147results about How to "Crystallization intact" patented technology

The invention discloses a method for preparing high-purity calcite calcium carbonate micropowder through shell hydro-thermal treatment and belongs to the field of inorganic materials. The method comprises the following process steps of: (1), grinding shells into powder and sieving the shell powder; (2), adding the shell powder to an alkali aqueous solution, and putting the mixture to a high-pressure kettle to carry out hydro-thermal treatment; and (3), separating, cleaning and drying the treated shell powder to obtain the high-purity calcite calcium carbonate micropowder, wherein the grain size of the powder is 0.5 micron to 2 microns. The method for preparing high-purity calcite calcium carbonate micro powder through shell hydro-thermal treatment disclosed by the invention has the characteristics of being low in material cost, simple in production process, environment-friendly and safe in production process; and besides, the method is suitable for large-scale high-value recycling of the waste shells.

The invention discloses a preparation method for carbon nano tube surface loaded magnetic alloy nano particle composite material, which belongs to the field of electromagnetic wave absorbing material preparation. The preparation method comprises the following steps: after purifying and activating a carbon nano tube, evenly dispersing the carbon nano tube to chloride salt solution of iron, cobalt and nickel, slowing adding an alkali solution dropwise into the solution in the fierce agitation process, and regulating the pH value of the solution and making iron ions, cobalt ions and nickel ions be coprecipitated onto the surface of the carbon nano pipe in the form of hydroxide according to the alloy proportion set when the solution is prepared; taking out a deposit by centrifugation or filtering; and after drying the deposit, carrying out the heat treatment of the deposit in the reducing atmosphere to obtain the carbon nano tube composite material loaded with magnetic alloy particles. The preparation method adopts a simple process. As no impurity element is introduced into the preparation process, the obtained magnetic alloy particles have high degree of crystallinity and excellent magnetic properties. In addition, the method has easy regulation of the alloy components. The composite material prepared by the method is significantly applied in the fields of electromagnetic interference resistance, stealth, microwave darkrooms, and the like.

The invention discloses a method for preparing rose calcium carbonate from low-grade limestone, which comprises the following steps: 1) proportionally calcining low-grade limestone and blind coal to prepare calcium oxide; 2) screening under vibrations to remove coal ash and lime powder, thereby obtaining lumpy lime; 3) adding water to slake the lumpy lime, removing impurities by hydrocyclone and vibration screening to obtain fine emulsion slurry, adding a whitener, and aging to obtain the Ca(OH)2 prime slurry; 4) after regulating the temperature and concentration of the Ca(OH)2 prime slurry, adding a crystal form control agent, carrying out bubbling carbonation reaction, and adding a dispersant; when the pH value of the slurry is lower than or equal to 7, stopping carbonation to obtain a cured slurry; and 5) after the cured slurry is thickened, dehydrating to obtain the rose calcium carbonate. Compared with common light calcium carbonate, the rose calcium carbonate disclosed by the invention has the advantages of higher crystal completeness, high surface porosity, high light scattering coefficient and stronger covering power; and the invention is applicable to the industries of paper making, rubber, plastics and paint.

A preparation method of a high-stability high-purity extra-coarse tungsten carbide powder contains the following steps of: (1) grinding a high-purity extra-coarse tungsten carbide powdered raw material with its chemical purity being greater than or equal to 99.98 wt%, and carrying out size grading to obtain the required average granularity and a high-purity extra-coarse tungsten powder according to the particle size distribution; (2) carrying out carbon addition by the use of carbon black according to the total carbon content of the obtained tungsten carbide powder being 6.13+/-0.05%, followed by ball milling and mixing to obtain a ball-milling mixture; (3) filling the obtained ball-milling mixture into a graphite boat and a carbide furnace, and carrying out high-temperature carbonization at 1600-2500 DEGC for the carbonization time of 1-10 hours; and (4) carrying out coarse crushing on the obtained carbonized material, followed by grinding and crushing, and carrying out size grading to obtain the high-purity extra-coarse tungsten carbide powder. The method provided by the invention can be adopted to produce the high-purity extra-coarse tungsten carbide powder with good crush resistance, morphology and structure and excellent thermal stability. The high-purity extra-coarse tungsten carbide powder is used to prepare an extra-coarse crystal cemented carbide product with high performance.

A process for synthesizing nanometre BaFe12O19 powder includes such steps as proportionally mixing the inorganic salt (nitrate or carbonate) of Ba2+ or Fe3+, citric acid and chloride (potassium chloride, sodium chloride, or their combination in mol ratio of NaCl/KCl=1:0.5-1.5), microwave inducing, low-temp. combustion for 2-10 min, heat treating under 900 deg.c for 0.2-10 hr and water washing to obtain nanometre hexagonal crystal of BaFe12O19. Its advantages are simple process, low energy consumption, and regulatable magnetic performance of product.

The invention discloses a nickel-cobalt composite oxide and a nickel-cobalt doped oxide. The molecular formula of the nickel-cobalt composite oxide can be represented by a general formula NixCo(3-x)O4+/-z, wherein x is more than or equal to 1.8 and less than or equal to 2.7, and z is more than or equal to 0 and less than or equal to 0.5; and the molecular formula of the nickel-cobalt doped oxide can be represented by a general formula NixCo(3-x-y)MyO4+/-z, wherein the x is more than or equal to 1.8 and less than or equal to 2.7, y is more than or equal to 0.03 and less than 0.3, and z is morethan or equal to 0 and less than or equal to 0.5. The invention also discloses a method for preparing the nickel-cobalt composite oxide and the nickel-cobalt doped oxide. The nickel-cobalt composite oxide and the nickel-cobalt doped oxide have the advantages of excellent sphericility degree, high density, complete crystal and good activity.

The invention provides a preparation method of molybdenum boride powder. In the preparation steps, the molybdenum boride powder which completely accords with material design phase compositions can be controlled to be prepared by means of a high-temperature and high-pressure synthesis mode according to setting of the B/Mo mole ratio n (n=0.5, 1, 2, 2.5, 4) before synthesis, controllable synthesis of target molybdenum boride material phase compositions is achieved, and the synthesized molybdenum boride powder is uniform in particle size, complete in grain crystallization and excellent in property. The method is controllable in technological process, short in technological route, high in targeted property, convenient to operate, efficient, economical in energy, safe and good in reliability. The finished molybdenum boride powder is uniform in particle size distribution and complete in grain crystallization, the chemical purity is higher than or equal to 99.8%, and the product quality stability is good, the properties are obviously improved compared with a molybdenum boride material synthesized through a conventional method, and therefore the produced molybdenum boride material shows excellent physical and chemical properties in industrial application.

The invention relates to a heat-conductive and flame-retardant PET composite material and a preparation method thereof. The composite material comprises 80-100 parts of PET, 16-18 parts of a heat-conductive and flame-retardant boehmite composite filler, 1-3 parts of nanometer titanium dioxide, 0.2-0.4 part of a compatibilizer and 0.1-0.5 part of an antioxidant. The heat-conductive flame-retardantboehmite composite filler is used, and boehmite is a small white crystal, and has the characteristics of completeness in crystallization, fine crystal grains, few crystal structure defects and high thermal coefficient, so the heat conductivity of the PET composite material is improved; and the boehmite generates water and Al2O3 in the thermal decomposition process, the water can dilute flammable gas, and the Al2O3 solid covers the surface of a PET substrate to block and delay the burning rate, so the effects of flame retardant and smoke suppression are achieved.

The invention discloses a preparation method of KNbO3 nano solid solution with adjustable optical band gap. The preparation method is as follows: adding citric acid monohydrate into deionized water for completely dissolving, then adding basic nickel carbonate, heating and stirring to form a transparent solution A; adding niobium oxalates into the deionized water for completely dissolving to form a solution B; slowly adding dropwise the solution B into the solution A, fully stirring, successively dissolving anhydrous potassium carbonate and barium carbonate into a mixed solution of the solution A and the solution B for full reaction and stirring to form a transparent solution C; finally adding ethylene glycol, and fully stirring to form a solution D; heating the D solution for evaporation and promotion of citric acid and ethylene glycol esterification, drying to form a dark yellow solid precursor; grinding the precursor, and calcining in air atmosphere to eventually obtain the nano solid solution with the chemical formula of [KNbO3] 1-x [BaNi1 / 2Nb1 / 2O3-Delta] x. The product exhibits better photocatalytic effect in visible region.

The invention provides a preparation method of a three-dimensional TiO2 crystal film. The method comprises steps of: letting discharge gas in medium block discharge plasma reactor by employing a normal pressure low temperature radio frequency medium block glow discharge method; the discharge gas discharging to generate plasma jet by radio frequency alternating current; sending a precursor and carrying gas to a plasma zone to carry out reaction and precipitate on a substrate, so as to obtain the three-dimensional TiO2 crystal film. The method is characterized in that the precipitate is inner glow precipitate. The TiO2 obtained by the invention has a large proportion of {001} active surface and a unique three-dimensional structure forming by intersecting growth of a {101} surface, a {001} surface and a {101} surface; and the titanium dioxide film irradiates strong visible fluorescence by excitation of laser of 325 nm wavelength at room temperature.

The invention relates to rare-earth type lithium iron phosphate serving as the cathode material of a lithium secondary battery and a preparation method thereof. The rare-earth type lithium iron phosphate contains 100 mole fractions of lithium iron phosphate, 3.9-7.8 mole fractions of rare-earth alloy and 1.1-2.2 mole fractions of cellulose acetate. The preparation method of the rare-earth type lithium iron phosphate comprises the following steps of: putting an iron source compound, a lithium source compound, a phosphorus source compound and a rare-earth material into a powder mixer for powder mixing; in the powder mixing process, gradually spraying cellulose acetate dissolved in acetone to the mixed powder so that cellulose acetate is uniformly stuck on the mixture particles of the four materials, and drying; pre-sintering the dried mixture particles in an atmosphere furnace under inert gas protection; and carrying out heat preservation on the pre-sintered powder in the atmosphere furnace under inert gas protection to obtain the rare-earth type lithium iron phosphate. The rare-earth type lithium iron phosphate provided by the invention has the advantages of good conductive performance, relatively short preparation time and the like.