Abstract: A method for recovery of precious metals from copper anode slime may include leaching a leach liquor out of the copper anode slime by mixing the copper anode slime with a mixture of nitric acid and sulfuric acid, separating silver from the leach liquor by forming a silver chloride precipitate in the leach liquor by mixing a supersaturated sodium chloride solution with the leach liquor at room temperature and obtaining a first filtrate by filtering the silver chloride precipitate out of the leach liquor. Copper may be separated from the first filtrate by forming a copper hydroxide precipitate in the first filtrate by adjusting pH of the first filtrate at 9 and obtaining a second filtrate by filtering the copper hydroxide precipitate out of the first filtrate. Metallic selenium may be recovered from the second filtrate by reducing the metallic selenium via a chemical reduction utilizing L-ascorbic acid (LAA) as a reducing agent.

Abstract: High photoluminescence, high stability, inorganic perovskite compounds comprising an alkali metal selected from potassium (K), rubidium (Rb), and cesium (Cs); copper (Cu); and at least one halogen selected from chlorine (Cl), bromine (Br), and iodine (I). The perovskites may be free of lead (Pb). The inorganic perovskite compound may be used in an optoelectronic device. The optoelectronic device optionally contains a phosphor such as a blue-emitting phosphor. The inorganic perovskite compound may be used as an anti-counterfeiting nanotaggant applied on or within an object that susceptible to counterfeiting to enable confirmation of an authentic object.

Abstract: A guide system for use in electro-processing a bore of a gun barrel includes a non-conductive external bore guide and a non-conductive internal bore guide. The external bore guide is an adapter that is configured to removably engage the outside of the gun barrel and includes a conduit formed therein. The conduit is disposed such that it is axially aligned with a bore of the gun barrel when the external bore guide is engaged with the gun barrel. The internal bore guide is elongated and includes an axial recess that is sized to seat an electro-processing electrode (an anode). A method for uniformly plating the bore includes moving an anode through the gun barrel at one or more rate(s) of travel to uniformly plate the bore is also disclosed. The plating is sufficiently uniform to conform to military specifications. The systems, methods, support structures, etc. described herein are particularly well-suited to plating small-bore gun barrels.

Abstract: Copper is produced by a looping oxidizing process wherein oxidation of copper sulfide concentrate to molten blister copper by conversion with copper oxides (and optionally oxygen from air) in a one step, molten bath operation to produce molten blister copper, iron oxide slag, and rich SO2 off gas. The blister copper is treated in an anode furnace to reduce the iron content and oxidize residual sulfur, and prepare it for either electrolysis or reoxidation.

Abstract: Various embodiments provide a process roasting a metal bearing material under oxidizing conditions to produce an oxidized metal bearing material, roasting the oxidized metal bearing material under reducing conditions to produce a roasted metal bearing material, leaching the roasted metal hearing material in a basic medium to yield a pregnant leach solution, conditioning the pregnant leach solution to thrill a preprocessed metal bearing material; and leaching the preprocessed metal bearing material in acid medium.

Abstract: The invention relates to the use of aqueous guanidinium formiate solutions, optionally combined with urea and/or ammonia and/or ammonium salts, for the selective catalytic reduction of nitrogen oxides using ammonia in exhaust gases of vehicles. The inventive guanidinium formiate solutions enable a reduction of the nitrogen oxides by approximately 90%. Furthermore, said guanidinium formiate solutions can enable an increase in the ammonia forming potential from 0.2 kg, corresponding to prior art, up to 0.4 kg ammonia per liter of guanidinium formiate, along with freezing resistance (freezing point below ?25° C.). The risk of corrosion of the inventive guanidinium formiate solutions is also significantly reduced compared to that of solutions containing ammonium formiate.

Abstract: The present invention relates to a process for chemical extraction of gold and silver from low grade and refractory pyritic concentrates containing minimum 1 ppm Au, by their leaching in enamelled cast iron reactors, steel plated lead or plastic coated steel, at room temperature, in ammoniac solutions (pH 8-10) of sodium thiosulfate (50-60 g/l Na2S2O3. 5 H2O) with a divalent copper salt as catalyst (3-4 g/l Cu).The suspension resulting after 2-4 hours of reaction is filtered. The thiosulfate solution containing minimum 5 mg/l undergoes an electrolysis process with insoluble anodes. Copper, gold and silver is deposited in the cell as a sludge, and the electrolyte having a maximum content of Au of 1 mg/l, is recycled to the leaching operation of raw material, after correction of copper content and alkalinity to the baseline values.

Abstract: Various embodiments provide a process roasting a metal bearing material under oxidizing conditions to produce an oxidized metal bearing material, roasting the oxidized metal bearing material under reducing conditions to produce a roasted metal bearing material, leaching the roasted metal hearing material in a basic medium to yield a pregnant leach solution, conditioning the pregnant leach solution to thrill a preprocessed metal bearing material; and leaching the preprocessed metal bearing material in acid medium.

Abstract: Combustion flue gas containing NOX and SOX is treated to remove NOX in a multistep system in which NOX is reduced in the flue gas stream via selective catalytic reduction or selective non-catalytic reduction with ammonia or an ammonia-forming compound, followed treatment with hydrogen peroxide to remove residual ammonia and, optionally, treatment with an alkali reagent to reduce residual NOX in the flue gas stream. The NOX-depleted flue gas stream may also be subjected to a desulfurization treatment for removal of SOX.

Abstract: Processes for metal leaching/solvent extraction are described which comprise: (a) providing a first aqueous leach pulp which comprises a mixture of leached solids and an aqueous leach solution comprising a metal, a leaching agent and water; (b) subjecting the first aqueous leach pulp to a first solid-liquid separation to provide a first clarified aqueous leach solution and a second aqueous leach pulp, wherein the second aqueous leach pulp comprises the leached solids at a % solids level greater than the first pulp; (c) subjecting the first clarified aqueous leach solution to a first solvent extraction prior to any significant dilution, whereby a first aqueous raffinate is obtained; (d) subjecting the second aqueous leach pulp to a second solid-liquid separation with dilution via an aqueous stream to obtain a second clarified aqueous leach solution; and (e) subjecting the second clarified aqueous leach solution to a second solvent extraction whereby a second is aqueous raffinate is obtained.

Abstract: The invention relates to a method for the selective catalytic reduction of nitrogen oxides using ammonia in exhaust gases of vehicles, whereby solutions of guanidine salts with an ammonia forming potential of between 40 and 850 g/kg, optionally in combination with urea and/or ammonia and/or ammonium salts, are catalytically decomposed in the presence of catalytically active, non-oxidation-active coatings of oxides selected from the group containing titanium dioxide, aluminum oxide, silicon dioxide or the mixtures thereof, and hydrothermally stable zeolites which are fully or partially metal-exchanged. The guanidine salts according to the invention enable a reduction of the nitrogen oxides by approximately 90%. Furthermore, said guanidine salts can enable an increase in the ammonia forming potential from 0.2 kg, corresponding to prior art, up to 0.4 kg ammonia per litre of guanidine salt, along with freezing resistance (freezing point below ?25° C.).

Abstract: Process for the production of ammonium thiosulfate from gas streams comprising ammonia and hydrogen sulfide. One embodiment of the invention provides absorbing SO2 into a solution of ammonium sulfite and then contacting gaseous feed streams with portions of the resulting solution in a plurality of contact zones where portions of ammonium sulfite in the liquid streams are converted to ammonium thiosulfate upon contact with the gaseous feed streams.

Abstract: Process for producing a copper-containing aqueous solution, in which a copper mass is dissolved in the presence of air in an aqueous leach liquor containing monoethanolamine and an acid, wherein the amount of acid equivalents is between 0.05 and about 0.7 times the equivalents of monoethanolamine, and wherein the rate of copper dissolution into the aqueous leach liquor is greater than about 4.3 grams of copper per liter of leach liquor per hour until a product having at least about 80 grams per liter is obtaine.

Abstract: A method for producing a copper/palladium colloid catalyst useful for Suzuki couplings.

Abstract: Process for producing a copper-containing aqueous solution, in which a copper mass is dissolved in the presence of an oxidant in an aqueous leach liquor containing monoethanolamine and (HMEA)2CO3. The leach liquor is produced by partially carbonating the monoethanolamine.

Abstract: A method for extracting metals from minerals is provided that involves the leaching of metals with a leaching agent comprised of a biomass of microorganisms having a chemo-organotrophic type of exchange which are grown in a nutrient medium. The microorganisms having chemo-organotropic type of exchange are selected from natural materials and may include acetic bacteria, pseudomonades, and sulfuric bacteria. The leaching is carried out with the consumption of biomass not less than 3×10−3 kg per 1 kg of mineral raw material. A water solution of higher carbohydrate polymers is used as a nutrient medium and a mineral additive may be added thereto. Phosphate of ammonia, ammonium chloride, a mixture of phosphate of ammonia and ammonium chloride, or sodium chloride is used as the mineral additive. Vegetative residues, sawdust, cane, sedge, and household wastes are used as the higher carbohydrate polymers.

Abstract: A process for refining noble metals from auriferous mines, wherein the auriferous material is first milled and treated with a cyanide solution, and comprising: a step for the pretreatment of the auriferous material, wherein the complexes of cyanide with noble metals are fixed on anionic resins and then incinerated; a predefining step, which comprises an etching of the materials incinerated during the pretreatment with a hydrochloric-nitric solution; and specific steps for refining the gold, palladium, platinum and silver.

Abstract: The invention relates to a process for recovering the transition metal component of catalysts used in the hydroconversion of heavy hydrocarbonaceous materials. In accordance with the invention, a slurry of a transition metal catalyst and hydrocarbon is catalytically desulfurized resulting in a desulfurized product and a solid residue containing the transition metal. The transition metal may be recovered by coking the residue and then dividing the coker residue into two portions are combusted with the flue dust from the first combustion zone being conducted to the second combustion zone. The flue dust from the second combustion zone is treated with ammonia and ammonium carbonate in order to obtain ammonium molybdate.

Abstract: Methods for decontaminating toxic waste, particularly solid carrier materials, such as soil contaminated with a toxin, or solid mixed wastes are more efficiently decontaminated with solvated electrons by first extracting the toxin from the carrier with a nitrogenous base at elevated temperatures, followed by a temperature reduction before initiating chemical reduction of the toxin with solvated electrons. Pre-extraction of the toxin at elevated temperatures followed by temperature reduction minimizes competing side reactions, improves selectivity of solvated electrons for the toxin and improves the economics of the process with more efficient metal utilization. The process can be performed without separation of the toxin from the extraction vessel holding the solid carrier material. Alternatively, elevated temperatures can be used to perform one or more extractions of toxin with nitrogenous base followed by reduction with solvated electrons by performing the reaction in a separate reactor.

Abstract: The process of recovering precious metals from ores containing precious metals, such as gold and silver, from an aqueous ammoniacal thiosulfate leach solution to provide a significant practical and economical process for the recovery of gold or silver is disclosed. After leaching of the ore with an aqueous ammoniacal thiosulfate solution, the leach solution is contacted with a precious metal extraction reagent to extract the precious metal values from the leach solution, after which the precious metal values are stripped from the extraction reagent to form a concentrated solution of the precious metal values from which the precious metals may be recovered by conventional methods such as electrolysis. The extraction reagents are those having guanidyl functionality or a quaternary amine functionality mixed with a weak organic acid such as a phenol.In the process, novel thiosulfate complexes of the precious metals are formed with the quanidyl or the quaternary amine extractants.

Abstract: A process for removing and recovering ammonia from the organic extraction phase in a metal liquid-liquid extraction process in which at least one ammoniacal aqueous solution (either a leach feed solution containing the metal to be extracted or an aqueous stripping solution employed to strip the metal values from the organic phase) is contacted with the organic phase which comprises a water insoluble, water immiscible hydrocarbon solvent solution of a water insoluble organic extractant for the metal.

Abstract: The quaternary Zintl material (Et.sub.4 N).sub.4 ?Au(Ag.sub.1-x Au.sub.x).sub.2 Sn.sub.2 Te.sub.9 ! that contains 1-D semiconducting chains composed of four metallic elements is prepared by treating ethylenediamine extracts of a pentanary K--Au--Ag--Sn--Te alloy with Et.sub.4 NI.

Abstract: A method for producing copper oxide. In the method, a copper bearing material, aqueous ammonia, and a sufficient amount of an ammonium salt to double the rate of production of copper oxide in the absence of the salt are placed in a single vessel. The vessel is closed, and oxygen is fed into the vessel. The mixture is stirred and heated to a temperature of between approximately 70.degree. and 130.degree. C. to dissolve the copper bearing material into aqueous ammoniacal copper ion. The aqueous ammoniacal copper ion is reacted with the oxygen in the vessel to form solid copper oxide particles, which are then recovered.

Abstract: After optional preliminary treatment, solid wastes are processed in accordance with the flowsheet FIG. 1: first, Cu is leached selectively with a leaching solution containing Cu(II) ammine as a leachant according to the autooxidation or the autocatalytic action which proceeds depending on the equations: ##STR1## and the Cu(II) ammine concentrated in the leaching solution is extracted with a solvent Lix-54; thereafter, Cu.sup.2+ is stripped so that it moves into a Cu electrolyte and Cu electrowinning is performed to have metallic Cu deposited at the cathode, with the total process being carried out in a closed circuit. By this process, copper and other nonferrous metals can be selectively recovered from motor scrap and shredded solid wastes such as abandoned automobiles and home electric appliances in a simple and economical manner.

Abstract: A method for the recovery of copper from copper-containing materials, for example, scrap, ores or dust. An aqueous cupric tetrammine sulfate lixiviant is contacted with the copper-containing material to produce a leachate containing cuprous, nickel, and zinc ions, ammonium sulfate and free ammonia. Copper can be recovered from the leachate by electrolysis. Nickel and zinc can be precipitated from the resulting spent electrolyte by oxidizing substantially all of the cuprous ions in the copper ammine sulfate solution to cupric ions and lowering the pH of the solution to a range from about pH 7.5 to about pH 8.0 in order to form a precipitate. Alternatively, copper sulfate can be added to the cupric ammine sulfate-containing solution in order to form nickel and/or zinc containing precipitate.

Abstract: Platinum group metals, gold and silver are extracted from complex ores, automobile scrap, refractory ores and as naturally occurring by leaching the precious metal containing materials with a solution containing halogen salts such as potassium or sodium iodide and bromide in the presence of ammonium ions and oxygen. The precious metal containing materials and reactants are charged into a reaction zone held at high temperatures and pressures to form a slurry containing a precious metal ion solution. The precious metal ion solution is separated from the slurry and subjected to recovering techniques to recover the precious metals.

Abstract: A method is described for providing a body of first material and a body of second material in a chemical environment wherein the first material contains first constituents having a lower and higher oxidation state and wherein the second material contains constituents having an oxidation state of energy greater than lower oxidation state of the first constituent. The environment is further provided with first cations energetically disposed for receiving electrons from the first constituents but not energetically disposed for receiving electrons from the second constituents. Electrons transfer from the first constituents to the first cations which are transformed thereby into second cations of lower oxidation state resulting in first body releasing into the environment third cations which are cations of the first (lower) oxidation state of the first constituent.

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: Method for recognition of noble metals otherwise not recognizable in base material clusters includes using an electron beam furnace in which base material clusters are vaporized by means of an electron beam gun, and the vaporized materials are condensed as free atoms or are alloyed with other components of the base materials, and are able to be recovered by conventional recovery techniques once they are recognized. The base material includes the products of smelting processes, pellets of compacted raw material, like anode-mud or waste material, and the base materials are remelted utilizing the heat from electron beam guns for the remelting.

Abstract: A process for recovery of metal from a feedstock comprising copper is provided. The process comprises the steps of:(a) contacting the feedstock with an aqueous mixture comprising ammonium nitrate having a concentration greater than about 1.5M and sulphuric acid having a concentration greater than about 6M at a temperature of from about 105.degree. C. to about 130.degree. C., to produce a first residue comprising a cuprous salt and a leachate comprising copper;(b) separating the residue from the leachate; and(c) electrowinning copper from the leachate.The process may also be used advantageously to recover iron present in the feedstock in a form other than jarosite.

Abstract: A hydrometallurgical method is provided for recovering copper from particulate copper sulfide flotation concentrate containing at least about 20% copper by weight as cuprous and cupric sulfide, a significant portion of the copper in the copper sulfide concentrate being in the cuprous state. The flotation concentrate in the finely divided state is subjected to leaching with an alkaline solution of ammonia plus ammonium sulfate at a temperature ranging from about 10.degree. C. to 95.degree. C., preferably about 20.degree. C. to 40.degree. C. the amount of concentrate being proportioned at least stoichiometrically to the ammonia concentration of the leaching solution.

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: Gold and silver are extracted from their elemental state or from complex ores and alloys by leaching them with a solution containing ammonia, ammonium salts and one or more oxidants. The process is particularly effective for refractory gold ores including sulfide and carbonaceous ores.

Abstract: A process for treating copper containing precious metal ores prior to cyanidation and recovery of the precious metal eg gold. The process involves addition to the ore before or after milling of a water soluble or water dispersible surface active agent in the form of a fatty alkyl amine preferably an ethoxylated fatty alkyl amine. The agent reduces the high cyanide consumption, which is caused by copper dissolution, by passivating the mineral surface.

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.

Abstract: A metal is dissolved by being brought into contact with at least one halogenated hydrocarbon in the presence of a cationic surfactant.

Abstract: The recovery of precious metals from refractory carbonaceous and sulfidic ores or concentrates is improved by subjecting an oxidized slurry of this type of ore to thiourea leaching in the presence of carbon instead of subjecting the slurry to cyanidation leaching.

Abstract: A method for obtaining silver and manganese metal from a silver-manganese ore includes the step of leaching the ore with acidified thiourea. More specifically, the method includes the step of leaching the ore with an acidic thiourea solution to form a leach liquor containing compounds of silver and manganese and an insoluble ore residue. The leach liquor is contacted with a quantity of activated carbon to adsorb the silver thiourea complexes on the carbon and to form an extract solution containing the manganese compounds. Next, the carbon which contains adsorbed silver thiourea complexes is contacted with an eluant to desorb the silver complexes from the carbon. The silver metal is recovered from the silver complexes obtained from desorbing the carbon. The manganese metal is recovered from the extract solution. The ore subjected to acidic thiourea leaching is selected from the group consisting of in situ ore, mined ore, comminuted ore, and ore concentrate.

Abstract: A process for the recovery of precious metals from ore containing the same is disclosed. The process includes the formation of a lixiviant solution including a thiourea compound, urea and an alkali lignin sulfonate. The ore is then exposed to this lixiviant solution to extract the previous metals therefrom, and the dissolved previous metals are then recovered from the solution.

Abstract: Precious metals such as gold and silver are recovered from difficult-to-treat ores, especially those containing manganese and/or copper, by lixiviating the ores using copper-ammonium thiosulfate in which the pH of the lixiviating solution is maintained at a minimum level of 9.5 in order to inhibit the action of metallic iron and its ferric salts that are present in the solution and which decomposes the double salt of copper-ammonium thiosulfate. Copper cement is used in a subsequent precipitation process to expose a large amount of area on which the gold and silver can precipitate without also causing precipitation of copper from the lixiviant solution.

Abstract: A process for the recovery of precious metals from ore containing the same is disclosed. The process includes the formation of a lixiviant solution including a thiourea compound, urea and potassium lignin sulfonate. The ore is then exposed to this lixiviant solution to extract the precious metals therefrom, and the dissolved precious metals are then recovered from the solution.

Abstract: Anhydrous zinc chloride is produced from an aqueous feed solution containing zinc chloride from an aqueous feed solution containing zinc chloride. The zinc chloride is extracted onto an organic extractant known to the art such as tributyl phosphate, primary, secondary or tertiary amines, and quaternary amine salts. The loaded extractant is then stripped with aqueous stripping solution containing ammonium chloride and ammonium hydroxide. The zinc ammine chloride formed in this aqueous stripping solution is separated from the stripping solution and can then be heated to form anhydrous zinc chloride and ammonia. This anhydrous zinc chloride is suitable as a feed material to a fused salt electrolysis process for the production of zinc.

Abstract: In a process for producing fine size cobalt metal powder from scrap material containing brazing compositions, the silver ions are removed by cementation with iron to form an insoluble mixture which is subsequently treated with concentrated hydrochloric acid to solubilize the silver which is then precipitated as silver chloride.

Abstract: Precious metals such as gold and silver are recovered from difficult-to-treat ores, particularly those containing manganese, by lixiviating using an ammonium thiosulfate leach solution containing copper, sufficient ammonia to maintain a pH of at least 7.0, and at least 0.05% sulfite ion, sulfite and thiosulfate requirements being maintained by the reaction in situ of sulfur dioxide and elemental sulfur.

Abstract: A novel process for enhancing the leaching rate of a mineral wherein the mineral is characterized by the tendency to form a reaction product layer during leaching. A suitable particulate modifier such as carbon is mixed with the mineral prior to leaching and selectively alters the characteristics of the reaction product layer. The process is particularly useful for leaching chalcopyrite, sphalerite and galena.

Abstract: Cuprous chloride is produced from the complex salt, 2KCl.CuCl, obtained as a by-product in the copper industry where chalcopyrite is decomposed in the presence of potassium chloride, by a series of steps involving reaction of an aqueous solution of the complex salt of potassium chloride and cuprous chloride with ammonia, separating the resulting solid potassium chloride from a solution containing cuprous chloride and ammonia, removing the ammonia from the solution to cause precipitation of the cuprous chloride and recovering solid cuprous chloride. Ammonia may then be recycled to the solution from which the cuprous chloride is removed and to which additional complex salt is added to repeat the cycle.

Abstract: Precious metals such as gold and silver are recovered from difficult-to-treat ores, particularly those containing manganese, by lixiviating using an ammonium thiosulfate leach solution containing copper, sufficient ammonia to maintain a pH of at least 7.5, and at least 0.05% sulfite ion.

Abstract: Process and apparatus for recovering a precious metal, either as pure metal or in alloyed form, from a bimetallic material in which the precious metal is mechanically bonded to a base material comprising at least one base metal, e.g., copper, brass or bronze. The base material is leached off with an ammoniacal solution of an ammonium salt, preferably ammonium carbonate, using a leaching liquid containing reactive oxygen. The base metal or metals are recovered as metal compounds by thermally decomposing the resulting pregnant leach liquor; and the ammonia and ammonium salt are reconstituted for recycling. The method and apparatus are particularly suited for recovering karat gold from filled gold scrap.

Abstract: The invention provides a process for the recovery of transition and post-transition metals the halides and pseudohalides of which are hyperlinearly soluble in excess halide or pseudohalide, and especially of silver as halide or pseudohalide from waste photographic paper, photographic film, and other sensitized materials.

Abstract: A process for the extraction of gold and silver from their ores in which the ore is reduced to a particle size of 1 mm or less and mixed with a lixiviant, e.g., alkaline sodium or potassium cyanide, in an amount to provide a liquor content of about 8 to 12%, the lixiviant coated particles are allowed to react for a time sufficient for the lixiviant to extract the noble metal and the particles washed with water to obtain a solution of the noble metal salt from which the noble metal is recovered.