Abstract: This invention describes a hydrometallurgical process for the recovery and separation of valuable elements, in particular gold and silver, from a feed material comprising a refractory, intractable or otherwise poorly responding to conventional treatment routes ores, concentrates and other materials. In particular, the process is a process integrated into one or more existing value element extraction processes.

Abstract: The invention generally relates to systems and methods for producing metal clusters; functionalized surfaces; and droplets including solvated metal ions. In certain aspects, the invention provides methods that involve providing a metal and a solvent. The methods additionally involve applying voltage to the solvated metal to thereby produce solvent droplets including ions of the metal containing compound, and directing the solvent droplets including the metal ions to a target. In certain embodiments, once at the target, the metal ions can react directly or catalyze reactions.

Abstract: This relates to mining and mineral or materials treatment industries that deal with gold and silver. Specifically, it is related to the process to recover gold and silver from thiosulfate or thiourea solutions, with an electrolysis that occurs simultaneously on both the anode and cathode. Increased velocity and greatly reduced energy consumption are obtained in relation to those found in conventional electrolytic cells.

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: 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 invention relates, generally, to a method and apparatus for recovering metal values from a metal-bearing materials, and more specifically, a process for recovering copper and other metals through leaching, electrowinning using the ferrous/ferric anode reaction, and the synergistic addition of ferrous iron to the leach step.

Abstract: Provided are a low impedance gold electrode, which has increased surface area, and can improve a bonding force with other materials, an apparatus for and a method of fabricating the low impedance gold electrode, and an electrolyte solution for use in the fabrication of the low impedance gold electrode. The gold electrode has a surface roughness that is increased through electrolysis using an acid electrolyte solution, has an impedance that is less than 1/10 of an impedance before the electrolysis and is higher than 0? when the low impedance gold electrode is disposed in the acid electrolyte solution or another electrolyte solution, and has a single-layered structure whose thickness is less than that before the electrolysis.

Abstract: Disclosed herein is a method for concentrating gold contained in a leach residue obtained in a copper hydrometallurgical process for recovering copper from a copper sulfide mineral to efficiently separate and recover gold from the leach residue: a gold-bearing copper sulfide mineral is subjected to pressure leaching with sulfuric acid at a temperature higher than 102° C. and 112° C. or lower to obtain a leach residue, and the leach residue is subjected to flotation to separate it into a float fraction and a sink fraction; the float fraction obtained by flotation is desulfurized to obtain a desulfurized product; the desulfurized product is subjected to oxidative roasting to obtain an oxidatively-roasted product; the oxidatively-roasted product is dissolved in a sulfuric acid solution to obtain a copper solution, and a gold-bearing residue is separated and recovered from the copper solution.

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: The present invention relates generally to a process for controlled leaching and sequential recovery of two or more metals from metal-bearing materials. In one exemplary embodiment, recovery of metals from a leached metal-bearing material is controlled and improved by providing a high grade pregnant leach solution (“HGPLS”) and a low grade pregnant leach solution (“LGPLS”) to a single solution extraction plant comprising at least two solution extractor units, at least two stripping units, and, optionally, at least one wash stage.

Abstract: A method of leaching copper from copper sulphide-containing concentrates, such as chalcopyrite, includes using pyrite as a catalyst for ferric reduction in order to eliminate passivation of the chalcopyrite surface, the process being carried out under conditions whereby the pyrite is not materially oxidized, for example by maintaining the operating solution potential at a suitable level. The leaching is carried out in an acidic sulphate medium and may include oxidation by oxygen-containing gas. The leached copper is then recovered, for example by solvent extraction and electrowinning. The leaching process can result in the virtually complete extraction of copper at atmospheric pressure in as little as four hours.

Abstract: The application relates to a method for treating waste containing precious metals, said method comprising the following successive steps: the waste is brought into contact with a composition based on molten lead; the mixture obtained is skimmed; and the skimmed mixture is refined by electrolysis in such a way as to recover the precious metals. The application also relates to a waste treatment installation for implementing said method.

Abstract: A method for recovering precious metals such as gold and silver from aqueous solution as solid is described The method includes mixing an aqueous solution (e.g, thiosulfate or thiocyanate lixiviant) containing precious metals with ferrous ions in the presence of an effective amount of hydroxide ions. The precious metal ions are reduced and co-precipitate with iron hydroxides and/or hydrated iron oxides The co-precipitate is collected and purified. De-oxygenation of the reaction solution is optional. The recover/method is fast, complete and clean.

Abstract: An apparatus and method utilizing a strip solution for removing gold from the loaded activated carbon used to accumulate such gold leached from gold bearing ore, and for electrically removing such gold from the strip solution by electrowinning. The apparatus includes a pair of strip columns fillable with loaded activated carbon. The strip columns are connectable individually and in series in respective continuous loops using a valved crossover pipe assembly to an electrowinning device, with the strip solution being pumped therethrough.

Abstract: The present invention is directed to an improved process for the recovery of metal ions from metal-containing aqueous solutions using a supported liquid membrane (SLM) whereby the pH of the metal-containing solution is preferably adjusted to between 5.5 and 8 and ammonia or other weak base is present in the metal-containing solution in a concentration sufficient to form a complex between the weak base and metal ions present in the solution. The present invention permits enhanced recovery of metal in the solution without any need to adjust the pH of the solution during the SLM process.

Abstract: The present invention is directed to a process for removing various contaminants (e.g., organic collectors, contaminant metals or spectator ions, and/or suspended and colloidal solids) from process streams in leaching processes. The contaminant removal is performed by one or more membrane filtration systems (e.g., nanofilters, ultrafilters, and/or microfilters) treating process streams including, the pregnant leaching solution, the barren raffinate, and the lean and rich electrolytes.

Abstract: A method is provided for processing a sulphide mineral composition which at least partly comprises an iron-containing mineral.

Abstract: An electrochemical apparatus and system for extracting and recovering metals from their compounds using electrochemical cells where the anolyte 10 is connected electrically to the catholyte 11 through an independent set of electrodes 13, 14 immersed in each electrolyte and connected to each other by a conductor 16. The specification details the application of this principle to commercial size cells and systems to extract metals from solutions, from ores in-situ, from ores in heaps and fixed beds, from fine metal concentrates dissolved either at the anode cell or in a separate leaching vessel. Alkaline electrolytes are also given for the extraction and recovery of nickel and copper from their oxide ores. A method for extracting gold from ores or residues is also included.

Abstract: Ores containing copper, zinc, silver in the form of sulfides are treated by a solution of sulfurated sulfite ions and ammonium ions in order to remove most of the metals from the sulfide ores. This treatment renders the resulting gold bearing ores much more amenable to cyanide extraction. Dissolved metals are reclaimed by appropriate techniques, such as electrowinning or liquid-liquid extraction, and the solution of sulfurated sulfites and ammonia is recycled for further lixiviation of fresh ores.

Abstract: A process for leaching gold, silver, platinum and palladium wherein an aqueous leaching solution containing bromine and bromide ion contacts a precious metal source to produce an aqueous leachate. A precursor composition for producing an aqueous leaching solution for leaching gold, silver, platinum and palladium. A process for electrogenerating bromine and a process for leaching gold, silver, platinum and palladium wherein bromine is electrogenerated and contacts a precious metal source to produce an aqueous leachate. A process for leaching gold, silver, platinum and palladium wherein bromine is electrogenerated from a solution containing chloride ions and bromide ions.