Abstract: Zinc is selectively extracted from zinc sulfate solutions that may also contain sulfuric acid and amounts of other metals with an organic extractant mixture containing both organic substituted phosphoric acid and organic substituted thiophosphinic acid. The phosphoric acids are preferably chosen from mono- and di-2-ethylhexylphosphoric acids and mixtures thereof, and the phosphinic acids are preferably chosen from bis- 2, 4, 4-trimethylpentyl mono- and dithiophosphinic acids. The use of an extractant mixture of the dithiophosphinic acid with mono- and di-2-ethylhexyl phosphoric acids or an extractant mixture of the dithiophosphinic acid with di-2-ethylhexylphosphoric acid is preferred. The pH during zinc extraction is controlled at a value in the range of about 1.3 to 5. Control of pH is carried out either by neutralization or by acid extraction with an organic amine-type extractant. The acid content of the feed solution may be reduced by neutralization or acid removal by dialysis.

Abstract: A method for making zinc electrodes for alkaline-zinc batteries comprising the steps of: mixing an amount of a zinc-magnesium binder alloy with an amount of a material chosen from zinc and a second zinc-magnesium alloy to form a mechanical mixture. The melting temperature of the material is at least 15 Celsius degrees higher than the melting temperature of the binder alloy. The mixture is applied to a current collector and the current collector with applied mixture is heated to a temperature at which incipient melting of the binder alloy causes sintering of the mixture with the formation of a coherent layer solidly bonded to the current collector. The compositions and the amount of the binder alloy and the second alloy are selected such that the active material in the layer of the electrode contains no more than about 15% magnesium, preferably no more than about 10% magnesium.

Abstract: A negative zinc electrode for use in an alkaline battery has an active material consisting of zinc-magnesium alloy containing magnesium in an amount in the range of greater than 0% to about 15% by weight. The zinc-magnesium alloy may also contain a small amount of an additive metal that reduces the hydrogen overvoltage or an effective amount of an additive metal that increases the porosity, such as from 5 to 25% aluminum by weight of the zinc. The zinc-magnesium alloy is applied in particulate form to a suitable current collector using any one of a number of conventional methods such as die-pressing, mixing with a filler or a polymer and heating, sintering or compaction. The electrode has a cycle life longer than that of a conventional zinc oxide-based electrode, and causes little or no formation of dendrites.

Abstract: Electrodialysis is used to separate at least one species of a first group of elements present in ionized form from at least one species of a second group of elements present in nonionized form in water-containing solutions, provided that the pH of the solutions and the oxidation state of species of the second group have the appropriate values. If necessary, either the pH, the oxidation state or both are adjusted in the solution fed to the electrodialysis unit such that species of the first group are present in ionized form and species of the second group are present in a nonionized form. The method is applicable to a large number of solutions from metallurgical and chemical processes. Species of the first group include at least one element of groups IA, except Fr, IB, IIA, IIB, IIIA except B, IIIB, IVB, VIIB and VIII except Os of the periodic table; the elements V, Cr, Sn, Pb and Bi; and acids of N, S, F, Cl, Br and I.

Abstract: There is provided a method for treating zinc-containing sulfate solutions which comprises an acid removal for the recovery of a substantially pure sulfuric acid solution and a solution low in acid and containing the zinc and metal impurities from the sulfate solution. The acid removal is carried out by a membrane process that consists of dialysis, electrodialysis or dialysis integrated with electrodialysis. The dialyzate or diluate is subjected to a dual-circuit, side-by-side, simultaneous solvent extraction of zinc and sulfuric acid. In one circuit sulfuric acid is extracted from the dialyzate or diluate and the raffinate from the zinc extraction with an amine-containing extractant. Acid is stripped from the loaded organic with water or an alkaline substance, and is recovered as sulfuric acid or as a sulfate, preferably as ammonium sulfate.

Abstract: A method for the recovery of acids from dilute aqueous acid solutions containing at least one metal cation such as Zn, Ca, Mg, Na, K, Mn, Al, Fe, Ni and Co comprises feeding solution to the dialyzate compartments of a dialysis unit. The dialyzate, substantially containing any metal cations, is removed from the process. The diffusate, containing the acid from the feed solution and being substantially free of metal cations, is fed into the dilute stream circulating through the diluate compartments of an electrodialysis unit. A portion of the circulating diluate is returned to the diffusate compartments of the dialysis unit. The concentration gradient of acid anions across the dialysis membranes is increased by adding a quantity of acid-receiving solution to the returned diluate portion. The feed rates of solutions to the compartments of the dialysis unit are at least double those in processes using only dialysis.

Abstract: Insoluble mercury salts and any mercury in mercury-containing material are converted into a soluble form by controlled chlorination. The soluble forms of mercury in the chlorination solution are reduced with iron, preferably iron powder, to elemental mercury. After separation from the reduced solution, the solids from the reduction containing entrained mercury, are subjected to a separation for the separation and substantially quantitative recovery of substantially pure mercury. Separation by elutriation through a body of mercury is preferred. Prior to separation, the reduction solids may be kneaded for coalescence of fine mercury particles, followed by slurrying of the kneaded material. Any selenium in the reduced solution may be recovered in a reduction with a suitable reductant, preferably by adding strong sulfuric acid in the presence of the ferrous chloride formed in the preceding reduction, and excess sulfur dioxide.

Abstract: Copper arsenate, substantially free from impurities that form sludge in wood preservatives such as chromated copper arsenate, is prepared by adding a solution of soluble arsenate to copper sulfate solution, either or both solutions containing sludge-forming impurities, to form a copper and arsenic-containing solution without precipitating copper arsenate. The pH during the adding is controlled at a value in the range of 1.8 to 2.2 to precipitate impurities. Precipitated impurities are removed, and the copper and arsenic-containing solution is neutralized with a suitable alkaline substance to pH 3.5 to 5.0 to precipitate copper arsenate. Arsenate solution is derived from arsenic oxides, soluble arsenic salts and compounds and metallurgical materials capable of yielding water-soluble arsenate. Copper sulfate solution is derived from crystals and compounds and metallurgical materials cable of yielding copper sulfate.

Abstract: A system for casting electrodes includes a row of stationary, adjacent, plate casting molds flanked by a launder containing molten metal and a walking beam conveyor. One or two travelling carriages straddle the molds, launder and conveyor. A travelling carriage comprises a pair of rotary dippers, a pair of tipping/dispensers and electrode lifting device. Each dipper scoops a predetermined amount of molten metal from the launder and, while rotating, discharges it into a dispenser. When filled, the dispensers simultaneously tip to fill a mold from both sides of a mold center line over substantially the full length of parallel sidewall portions of the mold, whereby wave action is dampened and molten metal solidifies with even thickness and without flash. The bottom of the mold is water-cooled during casting.

Abstract: An arsenate solution is treated by electrolysis with membranes for at least partial conversion into arsenic acid and hydroxide. Electrolysis is carried out in an electrolytic unit containing an arrangement of electrodes and membranes. Depending on the electrode and membrane type and configuration, arsenic acid having a reduced content of alkali metal or ammonium cations and impurities is recovered. Arsenic acid-containing solution and hydroxide solution are removed. An electrolysis unit comprises, preferably, a stack of 2- or 3-compartment cells, comprising at least one electrode/membrane group arranged between terminal electrodes with or without terminal membranes. Each group may comprise a bipolar or a monopolar electrode in combination with either cationic or cationic and anionic membranes. Hydroxide and acid compartments are defined between electrodes and membranes, and diluate compartments may be defined between membranes.

Abstract: Molten metals or alloys are poured into a stationary plate mold from at least one elongated pouring device such that melt overflows the length of the mold. The pouring energy is dissipated by flowing the elongated flow from one stationary device against an energy dissipating plate adjacent the pouring device in proximity to either one of the mold center lines such that the flow forms two balanced streams on the bottom of the mold. Alternatively, an elongated flow is poured from each of two stationary pouring devices positioned in opposing directions along the opposite sidewalls of the mold. Alternatively, the two pouring devices may move from one of the mold center lines towards the sidewalls while pouring molten metal. The pouring energy is dissipated by flowing two of the balanced streams formed on the bottom of the mold towards each other. The dissipation of pouring energy results in the substantial elimination of wave action and flash whereby castings with an even thickness are produced.

Abstract: A fire suppression system for use with ducts carrying corrosive gases has a multiplicity of sprinkler assemblies, each having an easily replaceable adapter with a sprinkler head having a fusible alloy fill. The head is screwed into one end of the adapter which has an integral flange at its opposite end. The adapter is inserted in a flanged nozzle which is part of the duct. The adapter flange is bolted to the nozzle flange which has a central opening adapted for connection to a source of extinguishing fluid. A continuous passage for fluid is provided through the adapter and the flanges together with a passage through the sprinkler head, the latter being opened when the system is activated. Only the face of the adapter and a small protruding portion of the sprinkler head are exposed to the corrosive gases. The sprinkler head has a corrosion-resistant body and has a central passage containing a seal plug and a fusible fill at opposite ends and a piston between the fill and the plug.

Abstract: Copper arsenate, substantially free from impurities that will form a sludge in the process for producing wood preservatives such as chromated copper aresenate and having a water content of less than 15%, is prepared by mixing a solution of soluble arsenate and a copper sulfate solution, either or both solutions containing sludge-forming impurities, to form a copper and arsenic-containing solution without precipitating copper arsenate. The pH during the adding is controlled at a value in the range of 1.7 to 2.2 to precipitate impurities. Precipitated impurities are removed, and the copper and arsenic-containing solution is neutralized with a suitable alkaline substance, preferably dilute sodium hydroxide solution, to pH 3.2 to 4.2 to precipitate copper arsenate.

Abstract: A tuyere for a metallurgical vessel comprising a solid metal tuyere body with a central gas feed bore. The gas feed bore contains at least one gas feed pipe. The tuyere body also has at least one water-cooled bore between the outer wall of the tuyere body and the gas feed bore. A water-cooled bore has a water passage for circulating water therethrough. A water cooling header with separated water inlet and outlet is attached to the tuyere body external to the metallurgical vessel. A water passage is provided for a flow of water from the water inlet through the water passage in the water-cooled bore to the water outlet. The cooling capacity of the tuyere is sufficient to cause the formation of a protective encrustation on the end of the tuyere, and to effectively reduce erosion and chemical reaction of the tuyere material and the vessel wall.

Abstract: An improved method for selectively rcovering Ge from acidic solution containing Ge and typically Zn, As, Cd, Sb, In, Cu and Fe (II) by multistage, countercurrent liquid-liquid extraction is described. The extractant used in the organic phase is an oxime, for example, 5,8-diethyl-7-hydroxy-6-dodecanone oxime, mixed with at least one alkylphosphoric acid, for example either di-2-ethylhexyl phosphate alone or admixed with mono-2-ethylhexyl phosphate, dissolved in a hydrocarbon diluent. This mixed system shows better efficiency and selectivity for germanium than known systems using either oximes or alkylphosphoric acids separately.

Abstract: Lead that forms dross upon melting is refined by treatment with refining agents consisting essentially of calcium metal and aluminum-silicon eutectic alloy. The refining agents are mixed into a bath of molten lead preferably at 600.degree. C., the bath is cooled to preferably 450.degree. C., and sodium hydroxide and sodium nitrate are added to remove the refining agents. The formed dross is skimmed and refined lead is recovered. The refined lead forms less dross upon remelting.

Abstract: A system for sparging aerated water into a column for the froth flotation of minerals, and located in the lower portion of the column, consists of water and air supply headers connected to a supply of pressurized water and air, respectively. The headers comprise a number of water and air passages, each having shut off valves. A multiplicity of sparger tubes is arranged, in one or more horizontal planes, either radially towards the column center or parallel to each other from opposite sides of the column. Each sparger pipe comprises a mixing tee attached to a water passage and an air passage, and a perforated portion provided with a number of small openings. The number of openings in each pipe is determined by the cross-sectional area covered by the sparger pipe. The openings may be arranged upwardly and/or downwardly at an angle in the range of about 5.degree. to 90.degree. from the horizontal.

Abstract: Gallium is zone refined in a stationary, vertical, double annulus refiner. Impure gallium is contained between walls of a first annulus that are made of a material that does not impart impurities to the gallium. At least one of the walls is made of a flexible material. A cooling fluid is circulated through a second annulus enveloping the first annulus. The gallium is zone refined by moving through the gallium ingot one or more molten zones formed by radio frequency waves from at least one reciprocating radio frequency heating induction coil. After the necessary number of passes, the ingot is cropped without introducing contaminants and refined gallium with purities between 79 and 89 is recovered. LEC single crystal GaAs made with the so refined gallium has very uniform electrical characteristics.

Abstract: Tungsten-titanium sputtering targets with improved characteristics are made from high-purity tungsten powder and a second powder consisting of high-purity titanium hydride powder or high-purity titanium hydride powder and high-purity titanium powder. The second powder contains at least 5%, preferably 25% to 100% by weight of titanium hydride powder. A powder mixture having a binodal particle size distribution with respect to the tungsten and second powders is placed under a containment pressure in a die. The die is heated in a vacuum hot-press chamber to a temperature sufficient to dehydride the titanium hydride, and to remove gases and alkali metals. The die is then heated to a second temperature in the range of 1350.degree. to 1550.degree. C. while maintaining the containment pressure and vacuum. A compaction force in the range of 2000 to 5000 psi is then applied to form a compact. The compaction force and vacuum are subsequently released and the compact is cooled.

Abstract: Lead with a low alpha particle emission is produced by selecting an orebody wherein lead mineral is present in a coarsely disseminated form and substantially free of impurities. The ore is selected from a host rock that is relatively low in alpha emitters, such as a carbonate rock. The ore is mined and is milled such that the lead mineral can be separated from the host rock and any other minerals. The ground ore may be screened into one or more fractions having a narrow range of particle sizes. Each fraction is formed into a fluid suspension, and each suspension is subjected to gravity separation to remove the host rock and any other minerals which substantially contain the alpha particle-emitting substances, and to recover the lead mineral as a concentrate with a low alpha count. The lead concentrate is subjected to a suitable smelting operation, without the introduction of alpha emitters for the recovery of a low alpha lead.