Abstract: THIS invention relates to a process for the enhanced recovery of chromite and platinum group metals (PGMs) from a mixed chromite/PGM ore. Ore is ground 12, classified 14, to produce a coarse fraction and a fine fraction 36. The coarse fraction is subjected to gravity separation 16 and coarse particle flotation 20 to obtain a chrome concentrate and a PGM concentrate. The fine fraction 36 and PGM concentrate are ground 28, and subjected to conventional flotation 30 to obtain a PGM concentrate product 32. The benefits of this novel configuration of gravity concentration and coarse flotation technologies, as applied to both chromite and PGM recovery, are higher recoveries of chromite in a saleable concentrate, higher recoveries of PGMs and base metals, and lower chromite content in the PGM concentrate.

Abstract: Discloses a hydrometallurgical process and system for the recovery of precious metals; specifically palladium, rhodium, and platinum metals, at high purity and with limited waste and environmental fouling.

Abstract: A cost-effective method for recovering precious metals in circuit board components utilizes the basic principle of oxidation-reduction reaction, adopts a mixed solution of sulfuric acid and hydrogen peroxide and a mixed solution of hydrochloric acid, sodium chloride and sodium chlorate, and also adopts ammonia water and formaldehyde to reduce silver. According to the characteristic that the redox potential of gold and palladium ions is higher, the gold and palladium ions in the chlorination leaching solution are selectively reduced into elements by using a reducing agent which is low in price and moderate in reducibility, then the elements are separated through filtration to realize resource recycling.

Abstract: Disclosed is a method and a device for retrieving, from an object A, elements G present in a matrix M, the method including at least the following steps: bringing said abject A into contact with a dense fluid Fd with a molar mass greater than 2 g mol?1 under temperature T1 and pressure P1 conditions suitable for transforming the intergranular phase and for releasing the elements G, modifying the temperature T2 and/or pressure P2 values to stop the reaction transforming the intergranular phase, and recovering the elements G separated front the matrix M.

Abstract: This invention relates to an industrial process of manufacturing hydroxide precursor for lithium transition metal oxide used in secondary lithium ion batteries. More particularly, this process utilizes highly concentrated nitrate salts and is designed to mitigate waste production.

Abstract: The disclosure relates to pre-treatment of precious metal-bearing oxide ores, prior to precious metal leaching by thiosulfate. The process comprises mixing oxide ore in oxygenated water in the presence of a carbon-based material (e.g., activated carbon or other type of carbon). The carbon-based material can be separated from the ore slurry, and, the gold is thereafter leached by a thiosulfate lixiviant.

Abstract: The present invention is characterized by comprising: an acid leaching step for obtaining a leach liquid by causing leaching of, by means of an acid, a metal mixture at least containing vanadium and at least one type of a divalent or trivalent metal selected from nickel, cobalt, manganese, palladium, platinum, copper, and zinc; a complex generation step for adding an ammoniacal alkaline aqueous solution to the leach liquid for adjusting the pH to 10-12 and generating, in the alkaline aqueous solution, an ammine complex of a divalent or trivalent metal ion and an anion complex of a tetravalent and/or pentavalent vanadium ion; a divalent or trivalent metal recovery step for adding a carrier having a carboxyl group to the alkaline aqueous solution in which the ammine complex and the anion complex are generated, causing the divalent or trivalent metal ion in the ammine complex to be selectively adsorbed onto the carrier, and recovering the divalent or trivalent metal ion; and a vanadium recovery step for recoveri

Abstract: Methods, systems and lixiviation compositions including an ammonium thiosulfate or a non-ammonium thiosulfate component in combination with one or more alkaline earth metal hydroxides, and optionally copper cations, for leaching precious metals from a precious metal containing material. The alkaline earth metal hydroxides may include magnesium hydroxide, calcium hydroxide, or a combination of magnesium hydroxide and calcium hydroxide.

Abstract: The present invention provides a method for efficiently leaching copper from copper sulfide ore by separating and recovering iodine, and iron(III) ions to be used are regenerated by a heap of stacked ore in the method for leaching copper from copper sulfide using a sulfuric acid solution containing iodide ions and iron(III) ions as a leaching solution.

Abstract: A process is provided in which a silver- and base metal-containing material is contacted with an aqueous solution comprising an alkali and/or alkaline earth metal halide and an oxidant at a solution pH of at least about pH 6 to dissolve the silver into a pregnant leach solution while maintaining at least most of the base metal in the silver- and base metal-containing material.

Abstract: A hydrometallurgical process for recovery of metals and/or semimetals from waste materials, such as high-tech or green-tech wastes, and/or electrical and electronic waste containing compound semiconductor materials and/or back contact materials and/or transparent electrically conducting oxides (TCOs), wherein the waste materials according to the invention are mixed thoroughly with a reaction solution of water, 1 to 5% by mass sodium bisulphate and 1-5% by mass sodium chlorite or with a reaction solution of water, 1 to 50% by mass organosulphonic acid and in the stoichiometric ratio to the organosulphonic acid 1-5% by mass of an oxidizing agent, and the metals and/or semimetals that are to be recovered are dissolved.

Abstract: Disclosed is a method of leaching copper and gold from sulfide ores, which includes Process (1) of bringing a first aqueous acidic solution which contains chlorine ion, copper ion and iron ion, but no bromine ion, into contact with sulfide ores under supply of an oxidizing agent, so as to leach copper component contained in the sulfide ores; Process (2) of separating, by solid-liquid separation, a leaching reaction liquid obtained in Process (1), into a leaching residue and a leachate; and Process (3) of bringing a second aqueous acidic solution which contains chlorine ion, bromine ion, copper ion and iron ion, into contact with the leaching residue obtained in Process (2) under supply of an oxidizing agent, so as to leach gold contained in the leaching residue.

Abstract: The invention relates to modifications of a non-ammoniacal thiosulfate process of leaching precious metals (e.g. gold or silver) from precious metal-containing ores. The process involves leaching the ore with an aqueous lixiviant containing a soluble thiosulfate other than ammonium thiosulfate, a copper compound and an organic compound that serves as a copper ligand (i.e. a ligand-forming compound). Four modifications of this process are effective for increasing the amount of precious metal that can be extracted, reducing the consumption of materials, or for improving the rate of extraction. These four process, which may be used singly or in any combination, include (a) additions of soluble lead (e.g. as lead nitrate), (b) additions of thiourea, (c) increases in dissolved oxygen, and (d) increases of temperature at ambient pressure. This avoids the use environmentally harmful chemicals and allows for extraction from a variety of ores, e.g., containing substantial amounts of sulfides and/or quartz.

Abstract: A process of leaching gold can be inexpensively and efficiently carried out from a mixture containing sulfur and gold, typically from the material containing sulfur and gold that is an intermediate product recovered by the flotation method in the hydrometallurgical method. Specifically, the mixture containing elemental sulfur and gold and an aqueous solution of hydroxide of one or more of metals of alkali metals and alkaline earth metals are combined, the hydroxides reacting with elemental sulfur to form thiosulfate of alkali and/or alkaline earth metal, and the gold thereby being leached by reaction with the thiosulfate.

Abstract: The invention provides a recycling step in an oxidative pressure leaching process for recovery of metals using halide ions, in which a portion of the leached solids are recycled back to the feed to the autoclave, to allow two or more passes through the high temperature leaching step.

Abstract: The present invention relates to a process for recovering non-ferrous metals from a solid matrix comprising the following phases: (a) leaching the solid matrix with an aqueous-based solution containing chloride ions and ammonium ions and having a pH within the range of 6.5-8.5, in the presence of oxygen, at a temperature ranging from 100° C. to 160° C. and a pressure within the range of 150 kPa-800 kPa, so as to obtain an extraction solution comprising the leached metals and a solid leaching residue; (b) separating said solid leaching residue from said extraction solution; (c) subjecting said extraction solution to at least one cementation so as to recover the metals in the elemental state.

Abstract: Disclosed are methods and compositions for improving metal extraction processes by introducing at least one cationically charged compound selected from a group consisting of amines, particularly quaternary amines such as alkyldimethylbenzylammonium chlorides (ADBAC compounds), polyamines and other suitable cationic organic materials, and mixtures thereof, for neutralizing and/or coagulating excess anionic organic compounds including, for example, flotation reagents, surfactants, polymers, flotation reagent by-products and/or anti-scalant additives found in metal concentrate streams, and thereby reduce the downstream fouling of the activated carbon by these compounds.

Abstract: Disclosed is a method and apparatus for recovering rare metal, which separates and collects rare metals by making use of chemical actions in an efficient combination of adsorption and separation, thereby reducing work load and improving work safety. The method for recycling rare metals includes a leaching step in which a rare metal of palladium, platinum, and rhodium is mixed with hydrochloric acid into a hydrochloric acid mixture, which is then stirred at one atmospheric pressure or lower at a temperature from 50 to 90 degrees Centigrade. The vapor resulting from the stirring is condensed, and the hydrochloric acid resulting from the condensing is fed back to the original hydrochloric acid mixture to produce a hydrochloric acid leaching solution. The hydrochloric acid leaching solution produced in the leaching step is used to collect the rare metals.

Abstract: According to the present invention, ruthenium or a ruthenium compound, which is expensive, can be collected with high efficiency even from an aqueous solution containing a water-soluble salt, a lower alcohol, an organic acid or the like, by adding at least one specific inorganic adsorbent to an aqueous solution containing ruthenium or the ruthenium compound, dissolving the entirety or a part of the inorganic adsorbent under an acidic condition, and then adding an alkali to adjust the solution to be an alkaline solution having a pH value of 7 or higher, thereby depositing the inorganic adsorbent while causing the inorganic adsorbent to adsorb ruthenium or the ruthenium compound.

Abstract: This invention relates to a process for the recovery of precious metal/s from a precious metal-containing material in an aqueous leach slurry or solution. The process includes the step of contacting the precious metal/s in the leach slurry or solution with a ligand selected from dithiooxamide (rubeanic acid), or a substituted dithiooxamide. The leaching of PGMs, gold and silver from their ores using the ligand of the present invention may take place under aqueous alkaline conditions, avoiding both corrosive acidic conditions and the use of cyanide.

Abstract: Discloses a hydrometallurgical process and system for the recovery of precious metals; specifically palladium, rhodium, and platinum metals, at high purity and with limited waste and environmental fouling.

Abstract: Disclosed is a method of recovering gold from an aqueous solution having a gold concentration of 10 mg/L or lower, using a plurality of extraction apparatuses for bringing the aqueous solution into contact with an extraction agent, arranged to configure a multi-stage extraction process, the method allowing the aqueous solution to continuously flow from the first-stage extraction process to the next-stage extraction process, while recycling the extraction medium used in each stage twice or more times for the extraction process of the same stage, without back extraction and reduction.

Abstract: The disclosure relates to pre-treatment of precious metal-bearing oxide ores, prior to precious metal leaching by thiosulfate. The process comprises mixing oxide ore in oxygenated water in the presence of a carbon-based material (e.g., activated carbon or other type of carbon). The carbon-based material can be separated from the ore slurry, and, the gold is thereafter leached by a thiosulfate lixiviant.

Abstract: A process and system for recovery of gold from an ore having the steps of i) providing the ore containing the gold to be recovered, ii) leaching the ore in an oxidative chloride medium, including a nitrogen species to produce a solution comprising gold; and iii) recovering the gold from the solution. The gold in a preferred embodiment is recovered from refractory and carbonaceous ores.

Abstract: Disclosed is a process of leaching gold that can be inexpensively and efficiently carried out from a mixture containing sulfur and gold, typically from the material containing sulfur and gold that is an intermediate product recovered by the flotation method in the hydrometallurgical method. Specifically, disclosed is a process of leaching gold from the mixture containing elemental sulfur and gold, the process involving combining the mixture containing elemental sulfur and gold and an aqueous solution of hydroxide of one or more of metals of alkali metals and alkaline earth metals, the hydroxides reacting with elemental sulfur to form thiosulfate of alkali and/or alkaline earth metal, and the gold thereby being leached by reaction with the thiosulfate.

Abstract: Methods for recovering gold from gold-bearing materials are provided. The methods rely upon on the self-assembly of KAuBr4 and ?-cyclodextrin (?-CD) in aqueous solution to form a co-precipitate, a 1:2 complex, KAuBr4•(?-CD)2 (“?•Br”), either alone or in an extended {[K(OH2)6][AuBr4]?(?-CD)2}n chain superstructure (FIG. 1). The co-precipitation of ?•Br is selective for gold, even in the presence of other metals, including other square-planar noble metals. The method enables one to isolate gold from gold-bearing materials from diverse sources, as further described.

Abstract: Recovering gold from gold-loaded fine carbon by application of thermo-kinetic chemical activation regime at a low temperature, while preventing vitrification of imputies found in the gold-loaded fine carbon.

Abstract: Processes are provided for recovering precious metals from refractory materials using thiosulfate lixiviants. The processes can employ lixiviants that include at most only small amounts of copper and/or ammonia and operate at a relatively low pH, reduction of polythionates, inert atmospheres to control polythionate production, and electrolytic solutions which provide relatively high rates of precious metal recovery.

Abstract: A method of recovering metal from heap leached ore is provided. The method includes supplying process fluid to a tank, distributing heap leached ore in the tank, optionally disrupting the flow of ore through the tank, creating a pregnant solution and discharging the process fluid, heap leached ore and pregnant solution from the tank to recover additional metal from the heap leached ore.

Abstract: A method and system are provided in which a gold and/or silver-collecting resin-in-leach circuit comprises both co-current and counter-current sections.

Abstract: A method for recovering a metal, capable of recovering a metal easily without requiring the use of an organic medium, is provided. A complex between a chelating agent and a metal present in a sample is formed in a mixture prepared by mixing the chelating agent and the sample under pH conditions where the chelating agent can be insoluble in an aqueous medium. Then, the complex is recovered from the mixture, and further, the metal is recovered by dissolving the recovered complex in an aqueous medium under pH conditions that are different from the pH conditions where the chelating agent can be insoluble in an aqueous medium. By this method, a metal can be recovered easily without requiring the use of the use of an organic medium.

Abstract: The present invention is directed to a precious metal recovery process in which an acid sulfidic feed material is subjected to acid pressure oxidation and an alkaline sulfidic feed material is subjected to alkaline pressure oxidation, with the discharge slurries from the pressure oxidation processes being combined to reduce neutralization requirements prior to precious metal recovery.

Abstract: The invention provides a novel process for improving the recovery of precious metals from recalcitrant refractory ores by the use of hydrofluoric acid dissolved in ionic liquids. The solution of hydrogen fluoride gas in an ionic liquid is contacted with dry crushed ore at a temperature and for a period of time commensurate with the fracturing of a specific recalcitrant refractory ore. The excess ionic liquid is separated from the ore and the fractured ore is further treated with dilute sodium cyanide solution to extract precious metals in greater yields.

Abstract: Processes are provided for recovering precious metals from refractory materials using thiosulfate lixiviants. The processes can employ lixiviants that include at most only small amounts of copper and/or ammonia and operate at a relatively low pH, reduction of polythionates, inert atmospheres to control polythionate production, and electrolytic solutions which provide relatively high rates of precious metal recovery.

Abstract: The present invention is directed to a precious metal recovery process in which an acid sulfidic feed material is subjected to acid pressure oxidation and an alkaline sulfidic feed material is subjected to alkaline pressure oxidation, with the discharge slurries from the pressure oxidation processes being combined to reduce neutralization requirements prior to precious metal recovery.

Abstract: Discloses a hydrometallurgical process and system for the recovery of precious metals; specifically palladium, rhodium, and platinum metals, at high purity and with limited waste and environmental fouling.

Abstract: This invention relates to a process for obtaining metal values, typically base metals, platinum or gold from a feed material. In a first step of the process of the invention, feed material containing metal values is ground to a particle size d90 of 100 microns or less to form an ultra fine pulp. In a second step of the process of the invention, the ultra fine ground pulp from the first step is oxygenated by pumping it in multiple passes through an in-line high shear static oxygenation device (30), while re-circulating it on a tank (28) or any other vessel. The process of the invention results in a significant reduction in the required leach time, improved recoveries, reduced cyanide consumptions, a steadier gold tail, as well as reduced capital and operational expenditure.

Abstract: According to the present invention, ruthenium or a ruthenium compound, which is expensive, can be collected with high efficiency even from an aqueous solution containing a water-soluble salt, a lower alcohol, an organic acid or the like, by adding at least one specific inorganic adsorbent to an aqueous solution containing ruthenium or the ruthenium compound, dissolving the entirety or a part of the inorganic adsorbent under an acidic condition, and then adding an alkali to adjust the solution to be an alkaline solution having a pH value of 7 or higher, thereby depositing the inorganic adsorbent while causing the inorganic adsorbent to adsorb ruthenium or the ruthenium compound.

Abstract: Processes are provided for recovering precious metals from refractory materials using thiosulfate lixiviants. The processes can employ lixiviants that include at most only small amounts of copper and/or ammonia and operate at a relatively low pH, reduction of polythionates, inert atmospheres to control polythionate production, and electrolytic solutions which provide relatively high rates of precious metal recovery.

Abstract: The copper sulfide ore is leached in the halide bath without using a special oxidant but with the use of only air. The copper and gold in the copper sulfide ore can be leached at high leaching ratio. The treating steps are as follows. (1) Copper leaching process (CL). The raw material is charged into the first acidic aqueous solution, which contains cupric chloride, ferric chloride, 7 g/L of hydrochloric acid, and sodium chloride. The post-leach liquor contains copper in cuprous state ions and copper in cupric state ions. (2) Solid-Liquid separation step. The resultant solid and liquid of CL step are separated. (3) Air oxidation step (OX). Air is blown into the post solid-liquid separation liquor. The copper in cuprous state ions are oxidized to the copper in cupric state ions. The iron leached in the step (1) is oxidized. Simultaneously, the impurities leached in the step (2) are precipitated. (4) Copper extracting step (CEX).

Abstract: A process for the extraction of gold from a gold-bearing ore or concentrate, comprising the steps of leaching the gold-bearing ore or concentrate with a lixiviant of hydrochloric acid and magnesium chloride at atmospheric pressure at a temperature of at least 90° C. and an Eh of at least 900 mV. After a liquid/solids separation step, the solution obtained is subjected to an organic solvent extraction step using an oxime to obtain a solution of organic solvent containing gold, which is stripped with sodium thiosulphate to recover gold. The extraction may be operated to extract gold with or without iron. Materials used in the process may be recycled. The process avoids environmental and other hazards associated with the use of cyanide to extract gold.

Abstract: A process and system for recovery of gold from an ore having the steps of i) providing the ore containing the gold to be recovered, ii) leaching the ore in an oxidative chloride medium, including a nitrogen species to produce a solution comprising gold; and iii) recovering the gold from the solution. The gold in a preferred embodiment is recovered from refractory and carbonaceous ores.

Abstract: A gold thiosulfate leaching process uses carbon to remove gold from the leach liquor. The activated carbon is pretreated with copper cyanide. A copper (on the carbon) to gold (in solution) ratio of at least 1.5 optimizes gold recovery from solution. To recover the gold from the carbon, conventional elution technology works but is dependent on the copper to gold ratio on the carbon.

Abstract: A high purity platinum recovery method including the steps of dissolving a platinum alloy containing ruthenium in aqua regia and eliminating residue, thereafter causing acid with platinum dissolved therein and an ammonium chloride solution to react so as to deposit chloroplatinic ammonium salt, and reducing the chloroplatinic ammonium salt to obtain a platinum sponge. The method is characterized in that acid with platinum dissolved therein and the ammonium chloride solution are caused to react at a temperature of 40° C. or higher.

Abstract: The invention relates to a method for recovering gold by solvent extraction from an acidic chloride-containing aqueous solution or from slurry containing gold-bearing solids using a diester-based reagent that is poorly soluble in water as organic extraction solution. In accordance with the method, gold is extracted extremely effectively, but other precious metals and many other metals quite sparingly. Gold is stripped from the extraction phase with pure water, from which the gold can be reduced either chemically or electrochemically.

Abstract: The present disclosure is directed to a process for recovering a precious metal from a pregnant leach solution using a resin extractant. The precious metal is eluted from the loaded resin using an eluant comprising trithionate. The barren resin is contacted with a sulfide, bisulfide, and/or polysulfide to convert sorbed trithionate to thiosulfate. The desorbed thiosulfate is contacted with an oxidant and converted to trithionate for eluant recycle.

Abstract: The invention relates to a method for the extraction of precious metals, using halogens. It has been found that introducing halogens in the reactor in the form of hypohalites rather than free halogens simplified greatly the recycling of halogens by electrolysis. It increases the rate of addition of the halogens and significantly reduces secondary reactions with base metals such as iron. Operating under acidic conditions, the gold recovery has been found as high with hypochlorite as with elemental chlorine, with an active chlorine to ore ratio reduced by a factor of two to five.

Abstract: A process of leaching gold comprising the steps of: a) leaching copper from copper sulfide ore material that contains gold or contains silicate ore containing gold until the copper grade is reduced to 7.9 wt % or less; b) mixing the resulting material having a copper grade of 7.9 wt % or less with a gold leaching solution selected from the group consisting of a first solution containing chloride ions and ferric ions, and a second solution containing chloride ions and iron ions, the iron ions having been oxidized to trivalent ferric ions by air bubbled into the second solution; c) adjusting the pH of the gold leaching solution to 1.9 or less with stirring to leach at least gold in the material into the gold leaching solution by the oxidative activity of the ferric ions contained in the gold leaching solution, wherein the concentration of gold is reduced by selectively removing gold from part or all of the gold leaching solution during gold leaching.

Abstract: This invention provides a process of leaching gold that can be inexpensively and efficiently carried out without using cyan from the mixture containing sulfur and gold, typically from the material which contains sulfur and gold and is an intermediate product recovered by the flotation method in the hydrometallurgical method. Specifically, this invention provides a process of leaching gold from the mixture containing elemental sulfur and gold, comprising contacting said mixture and an aqueous solution of hydroxide of one or more of metals selected from the group consisting of alkali metals and alkaline earth metals, and reacting said hydroxides and elemental sulfur so that thiosulfate of corresponding metal, and thus, gold is leached by the thiosulfate produced.

Abstract: A process for recovering a target metal from an oxidized metalliferous material comprises the steps of: in an acid generation stage, adding sulfuric acid to a solution comprising a metal halide to generate an acidic aqueous halide solution; in a leaching stage that is separate to the acid generation stage, leaching the oxidized metalliferous material with the acidic aqueous halide solution to leach the target metal into solution; passing the solution from the leaching stage to a target metal recovery stage in which the target metal is recovered from the solution while the metal halide is retained in solution; and returning the solution with the metal halide therein from the target metal recovery stage to the acid generation stage.