The invention relates to a method for preparing ultrafine tungsten trioxide, which comprises the steps of crystal seed preparation, material proportioning, hydrothermal reaction, separation by filtration, low-temperature roasting and the like. The invention has the advantages of short technical process, mild conditions and no need of complex equipment; the prepared tungsten trioxide has the advantages of high purity and small particle size; the mother solution can be recycled; and the utilization ratio of the sodium tungstate raw material is high.

A process for preparing ultrafine tungsten oxide, characterized by comprising the steps of:

(1) Preparation of seed: the preparation concentration of 10% ~ 52% of the sodium tungstate solution, with an organic acid or inorganic acid to adjust the solution pH to 4.0 - 8.0 range, in the hydrothermal autoclave for 4 to 15 hours, and the resulting precipitate was filtered, evaporation, crystallization, to obtain seed;

(2) Mole ratio of: the concentration of the preparation 10% to 55% solution of sodium tungstate, seed crystals are added to the solution, the seed crystal in the solution quality and the mass ratio of sodium tungstate in I: 2. 5 ~ I: 8. 5 range;

(3) High reaction: sodium tungstate solution with a seed crystal was placed on a stainless steel autoclave at 60 ~ 350 ° C reaction temperature and under strong stirring, stirring hydrothermal reaction, hydrothermal reaction for 4 to 20 hours After stirring was stopped, the autoclave was cooled to room temperature, taken out after one of the solid-liquid mixture;

4) It was isolated by filtration: the step (3) of the liquid mixture in the slurry was separated by filtration to obtain the tungsten trioxide fine cake and a mother liquor;

(5) Low-temperature firing: the fine tungsten trioxide cake was calcined in a baking furnace to obtain the low temperature of the tungsten trioxide fine product;

(6) The mother liquor was evaporated: the mother liquor and the washings were separated by filtration with heating evaporation stage , the concentration of sodium tungstate was prepared from 3% to 20% of the circulating liquor;

(7) Recycling the mother liquor: the loop back to the seed crystal mother liquor preparing step, for the preparation concentration of 5% to 45% of sodium tungstate water.




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The invention discloses a method for preparing ammonium tungstate by treating waste tungsten oxide, which comprises the following steps of:

Adopting an ammonia water pressure cooking method to dissolve waste tungsten trioxide, blue tungsten oxide, and other tungsten oxide to prepare an ammonium tungstate solution, ammonium paratungstate, ammonium metatungstate and other ammonium tungstate.

Compared the method that caustic soda or soda ash digestion or melting-poaching is adopted to dissolve the tungsten oxide to prepare a sodium tungstate solution, and the method that a solvent extraction or ion exchange process is adopted to prepare the sodium tungstate solution in the prior art, the method has the advantages and characteristics that the procedure process can be simplified, the auxiliary raw materials can be saved, energy saving and emission reduction can be realized, the environmental pollution can be relieved, and the production cost can be reduced.


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The present invention discloses a method for the production of tungsten slag Ball tungsten trioxide roasting process.

Characterized by: includes the following steps:

(1) The tungsten residue after drying join anthracite, mix crushed, then add the lime mud, soda and water , hexadecimal Handicap Ball, made of tungsten mixed slag pellets.

(2) Mixing the ball into the open hearth furnace slag tungsten roasting kiln firing semi-enclosed insulation, too tungsten slag clinker.

(3) Tungsten slag clinker immersion, have a high concentration of ion exchange of sodium tungstate liquor.

(4) Addition of high concentrations of sodium tungstate liquor quality after filtration, reprecipitation, and then the precipitate was rinsed, dehydrated and dried to obtain the product of calcium tungstate.

The invention uses a tungsten residue, anthracite, lime mud and recycling waste as an alternative to traditional baking agent, a wet pyrometallurgical process used is expensive, large consumption of soda ash and burning acid, metal tungsten production cost per ton reduced 6-7 million to make the conversion rate WO3 twenty five percentage points, and successfully resolved the sodium roasting kilns, kiln shutdown ills caked shovel, still in the traditional process, saving on production of wet fire energy consumption by 50 percent.




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Disclosed is a method for producing a tungsten trioxide powder for photocatalysts, which is characterized by comprising a sublimation step wherein a tungsten trioxide powder is obtained by subliming a tungsten metal powder or a tungsten compound powder by inductively coupled plasma processing in an oxygen atmosphere, and a heat treatment step wherein the tungsten trioxide powder obtained in the sublimation step is heated at 300-1000 DEG C for 10 minutes to 2 hours in an oxidizing atmosphere. A tungsten trioxide powder obtained by such a method for producing a tungsten trioxide powder for photocatalysts has high photocatalytic activity under visible light.

For the production of the photocatalyst powder, tungsten trioxide, said method comprising: a step of sublimation, in an oxygen atmosphere by using the following types of processing in the distillation of at least ー tungsten powder or the tungsten compound powder to obtain the tungsten trioxide powder : inductively coupled plasma processing, arc discharge processing, laser processing and electron beam processing; and the heat treatment step, in an oxidizing atmosphere at 300 ° C to 1000 ° C in said heat treatment step, the sublimation of the tungsten trioxide powder obtained 10 minutes to 2 hours inches, wherein said powder has a crane crab oxide selected from the monoclinic crystal, rhombic crystal and monoclinic crystal brother of at least two crystal structures, wherein the tungsten trioxide powder has a BET specific surface area of ​​8. 2m2 / g to 820m2 / g, wherein the tungsten trioxide powder obtained by the image analysis of particle size distribution (D90-D10) / D50 in the 0.3 to 2 range, and wherein said catalyst is a visible light photocatalyst and The wavelength of visible light of 390 to 830nm.




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The invention relates to a preparation method of nano tungsten trioxide powder, and belongs to the field of powder metallurgy technology.

The method comprises the following steps: heating a saturated ammonium tungstate solution till 65-70 DEG C, then adding ammonium chloride, tartaric acid, ethylenediamine tetra-n-propionic acid and diethanol amine respectively in sequence, keeping stirring during the adding process till being dissolved completely and continuously stirring for 1-2h; then adding nitric acid under the condition of keeping stirring to form tungstic acid gel; then putting the gel in a heating furnace for drying at 140-150 DEG C, then warming up till 340-380 DEG C for calcination, and finally ball-milling and smashing to obtain the nano tungsten trioxide powder with the average particle size of 23-28 nm. The method disclosed by the invention is mild and stable for reaction process and easy to control, prepared nano tungsten trioxide is thin and uniform in particles and high in powder purity. Moreover, the process is simple and easy to control, so that the industrial production investment is few, the production technology is simple and convenient, the production cost is low, and industrial large-scale production is convenient to realize.

A process for producing a tungsten trioxide powder of nanometer, which is characterized by comprising the steps of: a saturated ammonium tungstate solution was heated to 65-70 ° C, and then ammonium chloride was added an amount of 8-13g / L, stirring 0.5_lh; tartaric acid were added in sequence and, ethylenediaminetetraacetic acid and diethanolamine were added in an amount ll_14g / L ,23-32g / L and 6-9g / L, was stirred to completely dissolve and continue stirring for 1 - 2h; nitric acid was added and stirring was continued for 320-380ml / L, the formation of tungsten acid gel; the gel is placed in a furnace 140-15 (TC drying, heating rate 1_2 ° C / min, heat l_2h, then 2-3 ° C / min heating to 340_38 (TC insulation 2_3h calcination, ball milling to obtain the final nano tungsten trioxide powder.




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The present invention discloses a method for preparing , tungstic acid is a polyethyleneimine with a mass ratio of 1:1 in water and uniformly mixed, adjusted to pH 1-5, diluted with water to the solution of tungstic acid polyethylene imine mass fraction of 0.05 to 0.1, and the resulting reaction mixture was prepared by hydrothermal hydrogel, then freeze-dried hydrogel or supercritical drying to obtain a tungsten oxide airgel; which hot water assisted gel method by adding polyethyleneimine morphology directing agent, succeeded in the tungsten oxide nanowires grow into alignment, and entanglement between the nanowires to form a continuous three-dimensional spatial network structure, constituting the final oxidation Tungsten airgel, which is made by winding nanowires airgel favor fixed proteases, protease can be used as direct electron transfer of the baton, which will help direct electrochemistry of proteases, which could be used to build a stable and efficient direct electrochemical bio sensor test electrodes.




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The present invention discloses a surface-modified europium photoelectrode and the preparation method. Electrical characteristics of the present invention is a method of depositing a tungsten obtained amorphous oxide film as the substrate, by dropwise dropping method evenly europium oxide in the surface of the tungsten film, and then calcined at a temperature, to obtain a surface modified with oxides of europium Tungsten photoelectrode. Optical properties of the present invention is significantly improved, and laboratory equipment is simple, easy to operate, mild conditions and with environmental friendliness.

A surface-modified tungsten trioxide europium photoelectrode, wherein a) the atomic mass of the photoelectrode and the tungsten in the ratio of europium 1:99-30:70; photoelectric 2) of the electrode Composition smaller particles; 3) according to the photoelectrode with europium luminescence intensity increase and strengthen the modification; 4) the band gap of the photovoltaic electrode modified with increased europium widened; photoelectric 5) on the pole photocurrent 0.8V voltage than that of pure tungsten trioxide photoelectrode maximum increase of 12 times.

A surface-modified tungsten trioxide europium photoelectrode preparation method characterized by comprising the steps of: a) preparing an amorphous tungsten oxide film: In Na2WO4 H2O2 solution was added to obtain a clarified liquid electrolyte containing W20n2_ ; then electrodeposition, an amorphous tungsten oxide film; 2) surface modification method of Eu was added dropwise: The surface of the film of amorphous tungsten oxide was added dropwise a solution of europium nitrate in step I) obtained dried to obtain a surface-modified europium tungsten oxide film; 3): calcination step 2) to obtain a surface-modified tungsten oxide film at 450 ° C europium calcination under 3h, cooled to room temperature and taken out to obtain a surface-modified tungsten trioxide europium photoelectrode.




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The invention belongs to the field of preparation of nanomaterials, specifically relates to a preparation method based on tungsten oxide as the precursor of several tungstate nanomaterials.

Characterized by comprising the following steps:

1) Preparation of precursor;

2) According to the stoichiometric ratio of the different tungstate was dissolved in a reaction weighed 4mol / L nitric acid solution, and finally mixed with the precursor to form a mixed phase;

3) Hydrothermal reaction temperature of 120-180 ℃, the reaction time is 6-24h. The approach is novel and simple.

This approach has been successfully used to prepare a variety of morphologies, uniform size Bi2WO6, CoWO4, FeWO4 three kinds of tungstate nanomaterials.




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The invention relates to a tungsten oxide nano-wire ammonia-sensitive sensor and a preparation method thereof, belonging to the gas sensor technical field. The method comprises the following steps that: sodium tungstate is dissolved in deionized water to prepare a sodium tungstate solution; a hydrochloric acid and an oxalic acid are dripped slowly and stirred; a flaxen micellar solution is transferred into a reaction kettle, added with 25 to 30 grams of potassium sulfate and uniformly stirred, and the mixture undergoes hydrothermal treatment for 12 to 144 hours at a temperature of 180 DEG C; hydrothermal products are washed and fully dried in the presence of air with a temperature of 65 DEG C, and then a tungsten oxide nano-wire is prepared; adhesives and frit are added according to the tungsten oxide nano-wire prepared to prepare gas-sensitive materials slurry; and then the tungsten oxide nano-wire ammonia-sensitive sensor is prepared after element sintering and ageing. The method has simple steps, easily controlled parameters, and low energy consumption during the whole preparation process; the tungsten oxide nano-wire prepared has a large specific surface area; and the tungsten oxide nano-wire ammonia-sensitive sensor prepared has high sensitivity on low-concentration ammonia (between 1 and 100 pars per million), good repeatability and high stability.

A tungsten oxide nanowires, characterized in that the preparation steps are as follows: (1) 1.0 to 1.5 g of sodium tungstate was dissolved in 24 to 30 ml of deionized water and a magnetic stirring in an ice water bath 1 hours a colorless transparent solution of sodium tungsten; (2) in the step (1) in the resulting sodium tungstate solution was slowly added dropwise 3.5 to 4 ml 3M / L hydrochloric acid and continuously stirred for 0.5 hours and then slowly added dropwise 4.6 ~ 5.2 ml 0.3M / L oxalic acid and stirring was continued for 0.5 hours to form a pale yellow micellar solution; (3) 28 to 30 ml in step (2) of the micellar solution into 50ml reactor and adding 25 to 30 grams Stir potassium, and water at a temperature of 180 ℃ heat treatment of 12 to 144 hours; (4) in the step (3) of the hot products of water in deionized water and ethanol after repeated washing, the air atmosphere at 65 ℃ under fully drying, to prepare the tungsten oxide nanowires.

A tungsten oxide nanowires preparation of ammonia sensitive sensor, characterized in that the preparation steps are as follows: (l) the preparation of the slurry to the gas-sensitive material of the tungsten oxide nanowires adding a binder and a glass frit, stir to prepare a slurry sensitive material; wherein the binder is ethyl cellulose and terpineol; (2) element sintering step (l) of said sensitive material by screen printing paste with silver electrodes and leads alumina substrate, 70 ° C in air sufficiently dried in a box furnace at 300 to 500. The sintering temperature of C 1 to 2 hours to obtain a tungsten oxide nanowires ammonia sensitive sensor element; (3) aging of components in the step (2) was obtained in the ammonia tungsten oxide nanowires sensitive sensor element 300 ° C aging for 72 hours obtained tungsten oxide nanowires ammonia sensitive sensor.




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The invention discloses a method for preparing a gas-sensitive sensor element based on carbon nano tube microarray/tungsten oxide nano composite structure,which comprises the following steps:

(1) template cleaning: the porous alumina template with acetone for 30 minutes remove the solvent, and then ethanol into the ultrasonic cleaning for 5 minutes, allowing drying;

(2) Preparation of porous tungsten oxide films: the template on the ultrahigh vacuum clean target magnetron sputtering apparatus of a vacuum chamber, the use of a purity of 99 mass 6.9% of tungsten as a target, the quality of purity of 99.999% argon gas as the working gas, the quality of purity of 99.999% of oxygen as the reaction gas in the step (1) of porous alumina template on standby sputter deposition of tungsten oxide porous film;

(3) microarray CNT / tungsten oxide composite structure: a) Preparation in Step (2) deposited porous templates / tungsten oxide porous film structure as a cathode, electrophoretic deposition of carbon nanotubes tube film, the electrophoretic deposition process: electrophoresis voltage is 30 ~ 100V, the run time of 0. 5 ~ lOmin, cathode and anode spacing of 1 ~ 5cm, electrophoretic fluid pre-settling time 30min ~ 2h, electrophoretic fluid pre ultrasonic dispersion time 1 tank; electrophoretic fluid with water, isopropanol and n-butanol as a dispersing agent of any one; electrophoresis anode electrode may be copper, aluminum electrode, stainless steel electrode of any one; single-walled carbon nanotube multi-walled carbon nanotubes, the use of pre-grinding Ih; b) removal of the tungsten oxide film is deposited on the surface of the porous carbon excess, the air for 10min, 6 (TC drying Ih; c) in the program sintering furnace at 400 - 600 ° C air atmosphere heat for 3-4 hours, controlling the heating rate is less than 2. 5 ° C / min, to obtain carbon nanotube microarrays / tungsten oxide nanocomposite structure;

(4) carbon nanotube-based microarray / tungsten oxide nano- The gas sensor element composite structure Preparation: by RF magnetron sputtering in the step (3) of carbon nanotubes obtained in microarray / tungsten oxide film deposited on the surface of molybdenum composite structure point electrodes formed gas sensor element.




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