21 results about "Calcination" patented technology

The invention relates to a lithium silicate-coated Ni-Co lithium aluminate positive electrode material and a preparation method thereof. The mass percent of lithium silicate in the material accounts for 1-10wt%, a coating layer with a thickness being 2-20 nanometers is formed from the silicon silicate and is coated on Ni-Co lithium aluminate, and the positive electrode material is a spherical particle with a grain size being 5-15 micrometers. The method comprises the following steps of (1) adding a silicon source into an organic solvent, performing uniform stirring, adding water, adding Co-Alnickel hydroxide, performing heating and stirring reaction, and performing drying to obtain silicon dioxide-coated Co-Al nickel hydroxide precursor powder; and (2) grinding and uniformly mixing the silicon dioxide-coated Co-Al nickel hydroxide precursor powder and a lithium salt, placing the mixture in a tubular furnace, and performing two-segment calcination under an oxidization atmosphere, thereby obtaining the lithium silicate-coated Ni-Co lithium aluminate positive electrode material. The positive electrode has relatively good cycle stability and large-rate discharging performance; and bythe method, the problem of lithium resided on a surface during conventional coating can be effectively reduced, and the method is low in cost and simple in process and is suitable for industrial production.

The invention discloses a preparation method of high-purity rhenium powder, which comprises the following steps: purification, centrifugal atomization, primary reduction, secondary reduction and the like. A preparation method of high-purity rhenium powder is provided, starting from the two major processes of raw material ammonium rhenate powder preparation and ammonium rhenate calcination reduction, improving the reducibility of ammonium rhenate powder, reducing the driving force of powder growth, and achieving all stages The purity of raw materials is controllable; two-stage hydrogen reduction is adopted to increase the contact with hydrogen, which is conducive to the elimination of water vapor and provides powerful conditions for obtaining finer and more uniform powder.

The present invention relates to a method for preparing tungsten oxide and tungsten powder from scheelite. The method uses the scheelite as a raw material and comprises the following steps: (1) conducting leaching reaction; (2) conducting filtering and washing; (3) conducting hydrogen peroxide extraction-decomposition to extract tungsten; (4) conducting hydrogen peroxide multiple dissolution-decomposition to purify tungstic acid; (5) pure tungstic acid calcination to prepare tungsten trioxide; and (6) conducting peroxotungstic acid solution spraying pyrolysis to prepare tungsten oxide and tungsten powder. The method only consumes cheap and easily available sulfuric acid, greatly reduces the decomposition cost of the scheelite and uses sulfuric acid to decompose; decomposed residues are gypsum; the gypsum can be used as building materials; the method does not produce dangerous waste alkali cooking residues, greatly reduces production and operation costs of enterprises, uses hydrogen peroxide as an extractant of tungstic acid, does not produce ammonia nitrogen wastewater, eliminates the technology of producing the ammonia nitrogen wastewater for many years in tungsten smelting, greatly reduces environmental protection costs, directly produces various tungsten end products and tungsten powder, and improves added value of products of the tungsten smelting enterprises.

The invention discloses an alumina grinding ball preparation method, which includes the following steps: (1) preparing alumina ball seeds: alumina powder with purity of 99.99-99.995% and particle sizeD50 of 0.8-1.0um, screening, balling, adding a glue solution in the balling process, controlling the moisture content to be 15-30%, screening when balling occurs, and controlling the size to be 0.25-0.35mm to obtain alumina ball seeds; (2) making green balls: continuously sieving the alumina balls obtained in step (1), adding and spraying the glue solution, controlling the moisture content to be18-30%, and sieving and compacting to obtain balls with a density of 1.35-1.45g/ml as finished green balls for later use; and (3) calcination: selecting the finished green ball and calcining at 1620-1650 DEG C to obtain the alumina grinding ball finished product with the real density of 3.8-4.0g/cm3, purity > 99.99% and abrasion < 5g/kg. The method can reduce the cost of producing high-purity alumina powder for nanocrystallization; and the loss of alumina balls during use is low and the product quality is stable.

The invention relates to a preparation method of perovskite structure lead titanate single crystal nanoparticles. The method adopts hydrothermal reaction and subsequent high-temperature calcination, a mixed precipitate of titanium and lead ions introduces reactant material of hydrothermal reaction, a potassium hydroxide mineralizer promotes partial crystallization of a product to form precursor powder, then the precursor powder is completely crystallized in a subsequent high-temperature calcination process, therefore, synthesis of perovskite structure lead titanate single crystal nanoparticles is realized. The method provided by the invention has characteristics of simple process, easy control, no pollution and low cost, and is easy for large-scale production. The prepared perovskite structure lead titanate single crystal nanoparticles have high purity, good dispersity, and uniform size.

The invention discloses a method for preparing lithium manganate by a wet-doping method. By the wet-doping method, manganese chloride solution, ammonium bicarbonate solution and lanthanum nitrate solution are reacted in aqueous solution. Lanthanum hydroxide and manganese carbonate are generated in a coprecipitation way. Manganic manganous oxide-doped crystals are obtained after high-temperature calcination, crushing and grading. Lithium carbonate and the manganic manganous oxide-doped crystals are mixed according to the molar ratio of lithium to manganese, and the molar ratio is 1.15:2. After being mixed effectively and uniformly, the above mixture is put into a kiln to be sintered at a high temperature. After cooling, crushing, grading, sieving and deironing of the sintered materials, spinel-shaped and lanthanum-doped lithium manganate is obtained. The method can combine materials and doping elements tightly. During the high-temperature calcination reaction, the doping elements can be inserted into crystal structures to be doped completely and fused with the doped crystals together. The doping of lanthanum element can raise the average oxidation state of manganese ions, inhibit Jahn-Teller effect effectively, reduce the capacity fading and raise the cycle performance.

Disclosed is a preparation method of a residual-sludge-based particle electrode carrier. The invention relates to resource treatment of solid waste of sludge, and the technical problem of a low utilization ratio of residual sludge is solved. The method comprises: 1, preparation of absolutely-dried sludge powder, 2, preparation of raw material balls; and 3, calcination. Residual-sludge ceramic particles are taken as the particle electrode carrier, and a catalyst of Sb-SnO2 is loaded on the surfaces of the residual-sludge ceramic particles by utilizing a pyrolytic process to form a particle electrode of residual-sludge-based sludge ceramic particles loaded with Sb-SnO2. By using the prepared porous residual-sludge ceramic particles, the disposal cost of sludge is reduced. The particle electrode carrier with excellent performance is formed by loading Sb-SnO2 on the residual-sludge ceramic particles. The residual-sludge-based particle electrode carrier is applicable to treatment of printing and dyeing wastewater, the treatment efficiency is improved, and the treatment cost of waste water is reduced. The method is used for preparing the residual-sludge-based particle electrode carrier.

The present, invention relates to a process for the production of additives for catalysts for fluid catalytic cracking (FCC) based on zeolite that is selective for light olefins, with the aim of increasing the yields, in FCC units, of liquefied petroleum gas (LPG) and light olefins, of high added value, among others propene and isobutene. This invention provides a method of preparation of catalytic compositions, starting from zeolite modified with phosphate and alkaline-earth metal, that leads to the production of an additive with better performance than the additives, of similar compositions, obtained by other methods of the prior art. The process can be regarded as a development in relation to other processes, as it promotes interaction between the zeolite that is selective for light olefins and its activator, reagent “X”. For this, a separate stage is used during the sequence of stages in the preparation. Moreover, the zeolite does not undergo additional treatments such as filtration, washing or calcination after the treatment with its activator.

This additive can be obtained starting from any commercial zeolite that is selective for light olefins, such as zeolite of type ZSM-5.

The invention discloses a composite high-strength Nixing pottery material which is characterized by comprising, by weight, 3-6 parts of east mud, 3-6 parts of west mud, 2-3 parts of clinker after calcination of Nixing potteries, 5-9 parts of zinc oxide, 0.3-0.6 part of serpentine, 0.6-0.8 part of spodumene, 4-7 parts of fine silicon carbide powder and 2-4 parts of tungsten molybdenum rare earth alloy powder. Silicon carbide is added into the Nixing pottery material, so that a forged green body has high hardness, thermal shock resistance and an excellent heat conductivity coefficient, smaller heat stress is applied onto the green body in the heating or cooling process, and the green body has excellent abrasion resistance by a sprayed tungsten molybdenum rare earth alloy.

The invention relates to a composite heat-conductive material and a preparation method thereof. The composite heat-conductive material comprises a polymer matrix and carbon nanofiber cloth which is embedded inside the polymer matrix, wherein the carbon nanofiber cloth is arranged perpendicular to the extension direction of the composite heat-conductive material, and is of a wave shape, and the carbon nanofiber cloth is obtained through calcination of an electrospinning film. The carbon nanofiber which is prepared from the electrospinning are combined with metal nanoparticles, a simple low-temperature sintering process is performed so as to form coated carbon nanofiber, a crosslinked heat-conductive skeleton is formed by the carbon nanofiber together with the metal nanoparticles, and the high-heat-conductive material is prepared through compounding of the coated carbon nanofiber with the polymer matrix.

The invention provides a copper oxide/carboxymethyl cellulose gel modified composite film, and a making method and a use thereof. The making method comprises the following steps: washing and drying a copper net; cutting the dried copper net, carrying out high temperature calcination on the cut copper net in a tubular furnace, naturally cooling the calcined copper net to room temperature, and taking out the naturally cooled copper net; impregnating the calcined copper net in a carboxymethylcellulose sodium solution for a period of time, taking out the impregnated copper net, and impregnating the copper net in a Fe<3+> solution; and taking out the copper net a period of time later, placing the impregnating copper net in an oven, drying the copper net at a certain temperature for a period of time, continuously repeating the above impregnating operation to make the copper oxide/carboxymethyl cellulose gel modified composite film, and preserving the copper oxide/carboxymethyl cellulose gel modified composite film in water. The CuO-CMC modified composite film is produced through the method for high temperature calcination of the copper net and coating of the surface with an organic layer. The making method has the advantages of simplicity in operation, obvious separation effect and high practical values.

The invention discloses a novel method for preparing a recyclable graphene composite titanium dioxide nano material. The preparation method is characterized by comprising the following steps of: firstly, preparing nickel ferrite by a hydrothermal method, preparing graphite oxide by a Hummers method, and synthesizing the nickel ferrite, graphene and titanium dioxide into the composite material by ahydrothermal method in one step. The preparation process is easy to operate, reaction conditions are easy to control, the requirement for equipment is low, the loss is low, high-temperature calcination is not needed, the synthesis cost is reduced, good market prospects are achieved, and the prepared composite material has excellent photocatalytic performance, has magnetism, is convenient to recycle, can be repeatedly used and improves economic benefits.

The invention discloses a fish roe based porous carbon material. Fish roes are pre-carbonized at a low temperature to form a carbon precursor, and the carbon precursor and alkaline inorganic substances are directly mixed to prepare the fish roe based porous carbon material by calcination. A preparation method includes steps: 1) carbon precursor preparation; 2) carbon precursor activation; 3) porous carbon material aftertreatment. In application to an electrode material of supercapacitors, when the current density is 1A g<-1>, and a specific capacitance range is 222-396 F g<-1>. The method is simple in process, convenient to operate and easy to implement, and the prepared fish roe based porous carbon material serving as the electrode material of the supercapacitors is excellent in performance.

The invention discloses a method for preparing silicon and titanium composite powder, and belongs to the technical field of composite powder. The method has the advantages that stroke deposition and coating are carried out on silicon and titanium particles by means of wet organic surface modification, silicon titanium oxide bond formation can be ultimately increased by means of calcination, accordingly, the quantity of hydrogen bonds can be reduced, the stability can be improved, the specific surface area of titanium can be increased, and the chromaticity can be improved.

The invention discloses a preparation method of a special-morphology micro nano structural lithium-rich manganese-based cathode material, and belongs to the technical field of novel energy material energy storage material preparation processes. The method comprises the following steps: dissolving a manganese salt and a nickel salt into distilled water according to a ratio to obtain an A liquid; dissolving a homogeneous precipitant weighed according to a ratio into distilled water to obtain a B liquid, introducing a certain ratio of an ionic liquid into the B liquid, performing full stirring, and performing uniform mixing; mixing the A liquid and the mixed B liquid, and performing full stirring; transferring the mixed liquid to a hydrothermal reaction kettle, performing a hydrothermal reaction, performing cooling to room temperature, performing centrifugal separation, performing washing, and performing drying to obtain a manganese-based precursor material; and finally grinding the precursor and a certain ratio of lithium carbonate, performing uniform mixing, performing pre-sintering, and performing calcination to obtain the lithium-rich manganese-based cathode material. The method provided by the invention solves the problems of high energy consumption, long consumed time and difficulty in control of product topography characteristics in the preparation process in the prior art.