi, Catalysts & Chemical Co., Ltd.
    Inventors: Masaki Miyazawa, Norihisa Kobayashi, Hiromu Takatsuka, Atsushi Morii, Toshio Koyanagi, Touru Seto, Kozo Iida, Shigeaki Mitsuoka, Hiroaki Rikimaru, Makoto Imanari, Takeo Koshikawa, Akihiro Yamauchi, Masayuki Hanada, Morio Fukuda, Kiyoshi Nagano
  • Patent number: 4865833
    Abstract: A process is disclosed for the production of micaceous iron oxide using metallic iron, for example scrap iron, as a feed stock for the preparation of an iron chloride and the resulting iron chloride is oxidized at an elevated temperature in the presence of a salt of an alkali metal or alkaline earth metal, preferably sodium chloride. A reaction may be effected in a packed tower reactor comprising a refractory tube 7 containing an inert packing material e.g. aluminosilicate ceramic balls. The reaction charge including packing material, metallic iron and the salt is introduced via hopper 13. A tube 7 is externally heated by electrical resistance elements 10 and chlorine and an oxidizing gas are introduced at inlet 8 and the off-gas removed at outlet 9. The micaceous iron reaction product is obtained as a coating on the inert packing material. Micaceous iron oxide is used as a pigment for the formulation of metal protective paints.
    Type: Grant
    Filed: January 15, 1988
    Date of Patent: September 12, 1989
    Assignee: Cookson Laminox Laminox
    Inventors: Roy D. Laundon, Anthony J. Wickens, John H. W. Turner
  • Patent number: 4826671
    Abstract: Finely divided, acicular and pore-free .alpha.-Fe.sub.2 O.sub.3 is prepared from iron(III) salts in the presence of one or more organic substances which form complexes with iron(III) ions, in alkaline suspension, at from 80.degree. to 250.degree. C.
    Type: Grant
    Filed: March 11, 1987
    Date of Patent: May 2, 1989
    Assignee: BASF Aktiengesellschaft
    Inventors: Volker Arndt, Rainer Feser, Werner Steck, Helmut Jakusch
  • Patent number: 4806335
    Abstract: A process for producing acicular .alpha.-FeOOH particle powder having a narrow particle size distribution and a rectified shape and being highly dispersed is provided, which process comprises mixing with stirring an aqueous solution of a Fe(II) salt with an aqueous solution of an alkali in an equivalent ratio of alkali to Fe(II) salt of 1.5 or more, oxidizing the mixture with a O.sub.2 -containing gas, heat treating the resulting suspension of iron .alpha.-FeOOH particle powder to 60.degree. to 100.degree. C., further adding an aqueous solution of a FE(II) salt in a proportion of atom to molecule of Fe(II)/.alpha.-FeOOH of 0.5 to 10% and again oxidizing the mixture with a O.sub.2 -containing gas at 35.degree. to 55.degree. C.
    Type: Grant
    Filed: November 12, 1987
    Date of Patent: February 21, 1989
    Assignee: Chisso Corporation
    Inventors: Masayoshi Saito, Jiro I
  • Patent number: 4798622
    Abstract: Very small iron-containing particles that are in the shape of facetted nodules. Such particles can be non-magnetic particles such as delta ferric oxide hydrate particles or magnetic particles such as magnetic iron oxide particles or metallic particles. Magnetic layers containing such magnetic particles combine excellent remanent magnetization with increased output signal level. The facetted nodular particles are prepared in a process in which (a) an aqueous solution of ferrous salt is added to an aqueous solution of alkaline hydroxide while avoiding substantial local excesses of the ferrous salt, and subjecting the ferrous salt solution to reducing conditions before or during its addition to the alkaline hydroxide solution and (b) the ferrous hydroxide particles are oxidized to delta ferric oxide hydrate particles in the presence of an iron complexing agent, for example, pyrogallol, that is capable of selectively forming ferric iron complexes that are soluble in the reaction medium.
    Type: Grant
    Filed: October 8, 1986
    Date of Patent: January 17, 1989
    Assignee: Eastman Kodak Company
    Inventor: Bernard J. Pingaud
  • Patent number: 4774072
    Abstract: Acicular .alpha.-Fe.sub.2 O.sub.3 is prepared from iron(III) salts by heating an alkaline aqueous suspension of iron(III) hydroxide in the presence of one or more organic substances which form complexes with iron(III) ions to a temperature of 100.degree. C. or less.
    Type: Grant
    Filed: March 11, 1987
    Date of Patent: September 27, 1988
    Assignee: BASF Aktiengesellschaft
    Inventors: Volker Arndt, Bernd Meyer, Rainer Feser, Werner Steck, Helmut Jakusch
  • Patent number: 4758415
    Abstract: The subject matter of this invention relates to a process for removing the soluble metal cations contained in iron oxide pigments comprising washing said iron oxide pigments with a ligand compound having a pH greater than 6.0. The pigments can be used as colorants for substances ingested by man and animals, and they can also be used to stabilize plastics against ultraviolet degradation, and as pigments in base-coat clear-coat automotive finishing operations.
    Type: Grant
    Filed: May 10, 1985
    Date of Patent: July 19, 1988
    Assignee: BASF Corporation
    Inventor: Arvind S. Patil
  • Patent number: 4705762
    Abstract: A process for producing ultra-fine ceramic particles with the particle size of less than 1000 .ANG., which comprises the steps of forming powdered dust cloud of metal powder such as Si constituting a portion of aimed ceramic particles in a reaction gas containing the other portion of said aimed ceramic particles, igniting said powdered dust cloud to cause explosive burning and synthesizing said aimed ceramic particles and gathering said resulting ceramic particles. By the process, ceramic particles such as Al.sub.2 O.sub.3, MgO, SiO.sub.2, TiO.sub.2, TiN having particle size of 10-100 nm can be produced.
    Type: Grant
    Filed: February 8, 1985
    Date of Patent: November 10, 1987
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventors: Kazuhide Ota, Susumu Abe
  • Patent number: 4701221
    Abstract: A process for the production of black iron oxide pigments having a magnetite structure from iron ion-containing acidic waste water which comprises precipitating the iron ions with alkaline substances in a first stage at ambient temperature to produce a raw slurry and in a second stage, concentrating the raw slurry adjusted to a pH of from 5.0 to 8.0 with acidic substances and then ripening the concentrated slurry at temperatures above 70.degree. C.
    Type: Grant
    Filed: May 9, 1986
    Date of Patent: October 20, 1987
    Assignee: Bayer Aktiengesellschaft
    Inventors: Horst Brunn, Gerd-Hermann Schulten, Werner Fuhr
  • Patent number: 4670357
    Abstract: A ferric hydrous oxide of a character that retards the deposition of iron based compounds on the walls of a conduit is prepared by flowing an aqueous solution containing iron-based compounds including magnetite into a vented chamber, and boiling the solution at atmospheric pressure.
    Type: Grant
    Filed: June 17, 1985
    Date of Patent: June 2, 1987
    Assignee: International Fuel Cells Corporation
    Inventor: William A. Taylor
  • Patent number: 4655839
    Abstract: A solid, water impervious landfillable composition of a process for treating iron chloride wastes such as those obtained when chlorinating titanium ore is disclosed. The process involves reacting the iron chlorides with limestone in molten CaCl.sub.2.xH.sub.2 O, where x equals 3-6. The composition comprises CaCl.sub.2.xH.sub.2 O where x is from 3-6 and FeO.sub.Y where Y is from 1.0-1.5 and the weight ratio of CaCl.sub.2.xH.sub.2 O (calculated as CaCl.sub.2.2H.sub.2 O)/FeO.sub.Y is from 1/9-4/1.
    Type: Grant
    Filed: January 17, 1985
    Date of Patent: April 7, 1987
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: Tze Chao, Jack K. Nyquist
  • Patent number: 4652433
    Abstract: The method of the present invention is a novel comprehensive process for maximizing the recovery of valuable mineral values from coal ash. Options may also be included for the production of saleable inorganic chemical by-products. The process employs both physical and chemical extraction techniques that maximize the yield of products while reducing the quantity of waste produced. Valuable minerals and chemicals such as cenospheres (hollow microspheres), carbon, magnetite (Fe.sub.3 O.sub.4), alumina (Al.sub.2 O.sub.3), iron oxide (Fe.sub.2 O.sub.3) and iron chloride (FeCl.sub.3) may be produced. Due to removal of carbon, magnetite, and iron oxide from the coal ash, the processed ash comprises a quality pozzolan.
    Type: Grant
    Filed: January 29, 1986
    Date of Patent: March 24, 1987
    Assignee: Florida Progress Corporation
    Inventors: Robert A. Ashworth, Larry A. Rodriguez, Antonio A. Padilla, Ned B. Spake, W. Wes Berry, Rae A. Schmeda
  • Patent number: 4631140
    Abstract: Ferrimagnetic particles which are useful as magnetic material for magnetic recording media and consist of a core of a magnetic material exhibiting multiaxial anisotropy and a coating which surrounds the core and is composed of a magnetic material possessing uniaxial anisotropy, and a process for their preparation.
    Type: Grant
    Filed: October 15, 1985
    Date of Patent: December 23, 1986
    Assignee: BASF Aktiengesellschaft
    Inventors: Werner Steck, Helmut Jakusch
  • Patent number: 4624845
    Abstract: A process is disclosed for the production of micaceous iron oxide using metallic iron, for example scrap iron, as a feed stock for the preparation of an iron chloride and the resulting iron chloride is oxidized at an elevated temperature in the presence of a salt of an alkali metal or alkaline earth metal, preferably sodium chloride. A reaction may be effected in a packed tower reactor comprising a refractory tube 7 containing an inert packing material e.g. aluminosilicate ceramic balls. The reaction charge including packing material, metallic iron and the salt is introduced via hopper 13. A tube 7 is externally heated by electrical resistance elements 10 and chlorine and an oxidizing gas are introduced at inlet 8 and the off-gas removed at outlet 9. The micaceous iron reaction product is obtained as a coating on the inert packing material. Micaceous iron oxide is used as a pigment for the formulation of metal protective paints.
    Type: Grant
    Filed: February 22, 1984
    Date of Patent: November 25, 1986
    Inventors: Roy D. Laundon, Anthony J. Wickens, John H. W. Turner
  • Patent number: 4624843
    Abstract: Chlorine may be recovered from residues from the fluidized bed chlorination of iron-containing metalliferous oxidic materials, such as ilmenite, bauxite, chromite, wolframite, scheelite, tantalite or columbite, the residues containing condensed iron chloride and blow-over bed solids, by heating the residue to revolatalize the iron chloride and reacting it with oxygen. The quantity of iron chloride in the oxidic material is controlled relative to the quantity of blow-over carbon so that the quantity of carbon is sufficient on combustion to provide the required heat but is insufficient to cause undue dilution of the chlorine produced by virtue of its combustion products. Chlorine of a concentration suitable for direct recycle to a chlorination process, e.g. of 30% to 50% volume concentration is produced.
    Type: Grant
    Filed: June 10, 1985
    Date of Patent: November 25, 1986
    Assignee: SCM Chemicals Limited
    Inventor: Michael Robinson
  • Patent number: 4622281
    Abstract: A magnetic color toner stable to heat and light which does not fade or discolor for a long period of time is prepared by incorporating .gamma.-Fe.sub.2 O.sub.3 particles as a magnetic component in a toner.
    Type: Grant
    Filed: January 3, 1986
    Date of Patent: November 11, 1986
    Assignee: Canon Kabushiki Kaisha
    Inventors: Eiichi Imai, Hiroyuki Kobayashi, Yasuo Mitsuhashi
  • Patent number: 4597958
    Abstract: In a method of producing a hydrated iron oxide as a starting material for a magnetic powder by aging a suspension of a ferric hydroxide prepared by reacting a ferric salt with an aqueous solution of alkali, the aging temperature is controlled between 20.degree. and 100.degree. C. and pH is controlled between 1 and 6 for the first 5 to 240 minutes while nuclei of hydrated iron oxide crystals generate, and then the aqueous solution of alkali is added again to adjust the pH value to 10 to 13.5 to make the crystals grow. This production method is capable of producing an acicular hydrated iron oxide having a reduced particle-size distribution range and also capable of controlling the length of the crystals as desired.
    Type: Grant
    Filed: September 17, 1984
    Date of Patent: July 1, 1986
    Assignee: Mitsui Mining & Smelting Co., Ltd.
    Inventors: Nobuo Takagi, Masakazu Konno, Takeo Kobayashi
  • Patent number: 4560544
    Abstract: A process for preparing acicular .alpha.-FeOOH by partially neutralizing and then oxidizing a ferrous salt solution in the presence of phosphoric acid or a salt thereof to form seed crystals of .alpha.-FeOOH and optionally further oxidizing said solution while neutralizing said solution with an alkali to grow said seed crystals, wherein pyrophosphoric acid or a salt thereof is used as said phosphoric acid and the seed crystals of .alpha.-FeOOH are formed at a temperature of 50.degree. to 100.degree. C. The .alpha.-FeOOH obtained according to the process of this invention is composed of fine particles and appreciably improved in acicularity and particle size distribution. Also, a magnetic recording medium made from the magnetic iron oxides derived therefrom in a usual way have a low noise characteristic and, are excellent in coercivity and other magnetic properties.
    Type: Grant
    Filed: December 10, 1984
    Date of Patent: December 24, 1985
    Assignee: Ishihara Sangyo Kaisha, Ltd.
    Inventors: Kazuo Nakata, Tsuneo Ishikawa, Taro Amamoto, Toshihiko Kawamura
  • Patent number: 4543197
    Abstract: A process for producing magnetic metallic oxide which comprises the steps of pulverizing at least one member selected from the group consisting of ferro-manganese, ferro-nickel, electrolytic manganese, electrolytic iron and electrolytic zinc, adding to the substance thus pulverized at least one member selected from the group consisting of oxides of Fe, Mn, Ni, Cu, Mg, Zn and Co and salts of Fe, Mn, Ni, Cu, Mg, Zn and Co which become oxides by heating, wet pulverizing and mixing the mixture upon oxidation, thereby producing a slurry, and heating said slurry at 800.degree. to 1450.degree. C. By this process, a magnetic ferrite can be stably and inexpensively synthesized.
    Type: Grant
    Filed: April 25, 1983
    Date of Patent: September 24, 1985
    Assignees: Japan Metals & Chemicals Co., Ltd., Magune Co., Ltd.
    Inventors: Tadayoshi Karasawa, Katsumi Kawano, Katsuji Uchiyama, Michio Yamazaki
  • Patent number: 4532113
    Abstract: A process for treating iron chloride wastes such as those obtained when chlorinating titanium ore is disclosed. The process involves reacting the iron chlorides with limestone in molten CaCl.sub.2.xH.sub.2 O, where x equals 3-6 and separating the resulting iron oxide from the molten CaCl.sub.2.xH.sub.2 O.
    Type: Grant
    Filed: September 6, 1983
    Date of Patent: July 30, 1985
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: Tze Chao, Jack K. Nyquist
  • Patent number: 4495164
    Abstract: A process for producing acicular magnetite or maghemite of high axial ratio, which comprisespreparing an iron (II) hydroxide suspension at a pH of at least 11 with a magnesium sulfate or magnesium chloride in an amount of 0.5 to 7.0 atomic % based on the amount of the iron (II) hydroxide in the suspension and calculated as the ratio of Mg to Fe (II),oxidizing the resultant suspension with the oxygen-containing gas to form an acicular iron (III) oxide hydroxide in the form of particles having a long axis length of 0.3 to 2.0 .mu.m and an axial ratio of more than 20:1,reducing said acicular iron (III) oxide hydroxide into the acicular magnetite, and oxidizing the resultant acicular magnetite to form the acicular maghemite, if necessary.
    Type: Grant
    Filed: July 11, 1983
    Date of Patent: January 22, 1985
    Assignee: Toda Kogyo Corp.
    Inventors: Yosiro Okuda, Tosiharu Harada
  • Patent number: 4459276
    Abstract: Yellow iron oxide crystals having lengths in the range of 100 to 1000 nm and a major axis/motor axis length ratio in the range of 1.5 to 4.5 are produced by adding an aqueous ferric salt solution to an aqueous alkali solution, causing the two solutions to react with each other at a temperature in the range of -5.degree. to 30.degree. C. thereby inducing precipitation of iron hydroxide, allowing the precipitate to age, then subjecting the aged precipitate to a hydrothermal treatment thereby producing crystals and, when necessary, further allowing the crystals to grow.
    Type: Grant
    Filed: August 31, 1982
    Date of Patent: July 10, 1984
    Assignees: Agency of Industrial Science & Technology, Ministry of International Trade & Industry
    Inventors: Soichiro Nobuoka, Takashi Asai, Kazuaki Ado
  • Patent number: 4436681
    Abstract: A process for producing an iron oxide weighting material from an iron chloride solution. The iron chloride solution is introduced into an elevated temperature reactor as an atomized mist. The moisture is evaporated from the mist to form iron chloride solids which then react with the steam produced during the evaporation to form particulate iron oxides and hydrogen chloride gas. The iron oxides then are compacted and introduced into a calcination zone maintained at a temperature in the range of from about 400.degree. C. to about 1300.degree. C. The compacted iron oxide is calcined to reduce the surface area of the particles. The calcined iron oxide then is ground to a predetermined particle size.
    Type: Grant
    Filed: May 17, 1982
    Date of Patent: March 13, 1984
    Inventors: Virgil J. Barczak, Haywood A. Perkins, O. L. Daigle
  • Patent number: 4414196
    Abstract: A method of producing single crystalline, acicular .alpha.-ferric oxide particles of narrow particle size distribution is provided. The method comprises heating an aqueous suspension of ferric hydroxide at temperatures of 100.degree.-250.degree. C. at an alkaline pH in the presence both a water soluble organic or inorganic compound capable of forming complexes with iron as a growth regulating agent and .alpha.-ferric oxide seed crystals of minor axes not larger than 0.4 microns in average in amounts of 0.1-25 mole % in terms of the Fe content thereof in relation to the ferric hydroxide.
    Type: Grant
    Filed: November 18, 1981
    Date of Patent: November 8, 1983
    Assignee: Sakai Chemical Industry Co., Ltd.
    Inventors: Seiji Matsumoto, Tadashi Koga, Kiyoshi Fukai, Hideji Yamamoto
  • Patent number: 4404254
    Abstract: Synthetic, hexagonal, lamellar iron oxide particles, suitable as corrosion-inhibiting or decorative colored pigments, containing about 0.1 to 12% by weight of at least one oxide of an element of the IVth, Vth or VIth Main and Secondary Groups and of the IInd Secondary Group of the Periodic System of Elements.
    Type: Grant
    Filed: July 7, 1981
    Date of Patent: September 13, 1983
    Assignee: Bayer Aktiengesellschaft
    Inventors: Gerhard Franz, Franz Hund
  • Patent number: 4396596
    Abstract: A method of preparing gamma ferric hydroxyoxide in which ferrous ions are reacted in an alkaline solution to produce a suspension of ferric hydroxide, the resulting suspension is treated with an oxidizing gas in a first oxidizing step at a relatively high oxidation rate, sufficient to cause nucleation of gamma ferric hydroxyoxide to occur, and then the oxidation rate is reduced in a second oxidizing step to cause crystal growth to occur on the nuclei formed in the first oxidizing step. The resulting product has magnetic and physical characteristics making it extremely suitable for use in the manufacture of magnetic recording media.
    Type: Grant
    Filed: October 19, 1981
    Date of Patent: August 2, 1983
    Assignee: Sony Corporation
    Inventors: Kenji Ogisu, Makoto Inoue, Kenji Yazawa, Haruko Masuya
  • Patent number: 4389391
    Abstract: An improved method of beneficiating ilmenite using two chlorinators in order to oxidize by-product iron chlorides to chlorine in the vapor phase and eliminate the necessity of separating the chlorine from combustion gas by cryogenic methods comprising using a first stage which produces beneficiated ore, and, inter alia, carbon dioxide, iron chlorides, predominantly ferrous chloride, which are condensed to gain the separation from CO.sub.2 ; solid iron chlorides are fed to an oxidation zone in the void above the second stage beneficiator and reacted with oxygen; heat required for vaporization of the condensed chlorides is supplied in part by beneficiation within the second stage. The fluidized bed overflow of the second stage beneficiator is magnetically separated to separate practically pure T.sub.1 O.sub.2, useful as a starting material for T.sub.1 O.sub.2 pigment and a recycle stream of magnetic partially beneficiated ore.
    Type: Grant
    Filed: June 28, 1981
    Date of Patent: June 21, 1983
    Inventor: Wendell E. Dunn, Jr.
  • Patent number: 4378252
    Abstract: A process for increasing the color purity of iron oxide pigment particles admixed with color-modifying impurities and obtained by the Penniman process or the aniline process, comprising introducing the particles into a magnetic field, and removing from the magnetic field two fractions of different magnetizability, the first fraction being iron oxide pigment particles of increased color purity and the second fraction being enriched in impurities.
    Type: Grant
    Filed: May 29, 1981
    Date of Patent: March 29, 1983
    Assignee: Bayer Aktiengesellschaft
    Inventors: Peter Kiemle, Franz Hund, Ingo Pflugmacher, Wolfgang Rambold
  • Patent number: 4376656
    Abstract: Yellow iron oxide pigments having improved heat stability are prepared by subjecting an alkaline slurry of conventional yellow iron oxide, a soluble ferric salt, sodium aluminate, and a third metal component, exemplified by antimony ion or a zinc ion/titanium ion combination, to a hydrothermal (autoclave) treatment at about 100.degree.-240.degree. C. The separated solid product has a heat stability temperature (based on the color change from yellow to red when heated) appreciably higher than that of the starting iron oxide.
    Type: Grant
    Filed: October 16, 1981
    Date of Patent: March 15, 1983
    Assignee: Titan Kogyo K.K.
    Inventors: Jihei Senda, Yoshihiro Inoue, Toshiaki Uenishi, Hidefumi Harada, Kouji Nakata, Akio Akagi, Yakanori Yamasaki
  • Patent number: 4374676
    Abstract: Yellow iron oxide pigments having improved heat stability are prepared by mixing a conventional yellow iron oxide pigment with an aqueous alkaline solution of a soluble antimony compound. This yields a yellow pigment whose particle surface is coated with "antimony-bloom", and this product has a higher heat stability temperature than does the starting yellow iron oxide. When the product coated with "antimony-bloom" is subjected to hydrothermal treatment (autoclaving), the resultant material has a yet-higher heat stability temperature. Other, related treatments furnish products with improved heat stability temperatures.
    Type: Grant
    Filed: December 7, 1981
    Date of Patent: February 22, 1983
    Assignee: Titan Kogyo K.K.
    Inventors: Jihei Senda, Yoshihiro Inoue, Toshiaki Uenishi, Hidefumi Harada, Kouji Nakata, Akio Akagi, Takanori Yamasaki
  • Patent number: 4374677
    Abstract: Yellow iron oxide pigments having improved heat stability are prepared by subjecting an alkaline slurry of conventional yellow iron oxide, a soluble ferric salt, and sodium aluminate to a hydrothermal (autoclave) treatment at 100.degree.-240.degree. C., separating and slurrying the resultant solid product, and subjecting that product to a second hydrothermal treatment of 250.degree.-350.degree. C. The original iron oxide has a heat stability (based on color change from yellow to red) temperature of about 203.degree. C., while the final product shows a change at 270.degree. C.
    Type: Grant
    Filed: October 5, 1981
    Date of Patent: February 22, 1983
    Assignee: Titan Kogyo K.K. Japan
    Inventors: Jihei Senda, Yoshihiro Inoue, Toshiaki Uenishi, Hidefumi Harada, Kouji Nakata, Akio Akagi
  • Patent number: 4362702
    Abstract: A hydrometallurgical process for the treatment of a raw material which contains oxides and ferrites of zinc, copper and cadmium is disclosed, wherein the raw material is neutral leached by means of a sulfuric-acid-bearing solution to leach the oxides without substantial dissolving of the ferrites, a ferrite-bearing residue is separated, and a sulfuric-acid-bearing or ferrisulfate-bearing solution is mixed with the residue in order to leach the ferrite and to precipitate the iron in the form of jarosite in the presence of alkali or ammonium ions under atmospheric conditions at 80.degree.-105.degree. C., and the solid phase is separated from the solution.
    Type: Grant
    Filed: September 29, 1981
    Date of Patent: December 7, 1982
    Assignee: Outokumpu Oy
    Inventors: Jussi K. Rastas, Jens R. Nyberg, Kauko J. Karpale, Lars-Goran Bjorkqvist
  • Patent number: 4358431
    Abstract: In the production of needle-shaped magnetic iron oxide pigments by treating iron with a nitro-aromatic in the presence of .alpha.-FeOOH nuclei to form .alpha.-FeOOH particles and an amino-aromatic, and thereafter dehydrating the .alpha.-FeOOH particles and reducing them, the improvement which comprises forming the .alpha.-FeOOH nuclei at about 0.degree. to 90.degree. C. in a suspension of metallic iron, an iron-(II)-salt and a nitro-aromatic by adding a basic precipitant in about 10 to 95% of the amount required for the complete precipitation of the iron in the iron-(II)-salt. Advantageously the metallic iron comprises cast iron, the nitro-aromatic comprises nitrobenzene, the amino-aromatic comprises aniline, the basic precipitant comprises at least one of ammonia and a basically reacting alkali metal, alkaline earth metal or ammonium salt, the nuclei formation is carried out at about 10.degree. to 60.degree. C.
    Type: Grant
    Filed: July 23, 1981
    Date of Patent: November 9, 1982
    Assignee: Bayer Aktiengesellschaft
    Inventors: Horst Brunn, Peter Kiemle, Franz Hund, Heribert Bade
  • Patent number: 4355005
    Abstract: A process for the treatment of a raw material which contains oxides and ferrites of zinc, copper and cadmium is disclosed, in which the raw material is neutral leached with a sulfuric-acid-bearing solution in order to leach the oxide without substantial dissolving of ferrite, the ferrite-bearing residue is separated, and a sulfuric-acid-bearing or ferrisulfate-bearing solution is mixed with the residue in order to leach the ferrite and to precipitate the iron as jarosite in the presence of alkali ions or ammonium ions under atmospheric conditions at 80.degree.-105.degree. C., the sulfuric-acid-bearing or ferrisulfate-bearing solution being added to the ferrite-bearing residue in such an amount that approximately 50-60% of the ferrite dissolves and its iron precipitates as jarosite, the solid phase is dried and heated to so high a temperature that the zinc of the solid phase is converted to zinc sulfate and its iron to hematite according to the following reaction:(8) 3ZnFe.sub.2 O.sub.4(s) +2A[Fe.sub.3 (SO.
    Type: Grant
    Filed: September 29, 1981
    Date of Patent: October 19, 1982
    Assignee: Outokumpu Oy
    Inventors: Jussi K. Rastas, Pekka J. Saikkonen, Risto J. Honkala
  • Patent number: 4349456
    Abstract: Shaped and fired, porous or impermeable nonvitreous ceramic microcapsules of metal oxide, preferably transparent and polycrystalline, are made by a non-melt process comprising the liquid-liquid extraction of aqueous metal oxide precursor with a dehydrating liquid having a limited water solubility, and drying and firing the resulting gelled microcapsules. For example, an aqueous titania sol is added to an agitated body of n-butanol to form a dispersion of droplets of said sol and water is rapidly extracted from the droplets to form gelled microcapsules; the latter are recovered by filtration, dried, and fired to convert them into transparent, sealed or heat-sealable, non-vitreous ceramic, spherical microcapsules of polycrystalline titania. The microcapsules can be used as fillers for plastic and other composites or filled with a selected solid, liquid or gas for purpose of storing, transporting, or facilitating the use of the same.
    Type: Grant
    Filed: August 27, 1979
    Date of Patent: September 14, 1982
    Assignee: Minnesota Mining and Manufacturing Company
    Inventor: Harold G. Sowman
  • Patent number: 4339425
    Abstract: Acicular hydrated ferric oxide particles are produced by premixing an aged ferric hydroxide with a newly formed ferric hydroxide or a mixture of ferrous hydroxide and an oxidizing agent and treating the pre-mixture by a hydrothermal reaction of said pre-mixture at 100.degree. to 250.degree. C.
    Type: Grant
    Filed: November 25, 1980
    Date of Patent: July 13, 1982
    Assignee: TDK Electronics Co., Ltd.
    Inventor: Yasumichi Tokuoka
  • Patent number: 4323464
    Abstract: A hydrated iron oxide comprising a silicon component and a phosphorus component is produced by adding a silicate and a phosphate in an aqueous solution of a base and mixing it with an aqueous solution of a ferrous if necessary with a small amount of zinc ion and oxidizing it under controlling pH in a range of 5.5 to 7.5.
    Type: Grant
    Filed: April 24, 1980
    Date of Patent: April 6, 1982
    Assignee: TDK Electronics Co., Ltd.
    Inventor: Shinji Umeki
  • Patent number: 4309459
    Abstract: An SiO.sub.2 coated iron oxide powder used for the preparation of an acicular metallic iron powder or an acicular magnetic iron oxide powder, is produced by forming a slurry of hydrated iron oxide as a starting material or a iron oxide powder having pH of 8 to 14; admixing a water soluble silicate at a ratio of 0.1 to 10 mol % as SiO.sub.2 based on Fe; hydrothermally reacting said mixed slurry at 100.degree. to 250.degree. C. for 5 minutes or longer in a closed reactor, and washing, filtering and drying the product.
    Type: Grant
    Filed: November 25, 1980
    Date of Patent: January 5, 1982
    Assignee: TDK Electronics Co., Ltd.
    Inventor: Yasumichi Tokuoka
  • Patent number: 4304759
    Abstract: The invention provides a process for thermally decomposing salts, containing mainly ferrous sulfate wherein said feed material is contacted in a single suspension-type exchanger with exhaust gases formed by reaction of the oxygen-containing gases in the fluidized bed reactor, the fluidizing gas and at least a partial stream of the secondary gas stream are heated by an indirect heat exchange in a fuel-heated heat exchanger, and the quantity of oxygen introduced via which consists of the fluidizing gas and the secondary gas, is controlled in dependence on the quantity of fuel in order to receive an exhaust gas from the suspension-type exchanger with a free oxygen content of 1-6% by volume and a temperature of 300.degree.-450.degree. C.
    Type: Grant
    Filed: May 1, 1980
    Date of Patent: December 8, 1981
    Assignee: Metallgesellschaft AG
    Inventors: Georg Daradimos, Martin Hirsch, Lothar Reh, Jorg Thomas
  • Patent number: 4299635
    Abstract: Copperas is calcined, ground, washed, dried, and milled to give a roasted copperas red, suitable as a paint pigment. The flow characteristics of the oxide, during processing, and the dispersibility of the pigment in paint are improved by the addition of 0.5-10 wt. % SiO.sub.2 to the iron oxide after the washing step.
    Type: Grant
    Filed: March 23, 1979
    Date of Patent: November 10, 1981
    Inventor: Theodore Dickerson