Abstract: Embodiments of the present invention relate to a process for obtaining silicon crystals from silicon. The method includes contacting silicon powder with a solvent metal to provide a mixture containing silicon, melting the silicon under submersion to provide a first molten liquid, contacting the first molten liquid with a first gas to provide dross and a second molten liquid, separating the dross and the second molten liquid, cooling the second molten liquid to form first silicon crystals and a first mother liquid and separating the first silicon crystals and the first mother liquid.

Abstract: The invention publishes a process to increase the bioleaching speed of ores or concentrates of sulfide metal species in heaps, tailing dams, dumps, or other on-site operations. The process is characterized by the continuous inoculation of the ores or concentrates with isolated microorganisms of the Acidithiobacillus thiooxidans type, together with isolated microorganisms of the Acidithiobacillus ferrooxidans type, with or without native microorganisms, in such a way that the total concentration of microorganisms in the continuous inoculation flow is of around 1×107 cells/ml to 5,6×107 cells/ml. In particular, the invention publishes the continuous inoculation of Acidithiobacillus thiooxidans Licanantay DSM 17318 together with Acidithiobacillus ferrooxidans Wenelen DSM 16786 microorganisms, or with other native microorganisms at a concentration higher than 5×107 cells/ml.

Abstract: Toxic substances such as heavy metals are extracted from a medium using a sorbent composition. The sorbent composition is derived by sulfidation of red mud, which contains hydrated ferric oxides derived from the Bayer processing of bauxite ores. Exemplary sulfidizing compounds are H2S, Na2S, K2S, (NH4)2S, and CaSx. The sulfur content typically is from about 0.2 to about 10% above the residual sulfur in the red mud. Sulfidized red mud is an improved sorbent compared to red mud for most of the heavy metals tested (Hg, Cr, Pb, Cu, Zn, Cd, Se, Th, and U). Unlike red mud, sulfidized red mud does not leach naturally contained metals. Sulfidized red mud also prevents leaching of metals when mixed with red mud. Mixtures of sulfidized red mud and red mud are more effective for sorbing other ions, such as As, Co, Mn, and Sr, than sulfidized red mud alone.

Abstract: Processes for metal leaching/solvent extraction are described which comprise: (a) providing a first aqueous leach pulp which comprises a mixture of leached solids and an aqueous leach solution comprising a metal, a leaching agent and water; (b) subjecting the first aqueous leach pulp to a first solid-liquid separation to provide a first clarified aqueous leach solution and a second aqueous leach pulp, wherein the second aqueous leach pulp comprises the leached solids at a % solids level greater than the first pulp; (c) subjecting the first clarified aqueous leach solution to a first solvent extraction prior to any significant dilution, whereby a first aqueous raffinate is obtained; (d) subjecting the second aqueous leach pulp to a second solid-liquid separation with dilution via an aqueous stream to obtain a second clarified aqueous leach solution; and (e) subjecting the second clarified aqueous leach solution to a second solvent extraction whereby a second aqueous raffinate is obtained.

Abstract: Process for removing halide compounds adhering to finely divided metal oxide particles by means of steam, wherein the metal oxide particles are applied to the upper part of an upright column and migrate downwards by means of gravity, the steam is applied at the bottom end of the column, the metal oxide particles and the steam are fed counter-currently, the metal oxide particles freed of halide residues are removed at the base of the column, steam and halide residues are removed at the head of the column, wherein the column is heated in such a manner that the temperature difference Tbottom?Ttop between the lower part and the upper part of the column is at least 20° C. and a maximum temperature of 500° C. prevails in the column, and the metal oxide particles have a residence time in the column of from 1 second to 30 minutes.

Abstract: Toxic substances such as heavy metals are extracted from a medium using a sorbent composition. The composition is derived by sulfidation of red mud, which contains hydrated ferric oxides derived from the Bayer processing of bauxite ores. Exemplary sulfidizing compounds are H2S, Na2S, K2S, (NH4)2S, and CaSx. The sulfur content typically is from about 0.2 to about 10% above the residual sulfur in the red mud. Sulfidized red mud is an improved sorbent compared to red mud for most of the heavy metals tested (Hg, Cr, Pb, Cu, Zn, Cd, Se, Th, and U). Unlike red mud, sulfidized red mud does not leach naturally contained metals. Sulfidized red mud also prevents leaching of metals when mixed with red mud. Mixtures of sulfidized red mud and red mud are more effective for sorbing other ions, such as As, Co, Mn, and Sr, than sulfidized red mud alone.

Abstract: The invention concerns a process for the extraction of acid or basic oxides contained in a vegetal matter, more specifically it concerns the extraction of silica from rice husks. The invention also concerns pure oxides extracted from vegetal matter. The invention also concerns the process for the extraction of carbon-rich oxide compositions from vegetal matter, and compositions obtained through said process.

Abstract: The invention relates to a method and equipment with which an organic solution extraction solution is purified from entrainment of aqueous solution and impurities during hydrometallurgical liquid-liquid extraction. The method treats an organic extraction solution, which is loaded with a valuable metal or valuable substance from the aqueous solution. The purpose is to carry out the physical separation of water droplets and the chemical removal of impurities from the organic extraction solution simultaneously.

Abstract: A microbiological heap leaching simulation process wherein material, representative of ore in a heap, is microbiologically leached in a housing and the temperature of the material at a plurality of locations in the housing is monitored and controlled to reduce heat loss from the housing.

Abstract: The invention relates to a method for reversing the dispersion formed in the mixing section of liquid-liquid extraction and kept condensed in the separation section and the separated solutions form the rear end of the separation section to flow back towards the feed end of the separation section. The invention also refers to the extraction equipment for implementing the reversed flow.

Abstract: The mercaptan-laden natural gas is contacted with a mercaptan-adsorbing sieve T1. The mercaptan-rich gaseous effluent obtained upon regeneration of sieve T2 is then contacted with an olefin-containing liquid feed in the presence of an acid catalyst. Under suitable conditions, the mercaptans are absorbed in the liquid feed and they react with the olefins so as to form solvent-soluble sulfides. A solvent regeneration stage allows the capture agent to be recycled.

Abstract: The invention concerns a process for the extraction of acid or basic oxides contained in a vegetal matter, more specifically it concerns the extraction of silica from rice husks. The invention also concerns pure oxides extracted from vegetal matter. The invention also concerns the process for the extraction of carbon-rich oxide compositions from vegetal matter, and compositions obtained through said process.

Abstract: A method for treating an oil shale formation comprising dawsonite includes providing heat from one or more heaters to the formation to heat the formation. Hydrocarbon fluids are produced from the formation. At least some dawsonite in the formation is decomposed with the provided heat. A chelating agent is provided to the formation to dissolve at least some dawsonite decomposition products. The dissolved dawsonite decomposition products are produced from the formation.

Abstract: A method for treating an oil shale formation comprising nahcolite includes providing a first fluid to a portion of the formation. A second fluid is produced from the portion. The second fluid includes at least some nahcolite dissolved in the first fluid. A controlled amount of oxidant is provided to the portion of the formation. Hydrocarbon fluids are produced from the formation.

Abstract: A sample preparation method for characterization of nanoparticles embedded in the supports of heterogeneous catalysts, with improved particle dispersion, is introduced. The supported catalyst is first ground or milled into fine powder. Then, the powder is mixed into an organic solvent, and an etchant is added to the solvent to digest the supports and release metallic nanoparticles. The resulting solution is then placed in an ultrasonic bath where ultrasonic waves are generated and applied to the solution. The ultrasonic waves suppress agglomeration of the particles and also break up those particle clusters resulting from agglomeration during the prior steps. Subsequently, a sample is extracted from the solution and prepared for analysis.

Abstract: A new method to strip metals from organic solvents in a manner that allows for the recycle of the stripping agent. The method utilizes carbonate solutions of organic amines with complexants, in low concentrations, to strip metals from organic solvents. The method allows for the distillation and reuse of organic amines. The concentrated metal/complexant fraction from distillation is more amenable to immobilization than solutions resulting from current practice.

Abstract: Disclosed is a process that relates to the recovery of a metal catalyst from an oxidizer purge stream produced in the synthesis of carboxylic acid, typically terephthalic acid. The process involves the addition of a wash solution to a high temperature molten dispersion to recover the metal catalyst and then subjecting an aqueous mixture or purified aqueous mixture so formed to a single stage extraction to remove organic impurities to produce an extract stream and a raffinate stream comprising the metal catalyst.

Abstract: The present invention relates generally to a process for recovering copper and other metal values from metal-containing materials through pressure leaching operations. In accordance with the various aspects of the present invention, metal-containing pregnant leach solutions from pressure leaching operations need not be significantly diluted to facilitate effective metal recovery using solvent extraction and electrowinning.

Abstract: Disclosed is a process that relates to the recovery of a metal catalyst from an oxidizer purge stream produced in the synthesis of carboxylic acid, typically terephthalic acid. The process involves the addition of a wash solution to a high temperature molten dispersion to recover the metal catalyst and then subjecting an aqueous mixture or purified aqueous mixture so formed to a single stage extraction to remove organic impurities to produce an extract stream and a raffinate stream comprising the metal catalyst.

Abstract: A process of diminishing the concentration of a transition metal complex from a first solution by adding a solubility-enhancing compound that enhances the solubility of said complex in a second solution and extracting the first solution with the second solution. The solubility-enhancing compound is a compound of formula A wherein, Ra is SH, SO3H, OH or COOH; Rb is SH, OH or COOH; Rc each independently is H, SH, OH or COOH; Rd each independently is H or COOH; n is 1, 2, 3, 4 or 5; or a salt or an activated form thereof.

Abstract: A method for removing impurities from a mother liquor comprising a carboxylic acid, a metal catalyst, impurities by (a) evaporating the mother liquor comprising a carboxylic acid, the metal catalyst, impurities, water and a solvent in a first evaporator zone to produce a vapor stream and a concentrated mother liquor stream; (b) evaporating the concentrated mother liquor stream in a second evaporator zone to form a solvent rich stream and a super concentrated mother liquor stream; (c) separating organic impurities with a water-solvent solution from the super concentrated mother liquor in a solid-liquid separation zone to form an aqueous stream and a second aqueous stream; (d) mixing in a mixing zone water and optionally and extraction solvent with the aqueous stream and second aqueous stream to form an aqueous mixture; and (e) adding an extraction solvent to the aqueous mixture in an extraction zone to form an extract stream and a raffinate stream.

Abstract: The invention relates to a method for the stabilization of the production capacity of an extraction plant extracting metals in a process, where the metal content of the feed solution varies. For the stabilization of capacity, the extraction cells and their piping are constructed and situated in such a way, that the extraction stages can be connected in different combinations, either in parallel or in a series. The method is especially suitable for the copper extraction process.

Abstract: A process for the oxidative leaching of sulphide mineral species, the method characterised by the method steps of: leaching a slurry containing the mineral species in one or more reaction vessels; circulating a stream of leach liquor to a flash cooler; flashing the liquor in the flash cooler at a pressure less than atmospheric pressure so as to dissipate heat; and recirculating the liquor to the or each reaction vessel.

Abstract: A method for removing impurities from an aqueous mixture or purified aqueous by extracting the aqueous mixture or purified aqueous mixture with an extraction solvent in an extraction zone to form an extract stream and the raffinate stream; and optionally separating the extract stream and a solvent rich stream in a separation zone to form a high boiling point organic impurities stream and a recovered extraction solvent stream.

Abstract: A solvent extraction composition is comprised of one or more orthohydroxyarylaldoximes and one or more othohydroxyarylketoximes, and one or more equilibrium modifiers in an amount providing a degree of modification of the orthohydroxyarylaldoximes from about 0.2 to 0.

Abstract: A process for selectively extracting metal values, including, uranium, thorium, scandium and zirconium, from starting materials which include the metal values. The process is particularly well suited to extracting metal and recovering metal values from tantalum/niobium production process ore residues.

Abstract: A process for treating a composition comprising one or more undesired compounds and one or more desired compounds so as to reduce the concentration of the one or more undesired compounds is described. The process comprises the steps of (1) contacting the composition with a solid adsorbent, (2) eluting the solid adsorbent on which the composition is retained with an extraction solvent comprising a (hydro)fluorocarbon, and (3) collecting a solvent eluate containing a composition having a reduced concentration of the undesired compounds from the solid adsorbent. The process is particularly suited to reducing the terpene content of an essential oil.

Abstract: An apparatus and continuous process for the conversion of one solid iron compound to another solid iron compound in a heterogeneous suspension wherein the suspension is formed by dispersing a solid starting iron compound in a liquid that is continuously fed through one or more agitated conversion vessels under hydrothermal conditions and converted to a solid product iron compound having different physical, chemical, or structural properties from the solid starting iron compound.

Abstract: A method for treating a hydrocarbon containing formation is provided. In one embodiment, heat from one or more heaters may be provided to at least a portion of the formation. Heat may be allowed to transfer from the one or more heaters to at least a part of the formation. In certain embodiments, the heat from the one or more heaters may pyrolyze at least some hydrocarbons within the formation. In an embodiment, a first fluid may be introduced into at least a portion of the formation. The portion may have previously undergone an in situ conversion process. A mixture of the first fluid and a second fluid (or a second compound) may be produced from the formation. In some embodiments, a first fluid may be provided to the formation prior to pyrolyzing hydrocarbons in the formation, and a second fluid (or a second compound) may be produced prior to pyrolyzing hydrocarbons in the formation.

Abstract: The present invention relates generally to a process for the production of sulfuric acid and liberation of precious metal values from materials containing sulfur through pressure leaching operations. In accordance with various aspects of the present invention, the sulfur-bearing materials may comprise residues from pressure leaching operations, such as those carried out at medium temperatures. The process of the present invention can be advantageously used to convert such sulfur-bearing materials to sulfuric acid by means of pressure leaching. The sulfuric acid so produced can be used beneficially in other mineral processing operations, for example those at the site where it is produced. Metals, such as precious metals, that are contained within the sulfur-bearing materials advantageously may be recovered from processing products by established precious metals recovery technology.

Abstract: A method of extracting a halide and sulphate from an aqueous sulphate solution, such as a zinc sulphate solution, comprises subjecting the solution to solvent extraction to extract halide and sulphate from the solution and controlling the amount of sulphate extracted by selective adjustment of the acidity of the aqueous solution.

Abstract: An oil shale formation may be treated using an in situ thermal process. Heat may be provided to the treatment area. Fluids may be injected into the formation to remove a component within the formation. Hydrocarbons, H2, and/or other formation fluids may be produced from the formation. In some embodiments, fluids may be injected prior to production of formation fluids. Alternatively, fluids may be injected after production of formation fluids.

Abstract: A method for repeatedly converting a solvent from a state of solvent to a state of antisolvent with relatively little loss of solvent. The method is used to allow for processing of large amounts of solute material with minimum amounts of solvent.

Abstract: The present invention provides a process of extracting nucleic acid in a simple manner at a high efficiency with no use of any hazardous reagent from biological materials having required specific procedure for nucleic acid extraction, particularly from biological materials such as bacteria of the genus Mycobacterium; and a process of simultaneously carrying out the extraction and purification of nucleic acid in a simple manner from such biological materials existing in a biological sample such as feces having involved much difficulty in the purification of the nucleic acid. In the present invention, vigorous agitation of biological materials with fine particles in solutions containing chelating reagents or agitation of biological materials with aqueous solutions containing chelating reagents and quaternary ammonium salts, together with organic solvents and fine particles is performed.

Abstract: An apparatus and a process for producing zinc oxide from a zinc-bearing material are provided. The process comprises the steps of leaching the complex sulfide material with hydrochloric acid, ferric chloride, and oxygen; precipitating iron from the leach solution using lime and oxygen; removing copper, silver, cadmium, cobalt and lead from the leach solution by cementation with zinc dust; precipitating zinc oxide from the leach solution using lime; and regenerating HCl from a calcium chloride leach filtrate solution to regenerate hydrochloric acid and precipitate gypsum. Related processes for recovering copper, silver, lead, and iron from complex sulfide materials and for recovering lead from residue by solubilizing lead chloride and precipitating it with lime are also provided.

Abstract: A solid detergent dispenser for use with a dishwashing machine includes a chamber and a lid. The chamber is configured and arranged to receive a solid detergent having a particular composition. A water inlet receives water from a water source, and the water flows through a tunnel into the bottom of the chamber. The chamber is flooded with water from the bottom to ensure relatively constant erosion of the solid detergent, which ensures that a relatively constant concentration of the solid detergent is used in the dishwashing machine. A water outlet allows water to flow out of the chamber into the dishwashing machine. The water must flow into the chamber faster than it flows out of the chamber to ensure that the appropriate amount of dissolution of the solid detergent occurs. The only valve used in the preferred embodiment is a valve to control the amount of water flowing into the water inlet.

Abstract: There is described a process for the extraction of at least one relatively polar component from a material which may be naturally occuring or a synthetic mixture, the process comprising the steps of: (a) contacting the material with a solvent mixture comprising a C1 to C4 fluorinated hydrocarbon, especially 1,1,1,2-tetrafluoroethane and a co-solvent having a dielectric constant (at 20° C.) of at least 5; and (b) separating the charged solvent from said material, thereby to isolate said material.

Abstract: Ozone gas having a high ozone concentration is generated by a solid electrolyte electrolytic process. An ozone solution is prepared by injecting the ozone gas into an acidic solution of pH 6 or below. The ozone solution heated at a temperature in the range of 50° to 90° C. is supplied to a contaminated object to oxidize and dissolve a chromium oxide film by an oxidizing dissolving process. The ozone solution used in the oxidizing dissolving process is irradiated with ultraviolet rays to decompose ozone contained in the ozone solution, the ozone solution is passed through an ion-exchange resin to remove ions contained in the ozone solution. An oxalic acid solution is supplied to the contaminated object to dissolve an iron oxide film by a reductive dissolving process.

Abstract: A method for producing small spherical particles that are especially useful as catalysts and catalyst supports employed in chemical processes is disclosed. According to some embodiments, the method includes impregnating a porous support with a metal or metal oxide and dissolving the support to release spherical particles. In certain embodiments the support that is employed in the method comprises a number of spherical voids which determine the size of the spherical particles, and preferably have micrometer range diameters. One embodiment of an attrition resistant Fischer-Tropsch catalyst comprises a plurality of micrometer size spherical metal and/or metal oxide particles that are prepared according to the above-described method.

Abstract: A method for extracting copper from a mineral feed containing copper sulphide mineral 1, which involves crushing and blending the feed 2, 6, 10 followed by leaching of the feed in an autoclave 20. The conditions in the autoclave are controlled so that the presence of oxygen at superatmospheric oxygen pressure maintains the ratio of ferrous to ferric ions at a level so as to facilitate the leaching of copper from the feed. The leaching is carried out in the presence of acid which may be itself generated by oxidising conditions in the autoclave. Further leaching is carried out in a series of tanks 22, 24, 26 and 28 after which the solids are separated from solution in a series of steps including treatment in a hydroclassifier 30, a clarifier 32 and a polishing filter 38. Copper is extracted from the resultant leachant at a copper extraction station 44 with a final copper product 54 being retrieved in electrowin cells 52.

Abstract: A method of decontaminating a radioactively contaminated oxide on a surface. The radioactively contaminated oxide is contacted with a diphosphonic acid solution for a time sufficient to dissolve the oxide and subsequently produce a precipitate containing most of the radioactive values. Thereafter, the diphosphonic solution is separated from the precipitate. HEDPA is the preferred diphosphonic acid and oxidizing and reducing agents are used to initiate precipitation. SFS is the preferred reducing agent.

Abstract: This invention relates to a process for purifying a heteropolyacid which comprises: subjecting an aqueous solution comprising (i) the heteropolyacid and (ii) salt impurities to at least one liquid/liquid extraction step with an organic solvent, characterized in that the organic solvent comprises a dihydrocarbyl ether having at least 5 carbon atoms.

Abstract: The present invention relates generally to a process for the production of sulfuric acid and liberation of precious metal values from materials containing sulfur through pressure leaching operations. In accordance with various aspects of the present invention, the sulfur-bearing materials may comprise residues from pressure leaching operations, such as those carried out at medium temperatures. The process of the present invention can be advantageously used to convert such sulfur-bearing materials to sulfuric acid by means of pressure leaching. The sulfuric acid so produced can be used beneficially in other mineral processing operations, for example those at the site where it is produced. Metals, such as precious metals, that are contained within the sulfur-bearing materials advantageously may be recovered from processing products by established precious metals recovery technology.

Abstract: The starting material is conveyed in an extruder through zones of high and low pressure formed by different screw elements of opposing pitch. An extractant is fed in the high pressure zones located upstream of the screw elements of opposing pitch. The extractant then flows in a direction countercurrent to a direction of transport of the starting material and is discharged via a discharge opening located in or close to the low pressure zone, downstream of a screw element of opposing pitch.

Abstract: A method for purifying various nitrogen containing flavor and fragrance compounds is described. The method comprises at least one step of reverse crystallization for liquid compounds and may be followed by at least one step of forward crystallization for compounds that are solid at room temperature.

Abstract: A process for manufacturing a catalyst body for generating hydrogen having at least one thin, large-surface catalyst layer, through which the reaction mixture can be passed includes steps of pressing a copper powder (particularly dendritic copper) to form a thin and highly compressed layer which forms a formed body, sintering, the formed body in a reducing atmosphere so that a net-type carrier structure made of copper is formed, and activating a surface layer of the formed body.

Abstract: The present invention relates to microbiological processes for the oxidative treatment of refractory gold and base metal ores and concentrates, and specifically, to bacterial inoculums for use in such processes that are strongly resistant to thiocyanate toxicity. The present invention also relates to methods of developing and using these bacteria. The use of a bacterial inoculum with high thiocyanate resistance confers a number of technological advantages on biooxidation processes including improvements in operating flexibility, operation costs and environmental acceptability.

Abstract: A hydrometallurgical process is provided for producing pigment grade TiO2 from titaniferous mineral ores, and in particular from ilmenite ore. The ore is leached with a hydrochloric acid, preferably a recycled solution at high hydrochloric acid concentration, to form a leachate containing titanium and iron chloride and a residue. The leachate may be filtered to separate the leachate from the residue. The leachate is cooled to a temperature sufficient to form crystals of FeCl2, which are separated from the leachate. The leachate may be subjected to a reduction step to reduce Fe+3 to Fe+2, before crystallizing. The leachate is subjected to a first solvent extraction to form a pregnant strip solution containing titanium and ferric ions and a raffinate containing ferrous ions. This strip solution is subjected to a second solvent extraction to form a second strip solution containing ferric ions and a raffinate containing titanium ions.

Abstract: A method for repeatedly converting a solvent from a state of solvent to a state of antisolvent with relatively little loss of solvent. The method is used to allow for processing of large amounts of solute material with minimum amounts of solvent.

Abstract: A process is provided for preparing ammonium metavanadate from the combustion ashes resulting from the combustion of petroleum fuels in a boiler by using the ammonium sulfate and vanadium components in the combustion ash. Water is added to the combustion ash to form a slurry. The solids are removed from the slurry. Ammonia and an oxidizing gas, such as air, oxygen or ozone, are added to the aqueous solution obtained from the slurry to oxidize the vanadium, thereby producing an aqueous solution containing ammonium metavanadate. The ammonium metavanadate is crystallized and recovered from the aqueous solution. Calcium hydroxide or calcium oxide is injected into the aqueous solution and reacts with the ammonium sulfate to produce gypsum and ammonia. This gypsum and ammonia containing solution is flowed down a packed column, where it is counter-currently contacted with air or steam which strips the ammonia out of the solution.