Abstract: Reinforced composite magnesium-matrix articles, containing silicon carbide fibers or particles, are produced by a casting process wherein a small amount of lithium, less than about 0.7% by weight, is included in a melt of magnesium matrix alloy to facilitate wetting of the reinforcing material and ready dispersal thereof in the magnesium matrix alloy.

Abstract: A method is provided for the treatment of wastewater of pH ranging from about 1.5 to 3 containing at least about 100 ppm phosphorus as phosphate ions, at least about 50 ppm fluorine as fluoride ions and ammonia in excess of about 15 ppm NH.sub.3 (N)--T, the method comprising removing the phosphate and fluoride ions from the wastewater in a two-stage precipitation step; the first stage precipitation being conducted at a pH ranging from about 3.5 to 6.5 using an alkaline material selected from the group consisting of limestone (CaCO.sub.3) and lime [CaO or Ca(OH).sub.2 ] sufficient to form a precipitate which is removed to provide a filtrate of the wastewater which is treated in a second stage precipitation at a pH of at least about 10.5 using lime as the alkaline material sufficient to form a precipitate which is removed to provide substantially a clear effluent containing ammonia.

Abstract: A molybdenum-hafnium-carbon alloy is provided consisting essentially by weight of about 0.6% to about 1% Hf, about 0.045% to about 0.08% C, and the balance essentially molybdenum, the alloy being characterized such that during casting of an ingot and hot forging of a billet thereof, it has a substantially less tendency to crack compared to alloys containing Hf in excess of about 1% by weight and carbon in excess of 0.08% by weight, without substantial diminution in strength properties of said alloy at elevated temperatures.

Abstract: A method for electrochemically minimizing sulfide scale buildup on a metal surface by connecting the surface as an anode and periodically reversing the current flow at predetermined intervals.

Abstract: A process is disclosed for the hydrometallurgical treatment of finely divided iron-containing steel plant dusts containing zinc, lead and such other metal values as calcium, manganese, silicon, magnesium, aluminum, cadmium, copper, and the like. The process is carried out by forming an aqueous slurry of the flue dust with a mixed lixiviant comprising HCl and H.sub.2 SO.sub.4, the amount of sulfate ion concentration being in excess of the chloride ion concentration and in stoichiometric excess of that required to sulfate substantially all of the lead and calcium present. The amount of chloride ion present as HCl should be sufficient to maintain the pH at about 1 to 4. The leaching is conducted at a temperature ranging from ambient to below the boiling point for a time at least sufficient to effect dissolution of at least zinc and other metal values and form a residue containing iron oxide, calcium sulfate and lead sulfate.

Abstract: A process is provided for hydrometallurgical processing of steel plant dusts containing cadmium, lead, zinc, and iron values, along with impurities such as chloride and fluoride salts of sodium, potassium, magnesium, etc. The first step in the process involves leaching the dust in a mixed sulfate-chloride medium that dissolves most of the zinc and cadmium. Any iron and aluminum dissolved in this step is precipitated by oxidation and neutralization. Zinc is recovered from the resulting solution by solvent extraction which provides a raffinate which is recycled to the leaching step with a bleed stream also provided for recovery of cadmium and removal of other impurities from the circuit. The lead sulfate residue from the leaching step is leached with caustic soda, and zinc dust is used to cement the lead out from the caustic solution, which then joins the main solution for zinc recovery.

Abstract: A process is provided for selectively recovering zinc from steel plant dust containing substantial amounts of iron. The process comprises atmospherically leaching the steel plant dust in a first stage wherein an amount of steel plant dust is mixed with an amount of acidic zinc sulfate solution to leach zinc therefrom, the leaching of the dust being such that the solution is controlled to a terminal pH ranging from about 2 to 3.5 and preferably from about 2.5 to 3.5, thereby limiting iron dissolution. The mixture is then subjected to a crude liquid/solid separation step whereby a thickened pulp is produced containing zinc and iron values and a separated liquid containing low iron and substantial amounts of zinc, the solution being sent to zinc recovery.

Abstract: This invention relates to an improved corrosion resistant steel which nominally contains: 0.015-0.031% C, 11-12% Cr, 0.2-0.5% Mo, 1.5% max Ni, 1.5% max Mn, 0.8% max Si, 0.05% max Ti, 0.03% max N, 0.03% max P, 0.03% max S with the balance Fe. The steel of the present invention has good toughness with a relatively low ductile to brittle transition temperature. In the rolled and tempered condition the steel has a mixed microstructure consisting of tempered martensite and ferrite.

Abstract: Directed to a flotation process for recovering molybdenite from a ground ore pulp containing the same which includes a rougher flotation step in which no collector is used by relatively high recovery of molybdenite in a rougher concentrate uncontaminated with collectors, which rougher concentrate can be cleaned to yield a high grade product while the rougher tailing can be treated by flotation to obtain high overall recovery of molybdenite along with a high recovery of other co-present metal values.

Abstract: A method is provided for converting iron-containing steel plant dust to recyclable agglomerates. The method comprises mixing the dust with sufficient water and about 1 percent by weight Portland cement to permit pelletization. The pellets are dried at temperatures under 100.degree. C. to result in strong easy-to-handle agglomerates. In a preferred embodiment of the process, the dust is treated by hydrometallurgical processes to recover cadmium, lead, and zinc prior to agglomeration. The resulting pellets can then be recycled to the steel furnace or stored as a nontoxic waste.

Abstract: Sulfur-containing coal is combusted in a cyclone furnace under strongly reducing conditions with a sulfur fixing agent such as lime to produce a basic slag containing the ash and sulfur content of the coal and a product gas of high combustible content which may be burned as a fuel gas in a steam generator or otherwise to yield an exhaust gas which does not require scrubbing.

Abstract: Nickel and cobalt contained in aqueous sulfate solution are separately recovered by counter-current solvent extraction using a cobalt-selective organic extractant while scaling of equipment and cobalt recycle are minimized by controlling aqueous pH at the extraction, scrubbing and stripping stages to maximize cobalt loading and selectivity of the extractant while loading scale-causing ions such as calcium and magnesium in the extractant and removing them from the circuit with the aqueous cobalt strip solution.

Abstract: A process is provided for combusting sulfur-containing coal in a combustion stage to which is provided at least 60% of the oxygen stoichiometrically required for substantially complete combustion of the coal and combustion is conducted under highly turbulent conditions in a furnace burner cavity to which finely divided iron oxide and/or iron powder is provided and in which a high heat release rate is maintained to form a liquid iron oxysulfide phase which acts to scrub sulfur-containing gaseous species from the combustion atmosphere and is separated from the combustion atmosphere with substantially the sulfur originally contained in the coal. Following separation, the hot fuel gas resulting is burned to completion in a heat exchanging furnace, gas turbine or other energy extracting device.

Abstract: Metal substrates with a protective coating are provided, the coating being formed of a varnish-bonded, carbon-containing layer adherently bonded to the metal substrate. Optionally, the coating may also contain a dispersion of finely divided material selected from the group consisting of certain metal oxides and carbonates.

Abstract: Powdered coal is upgraded in utility and heat value by removal of ash and pyrite constituents by successively pressure caustic leaching the coal slurry at a temperature of at least about 175.degree. C., hydrochloric acid leaching the caustic leached coal to dissolve ash and pyrite residues not dissolved by the caustic, and pressure leaching the acid leached coal to remove alkali metals and chloride. Vanadium is also removed by the process.

Abstract: A bearing steel containing about 0.8% to about 1.2% carbon, about 0.5% to about 1.33% manganese, about 0.25% to about 0.7% silicon, about 0.14% to about 0.5% molybdenum, up to about 0.75% chromium and the balance essentially iron has improved hardenability and resistance to rolling contact fatigue than does the standard 52100 bearing steel.

Abstract: Magnesium and magnesium alloy castings are produced using porous, calcined plaster of Paris molds by filling the mold cavity and the pores communicating therewith with a pressurized inhibitor gas comprising sulfur hexafluoride and monitoring temperature conditions during cooling of the cast metal using a thermocouple placed in the mold close to the sprue whereby, in the event of an exotherm as indicated by non-decreasing temperature, the mold may be broken to prevent an explosion.

Abstract: A process is provided for recovering zinc from zinc residues containing iron, and lead. The residue is leached with hydrochloric acid to provide a pregnant liquor containing zinc, iron, and lead. The iron is selectively removed from the pregnant liquor and the zinc extracted from the liquor by an organic solvent extraction system. The zinc is subsequently stripped from the organic solvent using water or hydrochloric acid to provide a zinc chloride solution which is then fed to an electrowinning cell for the production of marketable electrolytic zinc.

Abstract: A process is provided for combusting sulfur-containing coal in a single step while producing an off-gas low in sulfur. The process comprises combusting finely divided coal in a furnace burner cavity in the presence of a finely divided iron oxide or iron powder and at least about 60% of the oxygen stoichiometrically required for substantially complete combustion of the coal to form a liquid iron oxysulfide phase and a turbulent atmosphere of combustion-product gases, liquid iron oxysulfide acting to scrub sulfur-containing gaseous species from the atmosphere to yield an essentially sulfur-free flue gas and a liquid iron oxysulfide slag containing substantially the sulfur originally contained in the coal.

Abstract: Molten sodium is alloyed with molten lead by using apparatus comprising a vessel adapted to hold molten sodium under gas pressure and a conduit to convey molten sodium under the impetus of gas pressure from a point low in the vessel to a point beneath the lead surface so as to effect alloying of sodium with lead without escape of sodium vapor.