Matches 201 - 250 out of 348 < 1 2 3 4 5 6 7 >


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4842832 Ultra-fine spherical particles of metal oxide and a method for the preparation thereof  
Ultra-fine spherical particles of a metal oxide having an average particle diameter of 40 nm or smaller can be prepared by a method in which a vaporizable metal compound is vaporized and...
4826664 Methods of desulfurizing gases  
A method for desulfurizing gases in which the sulfur is mainly in the form of hydrogen sulfide by reacting with one of the forms of cerium oxide with the formation of a cerium-oxygen-sulfur...
4815516 Method for recovering casting refractory compositions from investment casting shell molds  
Y2 O3 is recovered from investment casting shell molds by introducing used mold materials into a dissolution reactor preferably consisting of a rotating vessel having an interior lining of acid...
4814046 Process to separate transuranic elements from nuclear waste  
A process for removing transuranic elements from a waste chloride electrolytic salt containing transuranic elements in addition to rare earth and other fission product elements so the salt waste...
4808384 Recovery of tungsten, scandium, iron, and manganese from tungsten bearing material  
A process is disclosed for recovering tungsten, iron, and manganese from tungsten bearing material. The process involves digesting the material in a sufficient amount of sulfuric acid at a...
4769351 Hydrothermal process for preparing zirconia-alumina base ultra-fine powders of high purity  
A process for preparing a zirconia-alumina base composite ultra-fine powder is described, including the steps of: mixing an aluminum salt or an alumina hydrate with an aqueous zirconium...
4758412 Production of rare earth hydroxides from phosphate ores  
The rare earth hydroxides are improvedly prepared by (i) treating a rare earth phosphate mineral, e.g., monazite or xenotime, with an aqueous solution of an alkali metal hydroxide, (ii) separating...
4752454 Process for the preparation of ultrapure active metal fluorides  
This invention provides a method for the preparation of ultrapure active metal fluorides of increased purity from their metal oxides by reacting an active metal with a predetermined amount of...
4744960 Process for the separation of rare earths and uranium of a UF4 concentrate and for putting them into useful form  
The present invention relates to a proces for separating rare earths and uranium from a UF4 concentrate and for placing them into useful form, comprising attacking the UF4 concentrate with...
4699774 Gas-tight sintered translucent aluminum oxide and method  
The invention relates to gas-tight sintered translucent aluminum oxide having a density of at least 99.5%, which contains at most 1000 ppm by weight of MgO. According to the invention, the...
4698175 Neodymium hydroxy/ammonium nitrate  
A novel neodymium hydroxy/ammonium nitrate, readily calcined into, e.g., neodymium oxide, Nd2 O3, has the formula (I): Nd(OH)x (NO3)y.n NH4 NO3.z H2 O (I)wherein 2≤x≤ 2.3,0.7≤ y≤1.0,0.8≤ z≤1.25;...
4670228 Process for the recovery of valuable metals, particularly rare earths and similar metals, from a carbonate-containing raw material  
Process for the recovery of valuable metals, particularly rare earths and similar metals, which occur in a finely distributed condition in a raw material containing calcium carbonate.The raw...
4650652 Process for recovering highly pure rare earth oxides from a waste rare earth phosphor  
A process for recovering highly pure rare earth oxides from a waste rare earth phosphor containing at least Fe and/or Ca as impurities, which comprises dissolving the waste rare earth phosphor in...
4649031 Process for recovering rare metals from the combustion residue of coal by digestion  
The invention relates to a method for recovering rare metals from the combustion residues of various coals, in particular brown coals. The recovery is performed by digestion, more particularly by...
4647401 Process for preparing colloidal ceric oxide and complexes thereof with free organic acids  
A process is provided for preparing colloidal dispersions of ceric dioxide in inert organic media which comprises (1) heating (a) ceric dioxide comprising ammonium nitrate or ammonium and nitrate...
4642177 Process for reducing sulfur oxide emissions from catalytic cracking units  
A sulfur sorbent for use in reducing the emissions of sulfur oxides from regenerators of cyclic catalytic cracking units comprises a rare earth component or mixture of rare earth components in...
4636369 Essentially complete recovery of uranium, yttrium, thorium and rare earth values from phosphate rock during wet-process production of phosphoric acid therefrom  
The uranium, yttrium, thorium and rare earth values contained in a phosphate rock are essentially totally recovered therefrom by, during the wet-process preparation of phosphoric acid from said...
4599201 Process for preparing ceric carboxylates  
A process is provided for preparing ceric carboxylates which comprises oxidizing cerous carboxylate with aqueous hydrogen peroxide in a two-phase system comprising an aqueous phase of hydrogen...
4473488 Process for reclaiming rare-earth metallic oxide and/or rare-earth metallic oxysulfide phosphors  
To a suspension of rare-earth phosphors and sulfidic or selenidic phosphors there is added about 1 to 2% of the amount of hypohalogenite which would be necessary to convert the entire sulfidic or...
4462970 Process for preparation of water-free oxychloride material  
The specification discloses a process for forming a water-free rare earth oxychloride powder by exposing a water-containing rare earth oxide powder to a reactive atmosphere of chlorine and oxygen...
4438078 Recovery of gadolinium and gallium oxides  
A process is described whereby gadolinium and gallium containing by-products can be reprocessed to yield the oxides of these elements in sufficient purity to be re-used in the process for...
4390507 Process for recovering yttrium and lanthanides from wet-process phosphoric acid  
Process for recovering yttrium and lanthanides from wet-process phosphoric acid by adding a flocculant to the phosphoric acid, separating out the resultant precipitate and then recovering yttrium...
4387077 Process for the recovery of substantially radium free calcium sulphate, yttrium and lanthanides, as well as calcium sulphate, yttrium and lanthanides obtained by this process  
Recovery of yttrium, lanthanides and radium free calcium sulphate in a phosphoric acid process by digesting phosphate rock with an excess of phosphoric acid in the presence of more than about 5...
4374805 Reductants for reducing metals in acid media  
Metals such as iron, uranium, vanadium, molybdenum and rare earths are reduced to lower oxidation states in various acid media using silicon metal or an iron-silicon alloy. In particular, ferric...
4315832 Process for increasing laser crystal fluorescence yield by controlled atmosphere processing  
The specification discloses a process for modifying the environment of active atoms in a selected material by removing impurities from the environment. The material is heated at an elevated...
4265862 Process for purifying rare-earth compositions using fractional sulfate precipitation  
A process is disclosed for purifying a composition comprising at least one rare-earth element. The process is useful for removing radioactive impurities from these elements. The process comprises...
4199396 Method for producing single crystal gadolinium gallium garnet  
Method for producing virtually perfect massive unicrystalline gadolinium gallium garnet from a melt of gadolinium and gallium oxides containing an addition of calcium, magnesium or strontium ions.
4198231 Recovery and separation of gadolinium and gallium  
Gallium and gadolinium are recovered and separated from scrap material of substances which contain both of these elements in the form of oxides or compounds which can be transformed to the...
4191727 Method for the separation of a mixture of fine particles  
A method for the separation of a mixture of fine particles wherein the fraction to be separated has a surface which is more reactive chemically than the remaining fractions by grinding the mixture...
4179492 Process for making rare earth metal chlorides  
A process for forming a metal chloride of a metal or its compound comprising forming a liquid fused salt bath mixture of at least two metal chlorides, the bath having the property of dissolving...
4156661 Method of modifying electrical properties of rare-earth chromite material  
A method of decreasing the electrical resistivity of a rare-earth chromite material by substituting bivalent metal ions for some of the chromium or rare-earth ions therein. The method includes...
4127989 Method for separating metal values from brine  
A process for separating and recovering metal values and salts from brine, such as brine produced from a subterranean geothermal reservoir, in which the brine is pressurized to above the bubble...
4119437 Method for removing Y2 O3 or Sm2 O3 cores from castings  
A weakly acid solution of either NH4 NO3, NH4 Cl, NH4 HSO4, CH3 COOH or equimolar CH3 COOH -- CH3 COONa is employed to remove cores of either Y2 O3 or Sm2 O3 from castings of advanced superalloy...
4065544 Finely divided metal oxides and sintered objects therefrom  
Finely-divided metal oxides are prepared by the steps of (a) contacting a compound of a metal with a carbohydrate material to obtain an intimate mixture thereof, (b) igniting this mixture to...
4053551 Methods of recovering terbium oxide from a glass  
A method for recovering Tb4 O7 from a glass containing terbium oxide is disclosed, the method including the steps of: I. fusing the glass containing terbium oxide with NaOH to provide a solid...
4051230 Liquid-liquid extraction process of metals  
In this process metal ions such as Ag+, Pb2+, Co2+, Cu 2+, Fe3+, etc., are extracted through a porous membrane impregnated with the first extractant containing chelating agents. The membrane...
4051219 Method of preparing fluorine-free rare earth metal compounds from such compounds containing fluorine  
A rare earth metal salt containing fluorine ions is separated from an acidic solution of the salt in the presence of an amount of boric acid sufficient to sequester the fluorine ions whereby the...
4041125 Process for separation of the lanthanides  
An improved liquid-liquid extraction process for the separation of the elements of the lanthanide series is disclosed. The process involves dissolving the lanthanides in a sulfuric acid solution...
4029733 Extraction of metals from sea nodules  
The method comprises the steps of crushing of the ore, neutralization by a mixture of water and sulphuric acid, introduction of a controlled quantity of sulphur dioxide gas at a pH value between...
3965238 Method of recovering uranium  
Uranium values are obtained from phosphate rock by acidifying phosphate rock containing uranium values and at least one other heavy metal with a mineral acid so as to obtain a crude acid, solvent...
3954657 Process for reclaiming rare earth oxysulfide phosphor material  
This disclosure depicts a process for reclaiming from contaminated color cathode ray tube screening waste rare earth oxysulfide phosphors, especially the red-emitting phosphor yttrium oxysulfide....
3947542 Process for treatment of pyrochlore concentrates  
A continuous process for extraction of niobium, rare earths and thorium from niobium ore concentrates which includes digesting the ore with a hot solution containing 13 to 16 moles of sulphuric...
3941714 Process for reclaiming rare earth oxysulfide phosphors  
A process suitable for reclaiming europium-activated yttrium oxysulfide contaminated with europium-activated yttrium oxide and other non-rare earth cathodoluminescent phosphors comprises forming a...
3937783 Recovery of fluorine, uranium and rare earth metal values from phosphoric acid by-product brine raffinate  
A method for recovering substantially all of the fluorine and uranium values and at least 90 percent of the rare earth metal values from brine raffinate obtained as by-product in the production of...
3925062 Process for treatment of ores  
Process for treatment of ores, in particular phosphate ores, comprising treating said ores in powder form at an elevated temperature, within an atmosphere consisting at least partially of a...
3914373 Method for separating isotopes  
Isotopes are separated by contacting a feed solution containing the isotopes with a cyclic polyether wherein a complex of one isotope is formed with the cyclic polyether, the cyclic polyether...
3912801 Solvent extraction of metals with a cyclic alkylene carbonate  
Cyclic organic carbonates have been found, along with mixtures of same with other organic liquids that are miscible therewith, to extract the following metals in stable complex or simple salt form...
3873473 SULPHIDE SOLID SOLUTION HAVING ROCK-SALT STRUCTURE AND METHOD OF PRODUCING THE SAME  
This invention provides a sulphide solid solution which is expressed by the general formula (Cd, A)S in which A is at least one element selected from the group consisting of Yb, Cr, Mg, Sr, Ca,...
3857919 SEPARATING METAL VALUES BY SELECTIVE EXTRACTION  
Double solvent extraction process wherein an aqueous solution of difficult to separate metals is alternately contacted with two different solvents and at least one metal is preferentially...
3853979 METHOD FOR REMOVING RARE EARTHS FROM SPENT MOLTEN METALLIC FLUORIDE SALT MIXTURES  
An improved method for reprocessing spent molten metallic fluoride salt mixtures of rare earths is provided wherein the rear earths are reductively extracted from the spent molten salt which is...

Matches 201 - 250 out of 348 < 1 2 3 4 5 6 7 >