Abstract: A process is provided for converting MoS.sub.2 to MoO.sub.2 wherein, MoS.sub.2 in particulate form is fed into a reactor while flowing MoO.sub.3 vapor therein to effect reaction thereof with MoS.sub.2 to form MoO.sub.2. The temperature in the reactor is maintained at a level sufficient to cause the reaction to go forward. A portion of the MoO.sub.2 is removed from the reactor as a product and the remainder is selectively oxidized at a temperature sufficient to generate gaseous MoO.sub.3 which is recycled to the reactor relative to the flow of MoS.sub.2 therein to convert the MoS.sub.2 to MoO.sub.2.

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.

Abstract: A process is provided for producing ammonium metatungstate comprising fluid bed roasting ammonium paratungstate at a temperature over the range of about 275.degree. C. to 305.degree. C. for a time at least sufficient to provide a roasted product in the form of a precursor of ammonium metatungstate, forming an aqueous slurry of the precursor and digesting the precursor at a pH of about 3 to 4 for a time at least sufficient to effect substantially complete dissolution of said precursor, filtering the digested slurry to produce a clear filtrate, and further processing the clear filtrate by evaporation to provide crystals of substantially pure ammonium metatungstate.

Abstract: A process is provided for recovering metal values from spent hydrodesulfurization catalyst, the process comprising forming in a pressure reactor an aqueous slurry of finely divided spent catalyst and sodium carbonate, the spent catalyst containing by weight about 2 to 10% Mo, up to about 12% V (e.g., about 2 to 10%), about 0.5 to 4% Co, up to about 10% Ni (e.g., about 0.5 to 5%), occluded oil, coke, sulfide sulfur and the balance essentially alumina. The amount of sodium carbonate employed is at least sufficient under oxidizing conditions to convert molybdenum and any vanadium present to soluble Na.sub.2 MoO.sub.4 and NaVO.sub.3 and to neutralize SO.sub.3 produced during oxidation, the amount of sodium carbonate being at least that required stoichiometrically. The slurry is heated to a temperature of about 200.degree. C. to 350.degree. C. (e.g., 275.degree. C. to 325.degree. C.) and a pressure of about 800 psig to 2500 psig (e.g.

Abstract: A process for stripping tungsten values from a tungsten-bearing acidic liquid organic phase into a basic aqueous ammoniacal stripping solution comprises mixing the organic phase and the stripping solution with a high-shear mixing device to maximize the pH gradient between the organic phase and the aqueous solution whereby growth of any precipitated ammonium paratungstate crystals is minimized and the dissolution thereof is maximized and to strip the tungsten values from the organic phase into the stripping solution.

Abstract: A hydrometallurgical process is provided for the recovery of molybdenum values from a molybdenum disulfide concentrate containing copper. The process comprises forming an aqueous slurry of finely divided molybdenum concentrate of carbonates and hydroxides of alkali metals, and pressure leaching the slurry in the presence of oxygen at an elevated temperature and pressure for a time sufficient to effect conversion of the contained molybdenum values to alkali metal molybdate and provide a residue containing copper oxide or basic copper carbonate from which copper is later recovered. The molybdenum values are recovered from solution by solvent extraction and the solvent thereafter stripped of the molybdenum as ammonium molybdenum using ammonium hydroxide. The molybdenum is recovered as crystals of ammonium molybdate by crystallization, e.g., by evaporating the stripping solution.

Abstract: Molybdenum is recovered from an ammonium molybdate solution containing phosphate anions by digesting in an ammonium molybdate solution at least one water-soluble compound of at least one metal selected from the group consisting of aluminum, calcium, iron and magnesium in small but effective amounts to precipitate at least about 50% of the phosphate anions for a time sufficient to precipitate the phosphate anion, separating the phosphate precipitate from the ammonium molybdate solution, then acidifying the ammonium molybdate solution with at least one mineral acid selected from the group consisting of sulfuric acid and nitric acid to lower the pH value of the solution to between about 2.5 and about 4.5 to precipitate ammonium polymolybdate, and calcining the ammonium polymolybdate at a temperature below about 750.degree. C. to produce a molybdenum trioxide product.

Abstract: An aqueous solution of at least one valuable oxyanion containing molybdenum, tungsten, vanadium, or uranium is refined to lower the content of contaminant anions such as PO.sub.4.sup.-3, SO.sub.4.sup.-2, NO.sub.3.sup.-, Cl.sup.-, ClO.sub.3.sup.-, and ClO.sub.4.sup.-, by subjecting the solution to electrolysis at a pH of from 0.5 to 4.0 between a cation-permselective membrane and an anion-permselective membrane having tertiary amine or quaternary ammonium anion exchange groups, to cause contaminant anions to pass from the solution into the anolyte. Ammonium molybdates, tungstates, vanadates, and uranates are formed from the thus-refined solution by subjecting it to a second stage of electrolysis at a pH of at least 7 between a cation-permselective membrane and an anion-permselective membrane to cause valuable oxyanions to pass from the solution into an anolyte which comprises an aqueous solution of ammonia and to form the desired ammonium compound.

Abstract: Molybdenum is separated from molybdenum-containing activated charcoal or char also containing small amounts of uranium obtained as a by-product in uranium leaching processes by stripping with an alkaline solution to provide a molybdenum-containing solution containing substantially less than 500 ppm U.sub.3 O.sub.8.

Abstract: Waste water containing over 2 ppm Mo and at least one heavy metal impurity selected from the group consisting of Fe, Mn, Cu, Zn, Pb, and Cd, and also containing cyanide ion (CN) is treated by passing waste water having an adjusted pH value ranging from about 3 to 4 through an ion-exchange resin column selective to the removal of Mo and provide an ion-exchange effluent containing at least one of said heavy metal impurities and said cyanide ion. The pH value of the effluent is then adjusted to a range of about 7 to 11 sufficient to precipitate the heavy metal impurity having the highest pH requirement for precipitation, following which the precipitate is flocculated and the effluent containing the flocculated precipitate then subjected to electrolysis using insoluble electrodes to form electrolytic oxygen and hydrogen and effect electroflotation of the flocculated precipitate and form a froth thereof which is separated from the effluent by skimming.

Abstract: A method is provided for leaching comminuted nickeliferous sulfide matte containing by weight about 20 to 75% nickel, about 5 to 50% copper, non-stoichiometric sulfur in the range of over 4 to about 24%, over 0.5 to about 20% iron, the sum of the nickel, copper and sulfur contents being at least about 80% of the matte composition, with the balance gangue or slag and incidental impurities.Nickel is selectively leached from the comminuted matte using sulfuric acid or spent copper electrolyte solution at substantially atmospheric pressure while vigorously aerating the solution, wherein the pH is raised sufficiently to produce a nickel solution with an iron content of less than about 10 ppm and a copper content of over 5 ppm, the copper being thereafter selectively removed from the nickel solution by passing the solution through an ion-exchange resin selective to the absorption of copper.

Abstract: Free flowing powders, such as for flame spray applications, are produced by spray drying a slurry of finely divided particles of the metal in a solvent-binder system to produce agglomerates, wherein the binder is a soluble compound of the metal. These agglomerates possess sufficient green strength to be screened and exhibit higher apparent densities than comparable powders agglomerated with conventional organic binders. When these powders are heated in a reducing atmosphere above the decomposition temperature of the binder, the binder converts to base metal and harmless by-products, such as nitrogen and water thus avoiding contamination of the product, equipment and work area usually associated with conventional organic binders.

Abstract: Selenium is removed from copper electrolytes by adding a substance selected from the group consisting of metals above copper in the electromotive series, excluding alkali metals, such as nickel powder, cobalt powder and iron powder. Sodium sulfide can also be used along with a subsequent addition of ferric sulfate. The amount of the reactive substance added should be sufficient to reduce the selenium content to below 2 ppm.

Abstract: Free flowing powders, such as for flame spray applications, are produced by spray drying a slurry of finely divided particles of the metal in a solvent-binder system to produce agglomerates, wherein the binder is a soluble compound of the metal. These agglomerates possess sufficient green strength to be screened and exhibit higher apparent densities than comparable powders agglomerated with conventional organic binders. When these powders are heated in a reducing atmosphere above the decomposition temperature of the binder, the binder converts to base metal and harmless by-products, such as nitrogen and water thus avoiding contamination of the product, equipment and work area usually associated with conventional organic binders.