Showing papers on "Iron oxide published in 1972"
Patent•
26 Jul 1972
TL;DR: In this paper, a process for producing MAGNETIC FLUIDS from AQUEOUS INDUSTRIAL WASTE STREAMs CONTAINING FERROUS IRON SALTS is described.
Abstract: 1. A PROCESS FOR PRODUCING MAGNETIC FLUIDS FROM AQUEOUS INDUSTRIAL WASTE STREAMS CONTAINING FERROUS IRON SALTS WHICH COMSPRISES: OXIDIZING A PORTION OF THE FERROUS IRON CONTAINED IN THE WASTE STREAM TO THE FERRIC STATE; REACTING THE WASTE STREAM, NOW CONTAINING FERROUS AND FERRIC IRON SALTS, WITH AN EXCESS OF AMMONIUM HYDROXIDE TO PRECIPITATE A SLURRY OF COLLOIDAL SIZE FERROSO-FERRIC IRON OXIDE PARTICLES; ADDING A LONG CHAIN FATTY ACID HAVING ABOUT 18 CARBON ATOMS TO THE IRON OXIDE PARTICLE SLURRY WHEREBY THE FATTY ACID REACTS WITH AMMONIUM HYDROXIDE TO FORM AN AMMONIUM SALT OF THE FATTY ACID AND TO THEREAFTER COAT IRON OXIDE PARTICLES CONTAINED IN TH SLURRY WITH AN ADSORBED LAYER OF AMMONIATED FATTY ACID TO HEATING THE SLURRY TO A TEMPERATURE ABOVE THE DECOMPOSITION TEMPERATURE OF THE AMMONIATED FATTY ACID TO CONVERT THE ADSORBED LAYER OF AMMONIATED FATTY ACID TO THE ACID FORM AND TO EXPEL AMMONIA FROM THE SLURRY, AND RECOVERING FROM THE SLURRY A PRODUCT FRACTION COMPRISING FERRIMAGNETIC IRON OXIDE PARTICLES OF COLLOIDAL SIZE COATED WITH AN ADBSORBED LAYER OF FATTY ACID.
71 citations
TL;DR: In this paper, the authors measured the isotherms and rates for NO and CO chemisorption on supported and unsupported nickel oxide samples in the 0-140 °C temperature range.
50 citations
TL;DR: In this article, the mechanism of wear of spheroidal graphite cast iron in dry sliding was studied and it was shown that when the sliding velocity was greater than 3.00 m/sec, a 0.02 mm thick martensite layer was formed on the sliding surface, a phenomenon specific to the spheroroidal cast iron.
32 citations
31 citations
Patent•
07 Dec 1972TL;DR: In this article, the production of acicular ferromagnetic iron oxides from acicular iron oxide hydroxide prepared by precipitating at least one of iron hydroxides and carbonate from an aqueous iron (II) salt solution by the addition of a stochastic solution containing a stoichiometric excess of at least 1/2 of an alkali hyroxide and carbonates, oxidizing the precipitated product into an acicular oxides, and separating the product of oxidation from the reaction medium.
Abstract: In the production of acicular ferromagnetic iron oxides from acicular iron oxide hydroxide prepared by precipitating at least one of iron (II) hydroxide and carbonate from an aqueous iron (II) salt solution by the addition of an aqueous solution containing a stoichiometric excess of at least one of an alkali hydroxide and carbonate, oxidizing the precipitated product into iron oxide hydroxide, and separating the product of oxidation from the reaction medium, the improvement which comprises carrying out the oxidation of the precipitated iron hydroxide or carbonate at least partly at a temperature of about 45 DEG C to 75 DEG C, by passing a finely dispersed oxygen-containing gas through the solution at a volume (liter) ratio of from about 5:1 to 80:1 while stirring at an intensity such that the acicular iron oxide hydroxide accumulates in a volume-time yield of from about 6 to 25 g per liter per hour.
29 citations
TL;DR: In this paper, the reduction equilibria of the iron oxides with hydrogen carried out in a sealed apparatus provided with a palladium membrane were described, which enabled the total pressure (H2 + H2O) to be measured at the same time.
26 citations
TL;DR: In this article, it was concluded that the growth of all iron oxide layers must occur by outward diffusion of iron, and marker experiments were made during the oxidation of Fe 3 0 4 to Fe 2 O 3.
23 citations
TL;DR: In this article, the authors studied the exo-electron emission from a silver catalyst during partial oxidation of ethylene and showed that it is equivalent to a thermo-electric emission from thin semiconducting oxide layer on the surface of the metal.
21 citations
TL;DR: Four steelworkers employed as deseamers of steel ingots for periods of up to 16 years showed radiological evidence of pneumoconiosis classified as ILO categories 2 or 3, and it is probable that inhalation of pure iron oxide does not cause fibrotic pulmonary changes, whereas the inhalations of iron oxide plus certain other substances obviously does.
Abstract: Graham Jones, J., and Warner, C. G. (1972). Brit. J. industr. Med., 29, 169-177. Chronic exposure to iron oxide, chromium oxide, and nickel oxide fumes of metal dressers in a steelworks. Occupational and medical histories, smoking habits, respiratory symptoms, chest radiographs, and ventilatory capacities were studied in 14 steelworkers employed as deseamers of steel ingots for periods of up to 16 years. The men were exposed for approximately five hours of each working shift to fume concentrations ranging from 1·3 to 294·1 mg/m 3 made up mainly of iron oxide with varying proportions of chromium oxide and nickel oxide. Four of the men, with 14 to 16 years9 exposure, showed radiological evidence of pneumoconiosis classified as ILO categories 2 or 3. Of these, two had pulmonary function within the normal range and two had measurable loss of function, moderate in one case and mild in the other. Many observers would diagnose these cases as siderosis but the authors consider that this term should be reserved for cases exposed to pure iron compounds. The correct diagnosis is mixed-dust pneumoconiosis and the loss of pulmonary function is caused by the effects of the mixture of metallic oxides. It is probable that inhalation of pure iron oxide does not cause fibrotic pulmonary changes, whereas the inhalation of iron oxide plus certain other substances obviously does.
21 citations
Patent•
26 Jul 1972
TL;DR: In this article, the authors discuss the use of catalytic metal oxide(s) for use in conversion of gases containing carbon monoxide and/or hydrocarbons such as waste gases arising from automobiles and the like.
Abstract: Catalysts for use in conversion of gases containing carbon monoxide and/or hydrocarbons such as waste gases arising from automobiles and the like, which are characterized by containing particles of catalytic metal oxide(s) such as copper oxide(s), iron oxide(s), chromium oxide(s), nickel oxide(s), cobalt oxide(s), zinc oxide, lead oxide(s), bismuth oxide(s), etc. effective for oxidizing carbon monoxide, hydrocarbons, and the like and plated with such metal(s) as copper, iron, nickel, cobalt, chromium, tin, silver, etc. by such means as electroless plating, electroplating, etc.; and relevant methods of manufacturing these catalysts. relevant methods of manufacturing these catalysts.
19 citations
Patent•
26 Dec 1972TL;DR: Amorphous iron oxide is also used to provide a mask for subsequent diffusion processing, or the like as mentioned in this paper, which can be crystallized in 10 milliseconds or less using amorphous ferric oxide.
Abstract: Amorphous iron oxide is deposited on the surface of a substrate at a temperature within 7% of its crystallization temperature to provide a layer thereof which can be crystallized in 10 milliseconds or less. In a particular embodiment, the amorphous ferric oxide is deposited on a semiconductor surface to provide a mask therefor for subsequent diffusion processing, or the like.
Patent•
14 Mar 1972
TL;DR: In this article, the present invention relates to ammonia-synthesis catalysts, which contain iron oxide having a degree of oxidation corresponding to Fe3O4 and cobalt introduced in the form of salts, carbonates or oxides; the content by weight expressed as cobalt is 5 to 10 percent.
Abstract: The present invention relates to ammonia-synthesis catalysts The novel catalysts, in the oxidized state, contain iron oxide having a degree of oxidation corresponding to Fe3O4, and cobalt introduced in the form of salts, carbonates or oxides; the content by weight expressed as cobalt is 5 to 10 percent
Patent•
09 Feb 1972TL;DR: In this paper, a process for the execution of an OXIDATION of an IRON CHLORIDE is described, in which VAPORS of the chloride and an OXYGEN-constraining gas are caused to pass forward through a VERTICAL reaction zone.
Abstract: A PROCESS IS PROVIDED FOR THE OXIDATION OF AN IRON CHLORIDE WHEREIN VAPORS OF THE CHLORIDE AND AN OXYGENCONTAINING GAS ARE CAUSED TO PASS UPWARDLY THROUGH A VERTICAL REACTION AREA PROVIDED WITH A SERIES OF COMMUNICATING REACTION ZONE, EACH SEPARATED FROM THE NEXT ADJACENT ONE BY A FORAMINOUS MEMBER. THERE IS MAINTAINED UPWARD WITH THE FLOW GASES A FLOW OF INERT SOLID PARTICLES THROUGH AND OUT OF THE REACTION AREA IN AN AMOUNT AT LEAST EQUAL TO THE GAS FLOW RATE ON A WEIGHT BASIS. HIGH CONVERSIONS OF THE IRON CHLORIDE CAN BE ATTAINED IN THIS MANNER WITHOUT THE UNWANTED BUILD-UP OF IRON OXIDE SCALE ON THE REACTOR WALLS OR ASSOCIATED PARTS.
Patent•
13 Nov 1972
TL;DR: In this article, an iron oxide pigment consisting essentially of synthetic micaceous iron oxide rich in relfected light and a coating of a transparent metal oxide (including a hydrated oxide) having a high refractive index, such as titanium dioxide and zirconium dioxide.
Abstract: This invention relates to an iron oxide pigment consisting essentially of synthetic micaceous iron oxide rich in relfected light and a coating of a transparent metal oxide (including a hydrated oxide) having a high refractive index, such as titanium dioxide and zirconium dioxide. Various properties of the surfaces of synthetic micaceous iron oxide can be improved by the coating of the above metal oxide and various clear colors of a beautiful metallic luster can be manifested. Accordingly, the iron oxide of this invention can be used for preparation of various paints, plastics and articial stones. This invention also relates to a process for the preparation of such iron oxide pigment.
TL;DR: In this article, the dependence of Δ E Q on the chemical environment as the surface renders the shell model and lattice expansion model inadquate for the determination of microstalline size.
Patent•
19 Jul 1972
TL;DR: In this article, the authors describe a method to produce high-density recording devices by coating needle-like nuclear crystals of e.g. gamma-Fe2O3 or Fe3O4 with oxides of Fe and Co.
Abstract: Particles having uniform size and high coercive force, esp. suitable for high-density recording devices, are produced by coating needle-like nuclear crystals of e.g. gamma-Fe2O3 or Fe3O4 with oxides of Fe and Co deposited from an eg alkaline medium through which air is passed. Addition of zinc oxide increases the magnetic saturation flux.
Patent•
27 Nov 1972
TL;DR: In this paper, a process for obtaining the METALS from OCEAN FLOOR NODULE ORE and FEROM IRON SULFIDE MINERAL is described.
Abstract: THIS INVENTION PROVIDES A PROCESS FOR SIMULTANEOUSLY OBTAINING THE METAL VALUES FROM OCEAN FLOOR NODULE ORE AND FEROM IRON SULFIDE MINERAL. THE NODULE ORE COMPRISES PRIMARILY OXIDES OF IRON AND MANGANESE PLUS NICKEL, COPPER AND COBALT COMPOUNDS. THE ORE IS REACTED WITH THE IRON SULFIDE ORE, WHICH MAY ALSO CONTAIN DESIRED NONFERROUS METAL VALUES AT ELEVATED TEMPERATURES IN THE PRESENCE OF OXYGEN TO FORM IRON OXIDE AND THE WATERSOLUBLE SULFATES OF THE NON-FERROUS METALS. THE MIXED REACTED ORES ARE THEN LEACHED WITH WATER TO OBTAIN A SOLUTION AND THE RESULTANT PREGNANT LEACH SOLUTION IS TREATED, AS BY LIQUID ION EXHAANGE PROCESSES, TO OBTAIN SEPARATE STREAMS OF THE INDIVIDUAL METAL VALUES OF NICKEL, COBALT, COPPER AND MANGANESE. THE METALS CAN BE OBTAINED BY COTHODIC REDUCTION OF THE COMPOUNDS.
Patent•
17 Mar 1972
TL;DR: In this article, needle-like crystals of iron oxide or its hydrate (e.g. alpha-FeOOH) are suspended in a dil. soln of a Ni and/or Co salt, the Ni and or Co is deposited on the crystals by pptn.
Abstract: Fine, needle-like crystals of iron oxide or its hydrate (e.g. alpha-FeOOH) are suspended in a dil. soln of a Ni and/or Co salt, the Ni and/or Co is deposited on the crystals by pptn. with an alkali or evapn. of the soln in an amt. >0.05 at.%; teh crystals coated with the Ni and/or Co cpd are sepd washed dried and reduced (with e.g. H2) at 350 degrees C. Subsequently the powder is passivated with a N2-O2 mixt. at room temp. By this method the redn time is shortened so that unwanted sintering of the powder is prevented.
Patent•
05 May 1972TL;DR: A magnetite film is produced by depositing a thin film of pure iron on a substrate, oxidizing the film, depositing another film of iron on the iron oxide film, and annealing the composite film at a temperature below about 560*C and preferably from 350*C to 400*C as mentioned in this paper.
Abstract: A magnetite film is produced by depositing a thin film of pure iron on a substrate, oxidizing the film, depositing a second film of iron on the iron oxide film, and annealing the composite film at a temperature below about 560*C and preferably from 350*C to 400*C and then stripping excess iron from the film.
Patent•
10 Apr 1972
TL;DR: In this article, a method of preparing a pigment on an iron-oxide base from a sulphate solution containing in particular ferrous sulphate and derived from the leaching of zinc residues is described.
Abstract: In a method of preparing a pigment on an iron-oxide base from a sulphate solution containing in particular ferrous sulphate and derived from the leaching of zinc residues, said solution is neutralized and oxidized to simultaneously precipitate the hydrolyzable impurities together with a small quantity of iron, then the supernatant remaining liquid is separated from the precipitate and is neutralized and oxidized to precipitate most of the iron as an oxide, and the latter precipitate is treated in a basic medium to remove the small amount of sulphate ion present therein.
Patent•
24 Jan 1972
TL;DR: In this article, the authors describe a method to recover IRON SULFIDE BEARING MATERIAL with HYDROGEN CHLORIDE and the LEACH solution is described.
Abstract: IRON SULFIDE BEARING MATERIAL IS LEACHED WITH HYDROGEN CHLORIDE AND THE LEACH SOLUTION IS MAINTAINED SATURATED WITH HYDROGEN SULFIDE BY INTRODUCING AND PASSING HYDROGEN SULFIDE THERETHROUGH. THE PH CONDITIONS ARE CON- TROLLED TO RECOVER IRON VALUES ALONE IN THE LEACH LIQUOR OR WITH ZINC AND LEAD VALUES. ZINC AND LEAD VALUES MAY ALSO BE RECOVERED UNDER CONTROLLED CONDITIONS.
TL;DR: The low-field anhysteresis of small equidimensional multidomain particles of Fe 3 O 4 was found to be surprisingly large for particle sizes below about 0.075 μm as mentioned in this paper.
Abstract: The low-field anhysteresis of small equidimensional multidomain particles of Fe 3 O 4 is found to be surprisingly large. For particle sizes below about 0.075 μm the anhysteretic susceptibility equals or surpasses that of elongated or doped equidimensional single-domain γFe 2 O 3 particles used in conventional recording tapes.
Patent•
24 Jan 1972
TL;DR: A method for the beneficiation of an ore containing titanium and iron oxides to produce a beneficiate containing a reduced proportion of iron oxide, which comprises forming a mixture containing the ore and carbon, the carbon content of such mixture being in the range 20 to 40% by weight, and treating such mixture in a fluidized bed reactor with a treatment gas which comprises 20 to 50% by volume of chlorine and 0 to 10% of oxygen as discussed by the authors.
Abstract: A method for the beneficiation of an ore containing titanium and iron oxides to produce a beneficiate containing a reduced proportion of iron oxide, which comprises forming a mixture containing the ore and carbon, the carbon content of such mixture being in the range 20 to 40% by weight, and treating such mixture in a fluidized bed reactor at a temperature in the range 800*1000*C with a treatment gas which comprises 20 to 50% by volume of chlorine and 0 to 10% of oxygen.
Patent•
18 Dec 1972
TL;DR: In this paper, a process for converting low grade iron ores having a minimum specific gravity of about 3.45 to iron oxide containing material having a specific gravity 4.2 or greater is described.
Abstract: A process is disclosed whereby low grade iron ores having a minimum specific gravity of about 3.45 are converted to iron oxide containing material having a specific gravity of 4.2 or greater. The process includes calcining under oxidizing conditions of washed and crushed iron ore of low specific gravity followed by a quench and separation step whereby the high specific gravity iron oxide-containing material is recovered from lower specific gravity contaminants. The material thus prepared can be ground to a size suitable for use as a weighting agent in drilling muds meeting the API specifications for such materials.
Patent•
05 Jan 1972
TL;DR: In this paper, a reducing agent is used to selectively reduce iron oxide to metallic iron and the product is then treated with carbon monoxide in the presence of ammonium polysulfide solution to form iron carbonyl, which is then decomposed to produce metallic iron.
Abstract: Ilmenite is treated with a reducing agent to selectively reduce iron oxide to metallic iron. The product is then treated with carbon monoxide in the presence of ammonium polysulfide solution to form iron carbonyl, which is removed by volatilization leaving rutile. The iron carbonyl is then decomposed to produce metallic iron.
Patent•
30 Aug 1972
TL;DR: The DETONATION PRESSure of a BULK AMMONIUM NITRATE/FUEL OIL (ANFOO) COMPOSITION is increased SUBSTANTIALLY inDEPENDENTLY of its DETonation VELOCITY by the add addition of IRON OXIDE, CALCIUM CARBONATE, AND/OR CALCIum SULFATE as a DENSIFYING AGent to produce a mixture of COARSE and FINE AN, FUELOIL, and IRON ORXIDE as discussed by the authors.
Abstract: THE DETONATION PRESSURE OF A BULK AMMONIUM NITRATE/ FUEL OIL (ANFOO) COMPOSITION IS INCREASED SUBSTANTIALLY INDEPENDENTLY OF ITS DETONATION VELOCITY BY THE ADDITION OF IRON OXIDE, CALCIUM CARBONATE, AND/OR CALCIUM SULFATE AS A DENSIFYING AGENT TO PRODUCE A MIXTURE CONTAINING ABOUT 8-30% DENSIFYING AGENT. A DETONATING COMPOSITION CONTAINING A BLEND OF COARSE AND FINE AN, FUEL OIL, AND IRON OXIDE, CALCIUM CARBONATE, AND/OR CALCIUM SULFATE, AND A PROCESS FOR SHOCK-SYNTHESIZING DIAMOND BY USE OF THE DETONATING COMPOSITION.
Patent•
02 Feb 1972
TL;DR: In this paper, the authors proposed a catalysts consisting of 4-10% iron oxide, 5-15% nickel oxide and 4 -10% uranium oxide by weight to remove hydrocarbons from the exhaust gases of an internal combustion engine.
Abstract: 1,262,076. Oxide catalysts. GAS COUNCIL. 30 July, 1969 [8 May, 1968], No. 21791/68. Heading B1E. [Also in Division Fl] A catalyst comprising 4-10% iron oxide, 5-15% nickel oxide and 4-10% uranium oxide by weight is used to remove hydrocarbons from the exhaust gases of an internal combustion engine. The preferred composition is 7% iron oxide, 10% nickel oxide and 7% uranium oxide. The uranium oxide may be U 3 O 8 . The catalyst may be supported on a refractory material, e.g. α-alumina.
Patent•
14 Sep 1972
TL;DR: In this article, a continuous process for producing barium or strontium ferrites, starting from iron oxide and barium carbonates, was described, where a slurry consisting of IRON OXIDE, BARIUM OR STRONTIUM CARBONATE, WATER and BINDER, is dRIED and granulated, UTILIZING the hot gases FLOWING from step (B) SUPPLEMENTED with HOT BURNT GASES OBTAINED SEPARATELY; B.
Abstract: A continuous process is disclosed for producing barium or strontium ferrites, starting from iron oxide and barium or strontium carbonates, wherein A. A SLURRY CONSISTING OF IRON OXIDE, BARIUM OR STRONTIUM CARBONATE, WATER AND BINDER, IS DRIED AND GRANULATED, UTILIZING THE HOT GASES FLOWING FROM STEP (B) SUPPLEMENTED WITH HOT BURNT GASES OBTAINED SEPARATELY; B. THE GRANULES OBTAINED IN STEP (A) ARE CALCINED, FOR 0.5-4 HOURS AT 950*-1150*C, in a fluid bed reactor, heated by combustion, inside the fluid bed, of a carbonaceous, nonsulphurated fuel with air; and C. THE FERRITE OBTAINED IS COOLED AND WET GROUND. The atomic ratio between the iron and the barium or strontium ranges from 11.5:1 to 12:1. The iron oxide and the carbonate are preferably in the form of a submicronic powder.