1153 results about "Tungstic acid" patented technology

The invention provides a composite smoke denitration catalyst capable of oxidizing zero-valence mercury. The catalyst is composite oxide V2O5-CeO2-WO3/TiO2 or V2O5-CeO2-MoO3/TiO2 based on TiO2 as a carrier, wherein the weight proportion is as follows: the weight percent of TiO2 is 75-100, the weight percent of V is 1-1.5, the weight percent of Ce is 1-5, and the weight percent of W or Mo is 7.5-8.5. The preparation method comprises the following steps: depositing Ce(OH)3 on nano TiO2; dipping ammonium vanadate/ammonium molybdate; and drying and roasting so as to obtain the catalyst; or dipping a commercial SCR (selective catalytic reduction) catalyst in a cerous nitrate aqueous solution, and then drying and roasting. The catalyst provided by the invention maintains the denitraiton efficiency of the original SCR catalyst and simultaneously the oxidation rate of zero-valence mercury is obviously improved, and divalent mercury ions are captured in subsequent dedusting equipment and wet desulphurization system; and the application temperature range of the catalyst is wide, the combination control of emission amounts of nitrogen oxides and mercury in smoke of a fuel coal power plant can be achieved on the promise that the smoke purification facility of the fuel coal power plant is not added.

The invention relates to a method for recovering non-ferrous metals from waste denitration catalysts, particularly relates to a method for recovering vanadium, tungsten and titanium from a waste vanadium-tungsten-titanium-based denitration catalyst, belonging to the field of non-ferrous metal recovery technologies. The method mainly comprises the steps of preparing the catalyst into powder with the grain size being smaller than 100 meshes, and adding concentrated alkali liquor; heating to react vanadium, tungsten and titanium with alkali, so as to produce slightly-soluble titanate, water-soluble vanadate and tungstate; filtrating to obtain a titanate filter cake, wherein titanate or titanic acid can be prepared from the filter cake; adding ammonium salt into a filtrate so as to precipitate ammonium metavanadate, and filtrating to obtain ammonium metavanadate and a new filtrate; adding concentrated acid into the new filtrate, thereby preparing solid tungstic acid. The method has the advantages of simple process, low energy consumption, good solid-liquid reaction contact, high vanadium, tungsten and titanium recovery rate, and the like.

The invention discloses a compound nano material of graphene nano slice and tungsten disulfide (WS2), and a synthesis method and a preparation method thereof. The compound material is formed by mixing graphene and a WS2 nano material in a mass ratio of (1 to 1)-(4 to 1). The preparation method comprises the following steps of: preparing an oxidized graphite nano slice from graphite by a chemical oxidization method; then dissolving tungstic acid into deionized water so as to form 0.02 to 0.07M of solution; adding L-cysteine serving as a sulfur source and a reduction agent, wherein the mass ratio of the L-cysteine to the tungstic acid is (5 to 1)-(12 to 1); adding the oxidized graphite nano slice into the solution, and ultrasonically treating so that the oxidized graphite nano slice can be fully dispersed in the hydrothermal reaction solution; transferring the mixture into a hydrothermal reaction kettle and sealing; and synthesizing by a one-step hydrothermal method to obtain the compound nano material of graphene and WS2, wherein the mass ratio of the graphene nano slice to the WS2 is (1 to 1)-(4 to 1). The method has the characteristics of mild reaction condition and simple process. The compound nano material of graphene and WS2 synthesized by the method can be widely used as electrode materials of new energy batteries, high-performance national lubricants, catalyst carriers and the like.

The invention provides a method for separating and extracting tungsten-molybdenum from mixed solution of tungstate-molybdate. The method is characterized by: adding aluminum salt or magnesium salt for purification and impurity removal, adding calcium carbonate to precipitate tungsten selectively to obtain artificial scheelite, making the liquid obtained after tungsten precipitation subjected to absorption by ion exchange resin or extraction by a solvent extraction agent to obtain ammonium molybdate, adding acid into the artificial scheelite for decomposition to obtain artificial tungstic acid, and performing ammonia dissolution and crystallization of the artificial tungstic acid to obtain ammonium tungstate. Therefore, effective separation and recovery of tungsten and molybdenum are realized; and in addition, the method has the advantages of short flow, high process adaptability, low consumption of reagents, low processing cost, high recovery rate of metal, good operating environment, and the like.

An electroless deposition solution of the invention for forming an alkali-metal-free coating on a substrate comprises a first-metal ion source for producing first-metal ions, a pH adjuster in the form of a hydroxide for adjusting the pH of the solution, a reducing agent, which reduces the first-metal ions into the first metal on the substrate, a complexing agent for keeping the first-metal ions in the solution, and a source of ions of a second element for generation of second-metal ions that improve the corrosion resistance of the aforementioned coating. The method of the invention consists of the following steps: preparing hydroxides of a metal such as Ni and Co by means of a complexing reaction, in which solutions of hydroxides of Ni and Co are obtained by displacing hydroxyl ions OH⁻ beyond the external boundary of ligands of mono- or polydental complexants; preparing a complex composition based on a tungsten oxide WO₃ or a phosphorous tungstic acid, such as H₃[P(W₃O₁₀)₄], as well as on the use of tungsten compounds for improving anti-corrosive properties of the deposited films; mixing the aforementioned solutions of salts of Co, Ni, or W and maintaining under a temperatures within the range of 20° C. to 100° C.; and carrying out deposition from the obtained mixed solution.

The invention discloses a preparation method of cesium tungstate nanopowder. The preparation method comprises the following steps of A, dissolving reacting doses of tungsten raw materials and cesium carbonate raw materials into a solvent, drying the solution to obtain particles, and further smashing the obtained particles to obtain tungsten and cesium mixed powder; B, placing the tungsten and cesium mixed powder into a sealed reaction kettle with a stirring function, adding a reaction solvent in the sealed reaction kettle, and reacting at the temperature of 180-350 DEG C for 2-8h while stirring, wherein the mass of the reaction solvent is 1-3 times as mush as that of the tungsten and cesium mixed powder; and C, separating the reaction product obtained in the step B, washing by using deionized water or ethanol, then, drying, and milling by using a jet mill to obtain a target product, namely the cesium tungstate nanopowder. The cesium tungstate nanopowder prepared by using the preparation method is low in agglomeration degree; and the preparation method is high in production efficiency and low in cost.

The invention discloses a preparation method of a denitration catalyst. The method comprises the following steps: (1) with an intermediate product of metatitanic acid from a titanium dioxide factory as a raw material, washing with dilute nitric acid, weak aqua ammonia, deionized water respectively to remove impurity ions so as to prepare metatitanic acid slurry; (2) orderly adding ammonium tungstate, ammonium molybdate and ammonium metavanadate into the metatitanic acid slurry, beating the mixture by ultrasonic wave, adjusting the pH of the slurry to 4.0-6.5 by an acid; (3) allowing the mixed slurry to stand, drying to obtain the catalyst powder; (4) compacting and molding the catalyst powder into honeycomb by a mold, performing heat treatment at 200-600 DEG C for 4-10 hours to obtain the denitration catalyst of the invention. The method for preparing the denitration catalyst of the invention has low cost and simple process, and the denitration catalyst can increase the conversion rate of NO. The denitration catalyst of the invention can realize a conversion rate of NO in power plant flue gas flue gas components of up to above 97% at a reaction temperature of 350 DEG C.

The invention relates to a manufacturing method of an electronic-grade polyimide film with low linear expansion coefficient. The method is characterized by comprising the steps that (1) the step-by-step condensation polymerization technology or the blending compounding technology is used for obtaining two or more polyamide acid glue solutions comprising rigid structures and soft structures at the same time and are different in rigidity and softness; (2) ultrafine inorganic whiskers, like zinc oxide whiskers, silicon carbide whiskers and zirconium tungstate whiskers, which are subjected to surface organic modification already and/or nanoparticle materials are smashed and cavitated through high-energy-density supersonic waves, and then the functional fillers are compounded with polybasic polyamide acid in an in-situ micro-nano mode; (3) the compounded glue solutions are subjected to filtration, vacuum defoamation, extrusion casting filming, chemical amidization or thermal amidization, infrared complete amidization, high-temperature thermal forming processing, corona processing and a reeling process, and therefore the electronic-grade polyimide film with the thickness being 7.5-125 micrometers, the linear expansion coefficient being 5-18ppm/DEG C, and good physical mechanical performance is obtained.

The invention discloses a preparation technology of a visible-light response WO3 nanosheet array film electrode. The preparation technology comprises the following steps that Na2WO4.2H2O and ammonium oxalate are dissolved in deionized water to react with hydrochloric acid to obtain tungstic acid precipitates, and the tungstic acid precipitates react with H2O2 to obtain a clear peroxotungstic acid solution; an ethyl alcohol reducing agent is added into the peroxotungstic acid solution, fluorine-doped tin oxide (FTO) conducting glass serves as a substrate to be placed in the solution, under the water bath condition, the peroxotungstic acid is slowly reduced into tungstic acid, the tungstic acid is slowly separated out on an FTO film, and then a tungstic acid film is obtained; after being cleaned and dried, the tungstic acid film is calcined to obtain the WO3 nanosheet array film electrode. The preparation technology has the advantages of being simple, convenient, mild, efficient and suitable for large-scale preparation. The prepared WO3 nanosheet array film electrode has the good visible-light absorption property and good stability and is high in photoelectric efficiency, good in photoelectrocatalytic degradation effect on organic matter and capable of being applied to the fields of photoelectrocatalysis hydrogen production and organic matter degradation, and the better effect is achieved.

A recycling method for waste denitration catalyst is characterized by comprising the following steps: (1) the waste denitration catalyst is smashed into powder of 100 to 200 meshes; (2) the powder reacts with an alkali solution under a heating and stirring condition to obtain a titanium-rich material and a solution containing elements such as vanadium, tungsten, silicon and aluminum; (3) the titanium-rich material reacts with chlorine gas to generate titanium tetrachloride, then the titanium tetrachloride is condensed and reacts with oxygen to generate titanium dioxide, and the titanium dioxide is treated with surface finish and drying to obtain a titanium dioxide finished product; (4) the pH value of the solution obtained in the step (2) is adjusted; a magnesium salt is added into the solution to remove silicate ions and obtain a solution containing vanadium and tungsten; calcium chloride powder is added into the solution containing vanadium and tungsten to generate calcium tungstate; the calcium tungstate reacts with hydrochloric acid to generate tungstic acid; the tungstic acid is treated with ammonia dissolution and evaporative crystallization to obtain ammonium paratungstate crystals; (5) a precipitant ammonium chloride is added, and centrifugal drying is carried out to obtain solid ammonium vanadate. The method has the advantages that the operation is easy; three wastes are reduced; the economic efficiency is improved; the waste denitration catalyst is recycled.

The invention discloses a preparation method of cesium-tungsten bronze powder and a function film. The preparation method of the cesium-tungsten bronze powder comprises the following steps: carrying out an exchange treatment on tungstate solution and cationic resin to obtain tungstic acid sol; adding citric acid solution and cesium carbonate solution in the tungstic acid sol and then carrying out a mixing treatment to obtain hydrothermal reaction precursor solution; carrying out a hydrothermal reaction on the hydrothermal reaction precursor solution; after the reaction is finished, carrying out a washing treatment and a drying treatment to obtain the cesium-tungsten bronze powder. The function film disclosed by the invention contains the cesium-tungsten bronze powder prepared by the preparation method of the cesium-tungsten bronze powder disclosed by the invention; according to the preparation method of the cesium-tungsten bronze powder disclosed by the invention, by controlling reactants and carrying out hydrothermal method, the preparation process is effectively simplified and the production cost of the cesium-tungsten bronze powder is reduced; moreover, the cesium-tungsten bronze produced under a specific hydrothermal reaction condition has excellent shielding performance for infrared ray, particularly for near-infrared ray.

The invention relates to a comprehensive recycling method for a waste titanium based vanadium SCR (selective catalytic reduction) catalyst. The method comprises the steps of: removing dust from the waste SCR catalyst; crushing the treated SCR catalyst; subjecting the crushed powder material to acid leaching vanadium extraction in an acid leaching tank, conducting neutralization, reduction and purification on the leachate, then employing P204 to conduct organic extraction, and performing drying to obtain the product ammonium metavanadate; washing the leaching residue generated by vanadium extraction to be close to neutral, adding sodium carbonate to conduct roasting so as to obtain a roasted material, levigating the roasted material and then conducting water leaching, adjusting the obtained leachate with acid to a pH value of 6-9, adsorbing tungsten with weakly basic anions, resolving the loaded resin with a mixed solution of ammonia water and ammonium chloride; heating the resolved solution to boiling and volatilizing ammonia in the solution until the pH value of the ammonia solution is reduced to 7.0-7.7, performing cooling to obtain wet ammonium paratungstate, and finally carrying out drying to obtain the product ammonium paratungstate. The method provided by the invention can effectively recover valuable metals in the waste catalyst.

A method of desulfurizing/refining a hydrocarbon oil by which sulfur compounds are diminished to an extremely low concentration at a relatively low equipment cost and operating cost. The method of desulfurizing/refining a hydrocarbon oil comprises bringing a hydrocarbon oil containing at least one sulfur compound selected from the group consisting of thiophene compounds, benzothiophene compounds, and dibenzothiophene compounds and optionally further containing aromatic hydrocarbons into contact with a solid acid catalyst and/or an activated carbon having a transition metal oxide supported thereon to thereby desulfurize the oil. The solid acid catalyst preferably is a solid ultrastrong-acid catalyst selected among sulfuric acid radical/zirconia, sulfuric acid radical/alumina, sulfuric acid radical/tin oxide, sulfuric acid radical/iron oxide, tungstic acid/zirconia, and tungstic acid/tin oxide.

The present invention relates to a composite catalyst for preparing sec-butyl acetate by direct esterification of ethyl ester and butylene, which takes heteropoly acid as the catalyst active component and porous carrier as the dispersant; the weight proportion of the heteropoly acid and the porous carrier is 0.01:1 to 10:1. The heteropoly acid is one with Keggin structure, which consists of phosphotungstic acid, silicotungstic acid, germanium tungstic acid, arsenowolframic acid, phosphomolybdate, germanomolybdate or arsenicomolybdate. The porous carrier comprises porous SiO2, Al2O3, SBA-15, MCM-41, white carbon black, porous SiC, corallite, andalusite, cordierite, meerschaum, Attapulgite or kaolin. The composite catalyst of the present invention solves the problem that the catalysis efficiency is low if the heteropoly acid is separated out from the reaction system.

The invention relates to a tungsten trioxide (WO3) nano-plate and a preparation method thereof. The tungsten trioxide (WO3) nano-plate is characterized in that: the tungsten trioxide (WO3) nano-plate is monocrystal and monoclinic phase (JCPDS No.43-1035), and is shaggy and flocculent; the area is (100-800)nmx(100-800)nm; the apparent thickness is between 5 and 40 nanometers; and the BET specific surface area can reach 100-250 square meters per gram. The preparation method for the tungsten trioxide (WO3) nano-plate comprises the following steps that: a tungstenic acid organic or inorganic laminated mixed micron/nano belt (pipe) is taken as a precursor, and organic substances between precursor layers are removed through oxidation by a nitric acid, and then a tungstenic acid (WO3.H2O) nano-plate is prepared; the reaction temperature is between 15 and 50 DEG C, and the reaction time is between 5 and 120 hours; the tungstenic acid (WO3.H2O) nano-plate is heated up to between 250 and 600 DEG C at a heating rate of between 1 and 5 DEG C per minute, undergoes heat insulation for 1 to 5 hours, and finally naturally cooled to the room temperature so as to remove crystal water, and the tungsten trioxide nano-plate is prepared. The method has a simple technological process, a large variation range of operating parameters, strong adaptability, low facility requirement, controllable appearance of products, high repeatability, high efficiency and low cost.

This invention discloses a method for preparing controllable phase-transformation and tungsten-doped vanadium dioxide powder. In this invention, controlled, strictly, is the pH value (being at 7-9) of the solution for preparing prodecessor; selected is combined reductant containing organic amine and formic acid; protected by inert gas during whole process. By using this inventive method, obtained is high pureness single-phase VO2 nanometer powder. Due to the activity of white tungstic acid is far higher than that of other tungsten compounds, the adulteration of W6+ in VO2 crystal lattice is increased greatly, to achieve the effective adulteration, and then to realize controllable phase transformation temperature.

The invention discloses a method for preparing denitration catalyst carrier TiO2-WO3 composite powder, which comprises the following steps of: pulping and dispersing a metatitanic acid raw material; adjusting until the concentration of the slurry, calculated in terms of the titanium dioxide TiO2, is 15-25% by mass; adding ammonium paratungstate to the slurry according to a proportion, wherein calculated by the mass of tungsten trioxide WO3, the additive proportion of the ammonium paratungstate is 4.0%-10.0% of the sum of the TiO2 and the WO3; adding ammonia water to the slurry to adjust the pH to 6.5-9.0; filtering and dewatering to obtain a blocky filter cake; crushing the filter cake mechanically; drying and roasting the crushed filter cake at 200 DEG C to 580 DEG C for 6 hours; and crushing the roasted material falling in the kiln to obtain a TiO2-WO3 composite powder product serving as the denitration catalyst carrier. The method disclosed by the invention is low in manufacturing cost and simple in process; and the prepared product has the advantages of high specific surface area, high surface chemical activity, high catalytic efficiency and good processability.

A novel multi-phase W-contained catalyst for preparing glutaraldehyde by using the aqueous solution of hydrogen peroxide as oxidizing agent to selectively oxidize cyclopentene is prepared through in-situ introducing tungsten oxide in the process for synthesizing SBA-1.5 full-silicon mesoporous molecular sieve. Its advantages are high dispersity of active component, ultrahigh load capacity of tungesten oxide, and high selectivity.