Abstract: A method for the recovery of molybdenum from an ore that includes a molybdenum-bearing mineral, such as molybdenite. The ore is treated to recover metal values from the ore, such as base metals, by utilizing a depressant to depress the flotation of the molybdenite. The tailings, which can include insoluble silicate minerals in addition to the molybdenite, are then activated to render the molybdenite floatable in one or more subsequent flotation steps, thereby producing a high-grade molybdenum concentrate.

Abstract: Apparatus and processes are disclosed for treating materials by exposure thereof to sonic or ultrasonic oscillations produced by oscillating plates which form part of a processing chamber and which are each activated by a plurality of transducers adjacent thereto. The transducers are excited by an electronic circuit capable of driving each transducer at selectable frequencies, phase relationships and amplitudes. The invention also comprises processes for the treatment of materials by exposure thereof to oscillating plates excited at predetermined combinations of frequencies, phases and amplitudes.

Abstract: Copper, nickel and zinc are recovered from sulfide minerals or concentrates thereof by leaching with ammonia at or near atmospheric pressure. A slurry of such minerals or concentrates in an aqueous solution containing free ammonia is passed into a closed leaching vessel or a series of such vessels into which oxygen is admitted. The slurry in such vessel or vessels is mechanically agitated with a vigor input of at least 0.05 horsepower per cubic foot and preferably while recirculating oxygen from above the slurry to well below its surface. The temperature of the slurry is maintained between 50.degree. and 100.degree. C. or up to the boiling temperature at the prevailing pressure, and the pH preferably is in the range from 9 to 11. Solids separated from the leach solution at the conclusion of such leaching operation may be releached for additional copper recovery by a similar leaching procedure in one or a series of leaching vessels.

Abstract: High purity iron powder may be obtained by treating an iron bearing source which contains impurities such as silica along with minor amounts of aluminum, calcium and magnesium to a series of steps which include grinding the iron bearing source followed by subjecting the ground source to a caustic leach at an elevated temperature and pressure. Thereafter the soluble impurities may be separated from the residue, the latter then being reduced by treatment with hydrogen at an elevated temperature and pressure to convert the iron to the metallic form.

Abstract: The process of sulfidizing an acid copper leach pulp prior to flotation recovery of the copper therein comprising adding to and admixing with said pulp in a reaction zone an ionizable sulfide material, said sulfide material being added in an amount proportional to the amount of copper passing through said zone so that the sulfidization reaction is completed within about 30 seconds and the pulp leaving said zone has an aqueous copper concentration of from about 0.014 to 0.024 gram per liter and a reactor for such process comprising elongated tubular means, shaft means mounted in said tubular means, and a plurality of blade members attached to said shaft, said blade members being spaced along said shaft at approximately 30.degree. pitch angles relative to the axial direction of the shaft and there being a reverse pitch direction of certain of said blades at predetermined distances along the length of said shaft.

Abstract: Copper, zinc and nickel are recovered from sulfide concentrates prepared from ores of one or more such metals by subjecting such concentrate to a leaching operation which comprises slurrying the concentrate in an aqueous solution containing ammonium sulfate and free ammonia and vigorously agitating the slurry at 50 to 80.degree. C. and below 10 psig. in the presence of free oxygen while vigorously recirculating said oxygen from above the surface of the slurry to a substantial depth below such surface. The resulting pregnant leach solution contains copper, zinc, and/or nickel in dissolved form complexed with ammonia and such solution is treated to recover the dissolved metal. The undissolved sulfidic residue from the leaching operation is subjected to a secondary flotation operation to produce a sulfide concentrate containing the metal values not dissolved in the leaching operation, and such concentrate is treated to recover such values, as by smelting or by releaching.

Abstract: The process of sulfidizing an acid copper leach pulp prior to flotation recovery of the copper therein comprising adding to and admixing with said pulp in a reaction zone an ionizable sulfide material, said sulfide material being added in an amount proportional to the amount of copper passing through said zone so that the sulfidization reaction is completed within about 30 seconds and the pulp leaving said zone has an aqueous copper concentration of from about 0.014 to 0.024 gram per liter and a reactor for such process comprising elongated tubular means, shaft means mounted in said tubular means, and a plurality of blade members attached to said shaft, said blade members being spaced along said shaft at approximately 30.degree. pitch angles relative to the axial direction of the shaft and there being a reverse pitch direction of a certain of said blades at predetermined distances along the length of said shaft.

Abstract: Lead is recovered from lead sulfide concentrates or mixed lead-zinc concentrates containing iron sulfide by forming a slurry of such concentrates in an aqueous medium containing ammonium sulfate and free ammonia, and introducing such slurry into a closed reaction vessel at a pressure not exceeding 30 psig. Oxygen also is introduced into such vessel to establish therein a partial oxygen pressure of at least a few psi, while vigorously agitating the slurry. The lead sulfide content of the concentrates thereby is converted to the form of substantially water-insoluble oxidic lead compounds, while any zinc sulfide present is dissolved. The slurry then is withdrawn from the reaction vessel and the insoluble residue is separated from the aqueous solution. The latter is treated for recovery of its zinc and ammonia content, and the residue is subjected to a froth flotation operation to form a concentrate containing substantially all the iron sulfide and a tailing containing the oxidic lead compounds.