52 results about "Sodium tungstate" patented technology

The invention discloses a high-performance thermosetting resin plugging material, a preparation method and a water-based drilling fluid, and relates to the technical field of oilfield chemistry, and the preparation method of the plugging material comprises the following steps: stirring an aromatic compound containing two double bonds with sodium tungstate, a transfer catalyst and a hydrogen peroxide solution at room temperature for reaction, and purifying to obtain an epoxy compound; the preparation method comprises the following steps: heating an aromatic compound containing an aldehyde group, ammonium formate and a palladium-carbon catalyst with nitrogen to react to obtain an amine compound, transferring the epoxy compound and the amine compound into a size-adjustable mold, carrying out heating curing treatment, carrying out low-temperature ball milling on a crude product to obtain plugging material particles, and preparing the water-based drilling fluid by using the plugging material particles. The specific aromatic rigid framework monomer is selected, and the molar ratio of epoxy to the curing agent is accurately controlled, so that the mechanical strength and thermal stability of the material are remarkably optimized, and the plugging material has a good treatment effect on cracks and pores in complex stratums.

The invention relates to a scale inhibitor for an industrial circulating water system and an intelligent adding method thereof, and belongs to the technical field of industrial water treatment.The scale inhibitor is composed of a component A and a component B. The component A comprises, by mass, 5-15% of sodium molybdate, 5-15% of sodium tungstate, 15-25% of sodium polyacrylate, 5-15% of sodium borate, 15-25% of zinc sulfate, 5-10% of zinc chloride, 3-8% of sodium silicate and 2-6% of benzotriazole; the component B is prepared from the following components in percentage by mass: 15 to 25 percent of HEDP, 15 to 25 percent of PBTC, 35 to 50 percent of AA / AMPS copolymer and 15 to 25 percent of deionized water. According to the scale inhibitor for the industrial circulating water system and the intelligent adding method of the scale inhibitor, a phosphorus-free and chromium-free environment-friendly formula with sodium molybdate and sodium tungstate as cores is adopted, and phosphorus pollution and heavy metal risks are fundamentally eradicated; according to the formula, through cooperation of multiple components, a layer of compact and stable composite passivation film with self-repairing capacity can be formed on the metal surface in severe water with high chloride ions, and the corrosion inhibition rate gt of carbon steel is achieved; the copper corrosion inhibition rate is gt; and 98%.

This invention relates to the field of materials preparation technology, specifically disclosing a method for preparing tungsten-molybdenum alloy powder based on a coprecipitation precursor. The method involves mixing sodium tungstate, sodium molybdate, and water to prepare a tungsten-molybdenum mixed solution; mixing the tungsten-molybdenum mixed solution with a precipitant solution containing zinc or cadmium salts, and allowing the tungsten and molybdenum to coprecipitate under stirring; filtering and washing the reaction slurry to obtain a wet precipitate of tungsten-molybdate coprecipitate, with the filtrate serving as the mother liquor; drying and grinding the wet precipitate of tungsten-molybdate coprecipitate to obtain tungsten-molybdate coprecipitate powder; and reducing the tungsten-molybdate coprecipitate powder in a hydrogen stream at 700-1000°C to obtain tungsten-molybdenum alloy powder and zinc or cadmium vapor. This invention combines the reduction and alloying reactions into one, with a reaction temperature below 1000°C, shortening the tungsten-molybdenum alloy powder preparation process and significantly saving energy and reducing consumption.

The present application relates to alloy plating technical field, specifically relates to a tungsten alloy plating and its preparation method, and a hole lining pipe, the tungsten alloy plating is tungsten nickel alloy plating, plating is dense and has no defect, thickness is 40~100 μm, and Vickers hardness is not less than 900 HV1, the plating uses nickel sulfamate and sodium tungstate as main salt, is supplemented with specific composite complexing agent, conductive salt, buffer and additive, forms stable electroplating solution, is cleaned through plasma, and is combined with profiling anode and pulse electroplating technology, and is carried out electroplating under the matching pulse parameter and mechanical stirring.The method can deposit the high-hardness tungsten alloy plating of thickness uniformity, excellent performance on the inner wall, outer wall and all hole inner surface of the hole lining pipe of complex shape workpiece, in particular, solves the technical problem of uniformity of surface plating of deep hole and complex structure parts.

The invention discloses a preparation method of a biochar-zinc sulfide-tungsten sulfide heterojunction composite material, and the scheme comprises the following steps: S1, dissolving sodium tungstate, hydroxylamine hydrochloride, sodium hydroxide, thiourea and zinc chloride in deionized water, and uniformly stirring to obtain a light yellow transparent reaction solution; s2, biological carbon is prepared, the reaction liquid and the biological carbon are mixed in a reaction kettle and then subjected to a hydrothermal reaction for 8-48 h at the constant temperature, and the constant temperature is any one of the temperature values ranging from 180 DEG C to 240 DEG C; s3, filtering, cleaning and drying a product obtained in the step S2 to obtain a heterojunction composite material precursor; s4, the heterojunction composite material precursor is subjected to calcination treatment in the inert gas atmosphere, the biochar-zinc sulfide-tungsten sulfide heterojunction composite material is obtained, and the calcination temperature ranges from 850 DEG C to 950 DEG C.

The application relates to the technical field of copper foil and discloses an electrolytic copper foil and a roughening treatment method thereof. The roughening treatment method of the electrolytic copper foil comprises the following steps: S1, adding an organic-inorganic composite additive into a prepared base roughening solution to prepare a roughening solution, wherein the organic-inorganic composite additive comprises sodium molybdate, sodium tungstate and hydroxyethyl cellulose, the concentration of the sodium molybdate is 30-50 mg / L, the concentration of the sodium tungstate is 20-40 mg / L, and the concentration of the hydroxyethyl cellulose is 6-10 mg / L; and S2, performing cathode electrolytic roughening treatment on a pretreated copper foil by using the roughening solution to obtain the electrolytic copper foil. Through the above mode, the problem that a roughening layer is difficult to synchronously realize the comprehensive performance target of 'low roughness, high peeling strength and uniform compactness' can be solved.

The invention discloses a method for improving the binding force of an electrolytic copper foil and a base material under low roughness and the electrolytic copper foil. The method comprises the following steps: 1) carrying out smooth acid pickling on a 9-35 [mu] m raw foil; (2) performing picosecond laser selective ablation on bulges of more than 100nm on the surface of the pickled raw foil to enable Ra to be less than or equal to 0.1 mu m; (3) depositing a compact copper layer of 0.1-0.4 mu m to fill the micro pits; 4) coarsening in a coarsening solution containing copper ions, sulfuric acid, sodium tungstate and sodium molybdate; 5) curing in a curing liquid containing copper ions, sulfuric acid, MPS, HEC, PEG and hydrolyzed collagen; (6) heat-resisting treatment and passivating treatment are conducted in sequence; 7) spraying an organic silane coupling agent; and (8) drying at 130-140 DEG C for 5-10 seconds, and then rolling at the speed of 4-6 m / min. According to the method, the formation of a high-roughness structure is avoided through laser leveling, the compact copper layer reinforces the substrate to improve the uniformity of copper nodules, the lamination surface Rz of a final product is smaller than or equal to 1.5 microns, Ra is smaller than or equal to 0.2 microns, the peel strength is larger than or equal to 0.7 N / mm, no copper powder falls off during lamination, and the method is suitable for preparing the high-precision copper foil.

The invention discloses an O-phase sodium ion battery positive electrode material modified by a sodium tungstate-magnesium tungstate composite coating layer and a preparation method of the O-phase sodium ion battery positive electrode material. Relates to the technical field of sodium-ion battery materials. According to the preparation method, an in-situ coating strategy is adopted, the raw materials capable of reacting with the sodium compound are added, residual alkali on the surface of the material is consumed, meanwhile, a stable and uniform coating layer is formed on the surface of the material, and the prepared O-phase sodium ion battery positive electrode material has excellent electrochemical performance; a tungsten-containing compound and a magnesium-containing compound are added in the secondary sintering process, the tungsten-containing compound and the magnesium-containing compound form magnesium tungstate in the sintering process, and meanwhile, the tungsten-containing compound and a sodium source on the surface of the material form sodium tungstate; a double-coating layer formed by magnesium tungstate and sodium tungstate prevents the material from being in contact with an electrolyte, reduces side reaction and improves the cycling stability, and meanwhile, sodium tungstate is preferentially decomposed in the primary cycle of the battery and serves as a sodium supplementing agent, so that the first effect of the material is remarkably improved.

The invention relates to a method for recovering tungsten from tungsten-containing calcium sulfate slag, which comprises the following steps: S1, soda boiling: taking the tungsten-containing calcium sulfate slag, adding water for size mixing, adding sodium carbonate or sodium bicarbonate into the obtained size, and carrying out solid-liquid separation after reaction to obtain a sodium tungstate solution and residues; s2, acid dissolution: taking the residues in S1, adding water for size mixing, and adding hydrochloric acid into the obtained size to obtain a tungstic acid solution; s3, enriching, namely recycling the sodium tungstate solution obtained in the step S1 as alkali boiled mixed slurry; recycling the tungstic acid solution obtained in the step S2 as acid-soluble slurry mixing liquid; the operation of S1 and S2 is repeated until the tungsten content of the solution reaches 100 g / l, and high-concentration sodium tungstate and tungstic acid are obtained; s4, adsorption; and S5, desorbing to obtain a sodium tungstate solution. The method can realize 100% recovery of tungsten in the tungsten-containing calcium sulfate slag, and has industrial application prospects.

The invention relates to the technical field of catalysts, and discloses a catalyst for reducing the sulfur content of petroleum coke and a preparation method thereof.Sodium phytate containing multiple phosphate groups is used for replacing part of sodium phosphate salt, sodium tungstate, ammonium molybdate and lanthanum nitrate are subjected to a reaction, and obtained rare earth lanthanum phosphorus molybdenum tungsten heteropoly acid contains more anions; the rare earth lanthanum phosphorus molybdenum tungsten heteropoly acid and the citric acid quaternary ammonium salt containing a plurality of quaternary ammonium salt cations form stronger electrostatic interaction, and meanwhile, the citric acid quaternary ammonium salt contains a plurality of hydroxyl groups and can form hydrogen-bond interaction with the surface of the rare earth lanthanum phosphorus molybdenum tungsten heteropoly acid, so that the surface modification of the citric acid quaternary ammonium salt on the rare earth lanthanum phosphorus molybdenum tungsten heteropoly acid is effectively realized; after modification, the dispersity of the rare earth lanthanum phosphorus molybdenum tungsten heteropoly acid is improved, agglomeration is reduced, more catalytic active sites are achieved, the contact area between the rare earth lanthanum phosphorus molybdenum tungsten heteropoly acid and petroleum coke is increased, and sulfur-containing compounds such as thiophenic sulfur and the like which are difficult to degrade in the petroleum coke are efficiently oxidized and removed through synergistic oxidation catalysis with hydrogen peroxide.

This invention discloses a method for low-resistivity thin-film deposition, comprising the following steps: Step 1, the ceramic substrate is first pickled with 2% hydrochloric acid for 1-2 hours. After pickling, it undergoes initial treatment and activation to obtain an activated ceramic substrate; Step 2, preparation of the nickel plating solution: 7-12 g / L nickel sulfate, 15 g / L sodium tungstate, 31.5 g / L sodium hypophosphite, 35 g / L sodium citrate, 2 ml / L ammonia, and 5 g / L thiourea are stirred and mixed thoroughly to obtain the nickel plating solution. This invention enhances the contact effect between the activation solution and the substrate through the synergistic effect of the raw materials, thereby improving the performance of the product. Simultaneously, tungsten metal in the electroplating process possesses characteristics such as high temperature resistance, corrosion resistance, low temperature coefficient of resistance (TCR), and good thermal stability. Furthermore, the synergistic effect of the raw materials significantly improves the product's performance.

This invention relates to an antibacterial medical care pad and its manufacturing process. From top to bottom, it comprises a soft layer, an antibacterial layer, an absorbent layer, and a breathable layer. The antibacterial layer, by weight, comprises the following components: 100 parts polypropylene, 3-8 parts antibacterial powder, and 2-5 parts nanoparticles. The absorbent layer, by weight, comprises the following components: 100 parts acrylic resin, 10-15 parts viscose fiber, 15-20 parts long-staple cotton, and 3-8 parts antibacterial agent. The nanoparticles comprise modified nano-silica and an antibacterial core shell, with a mass ratio of 1:(2-5). The antibacterial core shell comprises the following components: cerium nitrate, lanthanum nitrate, sodium tungstate, and carboxymethyl chitosan. This invention improves the antibacterial performance of the pad by placing an antibacterial layer between the soft layer and the absorbent layer. The addition of an antibacterial agent to the absorbent layer enhances its antibacterial performance, thereby reducing the overall antibacterial performance of the pad. Furthermore, the breathable layer facilitates the timely removal of moisture, reducing patient discomfort.

A rare earth-based electrolytic coloring method, electrolyte, and alloy product are provided, where the method includes: after an oxide film is formed on a workpiece subjected to anodic oxidation in the electrolyte, rapidly increasing a voltage, and by using a constant-voltage mode, breaking down, melting, sintering, and reforming the oxide film cyclically multiple times under conditions of high frequency, a high voltage, and instantaneous high temperature, to generate a ceramic film layer metallurgically bonded to a substrate. The oxide film has a greater thickness and lower reflectance, and an appearance as a matte black anode, and has good color consistency and no chromatic aberration. Components of the electrolyte include sodium silicate at a concentration of 5-70 g / L, sodium tungstate at a concentration of 1-18 g / L, disodium ethylenediamine tetraacetic acid at a concentration of 2-10 g / L, and rare earth salts at concentrations of 1-2 g / L.

This invention provides a method and application for separating and recovering tungsten from spent denitrification catalysts, relating to the field of resource utilization technology for spent denitrification catalysts. The method includes the following steps: (1) mixing spent denitrification catalyst, silica, and alkali metal salts to form a mixture; (2) smelting the mixture, with the smelting temperature procedure as follows: first heating to 800-900℃ and holding for 30-60 min; then heating to 1100-1200℃ and holding for 40-90 min; then heating to 1300-1400℃ and holding for 30-60 min to obtain a melt; (3) cooling the melt, collecting and recovering sodium tungstate. This invention, through a segmented temperature-controlled smelting process and utilizing an alkali metal silicate glass melt medium, achieves the harmless treatment of spent denitrification catalysts and the efficient recovery of tungsten, effectively improving the tungsten recovery rate, and has good development prospects and industrial application value.

This invention provides a high-efficiency seedless grape cultivation technology. Through systematic innovation in seed pretreatment, compound growth regulator formulation, substrate optimization, and precise cultivation management, it overcomes traditional technological bottlenecks. Seed pretreatment employs a quicklime-distilled water activation method combined with wood ash-milk fermentation and ultrasonic-assisted treatment, significantly improving embryo activity and germination rate. The growth regulator is a golden ratio compound of gibberellin and chlorpyrifos, applied to the flower spikes twice, with sodium tungstate added to prolong efficacy, achieving a seedless rate >95% and a 20%-30% increase in berry weight. The substrate uses a multi-stage formulation system, adjusted to pH 5.0-5.5 after low-temperature sterilization, and incorporates 5% biochar to enhance water retention and pollution resistance. Innovative cultivation management includes optimized H-shaped trellis system combined with rain-sheltered cultivation and precise water and fertilizer management, resulting in a stable yield of over 1500 kg / mu, extended shelf life to 15 days, and a cultivation cycle shortened to 2 years before fruiting. This technology comprehensively improves fruit quality and planting efficiency, demonstrating significant application value.

The present application relates to a kind of indium-poor tungsten bronze phase mosaic block assembled composite material and its preparation method, and the indium-poor tungsten bronze phase mosaic block assembled composite material is by In 0.02 WO3 is formed by WO3 compound, there are many tunnels consisting of the interval between tungsten and oxygen atom in the indium-poor tungsten bronze phase mosaic block assembled composite material, and indium ions are randomly distributed on both sides of the tunnel center position.Method: step one, create supersaturated sodium sulfate solution environment;Step two, in the supersaturated sodium sulfate solution environment obtained in step one, add indium nitrate, add NH4Cl hydrothermal reaction;Step three, centrifugation;Step four, sodium tungstate, oxalic acid and ammonium chloride are sequentially added to deionized water, drop into HCL, add the product of step three hydrothermal reaction, centrifugation and washing, finally the indium-poor tungsten bronze phase mosaic block assembled composite material is prepared.The material has high sensitivity to acetone gas, and the working temperature is low.

The invention discloses a high-wear-resistance Co-W composite coating electrolyte based on bifunctional particles as well as a preparation method and an electro-deposition method thereof, and relates to the technical field of material surface engineering. The electrolyte takes water as a solvent, and the mass percent of solutes in an electrolyte system is as follows: 3.59 to 8.07 percent of cobalt sulfate, 6.4 to 14.4 percent of sodium tungstate, 7.69 to 17.3 percent of a complexing agent, 1.92 to 4.32 percent of sodium chloride, 2.56 to 5.76 percent of a buffering agent, 2.56 to 5.76 percent of silicon carbide, 0.07 to 0.15 percent of carbon powder and 0.01 to 0.03 percent of a surfactant. And based on the electrolyte, the high-wear-resistance Co-W composite coating is prepared by adopting an electro-deposition method. By means of the supporting effect of the Co-W alloy matrix and the synergistic interaction of the silicon carbide and carbon powder dual-function particles, the comprehensive performance of the coating is remarkably improved, the whole process is convenient, fast and efficient, and the surface protection requirements of all industrial parts are met.

The invention provides a method for determining the content of precious metal elements in an automobile purification catalyst, and belongs to the technical field of analysis and detection. According to the method, a composite melting system composed of sodium peroxide, anhydrous sodium metaborate and sodium tungstate is constructed, an automobile purification catalyst sample is subjected to efficient melting decomposition, complete leaching of a melt is achieved in combination with a hydrochloric acid and tartaric acid composite acidification system, a tin-tellurium coprecipitation enrichment technology is introduced on the basis, and the purity of the automobile purification catalyst sample is improved. Trace precious metal elements such as platinum, palladium and rhodium are selectively precipitated and effectively enriched, and matrix interference is remarkably reduced; and then adding an indium internal standard solution and carrying out quantitative determination by adopting inductively coupled plasma emission spectrometry, thereby realizing high-sensitivity and high-accuracy analysis of the noble metal element. The method effectively solves the problems of incomplete sample decomposition, low precious metal recovery rate, serious matrix interference, poor detection result stability and the like in the prior art.

The invention discloses a method for treating tungsten carbide-based waste, which comprises the following steps: mixing the tungsten carbide-based waste with an additive, smelting, controlling the ratio of the additive to the waste, the smelting temperature and the smelting time, cooling to obtain a smelted clinker, and carrying out mechanochemical leaching and filtering to obtain a high-quality sodium tungstate solution. The solution can be directly used as a raw material for extracting and producing ammonium paratungstate from N235, or can be sold as a sodium tungstate product. The anhydrous sodium sulphate is used as a main additive, so that the method is safe, low in cost, capable of efficiently recycling tungsten resources, simple in process, suitable for large-scale recycling of the tungsten carbide-based waste, and particularly suitable for the tungsten carbide-based waste which contains a coating and is difficult to treat.

The invention relates to the technical field of tungsten smelting and waste residue recycling, in particular to a method for recycling tungsten from aluminum salt dephosphorization slag of a sodium tungstate solution, which comprises the following steps: S1, uniformly mixing the aluminum salt dephosphorization slag with activated carbon to obtain a mixture; s2, performing aerobic roasting on the mixture to obtain a roasted material; s3, adding a first volume of water and an alkali adjusting agent into the roasted material to obtain a premix, and performing wet grinding and crushing on the premix to obtain a wet grinding material; and S4, water is added into the wet grinding material to obtain a second volume of feed liquid, the feed liquid is heated to a preset temperature and subjected to heat preservation, filtering is conducted after cooling, and a sodium tungstate solution and filter residues are obtained. The method has the beneficial effects that the tungsten in the aluminum salt dephosphorization slag is recycled; the method has the advantages of being short in technological process, efficient and low in cost.

The invention relates to the technical field of material preparation, and particularly discloses a preparation method of tungsten-molybdenum alloy powder based on a coprecipitation precursor, which comprises the following steps: mixing sodium tungstate, sodium molybdate and water to prepare a tungsten-molybdenum mixed solution; mixing the tungsten-molybdenum mixed solution with a precipitant solution containing zinc salt or cadmium salt, and carrying out coprecipitation reaction on tungsten and molybdenum in a stirring state; filtering and washing the reaction slurry to obtain a precipitate which is tungsten molybdate co-precipitation wet slag and a filtrate which is a precipitation mother solution; the tungsten molybdate coprecipitation wet slag is dried and ground, and tungsten molybdate coprecipitation powder is obtained; and reducing the tungsten-molybdate coprecipitation powder in hydrogen flow at 700-1000 DEG C to obtain tungsten-molybdenum alloy powder and steam of zinc or cadmium. According to the method, the reduction reaction and the alloying reaction are combined, the reaction temperature is lower than 1000 DEG C, the preparation process of the tungsten-molybdenum alloy powder is shortened, and energy conservation and consumption reduction are greatly achieved.

A rare earth-based electrolytic coloring method, electrolyte, and alloy product are provided, where the method includes: after an oxide film is formed on a workpiece subjected to anodic oxidation in the electrolyte, rapidly increasing a voltage, and by using a constant-voltage mode, breaking down, melting, sintering, and reforming the oxide film cyclically multiple times under conditions of high frequency, a high voltage, and instantaneous high temperature, to generate a ceramic film layer metallurgically bonded to a substrate. The oxide film has a greater thickness and lower reflectance, and an appearance as a matte black anode, and has good color consistency and no chromatic aberration. Components of the electrolyte include sodium silicate at a concentration of 5-70 g / L, sodium tungstate at a concentration of 1-18 g / L, disodium ethylenediamine tetraacetic acid at a concentration of 2-10 g / L, and rare earth salts at concentrations of 1-2 g / L.

The invention discloses a crack repairing agent for a zinc-aluminum-magnesium coated steel plate, and belongs to the technical field of metal surface treatment. The repairing agent comprises a component A, a component B and a component C. The component A comprises, by mass, 10%-12% of alkynediol, 12%-14% of ethylene glycol, 60%-62% of lithium silicate, 8%-16% of nano silicon dioxide and 2%-4% of bentonite, and the component B comprises, by mass, 5%-10% of cerous nitrate, 10%-15% of sodium tungstate, 4%-8% of KH-560, 3%-5% of a pH regulator and the balance water. And the component C comprises the following components in percentage by mass: 40%-50% of spherical zinc powder, 30%-35% of flaky zinc powder and 15%-30% of zinc-aluminum-magnesium alloy powder. The repairing agent disclosed by the invention has excellent protection performance and bonding performance, and can realize a rapid and deep repairing effect.

The invention relates to the technical field of rare earth metal electrolysis cathode protection coatings, in particular to an in-situ generated rare earth oxide diffusion barrier layer on the surface of a tungsten cathode. According to the method, fused salt electrodeposition and sol chemical deposition are combined, and a composite diffusion barrier layer of an yttrium tungstate binding layer / yttrium oxyfluoride barrier layer is constructed on the surface of a tungsten cathode in situ; the method comprises the following steps: firstly, enabling sodium tungstate to react with yttrium fluoride in fused salt through electro-deposition, and generating a compact and firmly combined yttrium tungstate layer on a tungsten substrate in situ; and then a compact surface layer of multiple yttrium oxyfluoride layers is constructed on the surface of the tungsten cathode by adopting a sol-gel method, strong interface bonding is realized by utilizing an in-situ reaction, surface hole sealing is realized by utilizing the densification characteristic of yttrium oxyfluoride, finally, a composite protection structure is formed, and the high-temperature oxidation resistance and molten salt corrosion resistance of the tungsten cathode are remarkably improved.

This invention discloses a method for preparing a WO3 photoanode rich in (002) crystal planes. The method employs a hydrothermal process, using sodium tungstate as the tungsten source. Hydrochloric acid is added to precipitate the sodium tungstate aqueous solution, followed by the addition of oxalic acid and hydrochloric acid to form a hydrothermal precursor. A WO3 seed layer is added to the hydrothermal precursor for a hydrothermal reaction, followed by annealing to obtain a WO3 photoanode film rich in (002) crystal planes. This method is simple, and the prepared WO3 rich in (002) crystal planes exhibits higher photocurrent density, more active sites for water oxidation, and superior hydroxyl radical generation compared to WO3 rich in (200) crystal planes. It also demonstrates good stability and highly efficient tetracycline degradation capabilities.

Disclosed in the present invention are the preparation and use of a supported photo-Fenton catalyst. The preparation method comprises: I, formulating a sodium tungstate solution and a potassium oxalate solution, adjusting the pH until acidic, and performing a hydrothermal reaction and calcination to obtain a tungsten trioxide composite material; II, formulating a sodium tungstate solution and an ammonium ferrous sulfate solution; III, ultrasonically dispersing the tungsten trioxide composite material in the ammonium ferrous sulfate solution to obtain a suspension; and IV, under continuous stirring, adding the sodium tungstate solution into the suspension in a dropwise manner, stirring same, performing a hydrothermal reaction, and washing and drying same to obtain a tungsten trioxide / iron tungstate nano material. In the present invention, an FeWO4 / WO3 heterojunction is formed by using a hydrothermal synthesis method, which improves the separation efficiency of carriers and the photo-Fenton catalyst activity of the tungsten trioxide / iron tungstate nano material, thereby increasing the catalytic efficiency thereof. The catalyst is suitable for the degradation treatment of photocatalyst wastewater or dye methylene blue and methyl violet, and the preparation process is simple and easy to implement, and has low pollution.

The application belongs to the technical field of photocatalytic materials, and particularly relates to a surface oxygen vacancy-containing tungsten trioxide and a preparation method and photocatalytic acetonitrile oxidation application thereof. The application adds a sodium tungstate solution dropwise into a hydrochloric acid solution under stirring, stirs after the dropwise addition is completed, centrifuges, washes and dries the precipitate after the reaction is completed, and obtains monoclinic tungsten trioxide; the obtained monoclinic tungsten trioxide is annealed to obtain the surface oxygen vacancy-containing tungsten trioxide. The surface oxygen vacancy-containing tungsten trioxide prepared by the application can photocatalyze the selective oxidation of acetonitrile to formic acid with high activity and high selectivity, realizes efficient degradation of acetonitrile and conversion into formic acid product which also has economic value. The application can degrade acetonitrile wastewater by means of photocatalysis, obtain formic acid product with high added value at the same time, greatly reduce the treatment cost, and the catalyst does not decrease in performance in a catalytic test of five cycles for 30 hours, and has wide application prospects in practical application.

This application discloses a tungsten carbide silver contact material and its preparation method. The preparation method includes the following steps: adding silver nitrate solution to sodium tungstate solution, stirring at a constant temperature, and allowing to stand for aging to obtain Ag2WO4· n The H2O colloidal precipitate was filtered, washed, dispersed, dissolved, and ultrasonically vibrated to obtain Ag2WO4· n H2O sol; WC powder added to Ag2WO4· n In H2O sol, a first ball milling is performed to obtain a two-phase mixed slurry. Silver powder and dispersant are added to the two-phase mixed slurry, and a second ball milling is performed to obtain a three-phase mixed slurry. Granulation and vacuum drying are then performed to obtain a composite feedstock. The composite feedstock is pressed to obtain a green body. The green body is placed in a sintering furnace for three-stage temperature gradient sintering to obtain tungsten carbide silver contact material. This tungsten carbide silver contact material is composed of the following percentage mass components: WC 35%-80%, Ag 15%-60%, Ag4WO3. x With a concentration of 1%–5%, tungsten carbide silver contact materials possess high density, high hardness, high conductivity, and good resistance to welding.

The application belongs to the technical field of tungsten hydrometallurgy, and particularly relates to a method for deep phosphorus removal from a crude sodium tungstate solution, which comprises the following steps: placing activated carbon in a dilute nitric acid solution for activation; adding the activated activated carbon into the crude sodium tungstate solution containing a flotation agent and phosphorus elements, performing first stirring, then adding calcium salt, performing second stirring and heating, and finally performing solid-liquid separation to obtain the phosphorus-removed sodium tungstate solution. The oxygen-containing functional groups on the surface of the activated carbon after activation can induce interface mineralization of calcium hydroxyl phosphate, overcome the phosphorus removal bottleneck that cannot be broken through by the traditional calcium salt precipitation method, remove the flotation agent by pre-adsorption of the activated carbon, avoid the wrapping of organic colloids on the precipitated particles, make the settling speed of the phosphorus removal residue fast and the filtration performance good, greatly improve the production operation conditions, significantly reduce the consumption of the subsequent phosphorus removal agent, further reduce the purification cost of tungsten smelting, and be easy to implement and popularize in the existing tungsten smelting production line.