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Patent Searching and Data


Matches 651 - 700 out of 3,841

Document Document Title
WO/1995/027085A1
A process for the extraction of palladium from an aqueous medium containing palladium and halide or pseudo-halide ions using as extractant a nitrogen-containing heterocyclic carbonamide or ester characterised in that the total concentrat...  
WO/1995/026418A1
A hydrometallurgical process for treating copper ores or concentrates containing gold by simultaneously leaching both copper and gold into an aqueous cyanide solution, recovering copper and gold in metallic form by electrowinning or ceme...  
WO/1995/018870A1
A method and an apparatus for recovering platinum group metals from a metal catalyst are disclosed, in order to separate the substrate containing the metal catalyst from the carrier, the sheets of the catalyst package are unwound. The sh...  
WO/1995/015403A1
A method of recovering precious metal values from refractory sulfide ores is provided. The method includes the steps of separating clays and fines from a crushed refractory sulfide ore (12, 24), forming a heap from the refractory sulfide...  
WO/1995/012001A1
Refractory ore is crushed (2) conveyed to a pug mill mixer (6) and mixed with sulfuric acid. Nitric acid is then added to the ore in a second pug mill mixer (12) and a third mixer (20). The ore is then conveyed to a curing/oxidation rota...  
WO/1995/011319A1
An improved process for dissolving gold metal in ligand and oxidant lixiviation systems, wherein the solubility of gold is enhanced by the addition of heterocyclic aromatic compounds containing nitrogen or sulfur in the ring.  
WO/1995/010636A1
Palladium catalyst is recovered from an organic solution by extraction with water/base solution. The water/base solution is then neutralized, and the palladium extracted with an organic solvent. The tramp metals remain in the water phase.  
WO/1995/008651A1
A powerful reducing agent such as hydrazine monohydrate is added to standard elution solutions such as NaOH-NaCN solutions with or without alcohol, thereby substantially increasing the elution kinetics of gold and silver.  
WO/1995/006141A1
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 t...  
WO/1995/004164A1
A hydrometallurgical process for the recovery of precious metal values from refractory precious metal ore materials containing organic carbonaceous matter in which solubilized gold complexes are absorbed by leaching the ore with a thiosu...  
WO/1994/025633A1
A method of dissolving and, if necessary, further recovering noble metals efficiently from industrial raw materials including gold plated materials such as waste electronic parts, platinum catalysts used in the petrochemical industry, an...  
WO/1994/021345A1
Toxic cyanide and anionic metal species are removed from aqueous alkaline solutions by contacting the aqueous alkaline solutions with a compound which is capable of being protonated at a pH of 9 or above.  
WO/1994/019500A1
The present invention relates to the recovery of zinc values from an acidic solution containing hydrocyanic acid. The zinc is recovered as complex zinc cyanide anions which may, if desired, be recycled for the (selective) preliminary rem...  
WO/1994/006944A1
A method for recovering precious metals from carbonaceous ore comprising leaching the ore with a lixiviant solution and then preg-robbingly concentrating the precious metal-lixiviant complexes in solution on to the native carbonaceous co...  
WO/1994/003649A1
A process for leaching 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 leach...  
WO/1994/000608A1
A method of treating a solid material (1) containing a substance of economic importance to recover or extract the substance from the material, characterised in that the method comprises forming a conducting mixture of the solid with a fl...  
WO/1994/000606A1
A process for producing one or more metals from a mineral feedstock (12) is defined. The mineral is fed to a leaching apparatus (10) wherein it is contacted with electrolyte (14). The leaching apparatus has zones of decreasing oxidation ...  
WO1993019212A3  
WO/1993/019212A2
An improved process for recovery of precious metals such as gold or silver using novel ion exchnage resins having aryl guanidyl functionality from aryl guanidine compounds having a pKa at 25°C less than 13 and preferably less than 12. T...  
WO/1993/018190A1
The binder composition for agglomerating ore fines of the invention is a mixture of (1) a reactive calcareous component, (2) a reactive siliceous and aluminous component, and (3) a sulfate compound. Preferably, the binder composition is ...  
WO/1993/014231A1
A process for recycling hydrogen cyanide from a cyanide-containing slurry (24) is provided. The process includes the steps of adjusting the pH (28) of a cyanide-containing slurry, volatilizing HCN (30) contained in the pH adjusted slurry...  
WO/1993/007980A1
A reductive process for making finely divided silver particles in which the silver particles are precipitated from an aqueous acid solution of silver salt containing silica sol.  
WO/1993/008310A1
A process suitable for the extraction or recovery of metal values from arsenic containing feeds and including the steps of: a) treating the feed with a nitric acid-containing leachant solution in order to dissolve the desired metals; b) ...  
WO/1993/000610A1
A process for treating a photographic developer solution containing silver ion comprises contacting the solution with a silver recovery element (10), which comprises a substrate (12) having thereon a hydrophilic colloid layer (16) contai...  
WO/1993/000611A1
An element and a process for recovering silver from a photographic developer solution containing silver ions. The silver recovery element (10) comprises a support (12) having a hydrophilic colloid layer (16) containing physical developme...  
WO/1992/022674A1
A method for the recovery of platinum and rhodium lost from a platinum-containing catalyst during ammonia oxidation processes at a temperature above 850 �C. Lost precious metal is brought into contact with a foraminate element fabricat...  
WO/1992/022673A1
The invention relates to a process for the treatment of complex metal sulphide materials and for the recovery of metal values from such materials. The process is characterized by first subjecting the material to a leaching process under ...  
WO/1992/021419A1
A method for the removal, separation, and concentration of Rh, Ir, and/or Ru from a source solution which may contain larger concentrations of other ions including H+ comprises bringing the source solution into contact with a compound co...  
WO/1992/019779A1
Disclosed is an oxidative process for recovering rhodium catalyst values from ''tars'' formed during the preparation of acetic anhydride by the rhodium catalyzed carbonylation of a mixture of methyl iodide and methyl acetate and/or dimet...  
WO/1992/018655A1
A method for extraction of gold and silver from a mineral raw material provides for sorption leaching of the pulped raw material in a cascade of installations and subsequent multi-stage desorption of gold, silver and admixtures from a sa...  
WO/1992/018654A1
An ion flotation process for the recovery of cyanides of metals including gold, platinum and palladium from a feed solution (10) is performed in an ion flotation vessel (12) using a selective surfactant (14) such as cetyltrimethylammoniu...  
WO/1992/018249A1
A process for recovery of a valuable species in an ore that contains constituents of absorbed microwave energy is disclosed. In particular, a process for recovery of gold values from a gold bearing ore is disclosed. The process comprises...  
WO/1992/018422A1
This invention relates to compositions for the hydrometallurgical recovery of precious metals, and the use of certain of such compositions in other applications. The composition comprises: water, at least about 25 % by weight bromine, be...  
WO/1992/012779A1
An improved process for stripping gold cyanide from activated carbon is disclosed. The process involves contact of gold-laden activated carbon with a strong base at ambient temperatures followed by elution with an aqueous solution contai...  
WO/1992/008812A1
A recovery method for base metal values (e.g. copper) from ore slurry or aqueous solution, comprising forming a solution of a metal complex (e.g. cyano-copper) having an affinity for adsorption sites on activated carbon, adsorbing the me...  
WO/1991/013177A1
A process for the hydrometallurgical recovery of gold from gold-bearing material comprising the step of treating gold-bearing material with an acidic lixiviant solution containing thiourea and ferric ions, characterized in that the said ...  
WO1991009145A3  
WO/1991/011539A1
A process is described for the recovery of gold from gold-loaded thiosulphate solution. The solution is treated with at least a stoichiometric amount of cyanide ions and the resultant gold complex is adsorbed by an adsorbent, such as car...  
WO/1991/009145A2
Waste liquors containing small amounts of silver salts are treated with aluminum hydroxide to produce a floc reduced in volume by the addition of an acid and mixed with a metal bicarbonate and metal carbonate in amounts sufficient to aff...  
WO/1991/008316A1
A variety of processes for recovering gold from gold ore are disclosed. Briefly, the methods include culturing at least one microorganism species capable of producing cyanide ion under conditions wherein the microorganism produces cyanid...  
WO/1991/005882A1
A process is disclosed for recovering silver sulfide from a spent photographic fixer solution, which contains silver. The process is particularly suited for treating the fixer solution in a manner which enables recycling of the solution ...  
WO/1991/002097A1
A method for ion flotation in which the flotation reagent employed is a compound of general formula (I), wherein R?1� is a C�10? - C�18? alkyl group, Y is O, S, NH, (CH�2?)�n? or (CHR)�n? where R is a lower alkyl group and n ...  
WO/1990/015887A1
Platinum group metals are recovered from lower-grade ores than hitherto considered economic by lixiviation with aqueous arsenate or thiosulphate, plus halide, in air.  
WO/1990/013678A1
The invention concerns methods and an apparatus for extracting precious metals and harmful matter from materials such as slag. The methods include freezing the pre-sized material; exposing it to ultraviolet and infrared radiation; roasti...  
WO/1990/013676A1
The recovery of noble metals by sodium cyanide leaching from complex refractory gold and silver bearing ores containing such complex silver sulphides as polybasite, pearcite, pyrargyrite, tetrahedrite and argentite presents difficulties ...  
WO/1990/012898A1
A method of recovering silver from used photographic fixer solutions characterised in that the solution contains an alkali metal sulphite as the sole silver halide solvent.  
WO/1990/012119A1
A method for ion flotation, especially in the extraction of gold uses as the flotation reagent a cationic surfactant of formula (I), wherein R?1¿ is a C¿10? - C¿18? alkyl group, R?3¿ is a lower alkyl group, or benzene ring optionally...  
WO/1990/010721A1
In the recovery of noble metals, including gold, silver and members of the platinum group, the ores or tailings are subjected to the action of various leaching agents, namely, sodium cyanide, thiourea, chlorine and aqua regia and optiona...  
WO/1990/009460A1
A process for the recovery of precious metal values as essentially pure gold from gold alloys in the form of thin strips 0.05 to 0.25 inch thick having a gold content of up to 80 % gold comprising chlorinating the strips at a temperature...  
WO/1990/009246A1
An air concentrator for dry separation of gold and other heavy minerals from alluvial deposits comprises a housing (50) having a number of open-topped chambers (52) arranged in a ring-like configuration and surmounted by a screen (14) ha...  

Matches 651 - 700 out of 3,841