Abstract: The present invention according provides a method of recovering silver from silver containing halide solutions, comprising the steps of: (a) providing an ion exchange column comprising a weak anion exchange resin; (b) introducing the silver containing halide solution to the ion exchange column to absorb silver in the weak anion exchange resin; (c) washing the loaded ion exchange resin with a first washing solution to rinse off absorbed zinc and optionally at least part of copper; (d) washing the loaded ion exchange resin with a second washing solution to rinse off remaining copper; and (e) optionally washing the loaded ion exchange resin with a third washing solution to rinse off absorbed lead; and (f) eluting the loaded ion exchange resin with an eluent to remove silver from the resin and to obtain a silver containing solution.

Abstract: The present invention provides a method of recovering copper and zinc from an aqueous sulfate and chloride containing solution. In the first process step zinc and copper are simultaneous extracting with an extraction solution comprising a liquid chelating cation exchanger and a liquid anion exchanger. The extraction is followed by consecutive stripping stages. First the anionic species are washed from the organic phase with one or more aqueous solutions and finally the copper is stripped with an aqueous acidic solution.

Abstract: A method is disclosed for recovering gold from a gold-containing organic solution containing soluble gold. The method comprises contacting the gold-containing organic solution with an aqueous stripping solution in order to extract gold from the gold-containing organic solution into the aqueous stripping solution. The aqueous stripping solution containing gold is separated from the organic solution. The separated aqueous stripping solution containing gold is contacted with a reducing agent containing sodium metabisulphite, in order to reduce gold from the aqueous stripping solution.

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: A method is disclosed for recovering gold from a gold-containing organic solution containing soluble gold. The method comprises contacting the gold-containing organic solution with an aqueous stripping solution in order to extract gold from the gold-containing organic solution into the aqueous stripping solution. The aqueous stripping solution containing gold is separated from the organic solution. The separated aqueous stripping solution containing gold is contacted with a reducing agent containing sodium metabisulphite, in order to reduce gold from the aqueous stripping solution.

Abstract: The present invention according provides a method of recovering silver from silver containing halide solutions, comprising the steps of: (a) providing an ion exchange column comprising a weak anion exchange resin; (b) introducing the silver containing halide solution to the ion exchange column to absorb silver in the weak anion exchange resin; (c) washing the loaded ion exchange resin with a first washing solution to rinse off absorbed zinc and optionally at least part of copper; (d) washing the loaded ion exchange resin with a second washing solution to rinse off remaining copper; and (e) optionally washing the loaded ion exchange resin with a third washing solution to rinse off absorbed lead; and (f) eluting the loaded ion exchange resin with an eluent to remove silver from the resin and to obtain a silver containing solution.

Abstract: The present invention provides a method of recovering copper and zinc from an aqueous sulfate and chloride containing solution. In the first process step zinc and copper are simultaneous extracting with an extraction solution comprising a liquid chelating cation exchanger and a liquid anion exchanger. The extraction is followed by consecutive stripping stages. First the anionic species are washed from the organic phase with one or more aqueous solutions and finally the copper is stripped with an aqueous acidic solution.

Abstract: The invention relates to a method whereby copper is recovered from a copper sulphide ore containing pyrite. According to the method the ore is ground and leached into a solution containing sulfuric acid in atmospheric conditions by means of trivalent copper. As the copper sulphide leaches out, the trivalent iron is reduced to divalent and is oxidized back to trivalent by means of oxygen during leaching. Leaching is carried out in a closed reactor, where the undissolved gas rising from the solution in the supper section of the reactor is circulated back into the suspension of solution, solids and gas. leaching is performed in the presence of both divalent and trivalent iron and preferably with the dissolved copper acting as a catalyst to promote leaching. The conditions are adjusted to be such that the pyrite of the ore essentially does not dissolve.

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: 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 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 invention relates to a method whereby copper is recovered from a copper sulphide ore containing pyrite. According to the method the ore is ground and leached into a solution containing sulfuric acid in atmospheric conditions by means of trivalent copper. As the copper sulphide leaches out, the trivalent iron is reduced to divalent and is oxidized back to trivalent by means of oxygen during leaching. Leaching is carried out in a closed reactor, where the undissolved gas rising from the solution in the supper section of the reactor is circulated back into the suspension of solution, solids and gas. leaching is performed in the presence of both divalent and trivalent iron and preferably with the dissolved copper acting as a catalyst to promote leaching. The conditions are adjusted to be such that the pyrite of the ore essentially does not dissolve.