56 results about "Sodium Vanadate" patented technology

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 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 present application relates to a kind of rack steel layered casting composite flux and its preparation, method for using, the component and content of composite flux are as follows: high-purity iron powder: 40%~50%, high-purity rare earth powder: 20%~30%, analytical pure sodium pyrovanadate: 20%~40%.Using layered casting process of composite flux with rack steel, the macrosegregation and shrinkage cavity defects of large rack steel ingot can be significantly improved, which provides a simple, feasible and effective way to improve the composition homogenization degree of ingot, helps to improve the overall quality of rack steel ingot, also shortens the production cycle and improves the production efficiency, thereby improves the production capacity of large rack steel ingot, reduces the production energy consumption and production cost;The present application has important significance for breaking through the bottleneck of high homogenization large rack steel ingot manufacturing, laying the new technical theoretical foundation and industrialization application of large rack steel ingot casting, and improving the manufacturing technology level of key components of large equipment in China.

The invention belongs to the technical field of energy storage batteries, and particularly relates to a method for preparing a vanadium oxide electrolyte based on a sodium vanadium oxide solution and a vanadium redox flow battery. The method comprises the following steps: S1, sodium treatment leaching: treating a vanadium-containing raw material by adopting a sodium-containing compound to generate a sodium vanadium solution; s2, valence state regulation and control: dividing the sodium vanadium solution into two parts, adjusting the pH value of the first part to be acidic, and then adding a reducing agent to carry out a reduction reaction to obtain a negative electrode electrolyte containing V < 3 + > / V < 4 + >; and adding an oxidizing agent into the second part for oxidation reaction to obtain the positive electrode electrolyte containing V < 4 + > / V < 5 + >. According to the method, the vanadium slag is used for replacing high-purity V2O5 to prepare the electrolyte, so that the cost of raw materials is reduced; according to the electrolyte prepared by the invention, the energy efficiency of the battery is high; meanwhile, the preparation method disclosed by the invention adopts an integrated process, and an intermediate product treatment link is omitted, so that the preparation steps are simpler, and the production efficiency is remarkably improved.

The application discloses a kind of high-efficiency heterogeneous catalyst for CO2 ring addition preparation cyclic carbonate and its preparation method and application, belong to catalyst technical field.The high-efficiency heterogeneous catalyst is transition metal doped polyoxometalate coordination polymer, chemical general formula is C 16 H 58 M2N2Na2O 48 V 10 Wherein, M is selected from Co 2+ , Ni 2+ , Cu 2+ Or Zn 2+ Its preparation method is: sodium vanadate, transition metal acetate and bis (2-hydroxyethyl) amino (trihydroxymethyl) methane ligand are dissolved in water with pH being 1~3, stirring reaction, after filtration, crystallization is stationary, and is obtained.In the ring addition reaction of CO2 and epoxide, the catalyst and cocatalyst tetrabutylammonium bromide synergistic effect, catalytic yield can be up to 98.2%, selectivity is more than 99%, and catalytic activity still remains at 88% after recycling five times.

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 relates to a method for green vanadium precipitation and sodium-ammonium circulation of a sodium modified vanadium solution, and belongs to the technical field of hydrometallurgy. The method comprises the following steps: adding hydrochloric acid and ammonium chloride into the sodium vanadium solution, adjusting the pH value, carrying out heating reaction, and carrying out solid-liquid separation to obtain ammonium polyvanadate and vanadium precipitation wastewater; adding a reducing agent into the vanadium precipitation wastewater for reduction reaction; adding a polycarboxylic acid water reducer, adjusting the pH value with ammonia water, and carrying out solid-liquid separation to obtain purified wastewater and vanadium-chromium filter residues; introducing carbon dioxide gas into the purified wastewater until the purified wastewater is saturated, cooling, crystallizing, and carrying out solid-liquid separation to obtain sodium bicarbonate solid and crystallization mother liquor; and evaporating and concentrating the crystallization mother liquor until the concentration of ammonium chloride is 65-75g / L, then cooling and crystallizing at the temperature of-10-20 DEG C, and carrying out solid-liquid separation to obtain ammonium chloride solid and residual wastewater. According to the invention, high-efficiency and high-purity recovery of sodium and ammonium ions and closed circulation of the system are realized, and the problems of sodium and ammonium circulation and impurity accumulation in the traditional process are solved.

The invention discloses a temperature response composite gel electrolyte for a wide-temperature-range zinc battery, a preparation method and the zinc battery, and solves the problem that the existing gel electrolyte is difficult to consider wide-temperature-range adaptability, low-temperature conduction efficiency and high-temperature safety at the same time. The electrolyte is of a temperature-sensitive hydrogel cellulose-high-conductivity ZIF-8 composite substrate membrane temperature-sensitive hydrogel three-layer structure. The substrate membrane improves the mechanical strength of each temperature range and the conductivity of zinc ions; the hydrogel is dimethyl sulfoxide modified poly (N-isopropylacrylamide), the hydrogel swells at a low temperature to prevent free water condensation so as to guarantee conduction, and shrinks at a high temperature to improve hardness so as to avoid dendritic crystal puncture and thermal runaway. The preparation method comprises the following steps: preparing a solvothermal ZIF-8, performing suction filtration to prepare a basement membrane, initiating in-situ polymerization of the hydrogel by ultraviolet and the like. The zinc battery takes the electrolyte, a sodium vanadate / ammonium vanadate positive electrode and a zinc metal / alloy negative electrode as cores, can stably work at-40 to 60 DEG C, is easy to industrially obtain raw materials and simple in process, and is adaptive to harsh energy storage scenes such as field military equipment and the like.

According to the method for preparing the vanadium electrolyte through targeted impurity removal and one-step vanadium precipitation of the sodium-modified vanadium solution, high-purity ammonium metavanadate is prepared through targeted impurity removal of the sodium-modified vanadium solution, and calcination is conducted under the protection of inert gas of ammonium metavanadate, so that the consumption of auxiliary materials and the generation amount of waste water are greatly reduced; the manufacturing process cost of the vanadium electrolyte is effectively reduced; by adopting a two-time silicon removal mode, the use amount of a silicon removal agent is reduced while high-efficiency removal of chromium is realized, and the generation amount of silicon removal slag and the vanadium loss in the silicon removal process are reduced. In addition, the pH value of the liquid subjected to deep silicon removal is lower than that of the liquid subjected to chromium removal, so that the aluminum concentration of the liquid subjected to deep silicon removal can be effectively reduced, and conditions are created for improving the subsequent hydrolysis aluminum removal effect; the crude ammonium metavanadate is pulped and washed by adding a complexing agent, the content of cations such as potassium, sodium and calcium is reduced, the ammonium metavanadate is calcined under the protection of inert gas to obtain low-valence vanadium oxide, the acid solubility of the vanadium oxide is improved, and the consumption of a reducing agent in the preparation process of the vanadium electrolyte is reduced.

This invention belongs to the field of battery electrode material technology, and discloses a calcium-doped sodium vanadate electrode material, its preparation method, and its application in aqueous ammonium-ion batteries. The preparation method includes the following steps: vanadium pentoxide is dispersed in water, hydrogen peroxide is added and stirred, and calcium nitrate and sodium hydroxide are added. The resulting mixed solution is transferred to a reaction vessel for hydrothermal reaction. After cooling to room temperature, the sample is washed, freeze-dried, and collected. When the calcium-doped sodium vanadate cathode material is applied to an aqueous ammonium-ion battery, electrochemical test results show that when paired with a 3,4,9,10-perylenetetracarboxylate diimide anode, it exhibits high reversible specific capacity and excellent rate performance, demonstrating its outstanding comprehensive electrochemical performance and great potential in practical energy storage applications. This invention features a simple synthesis route, is environmentally friendly, has low raw material costs, and the overall process has industrial application potential, making it suitable for promotion and application as a novel energy storage device.

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.

This invention discloses a method for the mass production of sodium polyvanadate nanowires. The method includes: adding a sodium vanadium extraction leachate to an inorganic acid to hydrolyze and precipitate vanadium, obtaining a hydrated sodium polyvanadate nanowire dispersion; obtaining hydrated sodium polyvanadate nanowires by vacuum filtration or pressure filtration of the hydrated sodium polyvanadate nanowire dispersion; and drying and high-temperature annealing the hydrated sodium polyvanadate nanowires to obtain sodium vanadium oxide nanowires. This nanofiberization process is rapid, simple, and operates under mild conditions. It allows for scalable containers, uses inexpensive and environmentally friendly dispersant (industrial water), and is suitable for large-scale production under conditions such as mechanical stirring and normal pressure. This technology breaks through the conventional thinking of ordinary technicians, overcomes the technical prejudices of traditional nanomaterial preparation, especially sodium polyvanadate nanowires, overcomes the shortcomings of existing hydrothermal synthesis or preparation techniques, solves long-standing technical problems, and achieves unexpected results.

The utility model discloses a device for preparing ammonium polyvanadate by continuously crystallizing a sodium vanadate solution. The device comprises a premixing tank, a liquid storage tank, a reaction kettle and a filter press, the premixing tank is provided with a sodium vanadate solution inlet, an ammonium sulfate inlet and a sulfuric acid inlet, an outlet of the premixing tank is communicated with an inlet of the liquid storage tank, an outlet of the liquid storage tank is communicated with an inlet of the reaction kettle, and an outlet of the reaction kettle is communicated with an inlet of the filter press; the reaction kettle is provided with a heating structure and a sulfuric acid inlet. According to the device, the pre-mixing tank is independently arranged, the process in the pre-mixing tank is controlled in the use process, so that no crystal precipitate is generated in the pre-mixed vanadium liquid, and the crystallization process is performed in the reaction kettle through the transition of the liquid storage tank, so that the stability of the ammonium polyvanadate crystallization process can be improved, and the particle size of the ammonium polyvanadate can be increased to reduce the cleaning difficulty; the stability and purity of the ammonium polyvanadate in the crystallization process are improved, and meanwhile the particle size of the ammonium polyvanadate is increased.

This invention belongs to the field of battery cathode material technology, specifically relating to an Al 3+ Sodium vanadate-coated nanocomposites, their preparation methods, and applications. The Al... 3+ Sodium vanadate-coated nanocomposite material, made of Al 3+ The sodium vanadate is coated to obtain the product. The vanadium in the sodium vanadate is pentavalent. Under bridging and coordination, the pentavalent vanadium self-assembles to form a polynuclear vanadium-oxygen cluster anion [V6O]. 16 ] 2‑ Al 3+ [V6O] on the surface of sodium vanadate 16 ] 2‑ The formation of surface complexes of the type =Al-O-V≡ coats sodium vanadate, forming Al 3+ Vanadic acid-coated nanocomposite materials. The Al of this invention... 3+ @NVO has a stable structure, and the batteries made from it have high discharge capacity and high rate performance.

The invention relates to the field of bone repair, and discloses a 3D printing bone-imitating biological scaffold and a preparation method thereof.The preparation method comprises the steps that firstly, ammonium bromide is added into a mixture of deionized water and absolute ethyl alcohol, and an ammonium bromide solution is obtained; sequentially adding an ammonia solution, tetraethoxysilane, triethyl phosphate, calcium nitrate and sodium vanadate, continuously stirring, centrifuging, and collecting a precipitate; washing, aging, heating, cooling, grinding, crushing, and screening to obtain V-MBG powder; preparing a TA solution and a V-MBG solution, mixing and putting the TA solution and the V-MBG solution, and freeze-drying to obtain TA-coated V-MBG powder; preparing a trichloromethane solution of PLGA (poly (lactic-co-glycolic acid)), adding the V-MBG powder, fully stirring, and pumping out the trichloromethane solution to obtain solid slurry; printing an inner-layer stent and a hollow-tube outer-layer stent to obtain a bone-imitating biological stent, and soaking the bone-imitating biological stent in a TA solution to obtain a PLGA / TA-V-MBG composite stent; the problems that in the prior art, the bone repairing effect is poor, the bone-like cell proliferation and differentiation effect is poor, and bone defect repairing caused by bone tumor treatment cannot be achieved are solved.

The application relates to the technical fields of biological medicine, nanomaterials and food safety, and particularly relates to a preparation method of a Ce6-mediated photodynamic sterilization film and application of the Ce6-mediated photodynamic sterilization film to fresh food preservation. The Ce6-mediated photodynamic sterilization film is prepared by the following method: yttrium nitrate, europium nitrate and bismuth nitrate are dissolved in deionized water, and then mixed with sodium vanadate; the mixed solution is subjected to hydrothermal reaction in a polytetrafluoroethylene reaction kettle; the product after the hydrothermal reaction is mixed with Ce6 and centrifuged to obtain Ce6-mediated nanomaterials; the nanomaterials have photosensitizer activity and can be used for inhibiting bacteria and fungi; the nanomaterials are dissolved in CMC, stirred and dried on a glass plate to obtain the Ce6-mediated photodynamic sterilization film. The Ce6-mediated photodynamic sterilization film generates active oxygen under ultraviolet light and has UV blocking function, can be used for photodynamic antibacterial and fresh food preservation, and realizes the double effects of UV sterilization and food loss prevention.

The application discloses a method for preparing vanadium oxide from high-concentration vanadium sodium solution, which comprises the following steps: S1, directly hydrolyzing and precipitating vanadium from high-concentration vanadium solution with a vanadium concentration of 40-140 g / L to obtain filter cake after filtration; S2, beating the filter cake with low-sodium ammonium-containing solution with a sodium concentration of less than or equal to 25 g / L, and then performing crystallization by adding acid to the obtained slurry to adjust the pH to 2.0-2.5 and by heating to 80-90 DEG C, and then obtaining ammonium polyvanadate after filtration; and S3, calcining or reducing the ammonium polyvanadate to obtain vanadium oxide. The application can reduce vanadium precipitation wastewater, improve the quality of ammonium polyvanadate, and also can reduce the use amount of ammonium salt.

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.

The invention belongs to the field of metallurgy, and discloses a clean vanadium extraction method for sodium salt roasting of vanadium slag. The method comprises the following steps: crushing and screening the vanadium slag to obtain fine powder vanadium slag; sodium salt is added into the fine powder vanadium slag for mixing, then oxidizing roasting is conducted, and roasted clinker is obtained; the roasted clinker is leached to extract vanadium, and vanadium-containing leachate and leached tailings are obtained; sodium metaaluminate is used for desiliconizing the vanadium-containing leaching solution, a sulfur-free chromium removal agent is added for chromium removal, and an impurity removal solution is obtained; concentrating the impurity-removed solution to obtain a concentrated solution and condensed water; after oxidizing the concentrated solution, cooling and crystallizing to obtain hydrated sodium vanadate and crystallized supernatant; after the hydrated sodium vanadate is heated and redissolved, ammonium salt is added for vanadium precipitation, and ammonium metavanadate and redissolved vanadium precipitation supernatant are obtained; performing deamination and oxidation calcination on ammonium metavanadate to obtain vanadium pentoxide, and performing sodium precipitation on the re-dissolving vanadium precipitation supernatant to obtain sodium bicarbonate and a sodium precipitation supernatant. The method provided by the invention realizes clean and efficient vanadium extraction by sodium salt roasting of the vanadium slag.

The invention relates to the technical field of blood miRNA preservation, and particularly discloses a disposable blood miRNA preservation tube and a preservation solution thereof, the preservation solution is composed of the following components: 30 mg / ml of glycine, 3 mg / ml of glutamine, 3 mg / ml of glucose, 600 mg / ml of sodium orthovanadate, 3 mg / ml of aluminum fluoride, 25 mg / ml of acetylcysteine, 300 mg / ml of diazoalkyl urea, 2.0 mg / ml of EDTA-2Na, 6 mg / ml of sorbitol, 6 mg / ml of trehalose, and the balance of water. The preservation tube is good in sealing performance and convenient to use, the preservation liquid can effectively slow down rupture of blood cells, DNA in the blood cells is prevented from diluting and polluting target miRNA, nuclease is prevented from degrading the target miRNA, and the preservation period of a blood sample containing target nucleic acid is prolonged.

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 a method for preparing a vanadium electrolyte through a sodium polyvanadate extraction method, and belongs to the technical field of vanadium electrolyte preparation, and the method comprises the steps that S1, sodium polyvanadate is dissolved in alkali liquor to remove impurity metal ions and insoluble substances, and a vanadium-containing alkaline solution is obtained; s2, a reducing agent is added into the vanadium-containing alkaline solution, the pH of the solution is adjusted to be strongly acidic, pentavalent vanadium is reduced into tetravalent vanadium, then alkali is added, the pH is adjusted to be within the optimal extraction pH range, and a tetravalent vanadium reducing solution is obtained; s3, extracting the tetravalent vanadium reduction solution by using an organic phase to obtain a loaded organic phase; s4, washing the loaded organic phase with a dilute sulfuric acid solution; s5, after washing is finished, reverse extraction is carried out with a sulfuric acid solution, and an organic phase-containing electrolyte is obtained; and S6, removing the organic phase in the electrolyte containing the organic phase through adsorption treatment to obtain the vanadium electrolyte. The method has the characteristics of short process, high efficiency and low-cost preparation potential of the vanadium electrolyte, can realize short-process preparation of the vanadium battery electrolyte, and greatly reduces the preparation cost of the electrolyte.

A method for forming a coating layer on a substrate includes the steps of: providing a substrate which is made of a magnesium alloy; preparing a permanganate conversion solution that contains a permanganate salt, sodium vanadate, and a buffering agent; impregnating the substrate and an inert conductive material into the permanganate conversion solution, followed by electrically connecting the substrate to a positive electrode of a power supply to serve as an anode, and electrically connecting the inert conductive material to a negative electrode of the power supply to serve as a cathode; applying a voltage ranging from 2 V to 15 V to the substrate in the permanganate conversion solution using the power supply, so as to form a coating layer on the substrate, thereby obtaining a coated substrate; and removing the coated substrate from the permanganate conversion solution. A coating layer formed by the aforesaid method is also provided.

The invention belongs to the technical field of vanadium compounds, and particularly relates to a sodium vanadate single crystal, a sodium vanadate composite metal single crystal, vanadium pentoxide and a preparation method and application of the sodium vanadate single crystal and the sodium vanadate composite metal single crystal. Vanadium in a system is adjusted to exist in a pentavalent form mainly by adjusting the pH value of the vanadium-sodium leaching solution and the pH value of a mixed system of the vanadium-sodium leaching solution and potassium salt, magnesium salt or cobalt salt, and high-purity large-size single crystals are directly obtained from the leaching solution at the specific crystallization temperature. According to the method, high-purity and large-size single crystals are used as raw materials, the high-purity vanadium pentoxide is obtained through calcination after ammonium salt vanadium precipitation, and the requirements of aviation, aerospace and other special industries for high-purity vanadium products can be met. The preparation method provided by the invention has the advantages that the process is simple, the cost is low, and a high-purity vanadium product can be directly extracted from the vanadium leachate. According to the method, the existence form and solubility of vanadium (V) are controlled by adjusting the pH value and temperature of a solution system, so that efficient crystallization and purification of vanadium compounds are realized.

The invention provides an alkaline impurity removal method for a sodium vanadate solution, which comprises the following steps: adding a calcium remover into the sodium vanadate solution to obtain sodium vanadate mixed slurry after calcium precipitation; adjusting the alkalinity of the sodium vanadate mixed slurry after calcium precipitation to obtain the sodium vanadate mixed slurry after alkalinity adjustment; adding a reducing agent into the alkalinity-adjusted sodium vanadate mixed slurry to reduce high-valence chromium so as to obtain reduction reaction slurry containing chromium precipitates; adding a filter aid into the reduction reaction slurry, stirring, filtering and separating to obtain a mixed chromium-calcium slag filter cake and a chromium-calcium-removed sodium vanadate solution; and adjusting the pH value of the sodium vanadate solution after chromium and calcium removal, stirring, filtering and separating to obtain a mixed silicon slag filter cake and a sodium vanadate purified solution. According to the method, impurities such as chromium, silicon and calcium are removed before vanadium precipitation of the sodium vanadate solution, a foundation is laid for preparation of high-purity vanadium oxide, the treatment difficulty and cost of the acid vanadium precipitation wastewater are reduced, and the purpose of low-cost, rapid and thorough impurity separation is achieved.

The application relates to a preparation method of a novel NiV2S4 and magnesium hydride composite hydrogen storage material and application thereof, the material takes magnesium hydride and NiV2S4 as main components, and belongs to the technical field of magnesium-based hydrogen storage materials. The hydrogen storage material is prepared by mixing magnesium hydride and NiV2S4 through a ball milling process. The preparation method comprises the following steps: firstly, uniformly dispersing nickel chloride hexahydrate, sodium orthovanadate and thiourea into water; then, transferring into a Teflon container and keeping at 150 DEG C-180 DEG C for 12-24 h, washing and drying to obtain NiV2S4. Finally, ball milling the NiV2S4 and magnesium hydride to obtain the magnesium hydride composite hydrogen storage material based on NiV2S4. The composite hydrogen storage material has excellent performance, compared with the ball-milled magnesium hydride, the initial hydrogen release temperature is reduced by 138 DEG C, the hydrogen release amount reaches 6.21 wt% at 350 DEG C in 5 min, the hydrogen absorption amount reaches 4.8 wt% at 150 DEG C in 20 min, and the capacity is greater than 90% after 60 cycles at 300 DEG C.