35 results about "Scandium nitrate" patented technology

Water tolerant Lewis acids are used in a process for the preparation of alkylene glycols by catalytic hydration of the corresponding alkylene oxide. The water tolerant Lewis acids can be a metal salt of a non-coordinating or weakly coordinating anion and a Group IIIB, rare earth or lanthanide, actinide or Group IVB cation. Optionally, carbon oxide may also be present. Examples of such water tolerant Lewis acids are scandium triflate, europium triflate, hafnium triflate, yttrium triflate, lanthanum triflate and ytterbium triflate. The catalyst may contain a coordinating anion instead, examples of which are scandium sulfate [Sc2(SO4)3], scandium chloride [ScCl3], scandium acetate [Sc(OAc)3] and scandium nitrate [Sc(NO3)3]. The catalysts may also contain both a non-coordinating or weakly coordinating anion and a coordinating anion, examples of which are scandium triflate sulfate [Sc(CF3SO3) (SO4)], scandium triflate chloride [Sc(CF3SO3)2Cl], scandium triflate acetate [Sc(CF3SO3)2(OAc)] and scandium triflate nitrate [Sc(CF3SO3)2(NO3)].

The invention relates to a negative thermal expansion material, in particular to a preparation method of a rod-shaped Sc2W3O12 negative thermal expansion material. The invention adopts the hydrothermal method to synthesize the negative thermal expansion compound Sc2W3O12 at low temperature, and the raw materials used are: Sc(NO3)3 xH2O (analytical pure), H40N10O41W12 xH2O (chemical pure), HNO3 (analytical pure). Dissolve scandium nitrate and ammonium tungstate in deionized water at a molar ratio of Sc3+:W6+ of 2:3, mix the two solutions of scandium nitrate and ammonium tungstate by double drop method, and add to the mixed solution under constant stirring Adjust pH=3~5 with nitric acid solution, stir evenly at 60~80°C; transfer the mixed solution into a reaction kettle lined with polytetrafluoroethylene, seal and heat at 150~180°C for 10~15h, and the reaction is complete Finally, use a centrifuge for centrifugal dehydration, pour off the supernatant, wash and centrifuge repeatedly for 3 times, and then dry at 80-110°C to obtain the precursor; place the precursor in a muffle furnace and heat it at 540-800°C The final product Sc2W3O12 is obtained. The method has the advantages of simple procedure, easy operation and industrialization.

A process for preparing the dispersed Sc-contained powder used as the raw material of cathode includes such steps as respectively dissolving scandium nitrate and ammonium metatungstate in water, mixing, adding the solution of citric acid and glycol, water-bath heating to 60-90 deg.C while stirring to obtain sol, baking at 80-150 deg.C to obtain gel, and thermal decomposing at 500-600 deg.C for 0.5-1 hr and then at 850-1000 deg.C for 1-2 hr.

The invention relates to an electrolyte corrosion inhibitor, an aluminum-air battery electrolyte and a preparation method of the aluminum-air battery electrolyte. The electrolyte corrosion inhibitor mainly comprises an inorganic phase type corrosion inhibitor and an organic adsorption type corrosion inhibitor, wherein the inorganic phase type corrosion inhibitor is selected from at least one of zinc acetate, manganate and scandium nitrate; the organic adsorption type corrosion inhibitor is selected from at least one of benzotriazole, a natural amino acid and a cationic surfactant; and the molar ratio of the inorganic phase type corrosion inhibitor and the organic adsorption type corrosion inhibitor is (1-5,000) to (1-1,000). The electrolyte corrosion inhibitor is prepared on the basis of the property of an electrolyte solution, has the advantages of the phase type corrosion inhibitor and the adsorption type corrosion inhibitor, and is a multifunctional additive with good overall performance.

The invention discloses a method for preparing ultrafine tungsten-rhenium composite powder containing scandium and strontium. The method comprises: 1. Ball milling tungsten oxide powder, ammonium perrhenate powder and carbon black to obtain tungsten-rhenium mixed powder; 2. Adding tungsten-rhenium mixed powder into the mixed solution to obtain a solid-liquid mixture; 3. Adding a solution containing carbonate to the solid-liquid mixture to react to obtain a precipitate; 4. Sintering to obtain ultrafine tungsten-rhenium composite powder containing scandium and strontium; The invention also discloses the application of one-step sintering of superfine tungsten-rhenium composite powder containing scandium and strontium to obtain hot cathode material. The present invention uses tungsten oxide powder and ammonium perrhenate powder as the source of tungsten and rhenium, uses scandium nitrate hexahydrate and strontium nitrate as the source of scandium and strontium, and uses a solid-liquid mixing method to combine carbon and hydrogen for two-step reduction without the need to prepare a matrix and The precursor active material has a simple and efficient method; the application process of the invention is simple, the production cycle is short, the cost is low, and the electron emission performance of the hot cathode material is improved.

The invention discloses a method for preparing barium scandium tantalate powder. The method comprises the steps of thoroughly dissolving a barium salt, a tantalum salt, a scandium salt and different cross-linking agents, which serve as raw materials, into a methanol-water mixture solution, then, carrying out cross-linking reaction at a certain temperature, then, mixing with a molten salt, grinding, so as to thoroughly mix uniformly, carrying out high-temperature reaction, then, cooling to room temperature, and then, carrying out water washing and drying, thereby obtaining the barium scandium tantalate powder, wherein the barium salt is either or a mixture of barium chloride and barium nitrate, the tantalum salt is either or a mixture of tantalum pentachloride and pentaethoxy tantalum, the scandium salt is either or a mixture of scandium chloride and scandium nitrate, the cross-linking agents are either or a mixture of urea and citric acid, and the molten salt is a mixture of sodium chloride and barium chloride. The method has the advantages that the preparation procedures are simplified, the preparation cost is low, the pollution to an environment cannot be caused, industrialized large-scale preparation is facilitated, and the prepared product can be applied to the fields of ferroelectrics, photoelectricity, photocatalytic hydrogen generation, fuel cells and the like.

The invention discloses a method for preparing an impregnated scandium-tungsten diffusion type cathode material, and belongs to the technical field of refractory metal cathode materials. The method for preparing the impregnated scandium-tungsten diffusion type cathode material comprises the following steps: 1) dissolving ammonium meta-tungstate and scandium nitrate into water to form solution respectively, adding the scandium nitrate solution into the ammonium meta-tungstate solution for mixing, controlling the concentration of the mixed solution to between 20 and 40 g / L, and adopting spray drying to prepare precursor powder of the cathode material, wherein the feeding speed is 400 ml / h; the blowing rate is 0.4 to 0.6 cubic meters per minute; the inlet temperature is 150 DEG C; and the outlet temperature is stabilized at 95 DEG C; 2) decomposing the precursor powder prepared by the spray drying at the temperature of between 500 and 550 DEG C for 2 hours in the atmosphere so as to obtain composite oxide powder; and 3) reducing in the hydrogen atmosphere in two steps: preserving the heat to between 500 and 600 DEG C for 1 to 2 hours, and then raising the temperature to between 800 and 950 DEG C and preserving the heat for 1 to 2 hours to obtain the precursor-doped tungsten powder. The method for preparing the impregnated scandium-tungsten diffusion type cathode material simplifies the preparation technology for the precursor powder, avoids the introduction of impurity elements in the preparation process, and has the advantages of strong repeatability, simple technology, and convenient mass production. The prepared cathode material has excellent emission characteristics at 850 DEG C.