Abstract: A method of recovering titanium from perovskite by leaching with a strong sulfuric acid solution is disclosed. The leaching produces a sulfate solution containing titanium and a calcium sulfate residue when the time and temperature of leaching are controlled as a function of the grind size of the perovskite and concentration of the sulfuric acid. The titanium-containing solution and the calcium sulfate residue are then separated. The titanium in the leach solution is precipitated by heating, as a mixture of titanium sulfates, which are then redissolved in water or dilute acid solution. Titanium dioxide may then be prepared by hydrolysis of the titanium in the resulting aqueous solution.
Type:
Grant
Filed:
August 27, 1984
Date of Patent:
November 12, 1985
Assignee:
The United States of America as represented by the Secretary of the Interior
Inventors:
Monte B. Shirts, Dale A. Martin, Allan E. Petersen
Abstract: A method is disclosed for removing tin from aqueous sodium tungstate solutions. The method involves adding ammonia to the sodium tungstate solution, adjusting the pH to above about 9.5 with an acid, adding magnesium chloride to form insoluble material containing the major portion of the tin, silicon, arsenic and phosphorus and a resulting sodium tungstate solution containing the major portion of the tungsten, and separating the insoluble material from the resulting solution.
Type:
Grant
Filed:
December 7, 1984
Date of Patent:
November 12, 1985
Assignee:
GTE Products Corporation
Inventors:
Michael J. Miller, Martin C. Vogt, Richard A. Scheithauer
Abstract: A process and system are provided for flash-sublimation of molybdic oxide containing slag-forming constituents. The process comprises feeding a pneumatically suspended stream of particulate molybdic oxide and a mixture of fuel and oxidizing gases through a nozzle into a confined furnace chamber, the fuel gas-oxidizing gas mixture exiting from the nozzle being ignited to provide a flame thereof, the flame being maintained at a condition to provide a temperature in the furnace chamber in excess of that required to sublime molybdic oxide. The temperature is preferably at least sufficient to melt slag-forming constituents contained in said molybdic oxide such that the slag formed is sufficiently liquid to separate from the gaseous mixture and collect at a selected portion of the chamber for removal therefrom.
Abstract: Alkali metal iron (IV) and iron (VI) ferrates are produced by the reaction at high temperatures of reactant mixtures of either (a) iron oxide and alkali metal oxide or peroxide or (b) elemental iron and alkali metal peroxide, wherein the reactions are conducted at least in their initial stages in the absence of free oxygen, e.g., in a vacuum or in a inert gas atmosphere.
Abstract: A method of recovering vanadium from an aqueous ammonium bicarbonate solvent strip solution is disclosed. The method includes adding sulfuric acid to the aqueous ammonium bicarbonate solution followed by addition of ammonia or ammonium hydroxide to precipitate out the vanadium.
Abstract: A process for converting molybdenite to molybdenum oxide by a flash roasting process wherein the molybdenum calcine produced in the flash roasting process is subsequently treated with a free chlorine-containing aqueous solution.
Abstract: A solvent extraction process is provided for transferring metal values from one immiscible liquid phase to another, whereby the two liquid phases are vigorously mixed together in a first mixer under conditions in which one liquid phase is rendered continuous, the mixing being continued to effect complete transfer of metal values, and the mixture then passed to a second mixer and the two phases mixed under conditions in which the other phase is rendered continuous, whereby when the two phases are fed to a settler, the rate of disengagement of the two immiscible liquids is substantially increased.
Type:
Grant
Filed:
April 11, 1984
Date of Patent:
November 5, 1985
Assignee:
Amax Inc.
Inventors:
Leo W. Beckstead, Linn D. Havelick, Robert F. Hogsett
Abstract: A leaching process employing acidic chloride solutions, whereby the iron content of aluminous materials such as lower grade iron-containing bauxite ores is reduced, enabling the obtention of valuable products such as metallurgical grade alumina and refractory grade bauxite, previously obtainable only from higher grade low-iron aluminous materials.
Type:
Grant
Filed:
May 10, 1984
Date of Patent:
October 22, 1985
Assignee:
Comalco Aluminum Limited
Inventors:
William H. Andrews, David J. Milne, Ronald W. Moyle, James P. Peters
Abstract: A method for precipitating vanadium from vanadium bearing liquors comprises adjusting the pH of the vanadium bearing liquor with a precipitating agent selected from the hydroxides of Na, K and Ca to a range of about 5.5 to 6.5, preferably 6.0 to 6.2 so as to precipitate vanadium in the trivalent and tetravalent states. Remaining traces of vanadium are then cemented by additions of calcium hydroxide, calcium oxide or mixtures thereof. The dried precipitate is then heated in the presence of air and Na and/or K so as to form a reaction product in the form of a water soluble salt which, when dissolved in water, results in vanadium in its pentavalent state.
Type:
Grant
Filed:
March 15, 1984
Date of Patent:
October 22, 1985
Assignee:
Intevep, S.A.
Inventors:
Domingo Rodriguez, Roberto Schemel, Ramon Salazar
Abstract: Molybdenum is recovered from an organic material, such as a spent epoxidation catalyst, by heating the material in a stream of non-oxidizing gas at a temperature of at least about 400.degree. C. to evolve the organic in the gas stream from which it is recovered and to leave a powdery residue containing essentially all of the molybdenum.
Type:
Grant
Filed:
March 14, 1984
Date of Patent:
October 15, 1985
Assignee:
AMAX Inc.
Inventors:
Roger F. Sebenik, Jerry D. Baker, John M. Laferty
Abstract: A method for manufacturing fine powder of SrZrO.sub.3 is described in which a hydrolyzate of a Zr compound and an Sr compound are reacted with each other in a strongly alkaline aqueous solution to obtain fine powder of SrZrO.sub.3.
Abstract: Alkali metal iron (IV) and iron (VI) ferrates are produced by forming a particulate mixture of reactants including an alkali metal nitrogen oxygen compound and an iron material selected from the group of iron oxide, Fe.sub.2 O.sub.3, Fe.sub.3 O.sub.4 and an iron compound which self-reacts at a temperature less than about 1100.degree. C. to form Fe.sub.2 O.sub.3. The mixture of reactants is subjected to a predetermined elevated temperature for a predetermined time duration sufficient to bring about a reaction between the reactants which produces at least one of iron (IV) and iron (VI) ferrates. The molar ratio of alkali metal nitrogen oxygen compound to the iron material is preferably in the range extending between about 4:1 and about 8:1.
Abstract: Lanthanum sulfide is maintained in the stable cubic phase form over a temperature range of from 500.degree. C. to 1500.degree. C. by adding to it small amounts of calcium, barium, or strontium. This novel compound is an excellent thermoelectric material.
Type:
Grant
Filed:
February 25, 1983
Date of Patent:
October 8, 1985
Assignee:
The United States of America as represented by the United States National Aeronautics and Space Administration
Inventors:
George H. Reynolds, Norbert B. Elsner, Clyde H. Shearer
Abstract: A method of recovering vanadium from an aqueous ammonium bicarbonate solvent strip solution is disclosed. The method includes heating the aqueous ammonium bicarbonate solution at a temperature of from 70.degree. C. to 100.degree. C., followed by addition of sulfuric acid to control the pH in the range of from 6.5 to 8.5 and addition of ammonium sulfate to precipitate out the vanadium.
Abstract: Spinel fine powders having high purity suitable for raw materials for producing a dense and uniform spinel sintered body, are produced by hydrolyzing an alcohol solution of specifically defined magnesium alkoxides and aluminum alkoxides in a specific mixing ratio.
Abstract: There is provided a multi stage process for nonselectively chlorinating a titaniferous ore containing iron to produce TiCl.sub.4. In this process a portion of the ore charge is subjected to conventional fluid bed chlorination to produce TiCl.sub.4 and FeCl.sub.2. A second portion is subdivided and submitted to chlorination in a dilute phase chlorination step using FeCl.sub.3 as the chlorinating agent to produce additional TiCl.sub.4. The FeCl.sub.3 is obtained by partial oxidation of the FeCl.sub.2 obtained in the first stage and/or second stage to yield Fe.sub.2 O.sub.3 and FeCl.sub.3. The product streams of TiCl.sub.4 are then combined for further treatment.
Abstract: A method for separating and recovering substantially pure aluminum, iron and silica from fly ash, a by-product of coal combustion, includes reacting the fly ash with aqueous fluosilicic acid and aqueous hydrogen fluoride at temperatures sufficiently high to form aqueous silicon fluoride vapor and fluorides and fluosilicate of aluminum and iron, separating the aluminum and iron fluorides and fluorosilicates from the aqueous silicon fluoride vapor, hydrolizing the silicon fluoride vapor to form silicon dioxide in substantially pure form and hydrogen fluoride, recovering and recycling the hydrogen fluoride for reuse in the process, and separating the aluminum and iron fluorides and fluosilicates from one another, and recovering substantially pure aluminum fluoride, substantially pure iron and other substantially pure metals, by electroplating or otherwise.
Abstract: A method for the removal and recovery of vanadium from a vanadium bearing material by leaching the vanadium bearing material in the presence of a leach promoter and removing the vanadium so leached from the leaching solution by precipitation. The leaching promoter forces the vanadium present in the vanadium bearing material into solution.
Type:
Grant
Filed:
March 15, 1984
Date of Patent:
September 3, 1985
Assignee:
Intevep, S.A.
Inventors:
Roberto Schemel, Domingo Rodriguez, Ramon Salazar
Abstract: Particulate alumina-base catalysts are treated to recycle the alumina by a two-step process: the first step involving conversion of the alumina to aluminum sulfate by reaction with gaseous sulfur trioxide, and the second step involving conversion of the aluminum sulfate to an aluminum hydroxide compound by reaction with an aqueous hydroxide. Both reactions are topochemical, and the aluminum hydroxide compound is prepared in particulate form.
Abstract: A process is disclosed for producing high purity tantalum oxide from impure tantalum oxide. The starting tantalum oxide is dissolved in a hydrofluoric acid solution and insolubles are removed. The hydrofluoric acid solution containing the tantalum values is adjusted to a pH of from about 6.0 to about 8.0 with a base to precipitate tantalum which is separated from the mother liquor. The tantalum precipitate is then dissolved in an oxalic acid solution, the pH adjusted to from about 5.1 to about 5.5, and the resulting solution digested to precipitate a high purity tantalum compound which is separated. The high purity tantalum compound is then digested in hydrochloric acid to dissolve the compound and then precipitate pure optical grade tantalum oxide which is then separated from its mother liquor.