Abstract: The invention relates to a method for removing metal and/or precious metal-containing depositions from substrates. The substrate is subjected to treatment with an organo amine protectant component P and an inorganic active component A. Component P may be formed in situ by reaction with component R. Component P is an organic amine and/or organic amine hydrochloride. Component A is an inorganic compound and component R is an organic compound that can be split along the C—N bond by the component A into an organic amine. The metals in the form of organo-metallic complexes can be isolated and/or separated by means of different chemical reactions and/or biosorption.

Abstract: The invention provides an apparatus for effectively removing ruthenium when ruthenium is removed from a solution containing platinum group metal by oxidation distillation. The invention provides an apparatus for selectively removing ruthenium from a solution containing ruthenium and other platinum group metal by adding an oxidizer to the solution to convert ruthenium into ruthenium tetroxide, wherein air is sucked into a reaction tank by reducing pressure within the reaction tank, and at least one outlet of the air is arranged in the apparatus such that the lowermost part thereof is located at the height of 5-20 m from the bottom of the reaction tank, whereby the solution within the reaction tank can be effectively stirred without ruthenium tetroxide, which has large specific gravity, being concentrated at the bottom of the reaction tank.

Abstract: The invention relates to a method for recovering gold in connection with the hydrometallurgical production of copper from a waste or intermediate product containing sulphur and iron that is generated in the leaching of the copper raw material. The recovery of both copper and gold occurs in a chloride environment. The gold contained in the waste or intermediate is leached by means of divalent copper, oxygen and alkali bromide in a solution of copper (II) chloride and alkali chloride, in conditions where the oxygen-reduction potential is a maximum of 650 mV and the pH a minimum of 0.5. The bromide accelerates the dissolution of the gold.

Abstract: A method for producing dispersed metal particles on a substrate and the compositions produced is disclosed. A method for producing the particles comprises exposing an organometallic and a particulate substrate to supercritical or near supercritical fluid under conditions to form a mixture of the fluid and the organometallic, allowing the mixture to remain in contact with the substrate for a time sufficient to deposit dispersed organometallic onto the substrate, venting the mixture, thereby adsorbing the organometallic onto the substrate, and reducing the dispersed organometallic to dispersed metal particles with a reducing agent.

Abstract: A process for the recovery of gold and the platinum group metals from sources that contain relatively low amounts of the metals is described. The process is environmentally acceptable and uses no expensive and potentially dangerous organic solvents.

Abstract: Ruthenium is separated from noble metal solutions, by:

Abstract: A method for dissociating metal-ligand complexes in a supercritical fluid by treating the metal-ligand complex with heat and/or reducing or oxidizing agents is described. Once the metal-ligand complex is dissociated, the resulting metal and/or metal oxide form fine particles of substantially uniform size. In preferred embodiments, the solvent is supercritical carbon dioxide and the ligand is a .beta.-diketone such as hexafluoroacetylacetone or dibutyldiacetate. In other preferred embodiments, the metals in the metal-ligand complex are copper, silver, gold, tungsten, titanium, tantalum, tin, or mixtures thereof. In preferred embodiments, the reducing agent is hydrogen. The method provides an efficient process for dissociating metal-ligand complexes and produces easily-collected metal particles free from hydrocarbon solvent impurities. The ligand and the supercritical fluid can be regenerated to provide an economic, efficient process.

Abstract: A process for recovering palladium, rhodium and ruthenium from aqueous solutions deriving from the treatment of nuclear fuels and containing also iron and nickel, by reducing carbonylation with carbon monoxide at a pressure up to 1 atmosphere in a nitric acid solution at a pH of between 2 and 4 and at a temperature of between room and 100.degree. C. and reaction times of from 6 to 100 hours.

Abstract: The present invention relates to the extraction and separation of low concentrations of precious group metals from acid chloride solutions, which are obtained by leaching catalytic converters, by utilizing a 8-hydroxyquinoline containing resin and a thiourea stripping process. The said process eliminates the phase separation problems and reagent losses which are normally associated with prior art methods. In addition to being used as a catalytic converter recycler, the present invention can be also employed by waste water treatment plants.

Abstract: Rhodium and certain other PGM's in oxidation state III complex with chloride is precipitated from a solution by mixing with a polyamine, especially diethylene-triamine, in the presence of a protonating agent for the polyamine. High selectivity and high yields, in comparison to known reagents, are observed.

Abstract: A method of treating a gold-bearing ore to render the gold component of the ore more amenable to standard cyanidation treatment in a reduced amount of time is disclosed. An aqueous slurry of the gold-bearing ore is introduced into at least one vessel. An oxidizing agent, such as chlorine gas, an alkali metal hypochlorite and an alkaline earth metal hypochlorite, is rapidly introduced into the vessel so that it intimately contacts the aqueous slurry. While the oxidizing agent is being introduced into the vessel, the slurry is agitated with agitating means including a plurality of impeller blades that provide high shear agitation and a large interfacial surface area between the oxidizing agent and the liquid phase of the slurry to enhance the mass transfer of the oxidizing agent so that it becomes substantially completely adsorbed by the aqueous slurry in about 5 to about 15 minutes.

Abstract: Gold is recovered from aqueous solutions which include a solubilizing reagent by contacting the solution with hydrogen under selected conditions until the gold precipitates, and removing the precipitate from the solution. The reagent comprises a thiourea or a thiosulfate and the solution is a leach, eluate or strip solution. The contacting may be by gas sparging or under hydrogen pressures, e.g. up to about 300 psi, and usually the temperature is within about 20.degree. to 170.degree. C. If the initial feed solution is too dilute, it can be concentrated by ion exchange or solvent extraction followed by elution or stripping respectively. Any silver present is precipitated with the gold.