42 results about "Sodium metavanadate" patented technology

The invention provides a high-temperature-resistant desulfurization catalyst and a preparation method thereof, and relates to the technical field of catalysis, and the high-temperature-resistant desulfurization catalyst comprises the following components in percentage by weight: 30-35% of cobalt phthalocyanine, 10-15% of Fe-PBTCA-EDTMP, 10-15% of manganese sulfate monohydrate, 10-15% of 2, 3, 4-trimethyl-1, 3-pentanediol monoisobutyrate, 10-15% of 2, 3, 4-trimethyl-1, 3 The cleaning agent is prepared from 5-10% of 1, 4-dinitrophenol, 15-20% of tannin extract, 8-10% of sodium metavanadate, 8-10% of ammonium phosphate and 4-8% of ammonia-ammonium chloride solution. The high-temperature-resistant desulfurization catalyst disclosed by the invention has the advantages of being small in dosage, small in waste liquid discharge, good in regeneration effect, low in corrosion rate, low in operation cost, not easy to block a tower, capable of overcoming hydrogen cyanide poisoning, high-temperature-resistant and not easy to inactivate. In a wet oxidation desulfurization system, the high-temperature-resistant desulfurization catalyst provided by the invention overcomes the defects that a PDS desulfurization catalyst, an MSQ desulfurization catalyst, a vanadium pentoxide + tannin extract catalyst and an ADA catalyst are easy to inactivate and secondary salts in a desulfurization solution are increased quickly when the desulfurization solution is at a high temperature of 70 DEG C. In addition, the high-temperature-resistant desulfurization catalyst overcomes the defects that a complex iron catalyst is high in corrosivity, large in usage amount, prone to tower blockage and the like.

The invention discloses a medium and low temperature organic sulfur hydrolytic agent applied to coal gas dry purification and a preparation method thereof, and relates to the technical field of coal gas purification and industrial catalysis, the hydrolytic agent comprises the following components: gamma-Al203, pseudo-boehmite, a pore forming agent, an active agent, an auxiliary agent, an adhesive and water. According to the medium-low temperature organic sulfur hydrolytic agent applied to dry purification of coal gas and the preparation method thereof, an alkali metal element is adopted as an active agent, and the characteristic that the alkali metal element can provide a large number of alkaline reaction sites is utilized, so that organic sulfur molecules are promoted to be preferentially adsorbed with the hydrolytic agent to generate hydrolysis reaction; meanwhile, sodium metavanadate is added as an active auxiliary agent, so that the low-temperature activity of the hydrolysis catalyst is further optimized.

The invention discloses a catalyst and method for preparing 3-methyl-2-aminobenzoic acid through continuous catalytic hydrogenation, and the method comprises the following steps: pretreating an activated carbon carrier by using pretreatment reagents such as nitric acid and hydrogen peroxide to remove impurities in the carrier; modifying the carrier by using an auxiliary component 1 such as sodium carbonate, stannic chloride, potassium carbonate and lanthanum nitrate, and then roasting and reaming; and finally, active components such as platinum chloride and palladium chloride are mixed and impregnated with an auxiliary component 2 such as oxalic acid, polyethylene glycol-400, sodium metavanadate and polyvinylpyrrolidone, the auxiliary component 2 promotes dispersion of the active metal, and the auxiliary component 2 and the auxiliary component 1 have a synergistic effect, so that the active metal is loaded more uniformly and firmly, and the obtained catalyst has higher activity and selectivity and longer service life. The catalyst is applied to preparation of 3-methyl-2-aminobenzoic acid through catalytic hydrogenation in a fixed bed reactor, the reaction can be continuously and automatically controlled, the three wastes in the reaction process are few, the yield of a target product is high, the service life of the catalyst is long, and the catalyst is suitable for industrial production.

The present invention relates to a method for preparing aluminum-vanadium alloy by aluminothermic reduction of sodium metavanadate, which comprises the following steps: S1, using powdered sodium metavanadate as a raw material, adding aluminum powder and calcium oxide, and mixing evenly; S2, pressing the mixed material into a columnar mass; S3, placing the mass into a tubular furnace, and performing a period of high-temperature insulation in an inert gas atmosphere, so as to obtain a mixture of an aluminum-vanadium master alloy and calcium aluminate-based slag. The method of the present invention adopts aluminothermic reduction to prepare an aluminum-vanadium master alloy, and its raw material is sodium metavanadate, an intermediate in the process of treating vanadium slag. The cost of using it as a raw material is lower, and the process of treating vanadium slag is shortened, avoiding the environmental pollution problem generated in the process of preparing V2O5 by sodium metavanadate using a traditional process, and obtaining an aluminum-vanadium master alloy in one step by a more efficient aluminothermic reduction method, thereby realizing efficient short-range green utilization of resources.

The invention discloses a sodium metavanadate-based catalyst activity gradient regulation and regeneration system and method, and relates to the technical field of industrial catalyst regeneration, the sodium metavanadate-based catalyst is of a unique layered structure, the sodium metavanadate-based catalyst comprises an outer layer, a middle layer and an inner layer from the surface to the interior in sequence, and active components and doping elements of all the layers are different; the outer layer is doped with high-content sodium metavanadate and manganese oxide, reactant molecules can be quickly adsorbed and activated in the initial stage of the reaction, the manganese oxide can provide additional active sites, reduce reaction activation energy and promote quick start of the reaction, and the middle layer is doped with a proper amount of sodium metavanadate and cerium oxide, so that the reaction is more stable in the process of the reaction. The cerium oxide can adjust migration and conversion of oxygen species on the surface of the catalyst, optimize the reaction path, improve the selectivity of a target product and reduce side reactions, the inner layer is doped with the low-content sodium metavanadate and tungsten oxide, and the structural stability of the catalyst under high-temperature and long-time reaction is maintained by means of the high stability of the tungsten oxide.

The present invention provides a method for producing a molybdenum-vanadium-aluminum-chromium alloy with high uniformity. The composition of the molybdenum-vanadium-aluminum-chromium alloy is as follows: Mo 25% - 28%, V 24% - 27%, Cr 28% - 31%, with the balance being Al, O ≤ 0.05%, C ≤ 0.05%, and the segregation of the main content being < 0.6%. It relates to the field of metallurgical technology. The technological steps are as follows: (1) Prepare an ammonium molybdate-ammonium dichromate-ammonium metavanadate precursor by hydrothermal method using sodium molybdate, sodium metavanadate, sodium dichromate, and ammonium chloride; (2) Perform high-temperature treatment on the precursor to obtain a MoO3 / V2O5 / CrO3 composite material; (3) Mix the MoO3 / V2O5 / CrO3 composite material, refined aluminum powder, and calcium oxide in proportion, load them into a furnace and ignite to undergo a thermite reaction to obtain a molybdenum-vanadium-aluminum-chromium alloy ingot. Compared with the molybdenum-vanadium-aluminum-chromium alloy produced by the traditional thermite method, the uniformity of the present invention is greatly improved, and it can be used for the production of titanium alloys such as TB2, TB9, TB15, and TB16.

The invention belongs to the field of polymer catalysis, and discloses a DMF (Dimethyl Formamide)-based heteropolyacid synergistic catalysis system as well as a preparation method and application thereof. The method comprises the following steps: adding sodium molybdate and disodium hydrogen phosphate into deionized water, adjusting the pH value to 2-3, then adding sodium metavanadate, heating and stirring at 95-100 DEG C, cooling at room temperature, and then adding diethyl ether and a sulfuric acid solution until an upper diethyl ether phase becomes light yellow from colorless; and drying the lowermost layer phase yellow oily substance, grinding and drying to obtain H5PMo10V2O40, and adding the H5PMo10V2O40 into a DMF (Dimethyl Formamide) solvent to prepare the DMF-based heteropolyacid synergistic catalysis system. According to the method, DMF is used as a solvent, the D-fructose is catalytically cracked in oxygen through a one-step method to be converted into DFF, gas does not need to be switched in the reaction process, and the prepared catalytic system is excellent in catalytic benefit, can be recycled, saves manpower and material resources in the catalytic process, is low in equipment requirement and can be suitable for reactions such as catalytic cracking of biomass.

The invention provides a sodium metavanadate purification process, and belongs to the technical field of high-purity vanadium processing. Comprising the following steps: A, coating a lower filter belt with sodium metavanadate-containing pug subjected to draining treatment through a feeding mechanism; b, after the sludge is dewatered by the first filter pressing station, part of cleaning liquid generated by cleaning an upper filter belt and a lower filter belt is used for humidifying the sludge which is dewatered for the first time at a primary water adding station; c, dewatering is completed at a second filter pressing station, and part of cleaning liquid generated by cleaning the upper filter belt and the lower filter belt is used for conducting water adding treatment on the pug subjected to secondary dewatering at a secondary water adding station; d, carrying out filter pressing dehydration for the last time; e, removing the filter residues which are finally dehydrated and adhered to the upper surface of the upper filter belt and the lower surface of the lower filter belt at a discharging station; and F, the remaining cleaning liquid is filtered through an upper filter belt in front of the feeding station, and ammonium chloride is added for vanadium precipitation treatment. The method has the advantages of simple process, high yield and the like.

The invention discloses a nickel-vanadium-iron-based self-supporting electrode and a preparation method and application thereof. According to the preparation method, sodium metavanadate and nickel chloride are respectively used as a vanadium source and a nickel source, a sphere-like precursor composed of a sheet structure is synthesized on a foamed nickel substrate through a hydrothermal reaction, anhydrous sodium hypophosphite and ferric nitrate are used as a phosphorus source and an iron source, and the NiO-VO-FeP-coated NF self-supporting electrode is finally formed through phosphating treatment and soaking treatment. According to the electrode obtained by the invention, an adhesive does not need to be added, the preparation process is simplified, the production cost is reduced, the catalytic material is tightly combined with the substrate, the catalyst is prevented from falling off, and the seamless contact provides conditions for rapid transfer of charges, so that the activity of the catalyst is obviously improved. The electrode obtained by the invention has excellent oxygen evolution reaction activity and stability, the oxygen evolution reaction activity of the electrode exceeds that of a commercial RuO2 electrode under high current density, and the electrode shows a good industrial application prospect.

A method for preparing vanadium pentoxide by using ammonium metavanadate, comprising the following steps: (1) preparation of an oxidant loaded with ozone and chloromethyl polystyrene resin of graphene oxide; (2) heating and dissolving crude ammonium metavanadate in water, adjusting the pH value to 8-9 by using a sodium hydroxide solution after dissolving, filtering to obtain a sodium metavanadate solution; (3) heating the sodium metavanadate solution to 60-80 DEG C, adding the oxidant loaded with ozone and chloromethyl polystyrene resin of graphene oxide, stirring for more than 20 minutes, filtering to obtain a filtrate; (4) adding ammonium metavanadate crystals to the obtained filtrate for recrystallization, obtaining ammonium metavanadate precipitate, and performing solid-liquid separation and drying to obtain ammonium metavanadate crystals; (5) calcining the ammonium metavanadate crystals to obtain vanadium pentoxide. The purity of the obtained vanadium pentoxide is greater than or equal to 99.99%, and the sum of the content of tetravalent vanadium and trivalent vanadium is less than or equal to 0.003%.

The invention discloses a catalyst for preparing N-(1-ethyl propyl)-3, 4-dimethylaniline through continuous catalytic hydrogenation and a preparation method and application thereof, the catalyst comprises a carrier, and an active component platinum and an auxiliary component which are loaded on the carrier, the auxiliary component is at least one of sodium citrate, disodium ethylene diamine tetraacetate, sodium metavanadate, oxalic acid, zirconium oxychloride, yttrium nitrate or sodium carbonate; and the active component and the auxiliary component both account for 0.1-10% of the mass of the catalyst. The catalyst is used for preparing N-(1-ethyl propyl)-3, 4-dimethylaniline through hydrogenation, the reaction can be continuous, the safety performance is better, and the catalyst has high catalytic activity and stability.

The invention provides a vanadium-doped Co9S8 nanosheet array as well as a preparation method and application thereof. The invention provides a vanadium-doped Co9S8 nanosheet array preparation method, which comprises: dissolving a cobalt salt and 2-methylimidazole in deionized water, adding foamed nickel, and carrying out a reaction at a room temperature to obtain a Co-ZIF nanosheet array precursor; then adding the VCo-ZIF nanosheets into a sodium metavanadate solution, and carrying out hydrothermal reaction to obtain a VCo-ZIF nanosheet array; and finally, adding the VCo-ZIF into a sulfur source solution, and vulcanizing to obtain the vanadium-doped Co9S8 nanosheet array. The formed porous nanosheet structure can provide a larger active specific surface area, the synergistic effect between Co and V ions can improve the charge storage capacity of the material, and sulfur vacancies on the surface of the electrode material can increase the conductivity and the number of active sites. Practice shows that when the material is used as a supercapacitor electrode material, the specific capacity and the rate capability are remarkably improved.

The application discloses an aluminum alloy micro-arc oxidation plating solution and a preparation method and application thereof. The aluminum alloy micro-arc oxidation plating solution comprises water, potassium hydroxide and the following preparation raw materials: sodium hexametaphosphate 8-15 g / L; sodium silicate 10-18 g / L; sodium metavanadate 10-15 g / L; sodium molybdate 10-18 g / L; ethylene glycol 1-5 g / L; beta-glycerophosphoric acid sodium 2-5 g / L; sodium hexafluorotitanate 3-6 g / L; boric acid 1-3 g / L; and alkaline aluminum oxide sol, wherein the content of the aluminum oxide is 0.1-0.3 g / L; and the pH of the micro-arc oxidation plating solution is 9-12. The plating solution is suitable for surface treatment of aluminum alloy, can significantly improve the hardness, wear resistance and corrosion resistance of the material, and makes the surface more smooth and flat. The application further provides the preparation method and application of the aluminum alloy micro-arc oxidation plating solution.

The invention belongs to the technical field of metal material micro analysis / welding processes, and particularly relates to an in-situ imaging method for the three-dimensional morphology of small-size inclusions of weld metal. According to the method, a weld metal sample is sequentially subjected to annealing, grinding and polishing, electrolysis and scanning electron microscope sample preparation, and an observable sample is obtained; wherein an organic electrolyte used for electrolysis is prepared from the following components in percentage by mass: 0.9 percent to 1.1 percent of tetramethylammonium chloride, 0.3 percent to 0.8 percent of triethanolamine, 8 percent to 12 percent of acetylacetone, 4 percent to 6 percent of glycerol, 0.4 percent to 0.8 percent of diphenylguanidine, 0.2 percent to 0.4 percent of triphenylphosphine oxide, 0.08 percent to 0.15 percent of sodium metavanadate and the balance of absolute methanol. According to the method, the three-dimensional morphology of the inclusions in the weld metal can be developed in situ.

The invention discloses a method for preparing high-purity vanadium pentoxide from acidic calcified vanadium liquid, which comprises the following steps: adding ammonia water into the acidic calcified vanadium liquid to adjust the pH value, adjusting the pH value to 6-8, reacting, settling to obtain vanadium-containing precipitate, washing the vanadium-containing precipitate once, re-dissolving to remove impurities, and removing impurities and calcium through calcium salt to obtain purified vanadium liquid. And finally, cooling and precipitating to obtain sodium metavanadate, and calcining the sodium metavanadate to prepare a high-purity vanadium pentoxide product. According to the method, the acidic calcified vanadium liquid serves as the raw material, vanadium and impurities Mn, Ca, Si, P, K and Na are fully separated through two-stage precipitation-dissolution and efficient chemical impurity removal, the high-purity vanadium pentoxide product with the purity reaching 99.9% or above is prepared, the process is simple, the cost is low, and development of the vanadium slag calcification vanadium extraction process is greatly promoted.

The scheme provides a cleavage method of low molecular weight aldehyde carboxyl rubber, which comprises the following steps: dissolving rubber in an organic solvent to obtain a rubber solution; heating the rubber solution, adding sodium metavanadate solution and mixing uniformly to obtain a mixed solution; adding hydrogen peroxide drop by drop into the mixed solution until the cleavage reaction is completed to obtain a reaction solution, wherein the molar ratio of the total amount of hydrogen peroxide to the carbon-carbon double bond in the rubber is (1.2-2.5):1; and treating the reaction solution to obtain low molecular weight aldehyde carboxyl rubber. The method can reduce the cost, improve the environmental protection, significantly improve the functional group content and reaction efficiency of the product, and provide a better choice for the large-scale production and application of low molecular weight aldehyde carboxyl rubber.

An organic-inorganic composite functional pigment preparation method, comprising the following steps: step 1, dissolving 10 parts of raw material A in 300 parts of water according to a mass ratio, and adding 2 parts of raw material B and 0.2 parts of polyethylene glycol; step 2, adding 5 parts of butyl titanate and 1 part of an organic acid, and heating at 75°C for reaction for 2 hours; step 3, adding 4 parts of ethylene glycol and 0.2 parts of hydrochloric acid, and carrying out stirring for 1 hour; step 4, carrying out aging under a sealed condition at 50°C for 24 hours, carrying out water washing and centrifugal separation, and carrying out oxygen-free calcination for 4 hours to obtain a pre-product; step 5, dispersing 10 parts of the product into 400 parts of N,N'-dimethylacetamide, adding 0.2 parts of 4-dimethylaminopyridine, adding 5 parts of a styrene-maleic anhydride copolymer, and heating at 45°C for reaction for 12 hours; and step 6, after washing with ethanol, separation, and drying, mixing a dispersing agent, a pigment, a coupling agent, and a solvent, and grinding a mixture to form a composite functional pigment. In step 1, A is a mixture formed by sodium tungstate and sodium metavanadate at a mass ratio of 2:8, and the raw material B is two or three selected from aluminum nitrate, zinc nitrate, cobalt nitrate, barium nitrate, manganese nitrate, and indium nitrate. The preparation method is simple and convenient, has low energy consumption and wide applicability, and has good economic efficiency and high efficiency in batch production.

The invention provides an efficient sodium metavanadate purification system, and belongs to the technical field of high-purity vanadium processing. A plurality of compression rollers and guide rollers for tensioning and pulling the upper filter belts are rotationally connected to the rack; the upper filter belts and the lower filter belts are pulled on the rack to form a feeding station, a first filter pressing station, a first water adding station, a second filter pressing station, a second water adding station, a third filter pressing station, a discharging station and a cleaning station which are arranged in sequence; the upper surface of the lower filter belt is coated with a cement-containing material through a feeding mechanism at the feeding station, and the upper filter belt and the lower filter belt are in an overlapped state at the first filter pressing station, the second filter pressing station and the third filter pressing station; the upper filter belt and the lower filter belt are in a separated state at the first water adding station and the second water adding station; the device further comprises a filtrate collecting tank and a cleaning liquid collecting tank, the cleaning station performs backwashing through water curtains arranged on the upper filter belt and the lower filter belt, and the cleaning liquid collecting tank collects cleaning liquid after the upper filter belt and the lower filter belt are cleaned. The method has the advantages of high efficiency and the like.

The invention belongs to the field of vanadium chemical industry, and particularly discloses a method for preparing anhydrous sodium metavanadate by using sodium vanadium solution. The method comprises the following steps: S1, removing silicon, chromium and aluminum from the sodium modified vanadium liquid to obtain an impurity-removed liquid; s2, concentrating the impurity-removed solution to obtain a concentrated solution; s3, putting the concentrated solution into crystallization equipment, and carrying out standing crystallization at the temperature of 10-30 DEG C to obtain anhydrous sodium metavanadate crystals and post-crystallization liquid; and S4, washing and drying the anhydrous sodium metavanadate crystal to obtain the anhydrous sodium metavanadate. According to the method disclosed by the invention, the anhydrous sodium metavanadate is prepared by taking the sodium vanadium solution as a raw material through impurity removal, concentration, crystallization, washing and drying. According to the method, the anhydrous sodium metavanadate can be prepared at low cost, the purity of the prepared anhydrous sodium metavanadate product is high, the technological process is simple, operation is easy, and the requirement for equipment is low.

This invention relates to the field of galvanized steel technology, and proposes a scratch-resistant galvanized steel strip and its preparation method. The scratch-resistant galvanized steel strip comprises, from bottom to top, a steel strip, a hot-dip galvanized layer, and a passivation layer. During the preparation of the passivation layer, each 1L of passivation solution includes the following components: 5-10g sodium molybdate, 1-2g sodium nitrate, 0.1-0.3g sodium metavanadate, 0.5-0.8g titanylfluoride, and 0.2-0.5g bis(1,6-hexanetriamine)pentamethylenephosphonic acid. This technical solution solves the problems of poor scratch resistance and low surface hardness of existing galvanized steel strips.

This application discloses a method for producing acetonitrile by reacting acetate with ammonia, comprising the following steps: in a reactor, acetate, ammonia, and a catalyst are contacted and reacted to obtain acetonitrile; the acetate is selected from at least one of methyl acetate, ethyl acetate, propyl acetate, butyl acetate, and cyclohexyl acetate; the catalyst is composed of a support and vanadate and alkali metal oxide of active components supported on the surface of the support; the vanadate is selected from at least one of bismuth vanadate, silver metavanadate, ammonium metavanadate, lithium vanadate, lithium metavanadate, sodium vanadate, sodium metavanadate, potassium vanadate, and potassium metavanadate; the alkali metal oxide is selected from at least one of lithium oxide, sodium oxide, and potassium oxide; the support is selected from at least one of silicon oxide, alumina, and molecular sieve; the mass content of vanadate is 0.1–10 wt%, and the mass content of alkali metal oxide is 0.01–5 wt%.

The invention provides a cracking method of medium-low molecular weight aldehyde-terminated carboxyl rubber. The cracking method comprises the following steps: dissolving rubber by adopting an organic solvent to obtain a rubber solution; heating the glue solution, adding a sodium metavanadate solution, and uniformly mixing to obtain a mixed solution; dropwise adding hydrogen peroxide into the mixed solution until the cracking reaction is finished to obtain a reaction solution, wherein the molar ratio of the total usage amount of the hydrogen peroxide to the carbon-carbon double bond in the rubber is (1.2-2.5): 1; the method has the advantages that the cost is reduced, the environmental protection property is improved, the functional group content and the reaction efficiency of the product are obviously improved, and a better choice is provided for the large-scale production and application of the medium-low molecular weight aldehyde-terminated carboxyl rubber.

The invention discloses a method for preparing sodium metavanadate by a sodium vanadate solution, comprising the steps of: (1): sodium vanadate solution, after purification and impurity removal, obtains a sodium vanadate purification solution; (2): sodium vanadate purification solution is adjusted to pH value to 5-6 with vanadium pentoxide to obtain a mixed solution; (3): mixed solution is heated for reaction, and in the reaction process, the pH value is adjusted to 7-8.5 by adding sodium vanadate purification solution, stirred, and a reaction solution is obtained; (4): reaction solution is subjected to cooling filtration, and crystals are precipitated through static precipitation, and sodium metavanadate is obtained by drying the crystals. The preparation method of the present invention, using sodium vanadate solution as raw material to react with vanadium pentoxide, adopts sodium vanadate purification solution to adjust pH value, then passes through cooling filtration, stands and precipitates crystals, and dries to obtain sodium metavanadate, the method does not introduce inorganic acid, does not introduce alkali, is conducive to the precipitation of sodium metavanadate crystals, can obtain sodium metavanadate with relatively high purity, and the preparation technology is simple.

The invention provides large-particle-size carbon-coated sodium vanadium phosphate and a preparation method and application thereof.The preparation method of the large-particle-size carbon-coated sodium vanadium phosphate comprises the following steps that a sodium source, a vanadium source and pure water are placed in a container, and the reaction temperature is controlled to range from 70 DEG C to 100 DEG C in a water bath; after a uniform solution is formed through the reaction, the container is placed in a water bath at the temperature of 40-60 DEG C for cooling crystallization, the crystallization time is 2-6 h, and a sodium metavanadate solid is obtained; the sodium metavanadate solid is placed in a reducing atmosphere to be roasted, and NaVO2 is prepared; the preparation method comprises the following steps: mixing NaVO2, a sodium source, a phosphorus source and a carbon source, and carrying out sanding and spray drying to obtain a sodium vanadium phosphate precursor; and placing the sodium vanadium phosphate precursor in an inert atmosphere for two-stage roasting to obtain the large-particle-size carbon-coated sodium vanadium phosphate. The prepared large-particle-size carbon-coated sodium vanadium phosphate is large and controllable in size, and when the large-particle-size carbon-coated sodium vanadium phosphate is used as a sodium-ion battery positive electrode material, the energy density of unit mass can be improved, so that the electrochemical performance of a battery is improved.

The application provides a method for co-extracting vanadium and chromium from high-chromium vanadium slag and application thereof. The method comprises the following steps: roasting high-chromium vanadium slag and calcium salt to obtain roasted clinker, leaching the roasted clinker with a leaching agent to obtain a leaching solution, cooling the leaching solution to obtain sodium orthovanadate and a crystallization mother liquor; adding calcium oxide to the crystallization mother liquor to obtain a chromium-containing solution, performing first reduction on the chromium-containing solution to obtain chromium hydroxide, and performing first calcination on the chromium hydroxide to obtain chromium trioxide; mixing the sodium orthovanadate, water and carbon dioxide to obtain sodium metavanadate, sequentially performing transformation and second reduction on the sodium metavanadate, and performing second calcination to obtain a reduction clinker; mixing the reduction clinker, washing water and sodium bicarbonate mother liquor to obtain a sodium-containing solution and primary vanadium trioxide, and washing the primary vanadium trioxide to obtain vanadium trioxide. The application realizes high-value conversion of high-chromium vanadium slag, and simultaneously considers simplicity and economy, and no high ammonia nitrogen, high salt water and ammonia-containing waste gas are generated.

The application discloses a sodium-rich sodium polyvanadate material and a preparation method and a positive plate and a battery thereof. 2+x V6O 16 ·2.9H2O, wherein 0 + The preparation steps comprise the following steps: dissolving sodium metavanadate in deionized water, adding an acid solution, stirring until the pH is 2-3.5, continuously stirring in a water bath, naturally cooling, and collecting the sodium-rich sodium polyvanadate material through filtration, washing and drying. + The sodium-rich sodium polyvanadate material is prepared by using a simple precipitation method, and cation defects (Na + ) are introduced into the sodium polyvanadate, so that the excessive Na + The ion / electron conductivity of the sodium polyvanadate electrode material is enhanced, the actual capacity of the battery is improved, the cation defects can further serve as interlayer pillars to ensure the structural stability of the sodium polyvanadate material, the structure collapse of the sodium polyvanadate positive material is prevented, and the cycle service life of the battery is improved.

The application provides a vanadium slag cleaning vanadium extraction method and application thereof. The method comprises the following steps: mixing vanadium slag and sodium salt, sintering, adding roasting clinker, water, chromium removal mother liquor and impurity removal slag, leaching to obtain tailings and leaching liquor, removing impurities from the leaching liquor to obtain purified liquor, performing precipitation treatment on the purified liquor to obtain vanadium precipitation mother liquor and calcium vanadate; adding a first reducing agent to the vanadium precipitation mother liquor to obtain chromium hydroxide, calcining to obtain chromium sesquioxide; performing vanadium leaching on the calcium vanadate, carbon dioxide, crystallization mother liquor and calcination tail gas to obtain calcium salt and sodium vanadate solution, evaporating and crystallizing the sodium vanadate solution to obtain sodium metavanadate, performing high-temperature reduction on the sodium metavanadate, an auxiliary agent and a second reducing agent to obtain reduced clinker, and performing sodium removal on the reduced clinker, sodium bicarbonate mother liquor and water to obtain vanadium sesquioxide. The application successfully prepares chromium sesquioxide and vanadium sesquioxide products, and realizes high-value utilization of high-chromium vanadium slag.

The invention relates to the technical field of magnesium alloy surface treatment, in particular to a bright pickling additive for magnesium alloy containing heavy metal elements and a preparation method of the bright pickling additive. Comprising the following components: 5 g / L of potassium fluotitanate, 10 g / L of sodium metavanadate, 50-70 g / L of ammonium bifluoride, 30-50 g / L of sodium metasilicate nonahydrate, 100-200 mL / L of lactic acid and 50-70 mL / L of phytic acid, by adding the potassium fluotitanate, the potassium fluotitanate is reduced into TiO2 when making contact with a metal magnesium alloy matrix, so that the surface potential of a workpiece is balanced, the polishing effect is achieved, and by adding the ammonium bifluoride, the surface of the workpiece is not prone to being damaged. By adding sodium metasilicate nonahydrate, dirt formed on the surface of a magnesium alloy workpiece due to precipitates formed by metal ions such as Cu and Ag is reduced, and by adding sodium metasilicate nonahydrate, generation of heavy metal cation precipitates is reduced, so that dust on the working surface is reduced. The cleaning agent can be matched with low-concentration inorganic strong acid and organic acid to perform bright cleaning on magnesium alloy surfaces containing various heavy metals in different processing states under the environment operation from low temperature to medium temperature.

The invention provides a composite sodium vanadium phosphate material and a preparation method thereof, a positive pole piece and a secondary battery, and relates to the technical field of sodium ion batteries. The preparation method of the composite sodium vanadium phosphate material comprises the following steps: mixing sodium metavanadate, sodium dihydrogen phosphate, phosphorous acid and an inorganic carbon source, and carrying out dispersion treatment to obtain a dispersed material; in an inert atmosphere, the dispersed material is subjected to segmented calcination, and a composite sodium vanadium phosphate material is obtained; the step-by-step calcination sequentially comprises first calcination and second calcination, the calcination temperature of the first calcination is 120-200 DEG C, and the calcination temperature of the second calcination is 600-650 DEG C. According to the preparation method, phosphorous acid with reducibility, sodium metavanadate with oxidability, sodium dihydrogen phosphate and an inorganic carbon source are mixed by a dry method, and a segmented calcination process is adopted, so that the composite sodium vanadium phosphate material with relatively high compaction density, relatively low powder internal resistance and relatively good electrochemical performance is prepared.

The invention discloses polyoxometallate containing rare earth neodymium as well as a preparation method and application of the polyoxometallate, and relates to the technical field of water treatment. According to the invention, reagents such as germanium dioxide, sodium metavanadate, potassium chloride, neodymium nitrate and the like are used as raw materials, and polyoxometallate K15Nd (GeW10VO39) 2. NH2O containing rare earth neodymium is synthesized. The prepared polyoxometallate containing rare earth neodymium has a remarkable degradation effect on reactive red X3B, and after ultraviolet irradiation is carried out for 40 min, the degradation rate of the reactive red X3B reaches 99.94%.