359 results about "Tungstate" patented technology

The invention belongs to the technical field of superfine tungsten powder, and particularly relates to superfine tungsten powder and a preparation method thereof.The preparation method includes the steps that an ammonium tungstate solution, hydrochloric acid and carbon black serve as raw materials to prepare a mixture of tungstic acid and a carbon precursor; calcining the tungstic acid and carbon precursor mixture in a nitrogen atmosphere to obtain a tungsten oxide and carbon mixture; a tungsten oxide and carbon mixture is calcined in an argon atmosphere, the argon atmosphere is kept for natural cooling, the superfine tungsten powder is obtained, the superfine tungsten powder is uniform in dispersion, complete in grain development, smooth in surface, free of pores and complex in morphology, the crystal structure of the superfine tungsten powder is a body-centered cube, the average particle size is smaller than or equal to 0.7 micrometer, and the specific surface area is smaller than or equal to 1.0 m < 2 > / g.

The invention relates to the technical field of electroplating, and particularly discloses a nickel-tungsten-phosphorus plating layer electroplating process which comprises the following steps: S1, preparing a nano composite electroplating solution which comprises nickel salt, tungstate, hypophosphite, nano silicon carbide powder, ZIF-67 (at) MXene core-shell nanosheets, a composite complexing agent and water; s2, plasma mixed gas is adopted for conducting etching treatment on the surface of the workpiece to be plated; s3, electroplating the to-be-electroplated workpiece subjected to surface treatment under the action of pulse current and an alternating magnetic field, and performing ultrasonic stirring on the composite electroplating liquid in the electroplating process; and S4, under nitrogen protection, the workpiece is subjected to annealing treatment. According to the electroplating process, through the synergistic effect of the nano SiC and the ZIF-67 (at) MXene, the component uniformity and the structural compactness of the nickel-tungsten-phosphorus coating can be effectively improved, and then the corrosion resistance of the nickel-tungsten-phosphorus coating in the complex oil gas environment is effectively improved.

The invention provides application of a silver-bismuth tungstate catalyst in preparation of methanol from light-driven CO2, and belongs to the technical field of CO2 conversion and reduction. Bismuth tungstate nanosheets, silver salt and water are mixed, the size of silver particles is controlled by adjusting the pH value, the silver-bismuth tungstate catalyst is obtained, and the size of the silver particles is 20-50 nm; silver is evenly distributed on the surface of bismuth tungstate, the obtained silver-bismuth tungstate catalyst is large in specific surface area and high in light response capacity, the silver-bismuth tungstate catalyst can generate a large number of high-energy hot electrons during illumination, in-situ photo-thermal conversion is achieved, no external heat source is needed for heat supply, the photo-thermal effect is enhanced, CO2 conversion is promoted, and the methanol yield is increased.

The invention belongs to the technical field of photocatalytic materials, and particularly relates to a manganese ferrite / bismuth tungstate heterojunction photocatalyst as well as a preparation method and application thereof. The preparation method comprises the following steps: 1) dissolving sodium tungstate dihydrate, bismuth nitrate pentahydrate and hexadecyl trimethyl ammonium bromide in deionized water, and obtaining bismuth tungstate by using a hydrothermal method; 2) dissolving ferric chloride hexahydrate and manganese chloride tetrahydrate in water, then adding a sodium hydroxide solution, and obtaining manganese ferrite by using a hydrothermal method; and 3) dissolving bismuth tungstate and manganese ferrite into a sodium hydroxide solution, stirring, and drying to obtain the manganese ferrite / bismuth tungstate heterojunction photocatalyst. The formation of the heterojunction can greatly improve the activity of the manganese ferrite / bismuth tungstate in photocatalytic reduction of carbon dioxide.

The invention provides a rapid preparation method of tungsten trioxide, which specifically comprises the following steps: step 1, weighing crude tungstic acid, dissolving in ammonia water, heating and stirring to obtain an ammonium tungstate solution; step 2, slowly dropwise adding the ammonium tungstate solution in the step 1 into a poor solvent to obtain an ammonium paratungstate suspension, and step 3, filtering the ammonium paratungstate suspension in the step 2 to obtain an ammonium paratungstate filter cake, and leaching the ammonium paratungstate filter cake with the poor solvent; 4, the ammonium paratungstate filter cake in the step 3 is placed in a drying oven to be dried; and (5) roasting the ammonium paratungstate filter cake in the step (4) at high temperature to obtain a faint yellow irregular flaky tungsten trioxide product. According to the preparation method, a mixed solvent crystallization and high-temperature roasting two-step process is adopted, the solubility of ammonium tungstate in water is reduced by adding a poor solvent, so that an ammonium tungstate solution rapidly reaches a saturated state and is separated out, the crystallization process of ammonium paratungstate is accelerated, and the preparation speed and the crystallization rate of a tungsten trioxide product are high.

An electrocatalyst, a method of producing hydrogen gas by a hydrogen evolution reaction, and a method of producing oxygen gas by an oxygen evolution reaction. The electrocatalyst includes manganese oxide nanoparticles, and silver containing nanoparticles disposed on the manganese oxide nanoparticles, the silver-containing nanoparticles include a shell of silver tungstate disposed on a core of Ag. The electrocatalyst has an electrical resistivity of 0.50×107 ohm (Ω) to 6.0×107Ω, a charge transfer resistance of 325Ω to 450Ω, a Tafel slope of 55 mV / dec to 125 mV / dec, and an overpotential at 10 mA / cm2 of 0.05 mV to 200 mV.

The application relates to a preparation method and application of a ball milling-calcination process-prepared cesium vanadium tungstate mixed heat insulation coating, and belongs to the technical field of heat insulation coatings. The application aims to solve the problems of high preparation cost, strict requirement on equipment, long preparation time and difficult morphology control of vanadium dioxide and cesium tungsten bronze used in the existing cooling coating. The prepared cesium vanadium tungstate mixed heat insulation coating is coated on the surface of glass, mainly aiming at blocking the infrared light thermal radiation in sunlight, the new type of high-efficiency heat insulation film utilizes the light absorption and phase change reflection characteristics of nanometer cesium tungsten bronze and vanadium dioxide to realize heat insulation. The application adjusts the proportion of cesium, vanadium and tungstate to adjust the heat insulation performance, the heat insulation coating is prepared through different proportions of acrylic resin / organic silicon resin, solvent, cesium vanadium tungstate mixed heat insulation coating and the like, and the heat insulation film with excellent infrared blocking property, good stability and excellent light transmittance is obtained.

The invention discloses AgCuSnTi-based composite brazing filler metal. Raw materials of the AgCuSnTi-based composite brazing filler metal comprise alloy powder and yttrium tungstate powder. The volume of the yttrium tungstate powder accounts for 0.5-5% of the total volume of the powder; and the alloy powder comprises the following raw materials in percentage by weight: 8.5 to 9.5 percent of Sn, 1.2 to 1.5 percent of TiH2 and 89.1 to 90.3 percent of AgCu eutectic powder. The invention further discloses a preparation method of the AgCuSnTi-based composite brazing filler metal. The invention further discloses the AgCuSnTi based composite brazing filler metal soldering paste. The invention further discloses the application of the AgCuSnTi-based composite brazing filler metal and the application of the AgCuSnTi-based composite brazing filler metal soldering paste in welding of diamond and copper. The invention further discloses a diamond and copper welding method. According to the brazing filler metal and the soldering paste, the residual stress of a diamond and copper welding joint can be greatly relieved, and the service stability of a welding assembly is improved.

This invention relates to a method of reducing abnormal combustion events in a hydrogen fueled internal combustion engine (HICE) during operation of the engine. The method includes the steps of: a) providing to the HICE a lubricating oil composition including or resulting from the admixing of: i) a base oil having a KV100 of less than or equal to 12 cSt and included at greater than 50 wt.% of the composition and comprising a Group I base oil, a Group II base oil, a Group III base oil, a Group IV base oil, or combinations thereof; ii) at least one organoammonium tungstate compound included at a treat level to deliver between 10 to 5000 ppm by weight of total tungsten to the composition; iii) at least one overbased metal containing detergent with a Total Base Number (KOH / g) greater than or equal to 9 and less than or equal to 500 and included at a treat level to deliver between 100 to 5000 ppm by weight of total metal and between 0.15 wt. % to 8.0 wt. % of total soap to the composition; and iv) the lubricating oil composition having a total sulfated ash of less than or equal to 2.5 wt.%, a total phosphorous level of less than or equal to 0.120 wt.%, and a SAE viscosity grade of 25W-X, 20W-X, 15W-X, 10W-X, 5W-X or 0W-X, where X represents any one of 8, 12, 16, 20, 30, 40, 50 or 60; b) providing a fuel comprising hydrogen to the HICE; and c) combusting the fuel in the HICE. Also provided are lubricating oil compositions and concentrates for use in a HICE to reduce the propensity for abnormal combustion events.

The invention discloses a high-voltage lithium nickel manganese oxide positive electrode material and a preparation method thereof, a battery positive electrode and a battery, and belongs to the technical field of lithium ion battery materials. Comprising an inner core composed of a lithium-containing compound, the inner core is coated with a shell composed of tungstate, and a transition layer is arranged between the inner core and the shell. The tungstate has good chemical and thermodynamic stability, can prevent erosion of HF in the electrolyte, inhibit dissolution of transition metal, reduce the shuttle effect, and can greatly improve the capacity retention rate of the battery. The preparation method is simple in process steps and convenient for large-scale preparation. Meanwhile, the cathode material coated with magnesium tungstate, calcium tungstate or bismuth tungstate has good dynamic performance, the capacity and the rate capability are remarkably improved, meanwhile, the stability of the material is also remarkably improved, and a good application way is provided for application of the high-voltage type lithium nickel manganese oxide cathode.

The invention relates to a WO-NiSe CeO2 self-supporting heterostructure catalyst and a preparation method thereof. The preparation method comprises the following steps: preparing Ni LDH at CeO2 on foamed nickel through a hydrothermal method, then realizing high-valence tungstate radical doping through impregnation exchange, and finally carrying out secondary hydrothermal selenylation to obtain a porous nanosheet heterojunction material with CeO2 nanoparticles attached to the surface, namely WO-NiSe at CeO2. The introduction of high-valence tungstate radicals and the coupling of CeO2 form a strong electron coupling interface on the surface of NiSe, and HER / OER charge transfer is accelerated. And according to a hard-soft acid-base (HSAB) theory, the high-valence metal serving as a relatively hard Lewis acid shows higher selectivity on OH <-> than Cl <->, so that accumulation of Cl <-> on the surface of the catalyst can be inhibited, the catalytic activity is remarkably improved, and the corrosion-resistant life is remarkably prolonged. According to the strategy, a new'activity-stability-cost 'ternary equilibrium normal form with the advantages of low overpotential, long-period stability and salt corrosion resistance is provided for seawater electrolytic hydrogen production, and the theoretical value and the industrialization potential are both achieved.

The invention relates to the technical field of catalysis, in particular to a Ru / WO3-x heterojunction catalyst, the chemical formula of the catalyst is Ru / WO3-x, and x represents oxygen vacancy; ru is loaded on the surface of a WO3-x support in the form of a metal simple substance, and the preparation method comprises the following steps: by taking tungstate as a tungsten source, ammonium sulfate as a morphology adjuvant and ruthenium trichloride as a ruthenium source, adjusting the pH value to 0-2, adding deionized water to prepare a hydrothermal reaction solution, performing hydrothermal reaction with a current collector, washing with deionized water, and drying, thereby obtaining the WO3-x support. And calcining in a reducing gas atmosphere to obtain the Ru / WO3-x heterojunction catalyst integrated electrode. Under the same test condition, nitrate can be effectively inhibited from being excessively hydrogenated into the final product ammonia, so that the product stays in the intermediate hydroxylamine.

The invention belongs to the technical field of functional materials, and particularly relates to ultra-thick tabular tungsten oxide and a preparation method thereof.The preparation method of the ultra-thick tabular tungsten oxide comprises the following steps that S1, ammonium tungstate is added into deionized water and stirred to be dissolved at the temperature of 70-90 DEG C, and a clarified ammonium tungstate solution is obtained; s2, cooling the clarified ammonium tungstate solution to normal temperature at a cooling rate of 0.5-2 DEG C / h, and then carrying out suction filtration to obtain plate-shaped ammonium tungstate crystals; s3, calcining the tabular ammonium tungstate crystal to obtain ultra-thick tabular tungsten oxide; ammonium tungstate is adopted as a raw material, controllability is high, tungsten oxide which is uniform in particle size and complete in plate shape is obtained through optimized crystallization and calcination, the purity is larger than or equal to 99%, the problems that traditional tungsten oxide is agglomerated and disordered in shape are solved, functional adaptability is high, the plate-shaped structure can be directionally oriented, the dielectric performance, the breakdown performance and other performance are improved, and the method is suitable for multiple high-end scenes; parameters are easy to control, and operation is simple, green and safe.

The invention relates to the technical field of catalysts, and discloses a foam structure catalyst and a preparation method and application thereof. The foam structure catalyst comprises a foam structure, metal M2, metal oxide M2Ox, heteropolyacid salt of the metal M2, optional tungsten oxide WOz1 and optional molybdenum oxide MoOz2, the metal M2, the metal oxide M2Ox and the heteropolyacid salt of the metal M2 grow on the foam structure, z1 is equal to 2-3, and z2 is equal to 2-3; wherein the heteropolyacid salt is selected from one or more of tungstate and molybdate, M2 is selected from one or more of Cu, Ni, Fe, Zn and Co, and x is equal to 0.5 to 1.5; the foam structure contains metals M1 and M1Oy, M1 is selected from one or more of foam iron, foam nickel and foam cobalt, and y is equal to 1-1.5. The foam structure catalyst can be used for stable hydrogenolysis of glucose, the glucose conversion rate stably reaches 100% in a continuous fixed bed reactor, and the selectivity of 1, 3-propylene glycol is larger than or equal to 55%, and the selectivity of ethyl alcohol is larger than or equal to 48%.

The invention discloses an ultraviolet curing organic silicon conductive adhesive and a preparation method thereof, and relates to the technical field of conductive materials, the ultraviolet curing organic silicon conductive adhesive comprises the specific components of organic silicon matrix resin, a photosensitive curing agent, a conductive filler, a reactive diluent, a coupling agent and a thixotropic agent; the photosensitizer further comprises carborane cluster particles, a phosphazene silane nanocage, a sulfur-doped tungstate nanosheet, a potassium fluoride modified hollow graphene ball and an additive of a germanoxane photosensitizer. The material is prepared based on the materials. According to the preparation method, multiple functional additives are introduced into a traditional ultraviolet curing organic silicon conductive adhesive system, a multi-dimensional conductive path is constructed on the molecular and nanoscale, and the photocuring initiation efficiency and the interface stability are optimized, so that the prepared conductive adhesive not only realizes low resistivity, but also can be rapidly and deeply cured in an adhesive layer with relatively high thickness; and meanwhile, excellent damp-heat resistance and corrosion resistance are achieved.

The invention provides a tungstate-based flexible composite material with a multimode dynamic color change characteristic, which comprises an optical function material and a carrier material, the optical function material is tungstate-based fluorescent powder, and the tungstate-based fluorescent powder comprises Li (1-x) YW2O8: xEu (0% lt; xlt; 10%). According to the tungstate-based flexible composite material with the multimode dynamic color changing characteristic and the preparation method of the tungstate-based flexible composite material, a force-induced and light-induced multimode dynamic light-emitting composite material is prepared by mixing a polydimethylsiloxane solution A and a polydimethylsiloxane solution B in proportion and adding a certain amount of fluorescent powder LiYW2O8: Eu < 3 + >, and the tungstate-based flexible composite material with the multimode dynamic color changing characteristic can be obtained only through simple temperature change. According to the present invention, the change of the light emitting characteristic can be observed according to the temperature of the tungstate fluorescent powder, such as the hand temperature or the environment temperature, such that the temperature change photoluminescence material of the dynamic mechanoluminescence tungstate-based fluorescent powder has characteristics of large temperature change range, good stability, high light emitting efficiency and no environmental pollution, and most importantly, the mechanoluminescence does not need energy charging, and has the self-recovery effect.

The invention provides a graphene-based Q-switched neodymium ruthenium tungstate human eye safety laser system, and relates to the technical field of laser, and the system comprises a laser diode pumping source control module which is used for controlling the output power and the on-off state of a laser diode pumping source; the optical focusing coupling control module is used for adjusting the focusing position and focal length setting of optical focusing coupling; and the resonant cavity control module is used for solving a final solution by using the whale optimization algorithm and adjusting the positions and angles of an input cavity mirror and an output cavity mirror of the resonant cavity so as to optimize the optical performance of the resonant cavity. The passive Q-switched neodymium-doped potassium ruthenium tungstate laser based on the graphene absorber is comprehensively and accurately controlled by integrating a multifunctional module, the performance of the laser is optimized, the output stability and adaptability are improved, and efficient and reliable laser pulse generation is ensured.

The invention provides a glass substrate through hole machining method, and belongs to the technical field of glass substrates. Comprising the following steps: S1, carrying out ultrasonic cleaning on a glass substrate by using a cleaning solution, and drying; s2, dissolving ammonium tungstate in water, dipping the glass substrate in the solution, dropwise adding concentrated nitric acid for reaction, taking out the glass substrate, calcining, carrying out reverse hydrogen heating reduction, scattering carbon powder on the surface for carbonization, taking out, washing and drying; s3, dissolving an organic zinc salt and an organic aluminum salt in water, adding citric acid and ethylene glycol, adjusting the pH value of the solution, dipping the glass substrate, carrying out a heating reaction, taking out the glass substrate, and calcining the glass substrate; s4, irradiating the target area of the glass substrate with laser to modify the glass in the target area; and S5, carrying out spray etching on the glass substrate to form a through hole, taking out, washing and drying. According to the invention, the problems of easy cracking, crack generation, low adhesion to metal and the like in the traditional glass substrate processing are solved, and the method has industrial application prospects.

The invention belongs to the technical field of electro-catalysis water decomposition, and relates to a self-supporting W-NiCoP / NF composite material and a preparation method and application thereof. Cobalt salt, terephthalic acid, acetic acid and foamed nickel are subjected to a first solvothermal reaction, and defect type Co-MOF / NF is obtained; immersing the defect type Co-MOF / NF into a tungstate solution, and then carrying out a second solvothermal reaction to obtain a defect type W-Co-MOF / NF precursor; and carrying out phosphating heat treatment on the defect type W-Co-MOF / NF precursor and a phosphorus source in an inert atmosphere to obtain the W-Co-MOF / NF composite material. According to the preparation method disclosed by the invention, the tungsten-doped nickel-cobalt bimetallic phosphide with rich defect structures is successfully constructed on the foamed nickel substrate through a step-by-step solvothermal and gas-phase phosphating strategy, so that organic combination of a bimetallic synergistic effect and defect engineering is realized; the prepared self-supporting composite material has more active sites, a better electronic structure regulation effect and better stability.

Modified iron phosphate, and a preparation method therefor and the use thereof. The preparation method comprises the following steps: (1) mixing a zirconium salt, a hydrogen phosphate and a tungstate with a solvent to obtain a mixed salt solution, and performing a heating reaction, so as to obtain zirconium phosphotungstate; (2) mixing the zirconium phosphotungstate serving as a seed crystal with an iron salt, a phosphate, phosphoric acid and an oxidizing agent, and performing a synthesis reaction, so as to obtain a modified material; and (3) sintering the modified material, and then grinding same, so as to obtain modified iron phosphate. In the present disclosure, zirconium phosphotungstate is used as a seed crystal to prepare iron phosphate, which can promote the generation of cracks in secondary particles, making iron phosphate easy to break and an iron phosphate precursor having a smaller particle size be obtained; therefore, a high-energy and high-power-density lithium iron phosphate positive electrode material is prepared.

The invention provides submicron high-purity tungsten powder and a preparation method thereof, and relates to the field of tungsten powder preparation. Ammonium paratungstate and ammonia water are mixed to obtain a mixture, the mixture is subjected to ammonia dissolving treatment, and a first ammonium tungstate solution is obtained through filtering; carrying out first ion exchange on the first ammonium tungstate solution by adopting strong acid cation exchange resin to obtain a first ion-exchanged solution; carrying out second ion exchange on the solution subjected to the first ion exchange by adopting chelating resin to obtain a high-purity ammonium tungstate solution; the high-purity ammonium tungstate solution is subjected to vacuum spraying and freeze drying, and a submicron tungsten precursor is obtained; and carrying out hydrogen reduction reaction on the submicron tungsten precursor to obtain the submicron high-purity tungsten powder. Insoluble particles and metal cation impurities in the solution can be effectively removed, and the high-purity tungsten precursor solution is obtained; raw materials are easy to obtain, and operation is simple.

The invention provides a cobalt tungstate and bismuth vanadate photocatalytic material as well as a preparation method and application thereof, and belongs to the technical field of material synthesis and photocatalytic application. In the presence of monoclinic-phase decahedron BiVO4, CoWO4 nanoparticles grow in situ on an electron-rich (010) crystal face of the CoWO4 nanoparticles through a hydrothermal reaction, and the cobalt tungstate and bismuth vanadate photocatalytic material is obtained. According to the cobalt tungstate and bismuth vanadate photocatalytic material, a simple hydrothermal method is adopted, in the synthesis process, a CoWO4 precursor is guided by electrostatic interaction, preferentially adsorbed and subjected to nucleation growth on the (010) crystal face of BiVO4, a compact chemical bonding interface is constructed through selective growth, the charge migration distance is effectively shortened, and the photocatalytic performance of the material is improved. The interface charge transfer resistance is reduced to the greatest extent, and the formed binary photocatalyst has excellent effects on photocatalytic hydrogen evolution and tetracycline degradation.

The invention belongs to the technical field of tungsten hydrometallurgy, and particularly relates to a method for improving the crystallization rate of ammonium paratungstate, which comprises the following steps: S1, obtaining an ammonium tungstate solution which comprises metatungstate ions; s2, adding a supersaturation degree regulator into the ammonium tungstate solution, wherein the supersaturation degree regulator comprises hydrogen peroxide and ammonia water; s3, heating the ammonium tungstate solution to a first temperature, and then adding superfine ammonium paratungstate; s4, the ammonium tungstate solution is heated to a second temperature, heat preservation and continuous stirring are conducted, and ammonium paratungstate crystals are obtained; by adjusting parameters such as temperature, pH value, solvent type and concentration, optimizing crystallization conditions with metatungstate ions and ammonium paratungstate at the same time, improving the crystallization rate, and by controlling the degree of supersaturation of the solution, the situation that the crystallization rate is affected due to non-uniform crystal growth caused by too high crystallization rate is avoided, and the quality of the product is improved. The supersaturation degree can be controlled by adjusting parameters such as solution concentration and temperature.

The invention discloses a copper particle catalyst electrode containing abundant dislocation defects and a preparation method and application thereof, and the preparation method comprises the following steps: (1) dissolving tungstate, copper salt and urea in water, stirring and mixing; (2) putting the solution into a hydrothermal kettle for hydrothermal reaction, and then washing and drying solid powder obtained by the reaction; (3) calcining the solid powder in air to obtain CuWO4 powder; (4) loading CuWO4 powder on an electrode substrate to prepare a working electrode; and (5) performing electrochemical reduction on the working electrode to obtain the copper particle catalyst electrode containing rich dislocation defects. The defect sites of the electrode can regulate and control the electronic structure of copper, construct low-coordination copper and enhance the binding capacity to nitrogen intermediate products, so that nitrite accumulation is reduced, and the reaction activity and ammonia nitrogen selectivity are improved.

The invention discloses a post-treatment liquid and application thereof in an anode foil formation post-treatment process, and the post-treatment liquid comprises the following components in percentage by mass: 0.1-5% of a main film-forming agent, 0.05-3% of a synergistic stabilizer and the balance of a solvent, the main film-forming agent is selected from at least one of a waterborne polyurethane emulsion and a silane coupling agent; the synergistic stabilizer is selected from at least one of organophosphate, molybdate and tungstate. The main film-forming agent and the synergistic stabilizer are compounded to obtain the post-treatment liquid, on one hand, the synergistic stabilizer is firmly combined with an aluminum oxide substrate to carry out deep passivation treatment on an oxidation film on the surface of the anode foil, and on the other hand, the synergistic stabilizer is subjected to network crosslinking with a hydrophobic protection layer formed by the main film-forming agent; the three-dimensional composite protective film can effectively isolate water molecules, repair microdefects on the surface of an oxidation film, prevent the phenomena of specific volume attenuation, leakage current increase and the like of the anode foil, and improve the long-term working reliability of the capacitor.

The invention relates to the technical field of catalysts, and particularly discloses a composite catalyst for preparing acrolein through catalytic oxidation of propylene and a preparation method of the composite catalyst, the composite catalyst comprises an active component I and an active component II, and the use mass ratio of the active component I to the active component II is 1: (1-19); the active component I is bismuth tungstate microspheres obtained by a hydrothermal synthesis method, and the general formula of the active component I is BiaW1Ox; the active component II is a multi-metal oxide obtained by a coprecipitation method, and the general formula of the active component II is Mo < 12 > Bi Co < c > Ni < d > Fe < e > A < f > B < g > O < y >; the bismuth tungstate microspheres obtained by a hydrothermal synthesis method and the multi-metal oxide obtained by a coprecipitation method are mixed to obtain the composite catalyst, so that the bismuth tungstate microspheres with microsphere structures can be used as active phases of reaction, and the specific surface area and the pore volume of the composite catalyst can be increased; the catalyst is suitable for a reaction for preparing acrolein through propylene catalytic oxidation under high load.

The invention discloses a method for recycling process water in an APT (ammonium paratungstate) production process, and relates to the field of water recovery in an APT production process, and the method comprises the following steps: S1, recycling wastewater of an alkali extraction system; s2, evaporating strip liquor and recovering ammonia water; s3, chemical treatment of pure ammonium tungstate evaporation ammonia water; s4, ammonium molybdate evaporation ammonia water closed-loop utilization; and S5, recycling ammonia gas in a crystallization section. According to the method, the recovery rate of tungsten and molybdenum in the tail liquid is remarkably increased by optimizing the processes of wastewater reuse of the alkali extraction system, strip liquor evaporation, ammonia water recovery and the like; one part of the tail liquid is recycled in the pulping process, the other part of the tail liquid is subjected to evaporation treatment, zero emission of wastewater is achieved, evaporated condensate water can be recycled to be used for preparing a stripping agent, the utilization rate of water resources is further increased, the production cost is reduced, and meanwhile the environment-friendly requirement is met.

A modified lithium iron phosphate, a preparation method therefor and a use thereof. The preparation method comprises the following steps: (1) mixing a zirconium salt, a tungstate and a solvent, to obtain a mixed salt solution, adjusting the pH, then adding lithium iron phosphate and performing a heating reaction; (2) separating a slurry obtained by the heating reaction into a solid and a liquid, and subjecting the obtained solid to a one-step sintering treatment, to obtain a first sintered material; (3) mixing an organic carbon source, a lithium source and the first sintered material, and performing a second sintering treatment, to obtain a modified lithium iron phosphate. A material having a negative thermal expansion effect is used as a coating layer, which is then coated with an electrically conductive material, causing pores to appear during a second coating process due to the negative thermal expansion effect, which is conducive to the embedding of organic matter and improves bonding tightness between the two layers of coatings. The pores generated during the negative thermal expansion process are conducive to the entry of lithium ions, which can better generate lithium tungstate and lithium zirconate from the tungsten oxide and zirconium oxide generated by decomposition.

The invention relates to a preparation method of a nano Fe < 3 + >-Bi2WO6 composite catalytic material, which comprises the following steps: dissolving bismuth salt and tungstate in water, doping ferric salt to prepare a precursor solution, adjusting the pH value to 1.0-5.0, carrying out hydrothermal reaction at 160-180 DEG C, and continuously calcining the hydrothermal reaction product at 200-400 DEG C to prepare the creamy white nano Fe < 3 + >-Bi2WO6 composite catalytic material. By means of Fe < 3 + > doping and calcination post-treatment, formation of oxygen vacancies is promoted, the service life of photon-generated carriers is prolonged, an energy band structure can be regulated and controlled, the visible light absorption range is widened, and separation of photo-generated electron-hole pairs and. O < 2-> activation are enhanced, so that the photocatalytic performance of the composite catalytic material is greatly improved; therefore, the catalyst shows extremely high catalytic degradation performance in the aspect of degrading antibiotics such as tetracycline and the like.

Provided in the present invention is a preparation method for a metal oxide / ruthenium-tungsten composite catalyst and the use of the metal oxide / ruthenium-tungsten composite catalyst in the catalysis of the cleavage of a C-O bond in lignin. The preparation method comprises: weighing a tungstate, dissolving same in deionized water, and stirring the resulting solution until uniform, so as to obtain a solution a; weighing ruthenium chloride, dissolving same in deionized water, and stirring the resulting solution until uniform, so as to obtain a solution b; mixing the solution a with the solution b, so as to obtain a solution c; dissolving a nanometer metal oxide in deionized water, and stirring same, so as to obtain a solution d; S4, adding, in a dropwise manner, the solution c to the solution d, so as to obtain a solution e, and subjecting the solution e to rotary evaporation and a vacuum drying treatment, so as to obtain a catalyst precursor; and S5, placing the catalyst precursor into a tubular furnace, and reducing same in a H2 / Ar atmosphere, so as to obtain a metal oxide / ruthenium-tungsten composite catalyst. In the present invention, a metal oxide carrier is loaded with ruthenium and tungsten by means of an impregnation method, the preparation process is simple, and environmental pollution and energy consumption are low; and a lignin model compound is efficiently catalytically cracked into an aromatic compound under mild conditions, and few by-products are produced.