Class / Patent application number | Description | Number of patent applications / Date published |
423053000 | Group VIB metal (Cr, Mo, or W) | 37 |
20080299025 | Oxidizing Reactor for Molybdenum Sulphide and its Associated Process - A reactor for molybdenum sulphide (MoS2), wherein MoS2 is ionized by an electric field generated by a first set of magnetrons at a frequency in the range of 2500-3500 MHz and heated by a variable magnetic field of 2500 Hz produced by a winding coil, resulting in the exclusive evaporation of molybdenite. MoS2 in gas state is then stimulated by a second set of magnetrons and, with the injection of air, oxidized until trioxide is obtained. Hot gases essentially containing molybdenum trioxide, sulphur dioxide, and nitrogen are conducted from a first body towards a second body though a first duct. Cold air is added to the second body through a second duct to cool the gas, and crystals formed by liquefaction settle and are removed through a lower duct while gases at a temperature of 600° C. are conducted through a higher duct. | 12-04-2008 |
20100098606 | PROCESS FOR THE EXTRACTION OF SPECIFIC TRANSITION METALS - A process is disclosed for separation and recovery of vanadium, molybdenum, iron, tungsten, cobalt and nickel from alumina-based materials, mattes, ores, manufacturing by-products and waste. These elements are oxidized. The oxides are reacted with gaseous HCl to form volatile chloride-bearing compounds that subsequently sublimate. The volatile compounds are condensed in a downward-stepped thermal gradient that allows collection of moderate to high purity compounds of individual elements with exception of a nickel-cobalt co-condensate. Nickel is separated from cobalt by precipitation of nickel chloride from concentrated HCl pressurized with gaseous HCl. | 04-22-2010 |
20110129397 | METHOD FOR RECOVERING VALUABLE METAL FROM WASTE CATALYST - A method for recovering high purity nickel, cobalt, molybdenum and vanadium from a waste catalyst in high yield by convenient means is provided. The method includes a step of heating a waste catalyst containing valuable metals in a non-oxidizing atmosphere, thereby deoiling an adhered oil content by thermal decomposition, a step of co-milling the deoiled waste catalyst and a chloride to form a chloride of nickel and/or cobalt, a step of water-leaching the co-milled waste catalyst to dissolve nickel and/or cobalt in water, a step of oxidizing leaching residue containing molybdenum and/or vanadium after water leaching to form an oxide of molybdenum and/or vanadium; and a step of subjecting the leaching residue containing the oxide of molybdenum and/or vanadium to alkali leaching to dissolve the molybdenum and/or vanadium in an alkali solution. | 06-02-2011 |
20120107200 | PROCESS AND PLANT FOR CONVERTING HAZARDOUS WASTE CONTAINING CHROMIUM VI INTO NON-HAZARDOUS WASTE - The instant invention relates to a process and plant for the transformation of dangerous wastes containing chromium six as contaminant into non dangerous wastes that can be stored without special care and will be degraded in the environment without time limit. | 05-03-2012 |
20120148461 | PROCESS FOR MULTI METAL SEPARATION FROM RAW MATERIALS AND SYSTEM FOR USE - An improved process for the separation of different metal values from raw materials, and an apparatus for carrying out such processes are disclosed. | 06-14-2012 |
20120251416 | PROCESS FOR RECYCLING OF TUNGSTEN CARBIDE ALLOY - The present disclosure is a process for the recycling of tungsten carbide alloy. Tungsten carbide alloy scrap is heated in an oxidizing atmosphere and the oxidized material is pulverized by grinding. The powder material is treated with a carburizing mixture for reducing and carburizing the powdered tungsten oxides and other metal oxides. The method is cost effective and environment friendly. | 10-04-2012 |
20130315804 | Fly Ash and Fly Ash Leachate Treatment - The present invention is directed to a process of treating fly ash and/or fly ash leachate to immobilize heavy metals contained in such fly ash and/or fly ash leachate, which process comprises treating such fly ash and/or fly ash leachate with a soluble ferrous compound under alkaline conditions. This process may be conducted in the absence of any pH modification, mixing (in the sense of a physical blending with a solid material), drying or heating steps, making it practical for treatment of alkaline fly ash (and other coal combustion by-products) which is currently stored in landfills or wet ash lagoons, particularly fly ash which has been recovered from flue gas streams treated with highly alkaline materials such as trona, bicarbonate or limestone and the like. | 11-28-2013 |
20150139872 | PURIFICATION OF TUNGSTEN CARBIDE COMPOSITIONS - In one aspect, methods of purifying WC compositions are described herein. A method of purifying a WC composition comprises contacting the WC composition with an electrolyte solution comprising a cationic metal oxidant and oxidizing one or more metal impurities of the WC composition with the cationic metal oxidant to solubilize the one or more metal impurities in the electrolyte solution. | 05-21-2015 |
20150147247 | METHOD OF PRE-TREATING MOLYBDENITE CONTAINING COPPER - Disclosed is a method of pre-treating molybdenite containing copper. The method includes mixing molybdenite containing copper with sulfuric acid, performing a sulfation reaction through a heating process after the mixing process is performed, performing a water leaching process by putting and stirring water after the sulfation reaction is performed, separating a cake from liquid after the water leaching process is performed, and drying the separated cake. | 05-28-2015 |
20150329935 | METHOD FOR RECOVERING TUNGSTEN COMPOUND - [Object] To efficiently recover tungsten from an object containing tungsten by a simple treatment process using a microorganism with reduced environmental load. | 11-19-2015 |
20190145707 | ROASTING FURNACE, USE THEREOF AND METHOD FOR THE PROCESSING OF ORES OR CONCENTRATES | 05-16-2019 |
423054000 | Ion exchanging or liquid-liquid extracting | 10 |
20090110620 | PROCESS FOR METALS RECOVERY FROM SPENT CATALYST - 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. | 04-30-2009 |
20090274598 | Process for Recovering Molybdate or Tungstate from Aqueous Solutions - 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. | 11-05-2009 |
20110014097 | SYSTEM AND METHOD FOR CONVERSION OF MOLYBDENITE TO ONE OR MORE MOLYBDENUM OXIDES - 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. | 01-20-2011 |
20130078167 | METHOD OF METALS RECOVERY FROM REFINERY RESIDUES - 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. | 03-28-2013 |
20130195737 | METHOD FOR EXTRACTING TUNGSTEN FROM SCHEELITE - A method for extracting tungsten from scheelite by: 1) adding a mixed acid including H | 08-01-2013 |
20130251609 | Process for the Conversion of Molybdenite to Molydenum Oxide - 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. Hallmarks of the process include one or more of economic ammonia recovery and recycle, use of ferrous sulfate to remove arsenic and/or phosphorus from the Mo-loaded aqueous ammonia strip liquor, two-stage calcination of ADM crystals, recovery of rhenium from a filtrate of the residual molybdenum precipitation stage, selenium removal from the liquid fraction from which rhenium is recovered, and caustic boil of the mother liquor from which the selenium is precipitated. | 09-26-2013 |
20140286839 | PROCESS FOR THE SELECTIVE REMOVAL OF MOLYBDENUM FROM A SOLUTION CONTAINING IT - 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 0.5, by the addition of an inorganic acid; adding at least one organic solvent, preferably toluene or xylene, to the solution and stirring continuously so as to create a water-organic emulsion; adding to the water-organic emulsion at least one alkaline metal xanthate having the general formula MeRX, wherein R is a linear or branched alkyl group having a number of carbon atoms higher than or equal to 2, Me is an alkaline metal selected from Li, Na, K, Rb, Cs and Fr, and X is the xanthate group, so as to form a complex with molybdenum wherein the molar ratio molybdenum/alkaline metal xanthate ranges from 1/6 to 1/2, keeping the emulsion at an acid pH by the addition of an inorganic acid, and interrupting the stirring so as to allow the separation of the aqueous phase from the organic phase. The linear or branched alkyl group R preferably has a number of carbon atoms higher than or equal to 2 and lower than or equal to 12. A reductant is optionally added to the starting solution which comprises Mo and V. | 09-25-2014 |
20140301918 | PROCESS FOR RECOVERY OF TECHNICAL GRADE MOLYBDENUM FROM DILUTED LEACHING ACID SOLUTIONS (PLS), WITH HIGHLY CONCENTRATED ARSENIC, FROM METALLURGICAL RESIDUES - A method for recovering technical-grade molybdenum from diluted acid leaching solutions (PLS) that have a high arsenic concentration is disclosed. The method includes: (a) bringing a pre-filtered acid leaching solution (PLS), originating from the leaching of smelter dust, into contact with an anionic ion-exchange resin; (b) washing the loaded resin with water; (c) extracting molybdenum from the ion-exchange resin with an alkaline ammonium regenerant solution to form ammonium molybdenum in solution; (d) washing the unloaded resin with water; (e) adding iron and/or magnesium salts to the recovered ammoniacal solution to obtain a precipitate which is transferred to the arsenic abatement step and a solution containing ammonium molybdate in solution; (f) adding sulphuric acid to the arsenic-free ammoniacal solution in order to precipitate the moylbdenum in the form of ammonium molybdate; (g) separating the precipitate by filtering the molybdate and re-circulating the solution obtained with the initial PLS solution; (h) calcining the separated precipitate to obtain ammonia and molybdenum trioxide; and (i) recovering the released ammonia for its subsequent use in the method as a recirculated regenerant solution. | 10-09-2014 |
20150104362 | METHODS AND APPARATUS FOR RECOVERING MOLYBDENUM IN URANIUM IN-SITU RECOVERY PROCESS - 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. | 04-16-2015 |
20150315672 | RECOVERY AND PRECIPITATION OF VARIOUS ELEMENTS AND COMPOUNDS - Systems and methods are disclosed for extracting a plurality of materials from a solution. These include a plurality of extraction devices. The extraction devices use a resin suspended above at least one screen, and the resin is used to extract at least one material from a fluid. A liquid is forced through the plurality of extraction devices and a separate material is extracted in each of the extraction devices. The resin is selected for each of the extraction devices and is based upon the material for which that extraction device is designed to remove from the fluid. Each of the extraction devices operate in series to remove at least one material from the fluid. | 11-05-2015 |
423055000 | Forming insoluble substance in liquid | 11 |
20090148362 | METHOD FOR RECOVERING TUNGSTEN - A method for recovering tungsten from a reaction mixture obtained by reacting an organic compound with hydrogen peroxide in the presence of a tungsten catalyst comprising blowing a gas into the reaction mixture to precipitate tungstic acid (WO | 06-11-2009 |
20100111787 | METHOD OF RECOVERING VALUABLE METALS FROM THE VRDS SPENT CATALYST - The present invention discloses method of recovering valuable metals, such as vanadium, molybdenum, nickel from the catalysts spent in the VRDS process for desulfurization of pertroleum. The method comprises leaching water-insoluble reactants after reacting the pre-treated waste crystals in solution of sodium hydroxide, maintaining the filtrate at pH 9.5 by adding sulfhuric acid or hydrochloric acid and then heating the filtrate, removing aluminium oxide from the soltuion, aerating the filtrate continously or priodically and agitating the filtrate below pH 1 at 80-100° C., thereby precipitating molybdenum oxide and vanadium oxide, and leaching and washing the precipitated molybdenum oxide and vanadium oxide. | 05-06-2010 |
20100135876 | PROCESS FOR SOLUBILIZING, REDUCING AND FIXING HEXAVALENT CHROMIUM CONTAINED IN CHROMITE ORE PROCESSING RESIDUE INTO TRIVALENT CHROMIUM - A process for reducing hexavalent chromium, Cr(VI), contained within a chromite ore processing residue matrix comprising the sequential steps of providing a chromite ore processing residue matrix containing Cr(VI), solubilizing the matrix to release Cr(VI), reducing the Cr(VI) to Cr(III) using Fe(II), and, fixing the residual Fe(II) using a effective amount of a Fe(II) precipitating agent to make a Fe(II) precipitate. | 06-03-2010 |
20130294985 | Titania-Supported Hydrotreating Catalysts | 11-07-2013 |
20140348729 | PROCESS FOR SEPARATING AND RECOVERING METALS - A process for treating spent catalyst containing heavy metals, e.g., Group VIB metals and Group VIII metals is provided. In one embodiment after deoiling, the spent catalyst is treated with an ammonia leach solution under conditions sufficient to dissolve the group VIB metal and the Group VIII metal into the leaching solution, forming a leach slurry. After solid-liquid separation to recover a leach solution, chemical precipitation and solids repulping is carried out to obtain an effluent stream containing ammonium sulfate (Amsul), ammonium sulfamate, Group VB, Group VIB and Group VIII metals. Following sulfidation, the Group VIII metal is fully removed and Group VB and Group VI metals are partially removed from the Amsul stream. In the additional steps of oxydrolysis and iron precipitation, an effective amount of ferric ion at a pre-select pH is added to form insoluble complexes with the Group VB and Group VIB metals, which upon liquid-solid separation produces an effluent ammonium sulfate stream containing less than 10 ppm each of the Group VB and Group VIB metals. | 11-27-2014 |
423056000 | Ammoniating or nitrating | 2 |
20090136399 | Process for Recovering Base Metals from Spent Hydroprocessing Catalyst - A method for recovering metals from a spent dispersed catalyst originating from a Group VIB metal sulfide catalyst containing at least a Group VB and Group VIII metal for hydrocarbon oil hydroprocessing is disclosed. In one embodiment, the method comprises the steps of: contacting the spent dispersed catalyst with a leaching solution containing ammonia and air to dissolve the group VIB metal and the Group VIII metal into the leaching solution at sufficient temperature and pressure; forming a slurry containing at least a group VIB metal complex and at least a group VIII metal complex, ammonium sulfate and solid residue containing at least a Group VB metal complex and coke; separating and removing the solid residue containing ammonium metavanadate and coke from the pressure leach solution (PLS); precipitating from the PLS at least a portion of the Group VIB metal and at least a portion of the Group VIII metal by controlling the pH at a pre-selected pH to selectively precipitate as metal complexes the Group VIB and Group VIII metals. | 05-28-2009 |
20090136400 | PROCESS FOR SEPARATING AND RECOVERING BASE METALS FROM USED HYDROPROCESSING CATALYST - A method is disclosed for separating and recovering base metals from a used hydroprocessing catalyst originating from Group VIB and Group VIII metals and containing at least a Group VB metal. In one embodiment, the method comprises the steps of: contacting the used catalyst with an ammonia leaching solution under conditions sufficient to dissolve the group VIB metal and the Group VIII metal into the leaching solution; forming a leached slurry containing at least a group VIB metal complex and at least a group VIII metal complex, ammonium sulfate and a solid residue containing at least a Group VB metal complex and coke; separating and removing from the leached slurry the solid residue and coke; precipitating from the remaining solution at least a portion of the Group VIB metal complex and at least a portion of the Group VIII metal complex by controlling the pH to form a liquid material substantially free of Group VB, Group VIB and Group VIII metals and another solid material comprising substantially Group VIB and Group VIII metal complexes. Said solid material is further processed by dissolution, means of separation, further means of precipitation and oxidative dissolution to produce, separately, a Group VIB metal product solution, a Group VIII metal product solution and a purified ammonium sulfate product solution. | 05-28-2009 |
423058000 | Forming compound containing plural metals | 4 |
20090028765 | PROCESS TO PRODUCE MOLYBDENUM COMPOUNDS, FROM SPENT MOLYBDENUM CATALYZERS, INDUSTRIAL RESIDUES AND METAL ALLOYS - A process for producing molybdenum compounds, from spent molybdenum catalyzers, industrial residues and metal alloys, particularly an integrated process for reclaiming molybdenum, vanadium, nickel, cobalt, aluminum and other metals, starting with the treatment of exhausted catalyzers, industrial residues and metal alloys, principally from petroleum de-sulfurization catalyzers; the molybdenum trioxide is obtained by precipitation of ammonium octamolybdate and its calcination. Starting from molybdenum trioxide, other compounds derived from molybdenum can be obtained, as sodium molybdate, molybdenum disulfite and ammonium molybdate. | 01-29-2009 |
20120039777 | PROCESS FOR SEPARATING AND RECOVERING METALS - A process for treating spent catalyst containing heavy metals, e.g., Group VIB metals and Group VIII metals is provided. In one embodiment after deoiling, the spent catalyst is treated with an ammonia leach solution under conditions sufficient to dissolve the group VIB metal and the Group VIII metal into the leaching solution, forming a leach slurry. After solid-liquid separation to recover a leach solution, chemical precipitation and solids repulping is carried out to obtain an effluent stream containing ammonium sulfate (Amsul), ammonium sulfamate, Group VB, Group VIB and Group VIII metals. Following sulfidation, the Group VIII metal is fully removed and Group VB and Group VI metals are partially removed from the Amsul stream. In the additional steps of oxydrolysis and iron precipitation, an effective amount of ferric ion at a pre-select pH is added to form insoluble complexes with the Group VB and Group VIB metals, which upon liquid-solid separation produces an effluent ammonium sulfate stream containing less than 10 ppm each of the Group VB and Group VIB metals. | 02-16-2012 |
20130243673 | SEPARATION OF TUNGSTEN FROM AMMONIUM MOLYBDATE SOLUTIONS - Disclosed is process for the separation of tungsten from molybdenum and more particularly from ammonium molybdate solutions. The method comprises dissolving technical grade molybdenum trioxide in an aqueous ammonium hydroxide solution and further adding certain metal generating compounds to the aqueous solution thereby generating a tungsten-containing precipitate. Calcium, iron and manganese are the preferred metal generating compounds of the invention. Certain temperature and pH values of the system, as disclosed, are preferred for the precipitation of the tungsten from the ammonia molybdate solution. | 09-19-2013 |
20140341791 | HYDROTHERMAL OXIDATION METHOD FOR PRODUCTION OF ALKALI METAL DICHROMATE FROM CARBON FERROCHROME - The present invention provides a hydrothermal oxidation method for producing alkali metal dichromate from carbon ferrochrome, and the method comprises the following steps: formulating an initial reaction liquid by mixing carbon ferrochrome, an alkaline substance and water, in which the actual addition amount of the alkali is controlled smaller than the theoretically required amount; adding the initial reaction liquid into a reaction kettle, charging an oxidizing gas into the reaction kettle, and allowing the reaction to proceed for 0.5 to 3 h at a temperature of 150° C. to 370° C. and a pressure of 2 Mpa to 24 MPa; carrying out solid-liquid separation, cooling the resultant filtrate to a temperature of −12° C. to −20° C. to precipitate crystals, and carrying out separation by centrifuge to obtain alkali metal dichromate solution; adding CrO | 11-20-2014 |
423059000 | Volatizing | 2 |
20100047141 | Method and Apparatus for the Recovery of Molybdenum from Spent Catalysts - This invention relates to an apparatus and process that utilizes high-temperature oxidation and sublimation techniques for the recovery of molybdenum from spent catalysts or other feedstocks that contain molybdenum. A preferred embodiment uses a counter-rotating vortex reactor and a cyclonic entrained-flow reactor to rapidly heat and oxidize the spent catalyst feedstock, such as carbon, sulfur, and molybdenum compounds, at temperatures in the range of about 2100° F. to 2900° F., resulting in a gas-solid stream containing molybdenum trioxide vapor. A high-temperature cyclone separator is utilized to separate the residue from this stream before this stream is rapidly quenched to a temperature sufficient to effect the condensation of solid molybdenum trioxide without condensing arsenic or phosphoric oxides. The condensed molybdenum trioxide material is separated from this stream by passing through a high-temperature filtration system. The remaining gaseous stream is then ducted to suitable unit operations for possible further material reclamation and entailed pollution control prior to its final discharge to the atmosphere. | 02-25-2010 |
423060000 | As a compound containing chlorine | 1 |
20130064742 | PROCESS FOR THE EXTRACTION OF SPECIFIC TRANSITION METALS - A process is disclosed for separation and recovery of vanadium, molybdenum, iron, tungsten, cobalt and nickel from alumina-based materials, mattes, ores, manufacturing by-products and waste. These elements are oxidized. The oxides are reacted with gaseous HCl to form volatile chloride-bearing compounds that subsequently sublimate. The volatile compounds are condensed in a downward-stepped thermal gradient that allows collection of moderate to high purity compounds of individual elements with exception of a nickel-cobalt co-condensate. Nickel is separated from cobalt by precipitation of nickel chloride from concentrated HCl pressurized with gaseous HCl. | 03-14-2013 |
423061000 | Forming compound containing plural metals | 3 |
20110300040 | METHOD FOR PRODUCING SODIUM TUNGSTATE, METHOD FOR COLLECTING TUNGSTEN, APPARATUS FOR PRODUCING SODIUM TUNGSTATE, AND METHOD FOR PRODUCING SODIUM TUNGSTATE AQUEOUS SOLUTION - Provided are a method for producing sodium tungstate by supplying an oxidant made of sodium nitrate or sodium nitrite to bring a tungsten containing material and the oxidant into contact with each other in an atmosphere containing oxygen to thereby continuously produce a reaction product; a method for collecting tungsten using the method; and an apparatus for producing sodium tungstate. Also provided are a method for producing a sodium tungstate aqueous solution in which a reductant is introduced into a melt containing the above-described reaction product which is then dissolved in water; and a method for collecting tungsten using the method. | 12-08-2011 |
20140112847 | METHOD FOR PRODUCING SODIUM TUNGSTATE, METHOD FOR COLLECTING TUNGSTEN, APPARATUS FOR PRODUCING SODIUM TUNGSTATE, AND METHOD FOR PRODUCING SODIUM TUNGSTATE AQUEOUS SOLUTION - Provided are a method for producing sodium tungstate by supplying an oxidant made of sodium nitrate or sodium nitrite to bring a tungsten containing material and the oxidant into contact with each other in an atmosphere containing oxygen to thereby continuously produce a reaction product; a method for collecting tungsten using the method; and an apparatus for producing sodium tungstate. Also provided are a method for producing a sodium tungstate aqueous solution in which a reductant is introduced into a melt containing the above-described reaction product which is then dissolved in water; and a method for collecting tungsten using the method. | 04-24-2014 |
20160024615 | SODIUM TUNGSTATE PRODUCTION METHOD - A method of producing sodium tungstate of this invention including allowing cemented carbide scrap containing tungsten to react with a molten salt containing sodium sulfate and having added thereto a metal oxide, to thereby obtain sodium tungstate. | 01-28-2016 |