416results about "Vanadium compounds" patented technology

The invention relates to a crystallization method of ammonium metavanadate crystals. The crystallization method comprises the following steps: cooling an ammonium metavanadate concentrated solution to obtain an ammonium metavanadate supersaturated solution; the cooling treatment process comprises the step of adding a crystallization regulating agent into the ammonium metavanadate concentrated solution; sequentially carrying out aging treatment and solid-liquid separation on the ammonium metavanadate supersaturated solution to obtain an ammonium metavanadate solid phase; by adding a crystallization regulating agent in the cooling treatment process, regulating the growth rate and growth direction of ammonium metavanadate crystals, matching with the steps of aging treatment and the like, the crystallization rate of the crystallization method is improved, preferably, the crystallization rate is up to 89.5% or above, and the high-purity ammonium metavanadate product with large grain size and regular morphology is obtained. Wherein the median particle size preferably reaches up to 86.5 microns or above, the purity reaches up to 99.97% or above, and the requirement for high-quality vanadium products at present is met.

The invention provides a method for preparing VOSO4 electrolyte through gas enhanced reduction and reverse extraction, which comprises the following steps: adding an extraction inhibitor into an acidic vanadium-containing solution, stirring and reacting to obtain a vanadium-containing solution, the extraction inhibitor being phosphoric acid and / or a phosphoric acid compound; adjusting the pH value of the solution to 0.5-3.0 by using sulfuric acid, mixing with an organic phase, extracting, and separating liquid to obtain a vanadium-loaded organic phase; washing the vanadium-loaded organic phase with dilute sulfuric acid; a stripping agent and the vanadium-loaded organic phase are mixed for stripping, meanwhile, gas is introduced for strengthening the stripping process, and a no-load organic phase and a vanadium electrolyte are obtained; and the vanadium strip liquor is subjected to galvanic pile electrolysis adjustment, and the vanadium electrolyte with the valence state meeting the standard is obtained. The invention provides a novel process for directly preparing the vanadyl sulfate electrolyte through gas reinforced reduction, and the novel process has the advantages of being simple in process, easy to operate, low in cost and environmentally friendly.

The invention relates to the technical field of hydrogen energy, and provides a vanadium oxide catalytic magnesium-based hydrogen storage material based on alkali metal enhancement and a preparation method. The material is prepared from spherical MgH2 powder and lamellar XV6O15 (at) C powder through a high-energy ball milling method, wherein X is one of alkali metals Li, Na and K. The material has a nanoscale composite structure, and the hydrogen storage performance can be remarkably improved. The preparation method comprises the following steps: 1) preparing XV6O15 (at) C nano powder through acid etching, alkali metal modification and heat treatment; and 2) mixing the powder with MgH2 in a protective atmosphere, and preparing the composite material by adopting high-energy ball milling. Results show that the catalyst improves the hydrogen absorption and desorption rate of MgH2, the hydrogen storage temperature is reduced to 50 DEG C for hydrogen absorption, and the hydrogen is rapidly desorbed at 200-225 DEG C. The hydrogen storage dynamics and temperature performance are remarkably optimized, an effective strategy is provided for design and application of a novel magnesium-based composite hydrogen storage material, and the method is suitable for hydrogen energy industrial application.

The present invention belongs to the technical field of battery materials, and specifically discloses a honeycomb vanadium tetrasulfide material and its preparation method and application. The preparation method of the honeycomb vanadium tetrasulfide material provided by the present invention comprises at least the following steps: adding a soluble sulfur source and a vanadium source to an organic solvent, stirring and dissolving, obtaining a mixed solution, placing the mixed solution in a hydrothermal reactor, reacting at 160°C-200°C, and obtaining a vanadium tetrasulfide solid product; under an inert atmosphere, calcining the vanadium tetrasulfide solid product at 250°C-350°C, grinding, and obtaining the honeycomb vanadium tetrasulfide material. The vanadium tetrasulfide counter electrode prepared by the present invention has a honeycomb 3D structure, improves the contact between the counter electrode and the perovskite back interface, and improves the extraction / transmission capacity of carriers at the perovskite layer and the back interface of the counter electrode layer, thereby improving the conversion efficiency of the perovskite solar cell.

The invention relates to the technical field of preparation of an electrolyte for a vanadium redox flow battery, in particular to a reduction method of an alkaline vanadium-containing solution during short-process preparation of a vanadium electrolyte. The reduction method comprises the following steps: (1) adding a reducing agent sodium sulfite into an alkaline vanadium-containing solution and dissolving; and (2) acid is added into the solution obtained after dissolving in the step (1), the pH is adjusted, a reduction reaction is conducted, and vanadium is reduced to be tetravalent. The method provided by the invention effectively solves the problem of vanadium loss caused by precipitation generated in the sequential operation process of acidification and reduction of the alkaline vanadium-containing solution in the prior art, and meanwhile, the method provided by the invention is easy for engineering implementation.

The invention discloses a fast-charging low-temperature graphite composite material, a preparation method and application thereof, the composite material is of a core-shell structure, the core is porous graphite and a carbon nanotube doped with the porous graphite, and the shell is composed of a lithium supplement agent and a lithium sulfonate complex of the lithium supplement agent. The preparation method comprises the following steps: soaking porous graphite in a conductive polymer solution, adding a catalyst, a cross-linking agent and an oxidizing agent, carrying out oxidative polymerization and carbonization to obtain catalyst-doped porous graphite, and introducing carbon source gas through a vapor deposition method to obtain carbon nanotube-doped porous graphite; and adding the obtained material into a lithium sulfonate solution, adding a lithium supplement agent, uniformly mixing, and carrying out spray drying to obtain the graphite composite material. According to the obtained material, the electronic conductivity of the material is improved by using the carbon nanotubes grown on the inner core, and the lithium sulfonate coated on the outer shell has relatively strong solvation capability, so that the transmission rate of lithium ions is improved, and the rate capability is improved; meanwhile, the lithium supplement agent releases lithium ions in the charging and discharging process, the first efficiency is improved, and the low-temperature and fast-charging performance is improved.

The invention discloses a method for yeast-assisted synthesis of porous carbon / vanadium sulfide nano-enzyme and application of the porous carbon / vanadium sulfide nano-enzyme in serum creatinine detection, and belongs to the technical field of serum creatinine detection. Comprising the following steps: (1) mixing saccharomycetes, vanadium chloride and ethanol, performing ultrasonic dispersion, and stirring until liquid is completely volatilized to obtain a first solid A; (2) mixing and grinding the first solid substance A, potassium carbonate and potassium chloride to obtain a second solid substance B; (3) respectively placing the second solid substance B and thioacetamide in grooves at the left end and the right end of a Joule thermal device graphite sample table, and carrying out rapid Joule thermal shock to obtain a third solid substance C; and (4) washing and drying the third solid C to obtain the porous carbon / vanadium sulfide nano-enzyme. A colorimetric sensing method is constructed based on the nano-enzyme prepared by the invention, is used for creatinine detection, and has extremely low detection limit, LOD is as low as 0.07 M / mL, and high specificity and sensitivity are embodied.

The invention discloses a method for removing chromium in ammonium polyvanadate through reduction precipitation, according to the method, the effect of efficient chromium removal can be achieved only through simple dissolution and chemical precipitation methods, the chromium content of a product is smaller than 300 ppm, and the requirement for the content of impurity elements is avoided; the method is high in chromium removal efficiency, low in energy loss, high in vanadium recovery rate, clean, environmentally friendly and suitable for industrial production; and the prepared high-purity ammonium metavanadate is relatively high in purity and low in impurity element content, and can meet the requirements on the purity of vanadium products in the aspects of electrolyte and aeronautical manufacturing.

The invention discloses a silver vanadate photocatalytic material, a preparation method thereof and an illuminating lamp. The preparation method comprises the following steps: firstly, respectively dissolving NH4VO3 and AgNO3 in deionized water, uniformly mixing by magnetic stirring, adjusting the pH value of the solution, and then carrying out hydrothermal synthesis reaction to obtain the Ag3VO4 photocatalytic material. The Ag3VO4 photocatalytic material with controllable morphology, uniform particle size and good dispersity is prepared by adopting a synthesis strategy of a one-step hydrothermal method, the performance of the photocatalyst is optimized by regulating and controlling the pH value, the raw materials and the process are simple, the conditions are easy to control, the cost is low, the photocatalytic degradation rate of the catalyst to organic pollutants is high, and the method is suitable for industrial production. The stability of a crystal structure and catalytic activity can be kept under long-term illumination, and the functional application of a photocatalytic air purification technology can be realized by integrating with an illumination lamp.

The invention relates to a method for recovering phosphorus and vanadium from a vanadium-containing salt-removed filter cake, and belongs to the technical field of aluminum oxide preparation. The method comprises the following steps: firstly, preparing vanadium-containing salt elimination filter cake slurry, then adding a dephosphorizing agent into the vanadium-containing salt elimination filter cake slurry, and promoting the dephosphorizing agent to generate precipitation reaction with phosphorus in the slurry to form a precipitate containing phosphorus element, so as to obtain a mixed solution containing the precipitate; next, solid-liquid separation is carried out on the mixed solution, precipitates containing phosphorus elements are filtered out, and the remaining vanadium-containing filtrate is further subjected to impurity removal treatment, so that residual carbonate radicals after the dephosphorization reaction and impurity elements such as arsenic and fluorine in the solution are removed, and adverse effects on the subsequent vanadium precipitation reaction are avoided. And after impurity removal is completed, vanadium precipitation reaction is carried out, and a pure vanadium-containing product is obtained. According to the method, by using the specific dephosphorizing agent, phosphorus in the vanadium-containing salt elimination filter cake is effectively recovered, and the tailing discharge amount is reduced. Meanwhile, the method also improves the concentration of vanadium, is beneficial to the recovery of vanadium, and realizes the simultaneous recovery of phosphorus and vanadium in the vanadium-containing salt elimination filter cake.

The invention discloses a separation and purification method of vanadium-containing tungstate. The method comprises the following steps: providing a vanadium-containing tungstate aqueous solution; providing an extraction liquid, wherein the extraction liquid comprises a sulfuric acid type quaternary ammonium salt extraction agent, a modifier and an organic solvent; mixing the vanadium-containing tungstate aqueous solution with the extraction liquid, and performing first extraction to obtain a first extraction phase and a first raffinate phase; providing strip liquor, wherein the strip liquor comprises alkali metal sulfate and alkali metal hydroxide; mixing the first extraction phase with the strip liquor, and carrying out first reverse extraction to obtain an alkali metal vanadate solution; and carrying out the same extraction and reverse extraction method on the first raffinate phase to obtain an alkali metal tungstate radical solution, thereby realizing respective separation and purification of vanadate radicals and tungstate radicals.

The invention provides a method for short-process all-component echelon recovery of a waste hydrogenation catalyst, and relates to the field of solid waste treatment. The recovery method of the waste hydrogenation catalyst comprises the following steps: roasting the waste hydrogenation catalyst and sodium carbonate to obtain a roasted product; the roasted product is leached with water, and leaching liquid and leaching residues are obtained; extracting the leaching solution by using an extracting agent to obtain a vanadium-molybdenum-containing organic phase, sequentially carrying out reverse extraction treatment on the vanadium-molybdenum-containing organic phase by using a strong alkaline reverse extraction agent and a weak alkaline reverse extraction agent to obtain a vanadium reverse extraction solution and a molybdenum reverse extraction solution, and carrying out vanadium precipitation treatment on the vanadium reverse extraction solution to obtain ammonium metavanadate; acidizing the molybdenum strip liquor to precipitate molybdenum to obtain ammonium molybdate; carrying out sintering treatment on the leaching residues and alkaline substances, leaching obtained calcine with water to obtain water leaching residues and filtrate, and carrying out aluminum precipitation treatment on the filtrate to obtain aluminum hydroxide, aluminum oxide or pseudo-boehmite; and reducing and smelting the water leaching residues to obtain the ferro-nickel alloy. According to the invention, multi-element comprehensive recovery of all components of vanadium, molybdenum, nickel, aluminum and sulfur can be realized, and high-value utilization of all components of the waste hydrogenation catalyst is realized.

The invention discloses a preparation method of atomic layer deposition synergistic doping modified sodium vanadate, which uses water as solvent, anhydrous sodium iodide and monohydrated vanadium oxyphosphate as sodium source, vanadium source and phosphorus source, and introduces cobalt acetate tetrahydrate and nickel acetate tetrahydrate, and realizes one-step hydrothermal synthesis of HNaV6O assembled by nanosheets and co-embedded with cobalt ions, nickel ions and phosphate ions by synergistically controlling their concentration and ratio, reaction temperature, reaction time and other parameters. 16 ·4H2O nanoflower structure. This method has a simple reaction process, low temperature, easy control, and does not require large equipment and harsh reaction conditions. On this basis, the atomic layer deposition technology was used to successfully realize the cobalt ion, nickel ion and phosphate ion co-embedded HNaV6O with ultra-thin nanoscale metal oxides. 16 Uniform coating of 4H2O positive electrode material. The present invention provides the application of the material in the positive electrode material of sodium ion battery.

The invention discloses a Fe < 3 + > doped nanobelt structure VO2 (B) / V3O5 heterojunction material and a preparation method and application thereof.The method comprises the following steps that 3 mmol to 5 mmol of V2O5 is added into 25 mL to 35 mL of deionized water, 7.5 mL to 12.5 mL of H2O2 is dropwise added, a clear dark red solution A is obtained, 0.15 mmol to 0.25 mmol of FeCl3. 6H2O and 40.5 mg to 67.6 mg of PEG-4000 are added into the solution A and fully stirred till complete dissolution, a mixed solution B is obtained, then the mixed solution B is transferred to a high-pressure reaction kettle, the temperature of the high-pressure reaction kettle is increased, and the Fe < 3 + > doped nanobelt structure VO2 (B) / V3O5 heterojunction material is obtained. The preparation method comprises the following steps: putting a high-pressure reaction kettle into a drying oven, reacting at 150-200 DEG C for 24-48 hours, and then sequentially cleaning and drying to obtain the powdery Fe < 3 + >-doped nanobelt structure VO2 (B) / V3O5 heterojunction material which has good structural stability, high power density and high area specific capacity and can promote rapid charging and discharging of an aqueous ammonium ion battery.

The invention discloses a bismuth vanadate material for carbon dioxide electroreduction and a preparation method and application, and belongs to the technical field of carbon dioxide electroreduction.The method comprises the steps that bismuth salt is dissolved in a nitric acid aqueous solution, a surfactant is added, and a mixed solution A is obtained through a stirring reaction; dissolving ammonium metavanadate in a sodium hydroxide aqueous solution, adding a surfactant, and carrying out a stirring reaction to obtain a mixed solution B; and mixing the mixed solution A and the mixed solution B, adjusting the pH value to be neutral, and carrying out stirring reaction, hydrothermal reaction, washing, drying and calcination reaction to obtain the bismuth vanadate material for carbon dioxide electroreduction. The preparation method comprises the following steps: uniformly mixing bismuth salt and ammonium metavanadate with a surfactant respectively, and roasting through a hydrothermal method and a template effect of the surfactant to prepare the bismuth vanadate material with high specific surface area for electroreduction of carbon dioxide. In carbon dioxide electroreduction, the catalyst has catalytic performance of high activity, good stability and high selectivity and electrochemical performance of low overpotential and high current density.

The present invention provides a general salt-assisted chemical vapor deposition (SA-CVD) synthetic method for the high-yield preparation of 1D hexagonal-phase MxV6S8(M=K, Rb, Cs) and KxV6SySe8-y nanowires. The resulting nanowires exhibit typical metallic properties, which can be used as a good van der Waals contact for achieving high-performance fermi level pinning free transistors. The present synthesis method allows a more systematic investigation of the intrinsic properties of hexagonal-phase V6S8 structures.

The invention discloses a method for synergistically extracting vanadium oxytrichloride, gallium trichloride and iron-titanium alloy from vanadium slag, and belongs to the field of recycling of complex multi-metal resources. The method comprises the following steps: uniformly mixing the gallium-containing vanadium slag, carbon and chlorinated waste salt according to a certain proportion, and carrying out vacuum melting treatment to obtain a Fe-Ti alloy; then chlorine is introduced for chlorination treatment, and a gaseous product is obtained; the gaseous product is adsorbed by a molecular sieve with a function of selectively adsorbing VOCl3 to obtain VOCl3, and then GaCl3 is obtained through a cold trap. According to the method, efficient collaborative conversion and recovery of multi-metal resources of vanadium, gallium, iron and titanium in the vanadium slag are achieved, and the problems that multi-metal collaborative extraction in existing vanadium slag is difficult, and the separation efficiency is low can be effectively solved.

The invention discloses a method for preparing low-chromium ammonium polyvanadate, which comprises the following steps: pretreating an impurity removal solution to ensure that the turbidity of the impurity removal solution is not more than 200UTN; adding an oxidizing agent into the pretreated impurity-removed liquid for oxidation to obtain a purified liquid; the purified liquid is subjected to acidic ammonium salt vanadium precipitation, and low-chromium ammonium polyvanadate is obtained; wherein the impurity removal liquid is obtained by selectively reducing sodium vanadium solution and removing chromium and silicon; in addition, different oxidation processes are selected based on the oxidation-reduction potential, the pH value and / or the chromium concentration of the impurity removal liquid. According to the method, different oxidation measures need to be adopted for impurity removal liquid with different properties, so that the oxidation efficiency is improved, the oxidation cost is reduced, and the quality of vanadium precipitates is improved. Different oxidation methods are designed by utilizing the reaction characteristics of chromium and different oxides and combining the pH value of a solution and the oxidation-reduction potential. The method has the characteristics of high oxidation efficiency, low oxidation cost, good vanadium product quality, high vanadium precipitation rate, easy determination of parameter boundaries and strong operability.

The invention discloses a modified solid-state electrolyte and a preparation method and application thereof, and relates to the field of solid-state batteries, in 300 crystal face grain size distribution of the modified solid-state electrolyte, Kn90 = (Ln90-Ln10) / Ln50, and Kn90 is more than or equal to 0.5 and less than or equal to 1.7; wherein Ln10 is the corresponding grain size when the volume distribution cumulative percentage of the 300 crystal face sub-grain size Ln of the modified solid electrolyte reaches 10%, and Ln50 is the corresponding grain size when the volume distribution cumulative percentage of the 300 crystal face sub-grain size Ln of the modified solid electrolyte reaches 50%; ln90 is the corresponding grain size when the volume distribution cumulative percentage of the 300 crystal face sub-grain size Ln of the modified solid electrolyte reaches 90%. According to the invention, the modified solid electrolyte has excellent ionic conductivity, good air stability, interface stability to metal lithium and relatively high oxidation potential stability.

The invention discloses a preparation method of an iron-based cocatalyst modified bismuth vanadate photo-anode, which belongs to a photo-anode preparation technology and comprises the following steps: firstly, introducing oxygen vacancies to the surface of BiVO4 through chemical reduction by using a mild reducing agent sodium sulfite (Na2SO3) under a low-temperature condition by a simple chemical reduction method; the introduction of oxygen vacancies improves the charge transfer efficiency and the carrier separation efficiency. And then loading the NiFeOX nano thin layer on the surface of BiVO4, and optimizing the loading capacity of the cocatalyst by adjusting the reaction time. BiVO4 is cooperatively modified through oxygen vacancies and a cocatalyst NiFeOX. And a feasible strategy is provided for simply designing and preparing a high-performance and high-durability BiVO4-based photo-anode material.

The invention relates to a novel layered sulfide positive electrode material of a lithium ion battery, which has a general formula of Li (1.33-0.33 x) VxTi (0.67-0.67 x) S2, and x is more than or equal to 0 and less than or equal to 0.5. The positive electrode material belongs to a hexagonal system O3 type crystal structure, the corresponding space group is # imgabs0 #, the microstructure of the positive electrode material is granular, the particle size of the particles is about 20-50 microns, and all elements are uniformly distributed on the surfaces and inside the particles. In the positive electrode material, almost all capacities come from the oxidation-reduction reaction of sulfur, and the capacity contribution of vanadium can be almost ignored. An electrochemical test and a solid-state nuclear magnetic characterization result show that the Li1. 27V0. 2Ti0. 53S2 positive electrode material has the reversible capacity as high as 308mAh g <-1 >, and reversible de-intercalation of all Li < + > in a system is realized. Meanwhile, the material shows extremely excellent rate and cycle performance, still has a capacity retention ratio of 81.0% after 4300 cycles, and almost has no voltage attenuation in the cycle process.

The invention discloses a method for preparing low-chromium ammonium metavanadate, which comprises the following steps: adding an oxidizing agent into an impurity removal liquid for oxidation to obtain an oxidation liquid; carrying out deep desiliconization on the oxidized liquid to obtain a purified liquid; carrying out alkalescence ammonium salt vanadium precipitation on the purified liquid to obtain ammonium metavanadate; wherein the step of adding the oxidizing agent into the impurity removal liquid for oxidation comprises the substeps of selecting a first type of oxidizing agent or a second type of oxidizing agent based on the oxidation-reduction potential and the chromium concentration of the impurity removal liquid; the impurity removal liquid is obtained after the sodium modified vanadium liquid is subjected to selective reduction and chromium-silicon co-removal. According to the method, different oxidation measures are adopted for impurity removal liquids with different properties to improve the oxidation efficiency, reduce the oxidation cost and improve the quality of vanadium precipitates, and the method has the characteristics of high oxidation efficiency, low oxidation cost, good desilicication effect and good vanadium product quality.

The invention discloses an anode active material and a preparation method thereof, a composite photoelectrode and a super capacitor battery, and relates to the technical field of electrochemical energy storage, the anode active material comprises oxygen-deficient bismuth vanadate and lanthanum chloride loaded on the oxygen-deficient bismuth vanadate, and the anode active material has pores. According to the invention, bismuth vanadate in the anode active material has oxygen defects, so that the conductivity of the bismuth vanadate electrode is improved, and the separation of electrons and holes in a bismuth vanadate bulk phase is promoted; lanthanum chloride in the anode active material promotes the injection efficiency of carriers on the surface of the bismuth vanadate electrode, the valence band structure of bismuth vanadate is changed, and the conductivity is greatly improved; in addition, the anode active material has pores, so that enough mechanical strain space is provided in the charging and discharging process, the volume expansion of bismuth is relieved, and the stability of the electrode is improved.

The present invention provides a preparation method for a 3 / 4-valent vanadium sulfate-hydrochloric acid electrolyte, comprising the following steps: adding hydrochloric acid into a 4-valent vanadium sulfate electrolyte to prepare a 4-valent vanadium sulfate-hydrochloric acid electrolyte; preparing a (4+x)-valent vanadium sulfate electrolyte; using the (4+x)-valent vanadium sulfate electrolyte and the 4-valent vanadium sulfate-hydrochloric acid electrolyte respectively as positive and negative electrode electrolytes of an all-vanadium redox flow battery to perform charging electrolysis, to obtain a (4+y)-valent vanadium sulfate electrolyte and a 3-valent vanadium sulfate-hydrochloric acid electrolyte at positive and negative electrodes, respectively; and adding oxalic acid into the obtained (4+y)-valent vanadium sulfate electrolyte for reduction to re-obtain the (4+x)-valent vanadium sulfate electrolyte, wherein the re-obtained (4+x)-valent vanadium sulfate electrolyte can be further used to prepare the 3-valent vanadium sulfate-hydrochloric acid electrolyte. The preparation method for a 3 / 4-valent vanadium sulfate-hydrochloric acid electrolyte provided by the present invention features high efficiency and low costs, and the obtained 3 / 4-valent vanadium sulfate-hydrochloric acid electrolyte has a high concentration and a wide operating temperature range.

The invention relates to a method for separating iron, vanadium and titanium dioxide in vanadium titano-magnetite or titanium concentrate through a wet method, and belongs to the technical field of chemical engineering. The method comprises the following steps: (a) mixing vanadium titano-magnetite or titanium concentrate with sulfuric acid with the concentration of 22-30wt.% to obtain mixed slurry; (b) treating the mixed slurry at 150-200 DEG C and 2-4 MPa under the condition that the Reynolds number is gt; reacting in a turbulent flow state of 4000, so that non-titanium elements are dissolved to generate sulfate; (c) carrying out solid-liquid separation on the reaction product in the step (b) to obtain a high-grade titanium-rich material and waste liquid; (d) the titanium-rich material reacts with a sodium hydroxide solution, silicon in the titanium-rich material is removed, and a sodium silicate solution is generated; and (e) reacting the silicon-removed titanium-rich material with a hydrochloric acid solution with the mass concentration of less than 15%, cleaning, carrying out solid-liquid separation, and calcining to obtain anatase or rutile titanium dioxide. According to the method, all iron, vanadium and titanium elements in the vanadium-titanium-iron concentrate and the titanium concentrate are recycled.

The invention discloses a method for preparing high-purity ammonium metavanadate by efficiently removing silicon, which is characterized in that a multi-step method of combining flocculation impurity removal, electrophoresis enhanced impurity removal and ammonium metavanadate crystallization is utilized in the preparation method, and the steps cooperate with one another, so that the silicon content in ammonium metavanadate can be effectively reduced to be less than 200ppm, and the purpose of efficiently removing silicon is achieved; the high-purity ammonium metavanadate obtained by the preparation method is relatively high in purity, low in impurity element content and high in vanadium recovery rate, and can meet the requirements of vanadium product purity in the aspects of electrolyte and aeronautical manufacturing.

The invention discloses a method for preparing vanadyl sulfate, which comprises the following steps: (1) mixing V2O5, concentrated sulfuric acid and distilled water in a reactor to obtain mixed slurry; (2) adding an organic reducing agent into the reactor, adjusting the reaction temperature, and carrying out an incomplete reduction reaction; (3) adding an inorganic reducing agent into the reactor, and carrying out complete reduction reaction to obtain a vanadyl sulfate solution after complete reaction; and (4) carrying out post-treatment on the vanadyl sulfate solution to obtain vanadyl sulfate crystals. According to the method, the adding sequence and adding amount of the organic reducing agent and the inorganic reducing agent are adjusted, the technical problem that the quality of vanadyl sulfate is reduced due to the fact that organic matter residues are serious when organic matter is adopted as the reducing agent is solved, and the problems that when inorganic matter is adopted as the reducing agent, reaction time is long, reaction is slow, and the like are solved. And the conversion rate is low. The method provided by the invention can be used for preparing vanadyl sulfate with low organic matter content, high purity and wide applicability.

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.

This application provides a KVOH nanomaterial, its preparation method, and an aqueous zinc-ion battery to address the technical problem of low performance of vanadium pentoxide cathode materials in the prior art. The KVOH nanomaterial provided in this application is obtained by a solvothermal reaction in an aqueous ethylene glycol solution. The introduction of potassium ions in the reaction expands the ion transport channels between the electrode material layers, improving the cycle performance of the battery. At the same time, the introduction of tetravalent vanadium also increases the specific capacity of the battery, thereby solving the technical problem of low performance of vanadium pentoxide cathode materials in the prior art.

The invention discloses a method for preparing alkali metal vanadate by a mechanochemical reaction method. The method comprises the following steps: mixing a vanadium-containing compound and an alkali metal compound according to the stoichiometric ratio of a target product, adding or not adding a protic solvent, and grinding to induce a mechanochemical reaction among the raw materials, so as to obtain the alkali metal vanadate, wherein the alkali metal vanadate is selected from one of NaVO3, KVO3, RbVO3, CsVO3, Rb3V5O14, Cs2V4O11 and Li3VO4, and the alkali metal vanadate is selected from one of NaVO3, KVO3, RbVO3, CsVO3, Rb3V5O14, Cs2V4O11 and Li3VO4. The preparation method has the advantages of being environmentally friendly, low in energy consumption, high in reaction efficiency and the like, efficient preparation of all series of alkali metal vanadate can be achieved, and the obtained alkali metal vanadate is high in purity, small in particle size and good in dispersity and has potential application value in the fields of lithium ion batteries, photocatalysis, laser crystals and the like.