Gte Products Corporation

Osram Sylvania Inc.

James N Christini

Michael J Miller

John A Powers

Martin C Vogt

Martin B MacInnis

Tai K Kim

Robert P McClintic

Clarence D Vanderpool

Richard G Gingerich

Michael J Cheresnowsky

Kenneth T Reilly

Richard A Scheithauer

Thomas J Patrician

Alan D Douglas

Eric F Husted

Carl W Boyer

Judy L Scheftic

James C Patton, Jr

David C Sheppeck

Thomas R Pinkowski

Vernon L Carr, Jr

Jeffrey A Eckert

A method is provided for producing molybdenum metal powders having consistently high tap densities. The method involves doping an ammonium molybdate solution with a soluble potassium compound, forming an ammonium dimolybdate precipitate and reducing the precipitate to form a metal powder.

Method for increasing tap density of molybdenum powder

A process for producing potassium and silicon doped molybdenum (KS molybdenum). The process involves mixing an aqueous ammonium molybdate solution and a dilute aqueous potassium silicate solution. The molybdate solution has a pH and a specific gravity sufficient to promote formation of diammonium molybdate crystals in the mixture. Preferably, the pH is about 8.8-11.0 and the specific gravity is about 1.20-1.32. The amount of potassium silicate and the amount of potassium silicate solution are selected to provide predetermined amounts of potassium and silicon in the mixture, preferably about 800-1300 ppm potassium and about 500-1100 ppm silicon, both amounts based on the amount of molybdenum. The mixture is heated to aid dissolution of the potassium silicate and ammonium molybdate in said mixture and to produce a homogeneous solution of ammonium molybdate, potassium, and silicon. The ammonium dimolybdate doped with potassium and silicon is then crystallized out of solution and calcined, for example in an atmosphere of dissociated ammonia, to produce molybdenum dioxide doped with potassium and silicon. The doped molybdenum dioxide is reduced, for example in a flowing hydrogen atmosphere, to produce a doped molybdenum powder, which then may be pressed and sintered to full density.

Process for producing KS molybdenum

A process for recovering tungsten as an ammoniacal tungstate which comprises reacting a tungsten containing material with sodium hydroxide to produce sodium tungstate and forming a first aqueous sodium tungstate solution therefrom, crystallizing sodium tungstate from the first aqueous sodium tungstate solution, dissolving the resulting sodium tungstate crystals in an aqueous medium to form a second aqueous sodium tungstate solution, extracting tungsten from the second aqueous sodium tungstate solution with an organic extracting agent wherein the extracting agent containing tungsten is capable of being stripped of the extracted tungsten by ammonia, and thereafter stripping the extracted tungsten from the organic extracting agent with ammonia to form an ammoniacal tungstate solution, crystallizing a portion of the tungsten contained in the ammoniacal tungstate solution to form a two phase system wherein an ammoniacal tungstate compound comprises the first phase and wherein the resulting mother liquor containing the balance of the contained tungsten comprises the second phase, and repeating the process using the mother liquor as at least a portion of the aqueous medium to dissolve the sodium tungstate crystals.

Process for recovering tungsten as an ammoniacal tungstate compound in

A method of making extrafine pure elemental metal powder from a highly malleable pure elemental metal powder. The pure elemental metal powder is oxidized, ground to a desired average particle size, reduced in a reducing atmosphere to a pure elemental metal powder, and then sieved to obtain the desired fraction of extrafine pure elemental metal powder.

Method for producing extrafine pure metal powder

A process for purifying molybdenum, which comprises first leaching impure molybdenum trioxide containing potassium in a liquid medium of nitric acid, and an ammoniacal liquor, wherein the nitric acid concentration is about 3.5 to 4.0 moles per liter and the ammonium nitrate concentration is about 0.5 to 1.0 moles per liter, at greater than 50.degree. C. to solubilize the major portion of the potassium and produce a once-leached molybdenum trioxide and a first liquor, removing the once-leached molybdenum oxide from the first liquor, re-leaching the once-leached molybdenum trioxide in nitric acid having a concentration of about 3.5 to 4.0 moles per liter, at greater than 50.degree. C. to produce a twice-leached molybdenum trioxide and a second liquor, removing the twice-leached molybdenum oxide from the second liquor, water washing the twice-leached molybdenum trioxide, digesting the molybdenum trioxide in ammonium hydroxide at greater than 50.degree. C. at a pH of greater than 9.0 to form an ammonium molybdate solution, crystallizing ammonium dimolybdate from the ammonium molybdate solution, separating the ammonium dimolybdate crystals from the spent mother liquor which contains the balance of the starting molybdenum, combining a sufficient amount of spent mother liquor with a sufficient amount of the second liquor to provide the ammonium ion required to maintain the concentration of ammonium nitrate and nitric acid in the liquid medium, and using the combined liquors as the liquid medium in the first leaching step.

Continuous process for purifying molybdenum

A tungsten extraction process wherein tungsten values are extracted from an aqueous alkali metal tungstate solution by an organic solution containing an amine extractant wherein the organic solution consists essentially of from about 6% to about 10% by volume of said amine extractant, and the balance of said organic solution being an aromatic solvent consisting essentially of a mixture of alkyl benzenes wherein the alkyl benzenes have molecular weights of 120, 134, or 148 and the total number of carbon atoms in the alkyl chains attached to the benzene ring are either 3, 4, or 5, and thereafter the tungstate values are removed from the organic solution by stripping with aqueous ammonia, is improved by carrying out the stripping step in the aqueous continuous mode, and having as the stripping agent, an aqueous solution of ammonium metatungstate having a tungsten concentration which allows the strip solution to have a specific gravity of no greater than about 1.5, the stripping agent having sufficient ammonia to maintain the pH of the stripping agent at from about 5 to about 8, with the temperature of the stripping agent being no greater than room temperature.

Process for recovering tungsten from organic solutions

A process is disclosed for separating tungsten from a solution containing tungstate and perrhenate ions. The process involves reacting a sufficient amount of hydrochloric acid with the solution at a sufficient temperature to form a solid containing essentially all of the tungsten and a liquor containing essentially all of the rhenium, and separating the solid from the liquor.

Separation of tungsten from rhenium

A method is disclosed for producing ammonium metatungstate from ammonium paratungstate. The method involves first roasting the ammonium paratungstate at from about 275.degree. C. to about 300.degree. C. for from about 10 hours to about 20 hours to remove some ammonia and some water. The roasted ammonium paratungstate is then added to dilute solution of an ammonium metatungstate which is at a pH of from about 3.6 to about 4.2, the rate of addition being such that a slurry is produced having a pH of from about 3.6 to about 4.2. The pH of the resulting slurry is then adjusted to stabilize it at from about 3.6 to about 4.2 followed by evaporation to form a relatively concentrated solution of ammonium metatungstate which is then separated from any insolubles. Ammonium metatungstate is then crystallized from the relatively concentrated ammonium metatungstate solution.

Method for producing ammonium metatungstate from ammonium paratungstate

In a process for producing pure ammonium paratungstate from ammonium tungstate solutions containing tin, sulfide is added to the ammonium tungstate solution in an amount sufficient to form a soluble complex of the sulfide with the tin. The solution is then evaporated to a volume at which essentially all of the tungsten is in the form of insoluble ammonium paratungstate and essentially all of the tin is in the mother liquor in the form of a soluble complex along with other impurities. The solid ammonium paratungstate is then separated from the mother liquor by filtration.

Method for removal of tin from ammonium tungstates

In a two component extraction system for producing ammonium tungstate from aqueous alkali metal tungstate from aqueous alkali metal tungstate solution, the stripped organic is washed to form a wash solution which is mixed with concentrated ammonia solution to form an aqueous ammonia solution which is mixed with product ammonia tungstate and fed as the stripping solution for contacting the loaded organic extractant.

Recovery of tungsten values from alkali tungstate solutions by solvent

A lubricating oil additive is produced by contacting an aqueous slurry of ammonium paratungstate with an organic phase comprising a major proportion by weight tertiary alkyl amines having the formula C.sub.n H.sub.2n+1 NH.sub.2, where n is from 18 to 22, to extract the tungsten into the organic phase from the aqueous phase while solid ammonium paratungstate is being solubilized into the aqueous phase. The aqueous phase is heated to drive off water so as to form the resulting lubricating oil additive.

Process of preparing lubricating oil additive containing tungsten

A calciner includes a rotatable cylindrical retort which is indirectly heated and has material receiving and material discharging ends. A reverse pitch tapered spiral is affixed internal of the material discharging end with the spiral tapering toward the material discharging end whereby uniformity of material discharge over 300 degrees of rotation is achieved and whereby uniformity of agitation and increased residence time are achieved.

Calciner with tapered reverse feed spiral

In a calciner having a rotatable cylindrical retort, an improved material feed spiral has a final turn and a 3/4 turn ending immediately adjacent the retort and a next to final turn connected to the final turn and extending outwardly therefrom away from the cylindrical retort. The final turn and 3/4 turn are of a height substantially equal to a given percentage of the inner diameter of the retort and the next to final turn tapers from a height substantially equal to the given height of the final turn to a height less than the given height.

Rotary calciner feed spiral

A calciner has a rotatable indirectly-heated cylindrical retort with a material receiving end and a material discharge end and a reverse pitch spiral is affixed internal of the cylindrical retort at the material discharge end.

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Towanda, PA, United States of America

James N Christini