Abstract: A method for removing sulfate iron-containing compounds from a low- to moderate-temperature metal sulfide leach circuit (1) is disclosed. A reactor (6) within a chloride leach circuit (5) and which is preferably maintained at a temperature between 20 and 150 degrees Celsius may be provided with a catalyst (4) comprising a material selected from the group consisting of: colloidal hematite, colloidal goethite, particulate containing FeOOH, particulate containing ?-FeOOH, particulate containing ?-FeOOH, particulate containing Fe2O3, particulate containing ?-Fe2O3, particulate containing ?-Fe2O3, particulate containing Fe3O4, particulate containing Fe(OH)SO4, and a combination thereof. The catalyst (4) may also be used with heap leach and/or dump leach circuits (22), without limitation. Methods for using and generating the catalyst (4) are also disclosed. In some embodiments, the catalyst (4) may be used as an anti-frothing agent (e.g., for zinc leaching, without limitation).

Abstract: A process for recovering gold from a gold-containing raw material, comprising leaching the gold-containing material with an aqueous solution comprising elemental bromine and bromide source to form a pregnant leach solution with the gold dissolved therein; separating said pregnant leach solution from the gold-depleted raw material, removing elemental bromine from said pregnant leach solution, extracting the gold from the pregnant leach solution in an acidic environment into an organic extractant, to form a gold-loaded extract and bromide-containing raffinate, stripping the extract with an alkaline aqueous solution to form a gold-bearing aqueous solution, generating gold (Au0) and treating bromide-containing stream(s) to produce recyclable elemental bromine.

Abstract: The invention relates to a method for preparing a gold-containing solution by chloride leaching from gold-bearing raw materials. A further object of the invention is to provide a method for recovering gold and optionally silver from the prepared gold-containing solution. The invention relates also to a process arrangement for recovering gold and optionally silver.

Abstract: Provided is a method of recovering copper and one or more precious metals comprising leaching copper-bearing ore and/or concentrate under atmospheric or slightly pressurized conditions at a temperature below the boiling point of the leach solution in a sulfuric acidic solution in the presence of one or more alkali metal or alkali earth metal halides, whereby the total halide concentration is from 30 to 115 g/L, to dissolve copper and to obtain a leaching liquor comprising copper, sulfur species, and halides in solution. The leaching liquor is then subjected to a solid-liquid separation after which a first aqueous pregnant leach solution and a copper depleted leaching residue are obtained. Copper is purified by solvent extraction from the first aqueous pregnant leach solution to obtain a first copper-containing loaded organic solution and a first aqueous raffinate. The copper containing loaded organic solution is stripped and copper is recovered.

Abstract: There is provided a composite tungsten oxide particle dispersion polycarbonate resin composition containing composite tungsten oxide particles expressed by a general formula MxWyOz, metal salt, and polycarbonate resin, wherein the metal salt is a salt of one or more kinds of metal elements selected from Mg, Ni, Zn, In, and Sn.

Abstract: A method for recovering precious metal from an acidic pregnant solution resulting from halogen or hypohalite leaching of an ore, comprising lowering the ORP of the pregnant leachate with a reducing agent in the presence of slurried non-carboneous particles. The precious metal deposits on the surfaces of the particles and a barren solution comprising substantially all the halogen values of the pregnant solution in the form of sodium chloride, sodium bromide or hypohalites is recovered.

Abstract: A process for recovering a metal chloride or mixed metal chloride from a solid waste material comprising recoverable metal containing constituents produced by lead, copper or zinc smelting and refining processes, said process comprising the steps of: (i) heating the solid waste material; (ii) treating the heated material of step (i) with a gaseous chloride to form a gaseous metal chloride containing product; and (iii) treating the gaseous metal chloride containing product of step (ii) to recover the metal chloride or mixed metal chloride. The metal chloride may be further treated to extract the metal itself.

Abstract: The present invention relates to methods for recovering precious metals including silver and gold, rare metals including indium and gallium, base metals including copper, lead and zinc or a combination of precious, rare and base metals from complex oxide ores, sulfide ores or oxide and sulphide ores using an acid chloride oxidizing leach.

Abstract: A process for chlorinating ore, slag, mill scale, scrap, dust and other resources containing recoverable metals from the groups 4-6, 8-12, and 14 in the periodic table. The process comprises: a) forming a liquid fused salt melt consisting essentially of aluminum chloride and at least one other metal chloride selected from the group consisting of alkali metal chlorides and alkaline earth metal chlorides, wherein the aluminum chloride content in the liquid salt melt exceeds 10% by weight; b) introducing the recoverable metal resources into said liquid salt melt: c) reacting the aluminum chloride as chlorine donor with said recoverable metal resource to form metal chlorides, which are dissolved in the salt melt; and d) recovering the formed metal chlorides from the salt melt.

Abstract: Provided is a method for separating and recovering iodine ingredients from acid solution containing iodide ions and iron (II) ions and for efficiently producing iron (III) ions. Said method is for treating acid solution containing the iodide ions and the iron (II) ions. Said method comprises a step of oxidizing the iron (II) ions in said solution into iron (III) ions with iron-oxidizing microorganisms, the step being performed in the presence of activated carbon.

Abstract: The present invention relates to methods for recovering precious metals including silver and gold, rare metals including indium and gallium, base metals including copper, lead and zinc or a combination of precious, rare and base metals from complex oxide ores, sulfide ores or oxide and sulphide ores using an acid chloride oxidizing leach.

Abstract: A method for recovering base metal values from oxide ore is provided, where the ore includes a first group metal selected from nickel, cobalt and copper. The method includes reducing ore particle size to suit the latter unit operation, favoring contact for the metal elements, contacting the ore with ferric or ferrous chloride, hydrated or anhydrous, to produce a mix of ore and iron (II or III) chloride subjecting the mixture of the ore and ferric or ferrous chloride to enough energy to decompose the chlorides into hydrochloric acid and a iron oxides from the second group, forming their respective chlorides, selectively dissolve the produced base metal chlorides, leaving the metal as oxides and in the solid state, and recovering the dissolved base metal values from aqueous solution.

Abstract: An object of the present invention is to provide a method of efficiently leaching copper from a copper sulfide ore containing chalcopyrite or enargite as a main constituent under versatile conditions for actual operation. A method of leaching copper from a copper sulfide ore, characterized by comprising using, as a leaching solution, a sulfuric acid solution containing iodide ions and ferric (III) ions in an excessive amount relative to the iodide ions and leaching copper from a copper sulfide ore; or a method of leaching copper from a copper sulfide ore, characterized by comprising leaching copper from a copper sulfide ore with the use of a leaching solution further containing water-soluble ligands such as chloride ions that can stabilize ferric (III) ions in addition to the above components, is provided.

Abstract: A heap leaching method to recover copper from a primary copper sulphide mineral wherein the mineral is leached in an acidic chloride/sulphate solution in the presence of oxygen with the surface potential of the mineral below 600 mV (vs. SHE) to cause dissolution of the copper sulphide.

Abstract: A process for leaching a value metal from a base metal sulfide ore, comprising the step of leaching the ore with a lixiviant comprising a chloride, an oxidant and hydrochloric acid is disclosed. The leaching is controlled, by use of low concentrations of hydrochloric acid and a redox potential, to effect formation of hydrogen sulfide from the base metal sulfide ore. The hydrogen sulfide is stripped from the leach solution, thereby reducing the amount of sulfate generated in the leach to very low levels. The leaching may also be conducted to limit the co-dissolution of platinum group metals and gold with the base value metals. The leach forms a value metal-rich leachate and a solids residue. The solids residue may be subsequently leached to recover the platinum group metals and gold. The value metal-rich leachate can be oxidized and neutralized to recover the value base metals. In an embodiment, the chloride is magnesium chloride and lixiviant solution is regenerated.

Abstract: A method for suppressing mercury dissolution during pressure oxidation of precious metal-containing materials in the presence of halogens and halides is provided. Pressure oxidation is performed under controlled oxidative conditions to maintain the mercury predominantly in the solid residue.

Abstract: A hydrometallurgical process for the treatment of complex silver-bearing sulfide ores and concentrates that recovers substantially all silver, lead, antimony, zinc, copper and sulfur, along with the chemical reagents utilized during the process. Finely ground ores and concentrates are leached under heat and pressure with water, sulfuric acid, nitric acid, oxygen, and a catalyst, and are further treated to recover silver in the form of silver chloride; iron in the form of iron hydroxide; copper and all traces of soluble toxic metals as sulfides; zinc as zinc ammonium sulfate and specifically nitric acid, sulfuric acid, oxygen, ammonia, and ammonium compounds as valuable fertilizer products.

Abstract: A process for recovering a precious metal from a sulfidic material comprises the steps of preparing an acidic aqueous halide solution having an oxidation potential sufficient to oxidize the sulfidic material and render the precious metal soluble in the solution, adding the material to the acidic aqueous halide solution so that the sulfidic material is oxidized and the precious metal is solubilized and separating the precious metal from the oxidized sulfidic material. In addition, a process for removing a contaminant from a contaminated sulfidic material comprises the steps of mixing the material in an aqueous solution wherein a multi-valent species of a relatively high oxidation state oxidizes the contaminant to render it soluble in the solution, produces a contaminant refined material, and is reduced to a relatively lower oxidation state; and removing the contaminant from the solution while regenerating the multi-valent species to its relatively high oxidation state.

Abstract: The invention relates to a method for recovering gold in connection with the hydrometallurgical production of copper from a waste or intermediate product containing sulphur and iron that is generated in the leaching of the copper raw material. The recovery of both copper and gold occurs in a chloride environment. The gold contained in the waste or intermediate is leached by means of divalent copper, oxygen and alkali bromide in a solution of copper (II) chloride and alkali chloride, in conditions where the oxygen-reduction potential is a maximum of 650 mV and the pH a minimum of 0.5. The bromide accelerates the dissolution of the gold.

Abstract: Methods and systems for removing copper minerals from a molybdenite concentrate. One embodiment provides leaching copper from the molybdenite concentrate with a leaching solution comprising ferric chloride, removing molybdenite from the leaching solution, introducing an acid into the leaching solution and introducing O2, O3, or a combination of both, into the leaching solution. A method for regenerating ferric chloride in a leaching solution is also provided. One embodiment provides adding a leaching solution comprising Fe(II) ions, Fe(III) ions, or a combination of both, to a mixture of mineral sulfides, introducing an acid into the leaching solution, and introducing O2, O3, or a combination of both, into the leaching solution.

Abstract: The invention relates to a method, by means of which the valuable metals contained in a sulphidic, multicomponent concentrate are recovered using hydrometallurgical treatment. One constituent of the concentrate is copper sulphide, which is leached using an alkali chloride-copper (II) chloride solution. The sulphides of other valuable metals, such as zinc, nickel, cobalt and lead are leached before copper leaching and each is recovered as a separate product before copper recovery.

Abstract: A process for leaching a value metal from a base metal sulfide ore, comprising the step of leaching the ore with a lixiviant comprising a chloride, an oxidant and hydrochloric acid is disclosed. The leaching is controlled, by use of low concentrations of hydrochloric acid and a redox potential, to effect formation of hydrogen sulfide from the base metal sulfide ore. The hydrogen sulfide is stripped from the leach solution, thereby reducing the amount of sulfate generated in the leach to very low levels. The leaching may also be conducted to limit the co-dissolution of platinum group metals and gold with the base value metals. The leach forms a value metal-rich leachate and a solids residue. The solids residue may be subsequently leached to recover the platinum group metals and gold. The value metal-rich leachate can be is oxidized and neutralized to recover the value base metals. In an embodiment, the chloride is magnesium chloride and lixiviant solution is regenerated.

Abstract: In a method for leaching gold from copper sulfides, the sulfide ores are first subjected to leaching of copper, thereby producing a leaching residue having 7.9% or less of the copper content. This leaching residue is mixed with a leach liquor, which contains the chloride ion and ferric ion and has 1.9 or less of pH. Gold and copper can be effectively leached from the copper sulfide ores. Ordinarily used oxidizing reagents such as hydrogen peroxide or nitric acid are not used. The gold, copper and iron can, therefore, be leached in a single process and by using an identical leaching liquor. The rate of gold leaching reaction can be enhanced by the co-presence of either copper or bromide ion or both together with the chloride and iron ion.

Abstract: A silica nanofiber is derived from a crystalline polymer filament of a polymer including straight chain polyethyleneimine backbones, which is capable of forming a water-insoluble crystal in the presence of water molecules at room temperature, and the crystalline polymer filament in the silica concentrates metal ions, thereby realizing a composite nanofiber including metals or metal ions in the silica. Furthermore, the composite nanofiber of the present invention can be easily produced by fixing a polymer structure in the silica as the scaffold for metal ions and concentrating metal ions at the scaffold or reducing the metal ions. Furthermore, a metal-containing silica nanofiber can be easily obtained by removing a polymer component from the composite nanofiber, the composite nanofiber association, and the complex nanofiber structure. These nanofibers can be assembled and integrated, and the assembled or integrated association or structure can realize various shapes.

Abstract: A method for treating a polymetallic sulfide ore containing gold and/or silver, and further containing base metals selected from the group consisting of iron, aluminum, chromium, titanium, copper, zinc, lead, nickel, cobalt, mercury, tin, and mixtures thereof, is disclosed. The method comprises the steps of grinding the polymetallic sulfide ore to produce granules, oxidizing the granules to produce oxidized granules, and chloride leaching the granules using a brine solution including dissolved halogens, as well as chloride and bromide salts.

Abstract: A chemical process to leach copper concentrates in the presence of a concentrated solution of sulfates and chlorides. The process includes forming a high reactivity chemical paste containing a high concentration of ions in the liquid phase of the paste which react with copper ores and forms a series of soluble salts. The salts are extracted by a simple wash. Mixing equipment for handling high viscosity liquids is used. The total mixing time is about 5 minutes, after which the paste is poured into a rectangular mold, of several hundred meters per side, and is left to settle and breathe. During settling, water and sulfuric acid are added at intervals to replace that consumed by the reactions taking place during the aeration, until the reactions have virtually end. This treatment results in a dry, very resistant mass, containing the copper extracted in form of chlorine salts, and sulfate.

Abstract: The invention concerns a method for detecting or quantifying a biological substance coupled with a colloidal metal particle by electrochemical detection, characterised in that it comprises a step which consists in dissolving by chemical treatment of said colloidal metal particle, prior to detection.

Abstract: A key-operating device includes a shell confining a chamber therein and connected to a video game apparatus with depressible keys, a lever pivotally mounted in the chamber and having protrusions projecting toward the keys, a wheel surrounding and connected to the shell and rotatable relative to the shell, and an actuating member projecting from the wheel and engageable with the lever in such a manner that rotation of the wheel results in engagement between the actuating member and the lever so as to permit fulcrum movement of the lever and pressing of the keys by the protrusions.

Abstract: A hydrometallurgical process utilizing an atmospheric calcium chloride leach to selectively recover from various metal feed stocks (consisting of elemental metals, metal oxides, metal ferrite, metal hydroxide, metal carbonates, metal sulfate/sulfur compounds, and their hydrates, specifically including but not limited to EAF Dust KO61) zinc, lead, cadmium, silver, copper and other valuable metals to the exclusion of iron, magnesium, halogen salts and other unwanted elements. The process solves the problem of iron and magnesium leach solution contamination because iron is unexpectedly converted to magnetite. The heavy metals are cemented out of solution using zinc or other selected dust at a pH of 6 or greater under unique and unexpected conditions, which do not require acid.

Abstract: The present invention is directed to microemulsion techniques for rapidly preparing photochromic glass nanoparticles and to the photochromic glass nanoparticles so prepared. More particularly, the method of the invention comprises the combination of two microemulsions, one containing a water-soluble silver salt and a glass precursor and the other containing a halide salt and an initiator for glass formation, which process rapidly yields silver halide particles. This invention gives nanometer-sized silver halide particles embedded in glass, thus providing photochromic glass nanoparticles without further annealing, or at most mild annealing. These nanoparticles are valuable as added components to any macro-material that one might wish to have photochromic properties. The particles would impart photochromism while not affecting the physical properties of the material.

Abstract: A process for the extraction of copper from a sulphide ore or concentrate comprises the steps of subjecting the ore or concentrate to pressure oxidation in the presence of oxygen and an acidic solution containing halide and sulphate ions to obtain a resulting pressure oxidation slurry. The slurry is subjected to a liquid/solid separation step to obtain a resulting pressure oxidation filtrate and a solid residue containing an insoluble basic metal sulphate salt. The basic metal sulphate salt is leached in a second leaching with an acidic sulphate solution to dissolve the basic metal salt to produce a leach liquor containing a metal sulphate, e.g. copper sulphate, in solution and a resulting solid residue. The leach liquor is separated from the solid residue and subjected to a solvent extraction process to produce metal concentrate solution and a metal depleted raffinate. At least a portion of the raffinate is recycled to the pressure oxidation after being subjected to evaporation.

Abstract: Precious metal values, e.g., platinum, palladium and rhodium, and, optionally, other valuable elements, e.g., one or more rare earths and cerium in particular, are recovered from a wide variety of compositions of matter and articles of manufacture, for example waste or spent catalysts such as vehicular postcombustion catalysts, by (i) optionally comminuting such composition/article into a finely divided state, (ii) intimately admixing the composition/article with sulfuric acid, (iii) calcining the resulting admixture at a temperature ranging from 150° to 450° C., and (iv) leaching the calcined admixture in an aqueous medium, whether simultaneously or separately, with H+ ions and chloride ions, whereby obtaining (1) a solid residue substantially depleted of such precious metal values and, optionally, of such other elements, and (2) at least one liquid solution comprising such precious metal values and, optionally, such other elements.

Abstract: A method for dissolving noble metals out of segregated ores containing noble metals, comprising: reducing noble metal oxides present to the individual metals in finely divided form; oxidating the segregated ores and/or the noble metals with HCl and chlorate to yield a solution or suspension having a concentration of H+ ions of at least 1 mol/l, a concentration of Cl− ions of at least 1 mol/l and a temperature of at least 50° C.

Abstract: Disclosed is a process for leaching copper from copper sulfide using bacteria, which ensures that the rate of leaching of copper increases to reduce the leaching time period and that the rate of leaching of primary copper sulfide contained in ores is increased. The process comprises using an acid leaching solution that includes both or any one of iron oxidizing bacteria and sulfur oxidizing bacteria in a concentration of 106 microbes/mL, the acid leaching solution having a redox potential of from 550 to 750 mV and 5 g/L or more of iron, the ratio of trivalent iron ions to bivalent iron ions (Fe3+/Fe2+) in the acid leaching solution being 50 or more.

Abstract: A method for extracting metals from metal-containing materials, especially waste, by pyrohydrolysis. The metal-containing materials which contain at least one or more of the metals from the group consisting of Zn, Cd, Pb, Hg, Cu, Sn (as Sn(0) and Sn(II)), As, Sb, Au, Ag and Bi, are made to react at 700-1100.degree. C., advantageously 800-900.degree. C., with a gas composition which at least comprises 25-45% by volume of water vapor, 0-12% by volume of carbon dioxide, 2-20% by volume of hydrogen chloride, 0-15% by volume of carbon monoxide, the remainder being nitrogen and possibly oxygen. The metals from the above-mentioned group are extracted in the form of volatile metal chlorides.

Abstract: Copper and nickel are extracted from their elemental state, complex sulfides, ores, and other materials such as scrap by leaching them with a solution containing halogen salts: bromine/bromide, or iodide/iodine, oxygen and sodium or potassium nitrate. The invented process is particularly effective for chalcopyrite and pentlandite in an autoclave at a temperature of 100.degree. C.-150.degree. C.

Abstract: The production of a silver halide emulsion in an aqueous protective colloid solution by the reaction of, on the one hand, silver nitrate, and, on the other, at least one water-soluble halide, may be performed particularly simply and with great apportioning accuracy, if, during at least part of the precipitation, at least the predominant part of one reactant is added in the form of a solid salt to the aqueous protective colloid solution.

Abstract: There is disclosed a process useful for the extraction of gold, silver, and the platinum metals from precious metal containing ores which poses no threat to the environment or the ground water. The process utilizes sodium bromide, sodium chloride, and potassium monopersulfate to react with a water slurry of the precious metal containing ore which has been reduced to a minimum particle size of 250 mesh. The leaching out of the gold, silver, and the platinum metals occurs when the oxidation-reduction potential is maintained at +600 to +900 with the pH at 3.2 to 3.6. After the precious metals have been dissolved into solution, the ore tailings are filtered and discarded. The pregnant leach liquor is pumped to a holding tank where it is subsequently reacted with a solution of sodium hydroxide and sodium borohydride at a pH of 8.2 to 8.6 and the oxidation-reduction parameter held at -550 to -650.

Abstract: A method is provided for the dissolution of at least one precious metal selected from the group consisting of platinum group metals, gold and silver. The method comprises subjecting a material containing at least one of the precious metals to dissolution with a sulfuric acid solution maintained at a pH at least sufficient to complex the precious metal with bromide ions in the presence of an oxidizing agent, the amount of bromide ions in the solution being at least sufficient to form a soluble complex of the precious metal. The amount of oxidizing agent is at least sufficient to maintain a redox potential at least high enough to convert the precious metal to an ionic form conducive to forming a soluble bromide complex thereof.

Abstract: A quaternary ammonium trihalide, a novel compound, represented by the formula:[A--R'].sup.+ .multidot.X.sub.3.sup.-(wherein A stands for a trialkyl-amino radical or a pyridyl radical, R' for an alkyl radical of 6 to 22 carbon atoms, and X for a halogen atom) and a method for the dissolution of a metal with a liquid consisting essentially of an organic solvent and the quaternary ammonium trihalide.

Abstract: Disclosed is a process for recovering precious metals using a combination of smelting and an effective utilization of molten salt chlorination. More specifically, disclosed is a process including the steps of (i) contacting, for example, a matte with a chloride salt containing at least one of potassium, cesium or rubidium, but not sodium or lithium to form a matte/salt solids mixture, (ii) introducing the solids mixture into a chloride melt having a temperature ranging from 300.degree. C. to 650.degree. C., said melt containing at least one of potassium, cesium, rubidium, sodium or lithium, (iii) introducing a chlorine containing gas into the melt, and (iv) maintaining the salt ratio in the matte/salt mixture at a stoichiometrically equivalent amount with the precious metals and base metals contained in the matte.

Abstract: A process for separating precious metals from an MnO.sub.2, sulfidic or carbonaceous refractory ore or refractory feed such as tailings is provided. The process includes the step of leaching a feed with a leach liquor that includes an acid selected from the group of HCl and H.sub.2 SO.sub.4 in the presence of MnO.sub.2 and a reductant. A source of chloride ion is added to the leach sufficient to dissolve at least about 50% of the precious metals present in the ore. A portion of the leach is removed and precious metals are recovered from the removed portion. A portion of the chloride carrier is recycled to the leach to carry chloride values to the leach. In one embodiment, HCl is regenerated by pyrohydrolysis, which minimizes harmful waste products. The present process can advantageously avoid the use of noxious reagents.

Abstract: Metal values are solubilized from ore by a lixiviant having a pH from 5 to 8, comprising an aqueous solution of a chloride salt and a hypochlorite salt. Cyanuric acid may be added to retard decomposition of the lixiviant. In one alternative embodiment, any remaining hypochlorite ions are then eliminated by adding hydrogen peroxide or a reducing agent to the pregnant lixiviant. Metal values are recovered by reduction using carbon, electrowinning, or other conventional techniques. In an alternative embodiment for extraction of gold or silver, the steps are combined by using finely ground ore containing sulfides or carbonaceous material to both reduce any remaining hypochlorite ions and precipitate the metal values from the lixiviant. The lixiviant can then be regenerated either by electrolysis or addition of hypochlorite salt.

Abstract: From an ore containing gold and silver, the gold and silver are extracted by a method which comprises pulverizing the ore and bringing the pulverized ore into contact with an elemental halogen, a halogenated salt, and an organic solvent thereby converting the gold and silver into polyhalogeno anionic complexes and consequently dissolving them in the organic solvent.

Abstract: Aqueous iodine-iodide etching solutions are employed in the recovery of precious metals. Elemental iodine is precipitated from spent etching solutions and used to supply both the iodine and iodide of new etching solutions. Prior to extraction of the elemental iodine, used solutions, if not substantially contaminated, may be oxidized and recycled for further precious metal recovery. Aqueous etching solutions of hydriodic acid and iodine, or of ammonium iodide and iodine may be employed. Etching in such solutions, as well as in solutions of iodine and an alkali metal iodide, such as potassium iodide, may be accelerated by the use of small amounts of hydrogen peroxide (or equivalents) during etching.

Abstract: A metal is dissolved by a method which comprises establishing contact of the metal with a quaternary ammonium compound and a halogenated hydrocarbon or with a quaternary ammonium compound, a halogenated hydrocarbon, and a polar solvent.

Abstract: The invention provides a hydrometallurgical process for extracting noble metals from raw materials containing the same, comprising(a) leaching the raw materials with a mineral acid to leave a residue containing the noble metals,(b) treating said residue with a substantially non-aqueous liquid comprising bromine and an apolar organic solvent in which bromine dissolves, to form a complex of the formulaR[MeBr.sub.x ]whereinx=4-6Me=Au, Ag, Pt, PdOs, Ru, Rh, Irand R is an organic moiety of the solvent, and(c) subjecting the complex-containing substantially non-aqueous liquid to electrolysis whereby noble metal is deposited on the cathode and removable therefrom and bromine liquid is formed at the anode and immediately dissolves in the organic solvent.

Abstract: A method of treating a gold-bearing ore to render the gold component of the ore more amenable to standard cyanidation treatment in a reduced amount of time is disclosed. An aqueous slurry of the gold-bearing ore is introduced into at least one vessel. An oxidizing agent, such as chlorine gas, an alkali metal hypochlorite and an alkaline earth metal hypochlorite, is rapidly introduced into the vessel so that it intimately contacts the aqueous slurry. While the oxidizing agent is being introduced into the vessel, the slurry is agitated with agitating means including a plurality of impeller blades that provide high shear agitation and a large interfacial surface area between the oxidizing agent and the liquid phase of the slurry to enhance the mass transfer of the oxidizing agent so that it becomes substantially completely adsorbed by the aqueous slurry in about 5 to about 15 minutes.

Abstract: A process for the hydrometallurgical recovery of metal value, particularly copper, from copper-containing sulphide materials in which the material is conventionally ground and reacted with a solution containing less than 3 moles per liter of chloride ion, and optionally as little as 15 g/liter, together with sulphate ions with continuous oxygen injection and vigerous agitation. The reacting may be carried out at a pH in the range of 0.5-4, at moderate pressure as low as atmospheric pressure and at a moderate temperature below the boiling point of the solution such as 85.degree. C.

Abstract: Aqueous effluent solutions containing metal cations may be treated with an extractant comprising an organophosphinic acid, a di-2-ethylhexyl phosphoric acid and/or an aliphatic amine to selectively separate chromium, nickel, cobalt, copper and lead cations from the aqueous solution. Typical extraction techniques include liquid-liquid extraction employing either mixer settlers or columns, liquid membrane extraction and selective supported membrane extraction.