Abstract: Disclosed herein is a method for extracting precious metals from supported catalysts. The precious metal in one embodiment is rhodium. The supported catalyst may be from equipment, such as a used catalytic converter. The method is carried out at low temperature, and does not require harsh conditions, such as the use of a strong acid. The method involves contacting the catalytic material with a polar molecule and a reactive gas.

Abstract: A process for digestion of fine iridium includes (a) alkaline oxidative digestion of 1 part by weight fine iridium and 3 to 20 parts by weight of a combination comprising 40 to 70 parts by weight sodium hydroxide, 15 to 30 parts by weight sodium nitrate, and 10 to 40 parts by weight sodium peroxide in the melt, whereby the sum of the weight fractions equals 100 parts by weight; (b) cooling the digestion material formed in step (a) to 20 to 70° C.; (c) dissolving the acid-soluble fractions of the cooled digestion material in water/halogen hydracid until an acidic aqueous solution with a pH value of ?1 to +1 is obtained; and (d) boiling the acidic aqueous solution obtained in step (c) until the formation of nitrous gases is completed. Insoluble ingredients can be separated from the acidic aqueous solution before or after step (d), if needed.

Abstract: A method for producing highly pure platinum on an industrial scale, as well as the use of said highly pure platinum. According to the method, a hexahalogenoplatinate is reduced to platinum in acidic conditions.

Abstract: A method recovers noble metals from noble metal-containing compositions and includes steps of (i) providing a noble metal-containing composition containing an adsorption agent that is based on an inorganic material and is functionalized by organic groups and has at least one noble metal adsorbed to it, and (ii) ashing of the noble metal-containing composition provided in step (i) in order to adjust a residual carbon content of at most 10% by weight, relative to the total weight of the noble metal-containing composition after ashing, to obtain an ashed composition.

Abstract: The proposed invention relates to methods of precious metal recovery and may be applied to the recovery of precious metals from various types of mineral raw source materials containing chlorides of alkali and earth metals, e.g. collective concentrate produced from clay-salt residue of potassium production, or marker clays, etc. This method includes chlorinating roasting of the collective concentrate produced during enrichment of the material with residual chlorides content of 7-13%, or natural concentrate with up to 15% chlorides content. Thereafter, the cinder is leached by an aqua-regia solution, the precious metals are recovered from the pulp via of sorption, chlorinating roasting is held at 600-700° C., the precious metals are leached from the cinder using diluted solution of aqua-regia, and then via sorption. The process is cost-efficient due to the use of chlorinating agent, reduction of the process steps number, decreasing of the roasting temperature, and the leaching by diluted acid.

Abstract: The present invention is directed to a method for the recovery of one or more trace elements including gold and one or more platinum group elements from coal. More particularly, the present invention may specify parameters for the selection of coal for combustion, the parameters for combustion of the pre-selected coal, the parameters for the preparation and mixing of a charge for a furnace including ash from the combustion of the coal with an inquart and a fluxing agent, the parameters for the heating of the charge and casting of a dore bar and the parameters for the production of an anode slime from the dore bar. The method of the present invention may also specify parameters for the recovery of silver, gold and one or more trace platinum group elements from the anode slimes.

Abstract: The process of the present invention recovers platinum group metal(s), such as platinum and palladium, from PGM-containing materials containing base metals, such as copper and nickel. The process controls sulfur levels by using solvent extraction 306 to remove acid in the nickel recovery circuit. The acid product 326 can then be neutralized and/or recycled as desired.

Abstract: A material benefication process and device for dressing a material comprising noble metals including platinum group metals. The device includes a reactor vessel with an inlet and an outlet for the processing medium. The material to be processed and a holder for the material are located inside the reactor vessel. The holder has a device for distributing the used processing medium flow. The process includes subjecting the material to an oxidizing treatment at a temperature within a first distinct temperature range, subjecting the material to a reducing treatment at a temperature within a second distinct temperature range, and chlorinating the material at a temperature within a third distinct temperature range different from at least the first distinct temperature range.

Abstract: A method of recovering precious metals from metal alloys produced aluminothermically from base metal smelter slag, includes treating the metal alloy with aqueous sulphuric acid solution having a pH of not greater than about 2 to cause dissolution of nickel and/or cobalt and iron and to cause formation of hydrogen sulfide which reacts with copper in the metal alloy to form a copper sulfide precipitate containing at least one precious metal, and separating the copper sulphide precipitate containing at least one precious metal from the remaining solution containing cobalt sulphate and/or nickel sulphate and ferrous sulphate.

Abstract: A powerful reducing agent such as hydrazine monohydrate is added to the standard eluent solutions such as NsOH-NaCN with or without alcohol. The kinetics of elution of gold or of silver are thus markedly enhanced.

Abstract: A process for extracting precious metal from volcanic ore includes the steps of crushing the ore, heating the ore in a hydrogen atmosphere to soften oxide mineral encapsulating the precious metal, cooling the ore, grinding the ore, and processing the ore to extract precious metal.

Abstract: A process for extracting iron, copper, and nickel from a solution containing iron, copper, nickel, and at least one contaminent selected from the group comprising magnesium, aluminum, calcium and sodium, wherein each of said solutes is present at its respective chloride. In the process, calcium oxide or calcium hydroxide are added as a precipitating agent in incremental steps to cause incremental increases in the pH of the solution. At each increasing pH, one of the aforesaid metals will precipitate as the corresponding metal hydroxide while leaving the remaining metals in solution. The metal hydroxide precipitate is separated from the remaining solution prior to the subsequent addition of the precipitating agent.

Abstract: The recovery of gold, silver and platinum group metals from volcanic cinders containing iron is achieved by mixing the cinders with a suitable flux, and metallic copper, and smelting the mixture at a sufficiently high temperature to produce a molten mass of metal containing iron and copper, and a molten slag. The molten slag is separated from the molten metal mass by a suitable means. The slag is discarded and the metal mixture is cooled to a solid state. The copper and iron are then dissolved in acid, leaving an undissolved portion which can then be separated from the resulting leach liquor by filtration. Alternatively, the iron and copper bearing metal can be cast into an anode and electrolyzed in a sulfuric acid solution where copper is deposited at the cathode and iron is put into solution as iron sulfate. The insoluble residue at the anode can be recovered from the sulfuric acid solution by filtration.

Abstract: A process for extracting metals from a flotation concentrate containing gold, platinum group minerals, copper, nickel and sulfur. The process involves roasting the concentrate in the presence of oxygen to reduce the sulfur content of the concentrate to approximately two percent; leaching the roasted concentrate with an acid solution containing hydrochloric and nitric acids to dissolve substantially all of the metals; and recovering the metals from the solution.

Abstract: Complex ores of the precious metals which also contain iron spinels and similar compounds are assayed and their precious metals content is extracted by subjecting the ores or concentrates thereof together with an iron-embrittling agent to a pyrometallurgical process which reduces at least a major portion of the iron compounds to liquid metallic iron. The liquid iron serves as a collector metal for the precious metals and, after cooling, the iron is brittle and easily comminuted and can be separated from the precious metals through use of either an electrolytic process or a selective chemical dissolution of the iron and other base metals leaving the precious metals available for analysis and recovery.

Abstract: A method of separating metals from carbon-supported catalyst materials comprises the steps of combusting the carbon at a temperature insufficient to cause volatisation of the metal followed by reduction with hydrogen of any oxidised metal and washing with acid or water.