11 results about "MOLYBDATE ION" patented technology

The invention relates to an application of a high-magnification nanocrystallization iron molybdate sodium ion battery positive electrode material, and the nanocrystallization iron molybdate sodium ion battery positive electrode material is an iron molybdate positive electrode material subjected to nanocrystallization optimization and is used for preparing a sodium ion battery. The reversible specific capacity of the nanocrystallized iron molybdate sodium ion battery positive electrode material in a sodium ion battery reaches up to 91 mAh / g, most of the capacity is kept under high current, and the capacity retention rate still can exceed 80% after 100 times of circulation. The nano-fibers are sintered into nano-particles, and the loading capacity can be controlled, so that the nano-fibers are used in the sodium-ion battery positive electrode material. Besides, by virtue of the greatly improved ion diffusion rate and structural stability of the nano-sized iron molybdate, high specific capacity, excellent rate capability and long cycle life can be realized at the same time, and the nano-sized iron molybdate is a high-performance sodium battery positive electrode material with great potential.

The invention provides a preparation method of Mo-Cu composite powder, which comprises the following steps: mixing molybdate and copper salt in an aqueous solution of organic amine, and complexing molybdate ions and copper ions with amido in the organic amine to form a precursor solution; then adding polyethyleneimine into the precursor solution, so that polyethyleneimine competitively complexes molybdate ions and copper ions complexed with amido in the precursor solution; adding an acid to reduce the pH value of the precursor solution so as to destroy the stability of a complex of polyethyleneimine, molybdate and copper ions, and inducing the molybdate and the copper ions to synchronously and uniformly precipitate to generate a Mo-Cu-O composite oxide precursor; calcining the Mo-Cu-O composite oxide precursor to obtain a composite oxide; and the composite oxide is reduced, and Mo-Cu composite powder is obtained. The invention further provides the Mo-Cu composite powder prepared through the method and the molybdenum-copper alloy prepared from the Mo-Cu composite powder.

The application belongs to the technical field of catalyst preparation, and particularly relates to a composite catalyst containing molybdenum oxide and a preparation method and application thereof. The preparation method comprises the following steps: (1) mixing molybdate and a ligand to obtain a mixed solution; (2) soaking foamed nickel in the mixed solution to obtain a suspension; wherein the soaking time is not less than 1 h; and (3) performing hydrothermal reaction and calcination. The preparation method utilizes the etching effect of molybdate on foamed nickel, and the foamed nickel is immersed in a mixed solution containing molybdate and a ligand, so that the nickel in the foamed nickel is dissolved in the form of ions, and a nickel-molybdenum complex transition layer is grown in situ on the surface of the foamed nickel by the molybdate ions and the ligand; a nickel-molybdenum-based catalyst precursor is grown on the complex transition layer through hydrothermal reaction, and the composite catalyst is obtained after calcination, so that the catalyst is firmly anchored on the foamed nickel substrate, thereby improving the stability and impact resistance of the catalyst and avoiding the shedding of active components in the catalyst.

The invention relates to the technical field of compound purification, and particularly discloses a heteropolyacid extraction and purification method based on temperature and acidity dual regulation, which comprises the following steps: reacting tungstate radical or molybdate radical with arsenic acid or phosphoric acid at a certain temperature in the presence of acid to prepare a crude heteropolyacid solution, then carrying out contact reaction with an oxygen-containing extraction agent, recovering heat by adopting a heat pump, and purifying the crude heteropolyacid solution. The temperature is kept below 40 DEG C, the obtained heteropolyacid loaded organic phase is mixed with water vapor for heat exchange, in the water vapor condensation process, heteropolyacid in the organic phase is reversely extracted to the water phase, reverse extraction liquid is obtained, the organic phase is regenerated, and a regenerated organic phase is obtained; and evaporating and concentrating the obtained heteropolyacid strip liquor to obtain heteropolyacid concentrated liquor, and returning water vapor containing heat for use. According to the method, the carbon emission can be reduced, the reverse extraction rate of heteropoly acid can be improved, the water consumption of the system is greatly reduced, and alkaline substances such as sodium hydroxide and ammonia water are not used.

The invention provides a method for preparing fine-grained ammonium heptamolybdate crystals by an aid crystallization method. The method specifically comprises the following steps: step 1, preparing an ammonium molybdate solution; 2, crystallizing an ammonium molybdate solution auxiliary agent; and step 3, performing reduced pressure evaporation to prepare fine-fraction ammonium heptamolybdate crystals. Molybdenum oxide is used as a raw material, ammonium heptamolybdate is formed under the synergistic effect of induced crystallization of assistant crystallization and reduced pressure evaporation, and the concentration of molybdenum in the solution is improved through reduced pressure evaporation, so that molybdate ions are induced to be converted towards a high polymerization degree direction, and formation of ammonium heptamolybdate is remarkably promoted; and the crystallization auxiliary agent can promote the formation of crystals and refine ammonium heptamolybdate crystal particles, so that a fine-fraction ammonium heptamolybdate crystal product with high purity and narrow particle size distribution is obtained.

The invention belongs to the technical field of martensitic stainless steel performance detection, and relates to a 4Cr13 stainless steel metallographic etchant and a corrosion method for displaying carbides, and the etchant is prepared from the following components: 10-15 mL of glacial acetic acid, 1-2 g of ammonium persulfate, 0.5-1 g of sodium molybdate, 70-80 mL of absolute ethyl alcohol and 10-15 mL of deionized water. Glacial acetic acid is organic weak acid, and compared with inorganic acid, glacial acetic acid is more environment-friendly and mild and can reduce grain boundary over-corrosion; ammonium persulfate is a mild oxidant, releases active oxygen in an acidic environment, selectively destroys a passive film, enhances grain boundary and phase boundary corrosion, and avoids use of strong acid or heavy metal. Molybdate ions in sodium molybdate are adsorbed on the surface of carbide to generate a MoO2 / MoO3 nano film, blue-black contrast is generated through light interference, the contrast of the carbide is remarkably improved, and toxic picric acid is replaced. Absolute ethyl alcohol is an environment-friendly organic solvent, so that the reaction rate is reduced, the uniformity is improved, and the method is environment-friendly.

The application belongs to the technical field of water purification, and particularly relates to a preparation method and application of a porous organic framework material. The preparation method comprises the following steps: S1. dissolving 1,3,6,8-tetra(1H-imidazole-1-yl)pyrene and 1,2,4,5-tetra(bromomethyl)benzene in an N,N-dimethylformamide organic solvent to obtain a mixed solution; S2. placing the mixed solution in a microwave reaction instrument for heating reaction, separating and washing the product, immersing the product in a saturated NaCl solution, separating and drying the product after the immersing, and obtaining the porous organic framework material CPN-M-1. The cationic polymer porous organic framework material prepared by the application has the advantages of high chemical stability, strong designability, easy functionalization modification and the like, is an effective material for treating radioactive anion pollutants, can specifically recognize and efficiently capture molybdate ions in a complex water environment, and can realize simultaneous separation of multiple radioactive anions.

The invention discloses a method for repairing polluted soil through chemical leaching, and relates to the technical field of soil repairing, the method comprises the following steps: pretreating the polluted soil, preparing a composite leaching agent, mixing the pretreated soil and the composite leaching agent according to a solid-liquid mass volume ratio, carrying out synergistic physical field treatment on the mixed system, and after the treatment is completed, carrying out chemical leaching to repair the polluted soil. The method has the advantages that the potassium phosphate solution is adopted as the eluting agent, molybdate ions immobilized on the surfaces of soil particles are directionally released through the ion replacement effect, and the remedied soil can be directly used for agricultural production; the problems that soil fertility is reduced and reclamation cannot be achieved due to a traditional leaching technology are effectively solved, the contact efficiency of a leaching agent and soil particles can be remarkably enhanced through ultrasonic-assisted treatment, the remediation period is shortened, the operation convenience is improved through flexible selection of oscillation multiple times of leaching, and the remediation requirements of contaminated soil of different scales are met.

The invention discloses a loss-resistant molybdenum disulfide additive for composite calcium sulfonate-based lubricating grease, and belongs to the technical field of lubricating materials. The preparation method of the molybdenum disulfide additive comprises the following steps: synthesizing polystyrene microspheres with rich carboxyl groups on the surface as a template by virtue of a dispersion polymerization method, and loading molybdate ions on the surface of the template by virtue of an electrostatic adsorption effect, so as to obtain the molybdenum disulfide additive. Then carrying out hydrothermal vulcanization reaction to enable molybdenum disulfide to directionally grow on the template; and finally, removing the template through controllable calcination. According to the invention, the problem of compatibility between molybdenum disulfide and composite calcium sulfonate-based lubricating grease is successfully solved by constructing the nano reticular molybdenum disulfide microspheres. When the molybdenum disulfide is used as an additive, the loss resistance, the extreme pressure anti-wear property and the high-temperature stability of the lubricating grease can be synchronously and greatly improved, and efficient and stable application of the excellent lubricating property of the molybdenum disulfide in the grease is realized.

The invention discloses a method for preparing ammonium rhenate from rhenium-rich molybdenum-containing slag. The method mainly comprises the following steps: (1) oxidizing and leaching the slag charge in sulfuric acid and hydrogen peroxide to obtain a leachate containing rhenium and molybdenum; (2) adjusting the pH to be weakly acidic to remove impurities such as iron and the like, then adjusting the pH to be neutral to change the form of molybdate ions, so that the molybdate ions are converted into a monomer form (MoO4 < 2->) with relatively weak adsorbability, and rhenium still exists in a ReO4 <-> form; (3) carrying out selective adsorption of rhenium on the neutralized liquid through weak base anion exchange resin, and (4) carrying out desorption by adopting an ammonia water solution, and then carrying out evaporation concentration and cooling crystallization to obtain high-purity ammonium rhenate. According to the process, efficient separation of rhenium and molybdenum is achieved, the total rhenium recovery rate is larger than or equal to 92%, the final product purity is larger than or equal to 99.99 wt% (4N grade), and good industrial feasibility is achieved.