Abstract: The invention relates to specific chrome tanning agents and also to their use for the tanning of hides and skins, and to the leather and pelts obtainable as a result. It further provides a new process wherein the protein-masked chrome tanning agents of the invention are obtained from materials containing chromium and collagen, more particularly from leather production wastes such as leather shavings, for example. This enables recycling of chromium-containing leather production wastes, thereby permitting a significant reduction in the amount of such wastes, a fact which leads to considerable economic, environmental and logistical advantages.

Abstract: Disclosed is a process for the selective removal of copper compounds, and other impurities with respect to molybdenum and rhenium, from concentrates of molybdenite (MoS2) with a copper content that is higher than 0.5% in dry weight.

Abstract: Coated microparticles for sustained-release of an active pharmaceutical ingredient after parenteral administration, and methods of producing such coated microparticles, are provided. The coated microparticles comprise core particles of an active pharmaceutical ingredient and a first polymeric coating on the core particles. The first polymeric coating is permeable to the active pharmaceutical ingredient forms a saturated solution within the coated microparticle, resulting in pseudo-zero-sustained release period. A second polymeric coating can be employed to add mechanical support or as a rate-controlling element.

Abstract: This invention relates to a method of quantitative analysis of hexavalent chromium in a chromate coating on a substrate. In this method a substrate on which the chromate coating is formed is immersed into an aqueous solution containing lithium hydroxide to extract hexavalent chromium within an extraction solution. Quantitative analysis of extracted hexavalent chromium in the extraction solution is then performed.

Abstract: A composite material comprising graphene oxide and an electrochemically active ingredient, in particular H4-xV3O8 with x ranging from 0.1 to 2.2, as well as a method for its manufacture were developed. The composite material is suitable for being used as electrode in an electrochemical cell.

Abstract: A method of processing a composite body comprising a super-hard structure and refractory metal material exposed proximate a boundary of the composite body, the refractory metal material comprising refractory metal. The method includes providing a basic corrosive agent, heating the corrosive agent to at least its melting point, contacting the composite body with the corrosive agent in the molten state and treating the composite body with the corrosive agent for a period of time to remove refractory metal material from the composite body.

Abstract: A process for recovering metals from a stream containing hydrocarbons and carbonaceous residues comprising sending the stream for extraction by mixing the stream with a hydrophilizing agent to remove the hydrophobic components of the stream, sending the mixture of the stream and hydrophilizing agent for separation, separating a liquid phase containing most of the hydrophilizing agent and hydrocarbons dissolved from a solid phase, sending the separated solid phase for leaching with an alkaline solution in the presence of air and/or oxygen, sending the leached mixture for separation, and separating the solid residue from the liquor.

Abstract: 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.

Abstract: 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.

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 mixed acid present in an amount of 3-8 L per kg of scheelite; allowing the components in the decomposition reactor to react for 1-6 h, and filtering the resulting mixture 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 a 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: 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: The invention relates to a system and method for the substantially permanent biogeochemical stabilization of solids impacted with hexavalent chromium/Cr(VI), including chromite ore processing residue (“COPR”). The invention comprises a novel treatment method of adding amendment(s) to COPR or other chromate impacted solids for the purpose of (1) weathering COPR minerals (when present) to convert the minerals that control alkalinity of the COPR to non-alkaline forms and liberate incorporated hexavalent chromium (Cr(VI)) in the process; (2) providing a chemical reductant (ferrous iron) to rapidly and permanently reduce the available Cr(VI) to trivalent form (Cr(III)); and/or (3) supporting longer-term biogeochemical Cr(VI) reduction enhanced by recycling of the chemical reductant, ultimately rendering the material non-hazardous as measured by acceptable methods.

Abstract: A metal recovery process for heavy effluent from a hydroconversion process. The effluent contains unconverted residue and a solid carbonaceous material containing group 8-10 metal, group 6 metal, and vanadium and/or nickel, and the metals are recovered according to the invention.

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: TiO2-supported catalysts include at least molybdenum or tungsten as active components for hydrotreating processes, in particular for the removal of sulfur and nitrogen compounds as well as metals out of crude oil fractions and for the hydrogenation of sulfur oxides.

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: The instant invention discloses a method for the valorization of spent catalyst from hydrocarbon processing slurry reactors as well as slurry flakes.

Abstract: A method for materials recovery from a catalyst comprising oxides of iron, cerium, molybdenum, and potassium, in which potassium and molybdenum are removed by treating the catalyst with an aqueous leachant, giving an aqueous solution S1 comprising potassium and molybdenum, and a solid residue R1 comprising cerium oxide and iron oxide, and recovering cerium in the form of a solid comprising a cerium(III) compound or cerium(IV) oxide from the solid residue R1.

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: Processes for reducing hexavalent chromium, Cr(VI) in a chromite ore processing residue matrix and processes for analyzing and determining effective treatment are disclosed.

Abstract: Methods for recovering base metals, including, among other metals, molybdenum and nickel, from metal sulfides containing a Group VIB metal and a Group VIII metal. Generally, the methods comprise: contacting metal sulfides with a leaching solution containing ammonia and air to dissolve the metals into the leaching solution, forming a slurry containing soluble complexes of the metals, ammonium sulphate and solid residue containing ammonium metavanadate and any carbonaceous materials. The solid residue containing ammonium metavanadate and carbonaceous materials is then separated from the slurry and metal complexes are precipitated from the slurry by adjusting the pH. A second slurry may be formed comprising a second solid residue and a primary filtrate comprising ammonium sulfate solution that is substantially free of metals.

Abstract: Methods to reduce hexavalent chromium (Cr(VI)) in chromite processing wastes include one or more of the following steps: contacting the chromite processing wastes with an oxygen scavenger or chemical reducer; permitting the chromite processing wastes to react with the oxygen scavenger or chemical reducer; contacting the chromite processing wastes with ferrous ion; contacting the chromite processing wastes with sulfide ion; and, contacting the chromite processing wastes with ferrous sulfide.

Abstract: The present invention concerns a process for the instantaneous control of the precipitation of nickel and cobalt present in a leach liquor by adjustment of the pH-value. Said leach liquor is obtained by pressurized acidic leaching of laterite ores and additionally contains aluminium, ferric and ferrous iron and chromium among others. The process comprises the following steps: precipitation of aluminium, ferric and ferrous iron, chromium etc. by increasing the pH-value by adding a suitable reagent such as lime and/or limestone, following precipitation of nickel and cobalt by further increasing the pH-value of the liquor, finally separating the precipitate from the low-content nickel and cobalt solution. The nickel and cobalt precipitate can be used for further refinement. In order to keep the process conditions constant, the steps of increasing the pH-value are controlled simultaneously.

Abstract: A method for selectively recovering a metal from mined ore and other metal-bearing raw source materials is disclosed.

Abstract: The invention relates to a process for recovering Group VIB metals from a catalyst, in particular a spent bulk catalyst, comprising one or more Group VIB metals and one or more Group VIII metals. Further, the invention relates to a solid Group VIB metal compound obtainable by the process according to the invention having the general formula H2XO4, wherein X=W1-yMoy, wherein y is between 0 and 1 and to its use in a process for the manufacture of a fresh catalyst.

Abstract: A method for detoxifying spent CCA (copper, chromium, arsenic) treated wood, from which CCA is efficiently removed from the wood, allowing both the CCA and the wood to be reused has been developed. The method comprises the steps of (1) microwave-enhanced acid extraction of CCA, (2) separation of the acid-containing CCA solution from the wood, (3) separation/precipitation of CCA from the acid extract, (4) recovery and regeneration of CCA-bearing precipitant for reuse in the wood preservation industry, (5) recycling recovered acid solution, (6) microwave-assisted liquefaction of the extracted wood, and (7) use of detoxified liquefied wood to form polymeric materials such as polyurethanes and phenolic resin adhesives. The recovered CCA may be used to treat wood. The recovered acids may be used to extract CCA from CCA-treated wood, and the liquefied wood may be used as phenolic or polyurethane resins.

Abstract: 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 (WO3.H2O) and separating tungstic acid precipitated.

Abstract: This invention relates to a method for producing chromates, especially for producing alkali metal chromates. The method comprises following steps: the obtaining of a mixture of alkali metal hydroxide, alkali metal chromate, and ferrous residue after the reaction of chromite ore with an oxidant in the reactor in the presence of molten salt or in aqueous solution of alkali metal hydroxide, the obtaining of a leaching slurry by leaching the reaction products with aqueous solution of alkali metal hydroxide, the separating of the primary chromate product from the leaching slurry, the obtaining of pure chromate crystal by purifying the primary chromate product. Both the primary chromate product and the pure chromate crystal can be used as the raw materials to manufacture other chromium compounds. Compared with the currently-used roasting method, the method has the advantages of decreasing the reaction temperature by about 700° C.

Abstract: Methods and apparatus relate to catalysts and preparation of the catalysts, which are defined by sulfides of a transition metal, such as one of molybdenum, tungsten, and vanadium. Precursors for the catalysts include a metal ion source compound, such as molybdenum trioxide, and a sulfide ion source compound, such as thioacetamide. Once the precursors are dissolved if solid and combined in a mixture, homogenous precipitation from the mixture forms the catalysts. Exemplary uses of the catalysts include packing for a methanation reactor that converts carbon monoxide and hydrogen into methane.

Abstract: 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 used catalyst is contacted with an ammonia leaching solution to dissolve and separate the Group VIB and VIII metals from the Group VB metal complex and coke associated with the used catalyst. The resulting Group VIB and VIII metal containing solution is processed through at least two additional precipitation and liquid/solid separation steps to produce, in separate processing streams, a Group VIB metal product solution (such as ammonium molybdate) and a Group VIII metal product solution (such as nickel sulfate). Additionally, two separate filtrate streams are generated from liquid-solid separation steps, which filtrate streams are combined and subjected to hydrolysis and oxidation (oxydrolysis) to generate a purified ammonium sulfate solution for further processing, such as for fertilizer.

Abstract: 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.

Abstract: A method for selectively recovering a metal from mined ore and other metal-bearing raw source materials is disclosed.

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: Methods and systems for removing copper minerals from a molybdenite concentrate. One embodiment provides leaching copper from the molybdenite concentrate with a leaching solution comprising ferric chloride, removing molybdenite from the leaching solution, introducing an acid into the leaching solution and introducing O2, O3, or a combination of both, into the leaching solution. A method for regenerating ferric chloride in a leaching solution is also provided. One embodiment provides adding a leaching solution comprising Fe(II) ions, Fe(III) ions, or a combination of both, to a mixture of mineral sulfides, introducing an acid into the leaching solution, and introducing O2, O3, or a combination of both, into the leaching solution.

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: 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 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.

Abstract: 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.

Abstract: Methods to reduce hexavalent chromium (Cr(VI)) in chromite processing wastes include one or more of the following steps: contacting the chromite processing wastes with an oxygen scavenger or chemical reducer; permitting the chromite processing wastes to react with the oxygen scavenger or chemical reducer; contacting the chromite processing wastes with ferrous ion; contacting the chromite processing wastes with sulfide ion; and, contacting the chromite processing wastes with ferrous sulfide.

Abstract: 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.

Abstract: 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 (WO3.H2O) and separating tungstic acid precipitated.

Abstract: 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.

Abstract: A method for treating a polymetallic sulfide ore containing gold and/or silver, and further containing base metals selected from the group consisting of iron, aluminum, chromium, titanium, copper, zinc, lead, nickel, cobalt, mercury, tin, and mixtures thereof, is disclosed. The method comprises the steps of grinding the polymetallic sulfide ore to produce granules, oxidizing the granules to produce oxidized granules, and chloride leaching the granules using a brine solution including dissolved halogens, as well as chloride and bromide salts.

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 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 method is provided for the removal of chromium from leach liquors produced during high pressure leaching of laterite ores in an autoclave, by addition to the autoclave of carbon in a quantity of about 0.5%-1% by weight with reference to the total dry feed.

Abstract: A method and system for decreasing the concentration of at least one metal in an aqueous solution. The metal may be molybdenum, tungsten, or both. An aqueous solution is introduced into at least one reaction zone, and at least one source of hydroxide ions is provided into the at least one reaction zone in an amount sufficient to precipitate at least some of the mass of the at least one metal. The aqueous solution includes a mass of the at least one metal and a mass of at least one reducing agent. The at least one reducing agent includes at least ferrous iron from at least one source of the at least one reducing agent. A composition of tungsten ferrite or molybdenum tungsten ferrite may be formed. The method may be used for purifying water, for the refining of metals, or to facilitate a chemical analytical determination.

Abstract: Process for selectively removing molybdenum from liquid mixtures containing it, in a quantity greater than (200) mg/l, together with vanadium characterized in that it comprises the following steps: bringing the liquid mixture to a pH of less than (3); adding a solution of an alkaline xanthate to the solution so that the molar ratio molybdenum/alkaline xanthate ranges from (¼) to (?), maintaining the pH constant by means of the addition of an inorganic acid; stirring the mixture causing the precipitation of the molybdenum present in the mixture.

Abstract: The invention relates to a method for the removal of metals from their aqueous solution with lime precipitation, in conditions where a precipitate of metal hydroxide and gypsum is formed, which settles well and is easy to filter. The metals are precipitated from their aqueous solutions at a high pH value and the slurry is recirculated several times in the precipitation space, whereby the gypsum is precipitated as separate crystals instead of a solid layer. The method is particularly suitable for neutralization of the aqueous solution from the pickling of refined steel. Using this method enables the removal of metals and fluoride from the water in question.

Abstract: A process for reducing the content of alkali metal impurities (e.g., potassium) in ammonium metallate solutions is described. The process involves subjecting a feed solution containing ammonium metallate and alkali metal impurities to membrane filtration. The membrane filtration results in the formation of a retentate having a reduced level alkali metal relative to the feed solution, and a permeate containing substantially the balance of alkali metal. The permeate may also be further treated, to remove alkali metal there from, by passage through a cation exchange column, thereby forming a cation exchange treated permeate that may be combined with the retentate of the membrane filtration step.