Abstract: A system for recovering rare earth elements from coal ash includes a leaching reactor, an ash dryer downstream of the leaching reactor, and a roaster downstream of the ash dryer that is cooperatively connected to both the leaching reactor and the ash dryer. Coal ash is mixed with an acid stream such that rare earth elements present in the coal ash are dissolved in the acid stream, thereby creating (i) a leachate containing the rare earth elements and (ii) leached ash. The leachate is heated to obtain acid vapor and an acid-soluble rare earth concentrate. Mixing of the coal ash with the acid stream can occur in a leaching reactor and heating of the leachate can occur in a roaster. The acid-soluble rare earth concentrate can be fed to a hydrometallurgical process to separate and purify the rare earth elements.

Abstract: A preparation method of phosphotungstic acid includes mixing a mixed solution containing tungsten, phosphorus and an inorganic acid with an organic-alcohol-containing oil phase for extraction, stripping the obtained supported organic phase and distilled water according to an oil phase:aqueous phase volume ratio of 3:1 to 10:1 to obtain a stripping solution; and carrying out thermal evaporation crystallization or spray drying on the stripping solution to obtain a phosphotungstic acid crystal, wherein the organic alcohol is a C7-C20 alcohol. The inventors have found out that the addition of an inorganic acid to a solution of phosphorus or tungsten and the use of an organic alcohol as an extractant can achieve simultaneous and efficient extraction of phosphotungstic acid. It has also been found that the organic-alcohol-containing oil phase has excellent selectivity for phosphotungstic acid molecules in the mixed solution.

Abstract: A process for recovering chromium from hexavalent chromium-containing wastewater comprises the following steps: (1) extracting hexavalent chromium in wastewater to an organic phase by using an extracting agent, and separating hexavalent chromium from a water phase, so as to acquire a hexavalent chromium-loaded organic phase; (2) reducing the hexavalent chromium-loaded organic phase by using an aqueous solution of an organic reducing agent, reducing hexavalent chromium into trivalent chromium, reversely extracting trivalent chromium into the water phase, and separating the organic phase from the water phase to acquire a solution of the trivalent chromium and a renewable organic phase, wherein the organic reducing agent is one or a mixture of alcohols, aldehydes and carboxylic acids having the carbon atom number ranging 1 to 3; and (3) performing solvent evaporation on the solution of trivalent chromium, catalyzing, and recovering the trivalent chromium.

Abstract: A method of production of a chemically treated steel sheet using cathode electrolysis to form a chemically treated coating which stably resupplies Zr ions in a treatment solution and uses an insoluble anode to continuously and stably treat a steel strip by cathode electrolysis in a treatment solution containing Zr ions and fluorine ions, characterized by using two or more types of zirconium compounds selected from predetermined Zr compounds to resupply zirconium ions in a plating solution consumed by the cathode electrolysis during the cathode electrolysis and maintaining a content of ions in the plating solution at zirconium ions: 0.05 to 30 g/liter, fluorine ions: 0.5 to 10 times the content of the zirconium ions, and ions derived from said two or more types of zirconium compounds other than zirconium ions and fluorine ions: not more than 10 times the content of the zirconium ions in performing the cathode electrolysis.

Abstract: The present invention relates to an apparatus for atomizing molten slag and recovering valuable metals, and more particularly to an apparatus for atomizing molten slag and recovering valuable metals, which enables molten slag of a blast furnace or a converter or an electric furnace to be atomized and valuable metals to be recovered.

Abstract: A method of recovering molybdenum includes introducing resin comprising molybdenum anions into an elution vessel and eluting (separating) the molybdenum anions from the resin to form a molybdenum rich eluent. Small amounts of uranium within the eluent is precipitated into sodium diuranate and removed. A further precipitation process is performed to form ferrimolybdate from the molybdenum rich eluent, thus recovering molybdenum. The resin comprising the molybdenum anions may be generated by (1) moving a pregnant lixiviant (containing uranium and molybdenum) through a first extraction apparatus to capture uranium anions in resin and producing a barren lixiviant (containing mostly molybdenum, with small amount of uranium), and (2) moving the barren lixiviant through a second extraction apparatus to capture mostly molybdenum anions in resin.

Abstract: A method for producing an ammonium tungstate aqueous solution includes the steps of: adding sulfuric acid to a solution containing tungstate ions; bringing the solution having the sulfuric acid added therein, into contact with an anion exchange resin; and bringing the anion exchange resin into contact with an aqueous solution containing ammonium ions.

Abstract: Provided herein are processes for recovering molybdenum and/or other value metals (e.g., uranium) present in aqueous solutions from a large range of concentrations: from ppm to grams per liter via a solvent extraction process by extracting the molybdenum and/or other value metal from the aqueous solution by contacting it with an organic phase solution containing a phosphinic acid, stripping the molybdenum and/or other value metal from the organic phase solution by contacting it with an aqueous phase strip solution containing an inorganic compound and having a ?1.0 M concentration of free ammonia, and recovering the molybdenum and/or other value metal by separating it from the aqueous phase strip solution. When the molybdenum and/or other value metal are present only in low concentration, the processes can include an organic phase recycle step and/or an aqueous phase strip recycle step in order to concentrate the metal prior to recover.

Abstract: Provided are methods method of recovering metal from an aqueous solution, the method comprising contacting an aqueous solution containing at least two metals selected from molybdenum, cobalt, nickel, zinc and iron with an organic solvent and an oxime-containing reagent composition at a predetermined pH, the predetermined pH selected to provide a high first metal extraction and a low second metal extraction; and separating the first metal from the solution.

Abstract: Various embodiments provide a process roasting a metal bearing material under oxidizing conditions to produce an oxidized metal bearing material, roasting the oxidized metal bearing material under reducing conditions to produce a roasted metal bearing material, leaching the roasted metal hearing material in a basic medium to yield a pregnant leach solution, conditioning the pregnant leach solution to thrill a preprocessed metal bearing material; and leaching the preprocessed metal bearing material in acid medium.

Abstract: A method for recovering technical-grade molybdenum from diluted acid leaching solutions (PLS) that have a high arsenic concentration is disclosed.

Abstract: The present invention relates to a process for selectively removing molybdenum from a solution which contains molybdenum, said process comprising the following steps: bringing the solution to an acid pH lower than or equal to 3, preferably lower than or equal to 2, even more preferably lower than or equal to 0.

Abstract: The present invention relates generally to a process for controlled leaching and sequential recovery of two or more metals from metal-bearing materials. In one exemplary embodiment, recovery of metals from a leached metal-bearing material is controlled and improved by providing a high grade pregnant leach solution (“HGPLS”) and a low grade pregnant leach solution (“LGPLS”) to a single solution extraction plant comprising at least two solution extractor units, at least two stripping units, and, optionally, at least one wash stage.

Abstract: Molybdic oxide is recovered from molybdenite by a multistep process in which (A) the molybdenite is converted to soluble and insoluble molybdic oxide by pressure oxidation, (B) the insoluble molybdic oxide is converted to soluble molybdic oxide by alkaline digestion and then combined with the soluble molybdic oxide, and (C) the molybdenum values of the combined streams are extracted into an organic phase using a nonprimary amine. The extracted molybdenum values are recovered from the organic phase using aqueous ammonia to form ammonium dimolybdate (ADM) which is recovered as refined crystals from a two-step calcination process.

Abstract: A solid composition comprises: MnO2; and a compound represented by the general formula (I) wherein: R is a polymer; each Y is independently a hydrogen or a negative charge; Z is either hydrogen or is not present; each n is independently 1, 2, 3, 4, 5 or 6; wherein the MnO2 is bound to the compound of formula (I) so as to coat the surface thereof. Such a composition may be used for the separation of polyvalent metal species, such as Mo, from one or more accompanying impurities.

Abstract: Compositions are provided that include nuclear fuel. Methods for treating nuclear fuel are provided which can include exposing the fuel to a carbonate-peroxide solution. Methods can also include exposing the fuel to an ammonium solution. Methods for acquiring molybdenum from a uranium comprising material are provided.

Abstract: Process for recovering molybdate or tungstate from an aqueous solution, in which molybdate or tungstate is bound to a water-insoluble, cationized inorganic carrier material from the aqueous solution at a pH in the range from 2 to 6, the laden carrier material is separated off and the bound molybdate or tungstate is liberated once again into aqueous solution at a pH in the range from 6 to 14. The process is suitable for recovering molybdate or tungstate in the delignification of pulp with hydrogen peroxide in the presence of molybdate or tungstate as catalyst. The recovered molybdate or tungstate can be recycled to the delignification.

Abstract: Molybdic oxide is recovered from molybdenite by a multistep process in which (A) the molybdenite is converted to soluble and insoluble molybdic oxide by pressure oxidation, (B) the insoluble molybdic oxide is converted to soluble molybdic oxide by alkaline digestion and then combined with the soluble molybdic oxide, and (C) the molybdenum values of the combined streams are extracted into an organic phase using a nonprimary amine. The extracted molybdenum values are recovered from the organic phase using aqueous ammonia to form ammonium dimolybdate (ADM) which is recovered as refined crystals from a two-step calcination process.

Abstract: Provided are methods using a ketoxime in metal extraction. One aspect of the invention relates to a method for the recovery of metal from a metal-containing aqueous solution at an elevated temperature using a ketoxime. Another aspect relates to a method of separating iron/copper using a specific ketoxime. Aldoximes may also be added to the reagent compositions used in these methods.

Abstract: Compositions are provided that include nuclear fuel. Methods for treating nuclear fuel are provided which can include exposing the fuel to a carbonate-peroxide solution. Methods can also include exposing the fuel to an ammonium solution. Methods for acquiring molybdenum from a uranium comprising material are provided.

Abstract: A method for extracting tungsten from scheelite by: 1) adding a mixed acid including H2SO4 and H3PO4 to a decomposition reactor; 2) heating the mixed acid to a temperature of 70-100° C.; adding scheelite while controlling the liquid-solid ratio at about 3:1-8:1 L/kg; allowing the components in the decomposition reactor to react for 1-6 h, and filtering to obtain a filtrate; 3) supplementing the filtrate with sulfuric acid consumed in the reaction; 4) crystallizing the filtrate to obtain phosphotungstic acid crystals and mother liquor; 5) dissolving the phosphotungstic acid crystals in water to obtain phosphotungstic acid solution; 6) transforming the phosphotungstic acid solution into an ammonium tungstate solution for the purpose of preparing ammonium paratungstate; and 7) supplementing the mother liquor with phosphoric acid and water to an initial level and reusing the mother liquor for ore leaching.

Abstract: Reagent compositions, methods for their manufacture and methods of their use are described. In particular, provided are reagent compositions comprising an aldoxime and ketoxime with an alkyl substituent. Also provided are methods of metal recovery using these reagent compositions.

Abstract: Provided are methods using ketoximes and/or aldoximes, including 3-methyl-5-alkylsalicylaldoxime and/or 3-methyl-5-alkyl-2-hydroxyacetophenone oxime, in reagent compositions for metal extraction/isolation. One such method is of extracting a metal from a nitrate-containing aqueous solution. Another such method is of extracting a metal from an aqueous ammoniacal solution. A third method is of multi-metal extraction based on a predetermined pH.

Abstract: A method for the extraction and purification of molybdenum, the method comprising the steps of: transferring an irradiated fuel solution to an extraction system, the irradiated fuel solution comprising iodine and molybdenum and other fission products, the extraction system comprising at least one sorbent column; passing the irradiated fuel solution upwards through the at least one sorbent-containing extraction column; directing the irradiated fuel solution towards a fuel management system by means of at least one discharge alignment valve; directing the extraction column eluate towards an iodine removal system; removing the iodine from the extraction column eluate; purifying the extraction column eluate; and collecting the purified eluate. Also disclosed is an apparatus for accomplishing the aforementioned method.

Abstract: A method for preparing ammonium heptamolybdate with the steps of: i) adding a molybdenum-containing organic phase to a liquid-liquid reextraction apparatus or to a desorption apparatus, and ii) directly cold-crystallization ammonium heptamolybdate by cooling the resulting reextraction or desorption solution.

Abstract: A method of recovering vanadium, nickel and molybdenum from heavy crude oil refinery residues comprises pyrolysis and combustion of the residues at temperatures up to 900° C. to produce an ash, converting the ash to an aqueous slurry comprising sodium hydroxide as leading agent and hydrogen peroxide as oxidizer, and extracting vanadium, nickel and molybdenum salts and oxides from the slurry. Extraction processes for the metals are disclosed.

Abstract: The present invention relates generally to a process for controlled leaching and sequential recovery of two or more metals from metal-bearing materials. In one exemplary embodiment, recovery of metals from a leached metal-bearing material is controlled and improved by providing a high grade pregnant leach solution (“HGPLS”) and a low grade pregnant leach solution (“LGPLS”) to a single solution extraction plant comprising at least two solution extractor units, at least two stripping units, and, optionally, at least one wash stage.

Abstract: The present invention relates generally to a process for controlled leaching and sequential recovery of two or more metals from metal-bearing materials. In one exemplary embodiment, recovery of metals from a leached metal-bearing material is controlled and improved by providing a high grade pregnant leach solution (“HGPLS”) and a low grade pregnant leach solution (“LGPLS”) to a single solution extraction plant comprising at least two solution extractor units, at least two stripping units, and, optionally, at least one wash stage.

Abstract: The oxine ligands 5-chloro-8-hydroxyquiniline and 5-sulfoxyl-8-hydroxyquinoline are covalently bound, using, for example, the Mannich reaction, to a silica gel polyamine composite made from a silanized amorphous silica xerogel and polyallylamine. The resulting modified composites, termed CB-1 (X?Cl) and SB-1 (X?SO3H), respectively, show a clear selectivity for trivalent over divalent ions and selectivity for gallium over aluminum. The compounds of the invention can be applied for the sequestration of metals, such as heavy metals, from contaminated mine tailing leachates.

Abstract: Provided herein are processes for recovering molybdenum and/or other value metals (e.g., uranium) present in aqueous solutions from a large range of concentrations: from ppm to grams per liter via a solvent extraction process by extracting the molybdenum and/or other value metal from the aqueous solution by contacting it with an organic phase solution containing a phosphinic acid, stripping the molybdenum and/or other value metal from the organic phase solution by contacting it with an aqueous phase strip solution containing an inorganic compound and having a ?1.0 M concentration of free ammonia, and recovering the molybdenum and/or other value metal by separating it from the aqueous phase strip solution. When the molybdenum and/or other value metal are present only in low concentration, the processes can include an organic phase recycle step and/or an aqueous phase strip recycle step in order to concentrate the metal prior to recover.

Abstract: A solid composition comprises: —MnO2; and—a compound represented by the general formula (I) wherein: R is a polymer; each Y is independently a hydrogen or a negative charge; Z is either hydrogen or is not present; each n is independently 1, 2, 3, 4, 5 or 6; wherein the MnO2 is bound to the compound of formula (I) so as to coat the surface thereof. Such a composition may be used for the separation of polyvalent metal species, such as Mo, from one or more accompanying impurities.

Abstract: The addition of a compatible metal salt crystal to the organic solution entering the mixer(s) in the solvent extraction stage(s) and/or the stripping stage(s), or to the emulsion mixture of the organic solution and the aqueous solution in the mixer(s), or to the mixture of the organic solution and the aqueous solution in a settler tank(s) following the mixer(s) in the solvent extraction and/or stripping stage(s) following the leaching of metal values from the ore containing that/those value(s) into an aqueous solution, and prior to the further refining of those values in processes, such as electrowinning, during mining operations for those metal values in order to improve the phase separation of the organic phase and the aqueous phase, and to promote the removal of contaminants from the organic phase.

Abstract: Process for recovering molybdate or tungstate from an aqueous solution, in which molybdate or tungstate is bound to a water-insoluble, cationized inorganic carrier material from the aqueous solution at a pH in the range from 2 to 6, the laden carrier material is separated off and the bound molybdate or tungstate is liberated once again into aqueous solution at a pH in the range from 6 to 14. The process is suitable for recovering molybdate or tungstate in the delignification of pulp with hydrogen peroxide in the presence of molybdate or tungstate as catalyst. The recovered molybdate or tungstate can be recycled to the delignification.

Abstract: Reagent compositions, methods for their manufacture and methods of their use are described. In particular, provided are reagent compositions comprising an aldoxime and ketoxime with an alkyl substituent. Also provided are methods of metal recovery using these reagent compositions.

Abstract: Provided are methods using ketoximes and/or aldoximes, including 3-methyl-5-alkylsalicylaldoxime and/or 3-methyl-5-alkyl-2-hydroxyacetophenone oxime, in reagent compositions for metal extraction/isolation. One such method is of extracting a metal from a nitrate-containing aqueous solution. Another such method is of extracting a metal from an aqueous ammoniacal solution. A third method is of multi-metal extraction based on a predetermined pH.

Abstract: Provided are methods using a ketoxime in metal extraction. One aspect of the invention relates to a method for the recovery of metal from a metal-containing aqueous solution at an elevated temperature using a ketoxime. Another aspect relates to a method of separating iron/copper using a specific ketoxime. Aldoximes may also be added to the reagent compositions used in these methods.

Abstract: A process for the removal of corrosion metal contaminants from a carbonylation catalyst solution comprising an iridium and/or rhodium carbonylation catalyst, an alkali and/or alkaline earth metal and corrosion metal contaminants in which the catalyst solution is contacted with a cation exchange resin having its active sites partially loaded with a sufficient amount of alkali and/or alkaline earth metal to maintain the concentration of said alkali and/or alkaline earth metal in the catalyst solution and recovering a catalyst solution of reduced corrosion metal contaminant content.

Abstract: The invention is directed to a process for the continuous preparation of ammonium paratungstate hydrate by back reextraction of a tungsten-laden organic phase with an ammonia-containing aqueous solution in a mixer-settler apparatus. The reextraction is carried out at an NH3:W molar ratio of from 0.83 to 1.30, and a volume feed ratio of the tungsten-laden organic phase to the ammonia-containing aqueous solution of from 5 to 25. The above crystalline is in high purity and in high yield. The production method can be carried out in a simple and energy-efficient manner.

Abstract: The present invention provides a method for extraction of metals selected from Cr, Mo, Pd, Tc, W, Re, and Pu using a new extractant of methyliminobisalkylacetamide represented by a formula (I): CH3—N—(CH2CONR2)2??(I) wherein R represents an alkyl group having 8-12 carbon atoms.

Abstract: A system and method for producing molybdenum oxide(s) from molybdenum sulfide are disclosed. The system includes a pressure leach vessel, a solid-liquid separation stage coupled to the pressure leach vessel, a solvent-extraction stage coupled to the solid-liquid separation stage, and a base stripping stage coupled to the solvent-extraction stage. The method includes providing a molybdenum sulfide feed, subjecting the feed to a pressure leach process, subjecting pressure leach process discharge to a solid-liquid separation process to produce a discharge liquid stream and a discharge solids stream, and subjecting the discharge liquid stream to a solvent extraction and a base strip process.

Abstract: A system and method for producing molybdenum oxide(s) from molybdenum sulfide are disclosed. The system includes a pressure leach vessel, a solid-liquid separation stage coupled to the pressure leach vessel, a solvent-extraction stage coupled to the solid-liquid separation stage, and a base stripping stage coupled to the solvent-extraction stage. The method includes providing a molybdenum sulfide feed, subjecting the feed to a pressure leach process, subjecting pressure leach process discharge to a solid-liquid separation process to produce a discharge liquid stream and a discharge solids stream, and subjecting the discharge liquid stream to a solvent extraction and a base strip process.

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: The present invention relates to a process for the removal of metal catalyst degradation products from a bleed stream of a catalytic chemical reaction process, wherein the catalyst is based on a metal selected from those in group VIII of the periodic table, chromium, copper, molybdenum, tungsten, rhenium, vanadium, titanium and zirconium, said process comprising treatment of the bleed stream with an alkali metal carbonate or ammonium carbonate source to form a solid complex or an aqueous solution of said solid complex, and removal of the solid complex or the aqueous solution of said solid complex from the bleed stream.

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 process of this invention is directed to the removal of metals from an unsupported spent catalyst. The catalyst is subjected to leaching reactions. Vanadium is removed as a precipitate, while a solution comprising molybdenum and nickel is subjected to further extraction steps for the removal of these metals. Molybdenum may alternately be removed through precipitation.

Abstract: A process for recovering catalytic metals from fine catalyst slurried in heavy oil comprises pyrolizing fine catalyst slurried in heavy oil to provide one or more lighter oil products and a coke-like material and recovering catalytic metals from the coke-like material.

Abstract: Process for recovering molybdate or tungstate from an aqueous solution, in which molybdate or tungstate is bound to a water-insoluble, cationized inorganic carrier material from the aqueous solution at a pH in the range from 2 to 6, the laden carrier material is separated off and the bound molybdate or tungstate is liberated once again into aqueous solution at a pH in the range from 6 to 14. The process is suitable for recovering molybdate or tungstate in the delignification of pulp with hydrogen peroxide in the presence of molybdate or tungstate as catalyst. The recovered molybdate or tungstate can be recycled to the delignification.

Abstract: A catalyst for the production of an oxygen-containing compound, comprising palladium, tungsten and zirconium, a production process thereof, and a production process of an oxygen-containing compound using the catalyst. The catalyst can provide an oxygen-containing compound from a lower olefin and oxygen with high productivity and high selectivity.

Abstract: The process of this invention is directed to the removal of metals from an unsupported spent catalyst. The catalyst is subjected to leaching reactions. Vanadium is removed as a precipitate, while a solution comprising molybdenum and nickel is subjected to further extraction steps for the removal of these metals. Molybdenum may alternately be removed through precipitation.

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.