Abstract: 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.

Abstract: A method for reducing impurity levels of calcium, magnesium and/or silicon in hexammine cobalt halide compounds involves the addition of ferric ions and, optionally, soluble fluorides to an aqueous hexammine cobalt (III) chloride solution having a pH of at least 9. Insoluble compounds of magnesium fluoride, calcium fluoride, and/or ferric hydroxide and silicon coprecipitates are removed from the solution by filtration.

Abstract: A method is disclosed for purifying cobalt of sodium and ammonia which involves heating a solution of hexammine cobalt (III) chloride at a temperature of at least about 80.degree. C., adding sodium hydroxide to the solution at a rate of addition not exceeding about 0.22 moles of sodium hydroxide per mole of cobalt per minute with the total amount of sodium hydroxide not exceeding about 1.4 times the stoichiometric amount required to form cobaltic hydroxide, separating the resulting cobaltic hydroxide precipitate from the resulting liquor, washing the precipitate with hot deionized water to remove sodium so that the level of sodium in the cobaltic hydroxide is equal to or less than about 60 weight parts per million on a cobalt basis, and firing the resulting washed precipitate at a temperature of from about 180.degree. C. to about 850.degree. C. to remove essentially all of the water and ammonia therefrom.

Abstract: A method is disclosed for purifying cobaltic hydroxide of sodium and chloride which involves firing the cobaltic hydroxide at a temperature of from about 180.degree. C. to about 850.degree. C. to remove essentially all of the water and to release sodium from the crystal matrix of the cobaltic hydroxide, slurrying the dried cobaltic hydroxide in a deionized water solution which contains a sufficient amount of an ionic compound to prevent the peptization of the cobaltic hydroxide, to solublize essentially all of the chloride and a greater portion of the sodium than would otherwise be solubilized without the firing step, and removing the purified cobaltic hydroxide from the resulting liquor.

Abstract: In a process for producing fine size cobalt metal powder from scrap material containing brazing compositions, the silver ions are removed by cementation with iron to form an insoluble mixture which is subsequently treated with concentrated hydrochloric acid to solubilize the silver which is then precipitated as silver chloride.