Abstract: A method for producing pure cobalt metal powder involves the removal of divalent cationic impurities from a trivalent hexamine cobalt chloride solution. This solution is then decomposed to an insoluble cobalt oxide-containing material, from which pure cobalt metal powder is obtained through a chemical reduction process.

Abstract: A method is disclosed for producing ammonium paratungstate from cemented tungsten carbide which comprises subjecting the cemented tungsten carbide to electrolysis by passing about 0.5 to about 20 volts through an ammoniacal solution selected from the group consisting of ammonium hydroxide-ammonium chloride solution, ammonium hydroxide-ammonium carbonate solution, and ammonium hydroxide-ammonium sulfate solution, wherein platinum and the cemented tungsten carbide serve as the anode and wherein the anode is immersed in the solution, to decompose the cemented tungsten carbide and form a solution of ammonium tungstate from which is crystallized ammonium paratungstate.

Abstract: A method is disclosed for removing organic and tungsten from sodium sulfate solutions to render the solutions suitable for ion membrane processing, which comprises contacting the solution wherein the pH of the solution is no greater than about 7, with activated carbon to remove essentially all of the organic and the tungsten therefrom and form a purified sodium sulfate solution.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A method is disclosed for purifying molybdenum which involves adding to an ammoniacal ammonium molybdate solution containing the impurities of phosphorus and arsenic with the phosphorus concentration being from about 0.01 to about 0.12 g/l, a soluble magnesium salt to form a precipitate comprising magnesium ammonium salts of the phosphorus and arsenic, and to form a purified ammonium molybdate solution. The amount of the magnesium salt is sufficient to result in a concentration of from about 0.005 to about 0.04 moles/l in the ammoniacal ammonium molybdate solution. The resulting purified ammonium molybdate contains no greater than about 0.01 g P/l. The precipitate is separated from the purified solution which is then contacted with a chelating cation exchange resin supplying a sufficient amount of a cation to result in removal of the major portion of the magnesium ions from the purified solution and form a further purified ammonium molybdate solution.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A method is disclosed for producing crystalline ammonium metatungstate from ammonium paratungstate. The method involves heating ammonium paratungstate in a multiple hearth furnace at from about 200.degree. C. to about 400.degree. C. to form a relatively uniformly heated ammonium paratungstate. A slurry of the heated ammonium paratungstate in water is then digested at from about 70.degree. C. to about 100.degree. C. for less than about 6 hours at relatively constant volume while maintaining the pH of the slurry at from about 4.2 to about 3.0 by the addition of ammonia as necessary to form a solution of ammonium metatungstate. The resulting ammonium metatungstate solution is then evaporated to a fraction of its original volume to concentrate it and any insolubles are removed. The ammonium metatungstate is then crystallized from the concentrated solution.

Abstract: Processes are described for preparing pure ammonium molybdate from impure roasted molybdenum concentrates. An aqueous solution of nitric acid and ammonium nitrate is contacted with impure molybdenum concentrate to solubilize a major portion of the impurities. The resulting molybdenum concentrate is digested in ammonium hydroxide under conditions that maximize iron precipitation and removal. The resulting ammonium molybdate solution is separated from the sludge and further purified by chelating cation exchange resin in the ammonium form.

Abstract: A process is disclosed for removing ammonia from a sodium tungstate solution. The process involves heating the solution at from about 80.degree. C. to about 95.degree. C., while at the same time maintaining the pH above about 9.4 by addition of sodium hydroxide to the sodium tungstate solution. The heating is carried out for a period of time sufficient to allow the essentially complete removal of the ammonia.

Abstract: 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.

Abstract: Processes are described for preparing pure ammonium molybdate from impure roasted molybdenum concentrates. An aqueous solution of nitric acid and ammonium nitrate is contacted with impure molybdenum concentrate to solubilize a major portion of the impurities. The resulting molybdenum concentrate is digested in ammonium hydroxide under conditions that maximize iron precipitation and removal. The resulting ammonium molybdate solution is separated from the sludge and further purified by chelating cation exchange resin in the ammonium form.

Abstract: In a continuous process for producing ammonium tungstate from aqueous alkali metal tungstate solution according to an extraction process, the loaded organic extractant is cleaned after stripping by contacting with activated carbon for improving phase separation and decreasing the concentration of alkali metal.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.