Abstract: A method is provided of rapidly increasing the bulk density of an iron oxide powder by preventing the powder, processed by a roller consolidation machine, from flying up. The method consists of feeding an iron oxide powder, whose apparent bulk density is 0.4-0.6, into a sealed tank, depressurizing the tank to a vacuum of 100-200 torr, and revolving the rotating roller and rotating plow at a revolving speed of 1-2 m/sec.

Abstract: The present invention relates to a process for the preparation of iron oxide black pigment granules which are stable to handling.

Abstract: A method of decorating a firable article which includes the step of mixing a metallic salt with a fuel material which can supply oxygen to the salt in a reaction. This mixture causes complex formation of the salt, characterized by raising the pH of the mixture to at least 5. Additives in the mixture promote stability and provide the required viscosity surface tension and conductivity for use in an ink jet printer. When applying a solution of this mixture onto a firable article by ink jet printing, the mixture is such that upon drying, the mixture reacts to form an oxide of the metal to provide a decorative color pigment on the article.

Abstract: Embodiments of an apparatus and method for ferrite formation and the removal of heavy metal ions by ferrite co-precipitation from an aqueous solution at ambient temperature have been developed. Magnetically susceptible ferrite crystals can be continuously formed from aqueous solution and the heavy metal ion solution can be continuously treated by the ferrite co-precipitation process. The heavy metal ions are incorporated into the lattice points of the spinel ferrite structures. The precipitates of ferrite materials can then be magnetically separated. The main apparatus includes a ferrous sulfate mixing tank with a feeder assembly; a reaction tank or, alternatively, neutralization and oxidation tanks; settling and polishing tanks; and a magnetic separator. The reaction tank or oxidation tank includes an air distributor; a pH controller; and promoter feeding and ferrite product recirculating systems.

Abstract: In one aspect of the invention, a composition is presented comprising restructured iron oxide particles. A method is also presented for restructuring iron oxide particles to form low surface area iron oxide particles. In this method, iron oxide particles are contacted with an effective mount of a restructuring agent and are then heated until restructuring occurs.

Abstract: Spindle-shaped goethite particles are produced by oxidizing a ferrous carbonate intermediate in the presence of a growth modifier, or alternatively by changing the flowrate of oxidizing gas during oxidation. The goethite particles thus produced have a narrow size distribution, high aspect ratio and are substantially dendrite-free. These properties make the inventive goethite particles suitable for use in preparation of high density magnetic recording media.

Abstract: This invention provides a method of producing goethite particles comprising the steps ofa) reacting, in aqueous solution, less than a stoichiometric amount of an alkali compound with an iron (II) salt to form a precipitated complex intermediate,b) oxidizing iron (II) in the complex intermediate to iron (III) at an average rate less than 10 g iron(III)/l/hr to form goethite seed particles until 20 to 70% of iron (II) in the precipitated complex intermediate has been converted to iron (III), andc) after 20 to 70% of iron (II) in the precipitated complex intermediate has been convened to iron (III), increasing the average oxidation rate to greater than 10 g iron(III)/l/hr.

Abstract: Disclosed herein is a process for producing fine metal oxide particles comprising the step of heat-treating an aqueous solution of a metal salt at a temperature of not lower than 200.degree. C. under a pressure of not less than 160 kg/cm.sup.2 for 1 second to 1 hour so as to bring into the decomposition reaction of said metal salt.

Abstract: The invention is directed to provide novel sunscreen materials which are to protect human skin from the harmful ultraviolet radiation. Said sunscreen materials, designated Bolite-S, according to the invention having a composition, expressed in terms of moles of oxides as follows:mRO:vB.sub.2 O.sub.3 :wFe.sub.2 O.sub.3 :xSiO.sub.2 :yTiO.sub.2 :zH.sub.2 Owherein "R" is selected from the group consisting of hydrogen, alkyl groups containing 1-4 carbon atoms, and mixtures thereof, "m" is a value between 0 and about 1200, "v" is a value between 0 and about 500, "w" is a value between 0 and about 100, "x" is a value between 0 and about 200, "y" is a value between 1 and about 300 and "z" is a value of from 0 to about 300, said Bolite-S materials in calcined form having a characteristic X-ray powder diffraction pattern which contains the interplanar spacings and their assigned strengths set forth in Table 1.

Abstract: Disclosed herein are spindle-shaped magnetic iron based alloy particles containing at least one selected from the group consisting of Ni, Al, Si, P, Co, Mg, B and Zn, which have a particle length of 0.05 to 0.40 .mu.m, a crystallite size of 110 to 180 .ANG., a specific surface area of 30 to 60 m.sup.2 /g, a coercive force of 1,300 to 1,700 Oe and a saturation magnetization (.sigma.s) of not less than 100 emu/g and a process for producing the same.

Abstract: A process for reducing the residual chloride present in iron oxides, particularly in regenerated iron oxides produced from hydrochloric acid waste liquid generated from steel pickling, by post-synthesis treatment of the iron oxides with yellow iron oxide, and subsequently heating the mixture at a temperature sufficient to release at least a part of the crystalline water contained in the yellow iron oxide to facilitate the removal of residual chloride present in iron oxides. The purified regenerated iron oxides are particular suitable for making high-grade ferrites.

Abstract: Ferrous chloride is used as a starting material and roasted in a steam-containing atmosphere for pyrolysis to prepare a magnetite magnetic powder having a saturation magnetization .sigma.s of 82-92 emu/g and a magnetite phase content of at least 90 wt. %. Prior to roasting, the ferrous chloride may be pre-treated by heat treating it at a low temperature in a non-oxidizing atmosphere, cooling it down to a predetermined temperature, and then exposing it to an oxygen-containing atmosphere. A mixture of ferrous chloride and ferric chloride may also be used as the starting material. These methods can produce magnetite magnetic powder having improved magnetic properties through fewer steps in a simple and easy manner.

Abstract: Acicular .gamma.-FeOOH particles useful as precursors for magnetic particles suitable for magnetic recording are produced advantageously in industry. In a reaction of the growth of .gamma.-FeOOH nuclei by oxidizing a suspension containing .gamma.-FeOOH nuclei in a ferrous salt solution while neutralizing with alkali, a phosphorus compound is added to the reaction mixture at the time before the end of said reaction and when the ratio of Fe.sup.++ /total Fe in the reaction mixture is 0.15 or less.

Abstract: Disclosed herein are granulated particles for magnetic particles for magnetic recording, comprising: acicular ferric hydroxide oxide particles or acicular iron oxide particles; and at least one selected from the group consisting of semisynthetic starch and semisynthetic cellulose and having a bulk density of not less than 0.3 g/cm.sup.3 and a powdering ratio of not more than 40%, and a process for producing the granulated particles, and magnetic particles obtained from such granulated particles.

Abstract: There are provided acicular berthollide particles comprising crystalline particles expressed by the formula FeOx (1.33.ltoreq.x<1.5) and modified with a specific amount of zinc ions and a process producing the same which comprises the steps of oxidizing acicular magnetic iron oxide particles expressed by the formula FeOx (1.0<x<1.33) and modified with a specific amount of zinc ions which are produced by (a) heating and dehydrating acicular hydrous iron oxide particles containing a specific amount of a zinc component, reducing, and heating the particles under specific conditions, or (b) reducing acicular iron oxide particles containing a specific amount of a zinc component and heating the particles under specific conditions, or (c) heating acicular magnetic iron oxide particles expressed by the formula FeOx (1.0<x<1.33) containing a specific amount of zinc ions under specific conditions.

Abstract: Hematite powder is mixed with a substance having a carbon-to-carbon single or double bond, and sintered in an inert gas to form magnetite powder. The magnetite powder can be provided with a desired electric resistance while retaining the properties characteristic of the magnetite powder by effecting a heating in an oxygenic atmosphere after the formation of the magnetite powder (or during a cooling subsequent to the sintering in the inert gas).

Abstract: A method for preparing a perpendicularly magnetizable material usable on magnetic recording media comprises the steps of: dissolving at least one member of the group consisting of strontium chloride and strontium nitrate with at least one member of the group consisting of iron chloride and iron nitrate in distilled water; adding citric acid to the resultant solution; controlling the pH of the solution to a range sufficient to completely dissociate the citric acid; heating the resultant solution with stirring to yield a gelatinous precursor; and subjecting the precursor to a temperature sufficiently high to remove the organic constituents thereof, which is characterized by controlling the pH of the solution to gelate the solution without the use of ethylene glycol, and can provide a perpendicularly magnetizable material superior in magnetic and particle properties.

Abstract: Disclosed herein are a process for producing acicular goethite particles comprising the step off: blowing an oxygen-containing gas into a ferrous salt reaction solution containing colloidal ferrous hydroxide or iron-containing colloidal precipitates which is obtained by reacting an aqueous ferrous salt solution with less than one equivalent of an aqueous alkali hydroxide solution, an aqueous alkali carbonate solution, or an aqueous alkali hydroxide and alkali carbonate solution based on Fe.sup.

Abstract: The present invention relates to a process for the preparation of finely divided metal and/or ceramic powders by reacting appropriate metal compounds and appropriate reagents in the gas phase (CVR) chemical vapor reaction, wherein the metal compound(s) and the further reagents are brought to reaction in the gaseous state in a reactor and are subsequently homogeneously condensed directly out of the gas phase, with exclusion of any wall reaction, and are subsequently separated from the reaction medium.

Abstract: A process for preparing transparent yellow iron oxide pigments by the precipitation of iron (II) hydroxide by adding an inorganic base to an iron (II) salt solution and subsequent oxidation to FeOOH.

Abstract: An apparatus provides high temperature and short residence time conditions for the production of nanoscale ceramic powders. The apparatus includes a confinement structure having a multiple inclined surfaces for confining flame located between the surfaces so as to define a flame zone. A burner system employs one or more burners to provide flame to the flame zone. Each burner is located in the flame zone in close proximity to at least one of the inclined surfaces. A delivery system disposed adjacent the flame zone delivers an aerosol, comprising an organic or carbonaceous carrier material and a ceramic precursor, to the flame zone to expose the aerosol to a temperature sufficient to induce combustion of the carrier material and vaporization and nucleation, or diffusion and oxidation, of the ceramic precursor to form pure, crystalline, narrow size distribution, nanophase ceramic particles.

Abstract: A heat treatment method heats an oxide optical crystal in an oxygen atmosphere containing ozone to improve the light absorption characteristics of the oxide optical crystal so that the light absorption of the oxide optical crystal with light in wavelength bands other than light in wavelength bands with which the oxide optical crystal exerts the intrinsic absorption is reduced to the least possible extent. Guided-optical-wave propagation devices and optical devices, such as optical isolators, optical recording media and second harmonic generators, employing the oxide optical crystal having these improved absorption characteristics, operate at a high efficiency.

Abstract: A composite metal hydroxide is provided for use as a flame-retardant in a resin or rubber composition. The composite metal hydroxide is a solid solution having the formula (1) Ca.sub.1-x M.sup.2+ x(OH).sub.2. M is at least one member selected from the group consisting of Mg, Mn, Fe, Co, Ni, Cu and Zn and x is in the range of 0.001.ltoreq.x<0.995. Two preferred composite metal hydroxides have the formula (2) Ca.sub.1-x Mg.sup.2+ x(OH).sub.2 wherein x is in the range of 0.001.ltoreq.x<0.995 and the formula (3) Ca.sub.1-x (Mg, Ni, Mn).sub.x (OH).sub.2 wherein x is in the range of 0.001.ltoreq.x<0.

Abstract: A process for the preparation of nanophase solid state materials having crystallite morphology and particle sizes in the range of from about 1 nm to 30 nm is disclosed. Novel nanophase solid state materials are also disclosed.

Abstract: Disclosed herein are a process for producing poreless plate-like magnetite particles which have as large a plate ratio (average particle diameter/thickness) as possible and which are discrete each other, the process comprising the step of: obtained by oxidizing a suspension containing FeCO.sub.3 obtained by reacting an aqueous ferrous salt solution and an aqueous alkali carbonate solution by passing an oxygen-containing gas therethrough, wherein the suspension is obtained by reacting a ferrous salt solution containing 0.2 to 5.0 mol % of a ferric salt, calculated as Fe(III), based on Fe(II) and an aqueous alkali carbonate the amount of which is so controlled that the equivalent ratio of an alkali carbonate to the Fe(II) and Fe(III) in the aqueous ferrous salt solution is not less than 1 and the following general formula is satisfied: ##EQU1## and if necessary, 0.01 to 8.

Abstract: A process for reducing the residual chloride present in iron oxides, particularly in regenerated iron oxides produced from hydrochloric acid waste liquid generated from steel pickling, by post-synthesis treatment of the iron oxides with sulfuric acid optionally followed by drying and calcining. The purified regenerated iron oxides are particular suitable for making iron oxide based catalysts such as ethylbenzene dehydrogenation catalysts and high-grade ferrites.

Abstract: Disclosed herein are a process for producing acicular goethite particles comprising the steps of: blowing an oxygen-containing gas into a ferrous salt reaction solution containing colloidal ferrous hydroxide or iron-containing colloidal precipitates which is obtained by reacting an aqueous ferrous salt solution with less than one equivalent of an aqueous alkali hydroxide solution and/or an aqueous alkali carbonate solution based on Fe.sup.2 + in said aqueous ferrous salt solution so as to oxidize said colloidal ferrous hydroxide or iron-containing colloidal precipitates and to produce acicular goethite nucleus particles, adding to the resultant aqueous ferrous salt reaction solution containing said acicular goethite nucleus particles not less than one equivalent of an aqueous alkali carbonate solution based on Fe.sup.

Abstract: The use of superparamagnetic particles and of paramagnetic materials (such as lanthanide chelates) as contrast agents in magnetometric analysis, especially imaging, and in particular structural and functional, diagnosis or imaging is described.

Abstract: Disclosed herein are a process for producing acicular goethite particles comprising the step of: blowing an oxygen-containing gas into a ferrous salt reaction solution containing colloidal ferrous hydroxide or iron-containing colloidal precipitates which is obtained by reacting an aqueous ferrous salt solution with less than one equivalent of an aqueous alkali hydroxide solution, an aqueous alkali carbonate solution, or an aqueous alkali hydroxide and alkali carbonate solution based on Fe.sup.

Abstract: A method for producing high-purity iron oxide which comprises pulverizing iron ore into powder having an average particle diameter of 20-150 .mu.m, removing fine particles from the powder, and subjecting the powder to wet magnetic separation in a magnetic field of 1000-15000 gauss for the removal of impurities. The iron oxide powder may undergo the secondary steps of pulverization and classification, which are performed by the combination of a wet grinding means and a wet cyclone, and drying and calcination.

Abstract: Disclosed herein are magnetic iron oxide particles which have a spindle shape and a substantially uniform particle size and shape, and are substantially free of dendrites and have a large axial ratio (major axial diameter/minor axial diameter) and an excellent print-through characteristic, and a method of producing the same.

Abstract: Fine particle coal is beneficiated in specially designed dense medium cyclones to improve particle acceleration and enhance separation efficiency. Raw coal feed is first sized to remove fine coal particles. The coarse fraction is then separated into clean coal, middlings, and refuse. Middlings are comminuted for beneficiation with the fine fraction. The fine fraction is deslimed in a countercurrent cyclone circuit and then separated as multiple fractions of different size specifications in dense medium cyclones. The dense medium contains ultra-fine magnetite particles of a narrow size distribution which aid separation and improves magnetite recovery. Magnetite is recovered from each separated fraction independently, with non-magnetic effluent water from one fraction diluting feed to a smaller-size fraction, and improving both overall coal and magnetite recovery.

Abstract: Ferritin analogs comprising an apoferritin protein shell and a core substantially devoid of ferrihydrite, e.g. of inorganic composition such as aluminum hydroxide or organic composition such as acetaminophen. The protein shell can be removed from ferritin analog to produce spherules having a substantially monomodal nominal diameter between about 45 and 100 Angstroms.

Abstract: Fine particle coal is beneficiated in specially designed dense medium cyclones to improve particle acceleration and enhance separation efficiency. Raw coal feed is first sized to remove fine coal particles. The coarse fraction is then separated into clean coal, middlings, and refuse. Middlings are comminuted for beneficiation with the fine fraction. The fine fraction is deslimed in a countercurrent cyclone circuit and then separated as multiple fractions of different size specifications in dense medium cyclones. The dense medium contains ultra-fine magnetite particles of a narrow size distribution which aid separation and improves magnetite recovery. Magnetite is recovered from each separated fraction independently, with non-magnetic effluent water from one fraction diluting feed to a smaller-size fraction, and improving both overall coal and magnetite recovery.

Abstract: Isometric iron oxide pigments are prepared by an improved process by precipitation of aqueous solutions containing iron (II) salts with alkaline precipitating agents followed by oxidation of the precipitate at temperatures of from 20.degree. C. to 100.degree. C., wherein the improvement comprises adjusting the iron (III) content to 1 to 25 mol %, based on the total iron, before precipitation.

Abstract: A crystalline zeolite SSZ-28 is prepared using an N,N-dimethyl-tropinium or N,N-dimethyl-3-azonium bicyclo[3.2.2]nonane cation as a template. Also disclosed is a process for converting hydrocarbons with crystalline zeolite SSZ-28.

Abstract: A method for producing a lead niobate-based complex oxide with an elevated proportion of pervoskite phase and lead niobate-based complex oxide produced by such method enables manufacture of small actuator or capacitor with an elevated dielectric constant k. Treatment of a raw material represented by a general formula Pb(A.sub.1/3 Nb.sub.#)x(ZN.sub.1/3 Nb.sub.2/3) yO.sub.3 or Pb(Fe.sub.1/2 Nb.sub.1/2)x(Zn.sub.1/3 Nb.sub.2/3) yO.sub.3 (wherein A is Mg or Ni; x is an atomic ratio in a range of 0-1; and y is an atomic ratio in a range of 1-0, with a relation x+y=1) and containing pyrochlore phase, under a high temperature of 500.degree.-1300.degree. C. and a high pressure of 1000-4000 kg/cm.sup.2, causes transition of pyrochlore phase into perovskite phase, thereby increasing the proportion of perovskite phase. Also treatment of a raw material represented by a general formula uPb(.sub.1/3 Nb.sub.2/3)O.sub.3 -vPbTiO.sub.3 (wherein u is an atomic ratio in a range of 0.5-1; and v is an atomic ratio in a range of 0.

Abstract: Low-silking iron oxide yellow pigments having improved color qualities are produced by a novel method which utilizes both precipitation process and the Penniman process. Pigments are nucleated and grown by precipitation to achieve multiplication factor of 2.5 to 7 and additional pigment growth is carried out by the Penniman process.

Abstract: A method for producing goethite having an axial ratio of at least 7 and a specific surface area of 20-80 m.sup.2 /g and suitable for use in the production of .alpha.-iron powder, which method comprises intermittently feeding an oxidizing gas into a suspension of ferrous hydroxide, which has been obtained by reacting a ferrous salt with an alkali hydroxide, preferably while controlling the oxidation rate of ferrous hydroxide below 7% per each feeding-feed-stopping cycle of the oxidizing gas and also controlling the feeding time period of the oxidizing gas within 10 minutes and shorter than a quarter of the feed-stopping time period per each feeding-feed-stopping cycle of the oxidizing gas.

Abstract: This invention is directed to the formation of homogeneous, aqueous precursor mixtures of at least one substantially soluble metal salt and a substantially soluble, combustible co-reactant compound, typically an amino acid. This produces, upon evaporation, a substantially homogeneous intermediate material having a total solids level which would support combustion. The homogeneous intermediate material essentially comprises highly dispersed or solvated metal constituents and the co-reactant compound. The intermediate material is quite flammable. A metal oxide powder results on ignition of the intermediate product which combusts same to produce the product powder.

Abstract: An activated magnetite catalyst is formed of activated iron oxide or iron particles with solid crystal lattice, from which oxygen is partly removed. When the activated mgnetite catalyst is prepared, oxygen is partly removed from solid crystal lattice of particles of Fe.sub.3 O.sub.4, Fe.sub.3 O.sub.4+x obtained by partly or entirely oxidizing Fe.sub.3 O.sub.4 or gamma-Fe.sub.2 O.sub.3. The catalyst is useful to decompose gaseous oxides.

Abstract: Disclosed herein are poreless, non-sintered plate-like magnetite particles having an average particle diameter of more than 0.5 .mu.m and not more than 2.0 .mu.m, and a BET specific surface area of not more than 6.0 m.sup.2 /g, and poreless, non-sintered plate-like maghemite particles having an average particle diameter of more than 0.5 .mu.m and not more than 2.0 .mu.m, and a BET specific surface area of not more than 6.0 m.sup.2 /g.

Abstract: Ceramic precursor mixtures containing a metal cation, a carbohydrate, and an anion capable of participating in an anionic oxidation-reduction reaction with the carbohydrate for continuous or batchwise drying and pyrolyzing to provide ceramic powders.

Abstract: The preparation and isolation of biodegradable superparamagnetic MR imaging contrast agents for the vascular compartment is described. These aggregates are comprised of individual biodegradable superparamagnetic metal oxide crystals which aggregates have an overall mean diameter less than about 4000 angstroms. The preferred vascular imaging contrast agent is comprised of aggregates of iron oxide crystals having an overall mean diameter less than about 500 angstroms. These contrast agents may be associated with a macromolecular species, which assist, among other things, in the preparation of these extremely small materials, and may be dispersed or dissolved in a physiologically acceptable medium. Preferred media also stabilize the materials against further aggregation even under harsh sterilization conditions.

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.

Abstract: A method for producing uniform mixed metal oxides, such as superconducting mixtures including Y.sub.1 Ba.sub.2 Cu.sub.3 O.sub.7-x, in which such metals are precipitated as their oxalates from alcoholic solutions of the metals as the salts of a carboxylic acid.

Abstract: Highly-coercive isometric iron oxide useful in magnetic toners for electrostatic photo-copying processes or for magnetic printers is produced by(a) subjecting Fe.sub.3 O.sub.4 pigment produced in a wet process to oxidation and(b) subsequently reducing the oxidized pigment from (a) to produce highly-coercive Fe.sub.3 O.sub.4 pigment.

Abstract: A process of producing a spinel structure Ni/Zn ferrite-modified, Co/Ti-substituted microcrystalline barium ferrite platelets having an average particle size of 0.03-0.15 .mu.m, a temperature coefficient of coercive force of not more than +1 Oe/.degree. C., including small absolute values in negative region, and a saturated magnetization of not less than 56 emu/g, which comprises: forming substantially amorphous preecursors of Co/Ti-substituted barium ferrites; adding an aqueous solution of nickel salts to the dispersion of the precursors of Co/Ti-substituted barium ferrites, and subjecting the slurry to hydrothermal reaction, thereby to provide precursors of spinel structure nickel ferrite-modified, Co/Ti-substituted barium ferrites; depositing a water insoluble zinc compound on the precursors; and calcining the precursors in the presence of barium chloride, washing the calcined products to remove therefrom the barium chloride, and drying.

Abstract: In a method of preparing high-purity manganese compounds, wherein the method comprises adding a member selected from ferromanganese and metallic manganeses to an aqueous electrolyte-containing solution, dissolving said member while stirring and maintaining a pH of 2 to 9, and then removing insolubles by filtration and recovering solubles by precipitation, heavy metal elements as well as non-metllic elements, such as P, Si, etc. can be removed efficiently, and high-purity manganese compounds of stable quality can be prepared.

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.