Gte Products Corporation

Robert P McClintic

Tai K Kim

Martin B MacInnis

Clarence D Vanderpool

Richard G Gingerich

James N Christini

Martin C Vogt

Kenneth T Reilly

Robin W Munn

Alan D Douglas

A method for removing magnesium and calcium from sodium sulfate solutions to render the solutions suitable for membrane processing, which comprises adjusting the pH of the solutions to about 11 to 13 with sodium hydroxide to form a precipitate containing the bulk of the magnesium and the calcium, removing the precipitate from the resulting partially purified sodium sulfate solution, and contacting the partially purified sodium sulfate solution with a polystyrene divinyl benzene copolymer chelating cation exchange resin having an aminophosphonic functional group and having sodium as the exchangeable cation, to remove essentially all of the magnesium and the calcium from the partially purified sodium sulfate solution.

Method for removing magnesium and calcium from sodium sulfate solutions

In a method for producing tungsten hexachloride which comprises reacting tungsten with chlorine gas at a temperature sufficient to result in the conversion of the tungsten to tungsten hexachloride, the improvement comprising reacting tungsten in the form of pressed pieces to convert the pieces to tungsten hexachloride having an oxygen content of less than about 0.5% by weight with the rate of conversion to tungsten hexachloride being at least about 2.3 times greater than the rate of conversion when the tungsten is in an unpressed form.

Method for producing tungsten hexachloride

An improvement is disclosed in a process wherein tungsten values are extracted from an aqueous alkali metal tungstate solution by an organic extractant, and then stripped from the organic with an ammonia solution, the improvement being removing bromine from the major portion of the stripped organic and thereafter using at least a portion of the resulting bromine-free stripped organic to make up at least a portion of the organic extractant.

Process for extracting tungsten from alkali metal tungstate solutions

A process is disclosed for recovering scandium from impure scandium bearing material. The process involves contacting a solution of scandium which contains impurities, with a solvent impregnated resin consisting essentially of a solid polymeric medium in which is dispersed a liquid alkyl phosphoric acid as a cation extracting agent to extract essentially all of the scandium by the extracting agent without extracting appreciable amounts of impurities, and removing the scandium from the resin.

Process for recovering scandium from waste material

A process is disclosed for producing a relatively pure solid ammonium metatungstate by precipitating the solid from a mixture of an ammonium metatungstate solution and a lower alcohol having the formula C.sub.n H.sub.n+1 OH. The ammonium metatungstate solution which is used can be made by any means including the adjusting the pH of an ammonium paratungstate solution followed by digestion of the solution to form ammonium metatungstate.

Method of producing crystalline ammonium metatungstate

A method is disclosed for producing crystalline ammonium metatungstate from ammonium paratungstate. The method involves heating the ammonium paratungstate with microwave radiation, then heating an aqueous slurry of the heated ammonium paratungstate at from about 80.degree. to about 100.degree. C. at relatively constant volume until the pH of the slurry becomes stabilized at from about 5.8 to about 6.8, adjusting the pH of the slurry to from about 4.2 to about 30, digesting the resulting pH adjusted slurry at from about 80.degree. to about 100.degree. C. for from about 2 to about 6 hours to form a solution of ammonium metatungstate, concentrating the resulting solution, separating insolubles from the solution, and crystallizing ammonium metatungstate from the concentrated solution.

A method is disclosed for producing crystalline ammonium metatungstate from ammonium paratungstate. The method involves heating the ammonium paratungstate at from about 100.degree. C. to about 250.degree. C. for from about 1 hour to about 8 hours to remove some ammonia and water, digesting a solution of the heated ammonium paratungstate in water at from about 80.degree. C. to about 100.degree. C. for from about 2 hours to about 6 hours at relatively constant volume while maintaining the pH of the slurry at from about 4.2 to about 3.0 by addition of ammonia as necessary to form a solution of ammonium metatungstate in water. The ammonium metatungstate solution is then evaporated to concentrate it. Any insoluble material is separated from the solution. Ammonium metatungstate is then crystallized from the resulting concentrated ammonium metatungstate solution.

A method is disclosed for producing crystalline ammonium metatungstate from ammonium paratungstate. The method involves heating the ammonium paratungstate at from about 130.degree. to about 400.degree. C. for from about 1 to about 8 hours to remove some ammonia and water, and heating a slurry of the resulting heated ammonium paratungstate in water at from about 80.degree. to about 100.degree. C. at relatively constant volume until the pH of the slurry becomes stabilized at from about 5.8 to about 6.0. The pH of the resulting pH stabilized slurry is then adjusted to from about 4.2 to about 3.0 by introducing a porous container containing a strongly acidic cation exchange resin into the slurry, the amount of resin being essentially sufficient to accomplish the pH adjustment. Thereafter the container and resin are removed from the resulting pH adjusted slurry which is then digested at from about 80.degree. to about 100.degree. C. for from about 2 to about 6 hours at relatively constant volume to form a solution of ammonium metatungstate. The solution is then evaporated to a fraction of its original volume to concentrate it. Any insoluble material is then separated from the solution, and ammonium metatungstate is crystallized from the solution.

In a two component extraction system for producing ammonium tungstate from aqueous alkali metal tungstate solution, the stripping solution consists essentially of water and from about 5 to about 21 percent by weight ammonium hydroxide at a pH of from about 12 to 13 wherein the stripping is carried out by dispersing the aqueous ammonia solution in the loaded organic extractant.

Recovery of tungsten values from alkali tungstate solutions by solvent

In a three component extraction system for producing ammonium tungstate from aqueous alkali metal tungstate from aqueous alkali metal tungstate solution, the stripping solution consists essentially of water and from about 5 to about 21 percent ammonium hydroxide at a pH of from about 12 to about 13 wherein the stripping is carried out by dispersing the aqueous ammonia solution in the loaded organic extractant.

After stripping tungsten values from a loaded organic extractant in a two component extraction system for producing ammonium tungstate from aqueous alkali metal tungstate solutions, the organic extractant and aqueous solution of ammonium tungstate are fed into a settling container which includes a pair of electrodes and means for applying a direct current voltage potential for promoting coalescence of the aqueous and organic phase.

Tungsten is reclaimed from heavy metal alloys of the type having tungsten metal dispersed throughout a matrix material by treating the heavy metal alloy with zinc to form a molten mixture and separating the zinc from the resulting alloy.

Recovery of tungsten from heavy metal alloys

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

In a process for preparing ammonium paratungstate from a heavy metal alloy, the metal alloy is introduced as an anode into an electrolytic cell containing an aqueous electrolyte solution comprising ammonium hydroxide and ammonium nitrate. Ammonium paratungstate is formed when a direct electric current is passed through the cell.

Growing community of inventors

Monroeton, PA, United States of America

Robert P McClintic