59results about How to "Well-developed grains" patented technology

The invention provides a film-coating production technology for nano zinc oxide and belongs to the technical field of fine petrochemicals and chemicals. The technological process is that an alkali carbonic acid zinc film is coated uniformly on the surfaces of light calcium carbonate and inner pores thereof, subjected to decentralized processing, and then calcined and activated in a dynamic calcination furnace at the temperature of 400 to 500 DEG C, so as to prepare the nano zinc oxide. The nano zinc oxide prepared through the technology belongs to a low-zinc product (containing 24 to 30 percent zinc), has the advantages of stable nano size, stable nano material properties, completely developed crystal grains, small particle diameter, uniformity in distribution, low reunion degree, high activity and good dispersivity, and can be widely applied to rubber, tires, catalysis, magnetism, optics, electricity, chemistry, physics, biology and the like.

The invention discloses a method for preparing a ZrO2-CeO2/CNTs composite nanotube by a hydrothermal method, which is a method for preparing a composite carbon nano tube based on nanoscale cerium oxide, nanoscale zirconia and a carbon nano tube. The preparation method comprises the steps of: sequentially adding the carbon nano tube, a surface active agent, zirconium oxychloride, cerous nitrate and deionized water which serve as raw materials according to stoichiometric ratio; performing ultrasonic dispersion to uniformly mix the raw materials; dripping ammonia water into the mixed raw materials until the pH value is 9.5; and performing hydro-thermal treatment to prepare a product, wherein the tube diameter of the prepared ZrO2-CeO2/CNTs composite nanotube is between 50 and 80 nanometers, and a specific surface area reaches 70-150 m<2>/g; and the ZrO2-CeO2/CNTs composite nanotube exists in the form of complete solid solution of a square/cubic system, the crystallinity reaches over 75 percent, and the ZrO2-CeO2/CNTs composite nanotube is uniform in loading and has no agglomeration phenomenon. The method has the advantages of simple process, no need of high-temperature calcination, low energy consumption and the like.

The invention discloses a method for treating arsenic-containing wastewater and solidifying arsenic. The method comprises the following steps: separating and enriching arsenic in the arsenic-containing wastewater in the form of calcium arsenate or/and calcium arsenite precipitate; and oxidizing the obtained arsenic enriched product in a ferric sulfate or ferrous sulfate solution, and carrying outnormal-pressure reaction or pressurized hydrothermal reaction or normal-pressure hydrothermal reaction, so that arsenic in the arsenic enriched product is solidified in the form of scorodite crystals.The obtained scorodite crystals are complete in grain development, uniform in grain distribution and stable in structure under acidic conditions. The method has the advantages of high operation efficiency, good arsenic fixation effect, convenience in operation, low arsenic solidification treatment cost and the like, and is suitable for industrial application of harmless treatment of arsenic-containing wastewater.

The invention discloses a Fe3O4/MoS2/BiVO4 material preparing method, a product and an application of the product. The method comprises the steps: firstly, dissolving ferric chloride hexahydrate, sodium acetate and polyethylene glycol in ethylene glycol, carrying out a reaction at the temperature of 180-200 DEG C for 8-9 h, and thus obtaining ferric oxide; then, mixing sodium molybdate dehydrate,sodium molybdate tetrahydrate and thiourea evenly, adding ferroferric oxide, and carrying out a reaction for 22-24 h at the temperature of 180-200 DEG C, to obtain a Fe3O4/MoS2 material; finally, dissolving bismuth nitrate pentahydrate and ammonium metavanadate in deionized water, adding the Fe3O4/MoS2 material, mixing evenly, carrying out a reaction for 15-17 h at the temperature of 160-170 DEG C, and thus obtaining a Fe3O4/MoS2/BiVO4 composite material. When the composite material is used as a photocatalyst for treating tetracycline hydrochloride wastewater, the degradation rate can reach 90% or more, and the photocatalytic efficiency can be improved. At the same time, because of the presence of Fe3O4, the photocatalyst can be recovered more conveniently and simply for repeated experiments, the recovery cost of the photocatalyst is reduced, and the repeated utilization rate of the photocatalyst is improved.

The invention provides a high-frequency high-impedance material of manganese-zinc ferrite and a preparation method of the high-frequency high-impedance material. Under the premise that scientific ratio of iron to manganese to zinc in the manganese-zinc ferrite is ensured, a certain amount of micro-constituents are also added, and contain a plurality of metal ions: Cu<2+>, Ta<3+>, Ca<2+>, Co<2+>, Ti<4+>, Ni<2+>, Sn<4+>, Bi<3+>, V<5+>, Nb<5+>, Si<4+>, Mo<6+>, Mg<2+>, Al<3+>. The main constituents and a plurality of trace constituents work together; and the electromagnetic property of the material is changed by changing the grain boundary resistivity. Through detection, the impedance value of the high-frequency high-impedance material of the manganese-zinc ferrite rises along with increase of frequency (1KHz to 100MHz); the surface direct current is greater than or equal to 1Mohm; and the magnetic conductivity is between 3200 and 4800, and thus the high-frequency high-impedance material meets the application requirements of high-end original elements such as temperature-adjusting transformer elements of large air conditioners.

A low-temp sintered AIN-base composition is prepared from AIN (50-80 wt%), lead borosilicate glass (15-50), and LiF (rest) through hot pressing and sinter, including heating and pressurizing by threestages, and holding temp at 950 or 1000 deg.C under 18-25 MPa for 2-8 hr. Its advantages include low sinter temp and density, high heat conductivity (11 W/m.k) and low cost.

The invention provides a method used for preparing flake-like silicon dioxide powder, and belongs to the technical field of powder particle size and morphology control. According to the method, bauxitic clay ore powder containing SiO2 is taken as a raw material; an activator, a dispersant, and a crystal grain morphology control agent are added into the raw material for uniform mixing; an obtained mixed powder is subjected to calcining in atmosphere containing halogen, and obtained silicon halide is subjected to hydrolysis so as to obtain silicon dioxide and halogen hydride; after calcining, the valve of a sealed reaction container is unsealed, so that high pressure gas in the sealed reaction container is delivered into a gas-solid separator with a larger volumn via expansion so as to realize gas-solid separation of silicon halide with gas phase and obtain the flake-like silicon dioxide powder, wherein the gas-solid separator is provided with a water cooling jacket. Thickness of the flake-like silicon dioxide powder is less than 0.2 <mu>m, and average diameter-to-thickness ratio is higher than 50. Reaction temperature of the method is relatively low; the method is simple; energy consumption is low; production cost is low; and the diameter-to-thickness ratio of the flake-like silicon dioxide powder can be adjusted.

The invention provides a method for preparing flaky alumina powder, belonging to the technical field of powder particle size and shape control. The technical process comprises the following steps: by using industrial aluminum hydroxide or transitional-phase alumina powder as a raw material, adding a crystal seed and a crystal grain shape control agent into the raw material powder, uniformly mixing the raw material powder, and pressing into a billet; and carrying out high-temperature calcination on the billet in an atmosphere containing hydrogen halide and shape control component, crushing the calcination billet into powder, carrying out secondary forming, and carrying out low-temperature calcination in an atmosphere containing higher-concentration hydrogen halide, thereby obtaining the flaky alumina powder, of which the thickness is less than 0.2 mu m, the average radius-thickness ratio is greater than 50 and the alpha-Al2O3 content is 100%. The method has the advantages of simple preparation technique and low manufacturing cost.

The invention discloses a preparation method of a LiNixCoyMnl-x-yO2 cathode material for a lithium ion battery. A NixCoyMnl-x-yCO3 precursor is prepared by adopting a solvent/hydrothermal method, wherein urea is utilized as a complexing agent, so as to avoid a phenomenon of segregation of transition metal ions, and ensure uniform precipitation of the transition metal ions, then by thoroughly mixing with a lithium source, LiNixCoyMnl-x-yO2 is prepared by utilizing a high-temperature solid phase method, and then the conductivity is improved by adding carbon fiber, thereby improving the rate performance of the LiNixCoyMnl-x-yO2 cathode material. The LiNixCoyMnl-x-yO2 cathode material obtained by the preparation method disclosed by the invention has relatively high specific capacity, good large rate performance and excellent cycle performance, and can be applied to various fields such as portable electronic devices, electric vehicles and energy storage equipment.

A preparation method of hexagonal-prism-shaped Sm(OH)3 nanocrystalline comprises the steps that a solution A with the Sm<3+> concentration being 0.010-0.150mol/L is prepared by dissolving Sm(No3)3*6H2O in distilled water; a reaction precursor solution is formed by adjusting the pH value of the solution A to 7.0-11.0 through diethylenetriamine; the reaction precursor solution is poured into a hydrothermal synthesis reactor, the hydrothermal synthesis reactor is put in an electrothermal blowing dry box after being sealed, a reaction is conducted for 6-24 hours at the temperature of 50-120 DEG C, and after the reaction is finished, the hydrothermal synthesis reactor is naturally cooled to the room temperature; products are centrifugally washed for 4-6 times through distilled water and absolute ethyl alcohol, the products are collected and dried for 2-4 hours at the temperature of 60-80 DEG C in a vacuum mode, and the hexagonal-prism-shaped Sm(OH)3 nanocrystalline is obtained. According to the preparation method, instruments and equipment are simple, control is easy, operation is convenient, energy consumption is low, safety is good, and the hexagonal-prism-shaped Sm(OH)3 nanocrystalline prepared in the method is high in purity, strong in crystallinity, uniform in morphology, good in dispersity and controllable in grain growth.

The invention provides a powder material for 3D printing. The powder comprises a wear-resistant phase and a binding phase, wherein a mixture of sintered WC-Co hard alloy spherical particles and tungsten carbide particles serves as the wear-resistant phase, and Co-based alloy serves as the bonding phase. The weight percentage of the wear-resisting phase is 20-60%, the weight percentage of the bonding phase is 40-80%, the weight percentage of the sintered WC-Co hard alloy spherical particles is 5-15%, and the weight percentage of the coarse-grained or monocrystalline tungsten carbide particles is 15-45%. The failure period can be effectively avoided or delayed, and the wear resistance and working efficiency of the material are improved.

The invention relates to MgO partially stabilized ZrO, MgO partially stabilized ZrO ceramic, preparation methods of MgO partially stabilized ZrO and the MgO partially stabilized ZrO ceramic and an application of the MgO partially stabilized ZrO ceramic. The preparation method of MgO partially stabilized ZrO comprises following steps: a Zr source and an Mg source in a molar ratio of Zr to Mg being4:1-40:1 are mixed with a dispersing gent in a solvent, and a mixed solution is obtained; the pH value of the mixed solution is regulated to 2-3, under the condition of continuous stirring at 60-80 DEG C, epoxypropane is added to the mixed solution until the pH value of the reaction system reaches 7-8, and a precursor is obtained by solid-liquid separation; the precursor is mixed with water, the mixed solution is subjected to a hydrothermal reaction at 50-220 DEG C, and MgO partially stabilized ZrO is obtained by the solid-liquid separation. With the adoption of the method, MgO partially stabilized ZrO with higher sintering activity can be prepared, so that the MgO partially stabilized ZrO ceramic with higher bending strength and higher toughness is obtained.

The invention relates to a lead-free piezoceramic material with manganese doping with bismuth titanate sodium group and a preparation method thereof, belonging to the field of functional ceramics. The invention selects 80.15-84.61wt% of Bil/2Nal/2TiO3, 10.26-13.19wt% of Bil/2K1/2TiO3, 2.17-5.44wt% of BaTiO3 as the substrate, and takes 0.32-1.28wt% of MnCO3 as the doping material, controls the pre-synthesizing temperature to a range of 800-950 DEG C and preserves the temperature for 1-4 hours; and keeps the sintering temperature to a range of 1130-1190 DEG C and preserves the temperature for 1-4 hours to obtain the novel lead-free piezoceramics. The piezoceramics obtained by utilizing the method provided in the invention have the advantages of high piezoelectric constant (191) and mechanical quality factor (314), good microcosmic structure, complete growth of crystal particles. The lead-free piezoceramics provided in the invention can be used for manufacturing piezoelectric devices such as piezoelectric sensor and actuator and the like.

The invention belongs to the technical field of pigment synthesis and discloses a low-hexavalent-chromium precipitated copper and chromium black pigment as well as a preparation method and applicationthereof. The method comprises the following steps: (1) preparing a nitrate solution, preparing raw materials into the nitrate solution containing Cu<2+>, Cr<3+> and Fe<3+>; (2) preparing a combustionsolution, mixing the nitrate solution and auxiliary fuel to obtain the combustion solution; (3) carrying out low-temperature self-propagating combustion: after evaporating and concentrating the combustion solution, heating the solution in a heating device and initiating the self-propagating combustion; collecting a combustion product; (4) mixing and carrying out ball milling: carrying out the ball mixing on the combustion product and inorganic salt and mixing to obtain a mixture; (5) carrying out high-temperature calcining: putting the mixture into the heating device and carrying out the high-temperature calcining; (6) carrying out post-treatment: carrying out water washing on a product obtained by the high-temperature calcining and drying to obtain the copper and chromium black pigment.The copper and chromium black pigment prepared by the preparation method has the advantages of high purity, complete crystalline grains, good dispersity and low hexavalent chromium content; the pigment has a small average grain diameter which can reach 0.5mu m.

The invention provides nano barium titanate microcrystals and a preparation method thereof, and barium titanate powder and a preparation method thereof, and relates to the technical field of nano materials. The preparation method of the nano barium titanate microcrystals comprises the following steps of: a nano titanium dioxide aqueous dispersion with the mass concentration of not less than 20% and a barium hydroxide aqueous solution are rapidly mixed to allow the temperature of the obtained mixed system to be at least 2 DEG C lower than the temperature of the barium hydroxide aqueous solutiondue to the rapid mixing of the two; under an inert atmosphere, the mixed system is subjected to normal pressure hydrothermal synthesis reaction at 90-110 DEG C, and reaction products are collected, washed and dried to obtain the nano barium titanate microcrystals. According to the preparation method of the nano barium titanate microcrystals, the nano barium titanate microcrystals with small particle diameter, uniform particle diameter distribution and high purity can be obtained, and the high-quality barium titanate powder can be obtained by calcining the nano barium titanate microcrystals serving as a raw material.

The invention relates to a transition element doped barium-strontium titanate based composite ceramic, which comprises 40 weight percent of xM-Ba0.6Sr0.4TiO3 and 60 weight percent of MgO, wherein M is a transition metal, and x is the molar ratio of the transition metal M to Ba0.6Sr0.4TiO3 and ranges from 0.25 to 1.25 percent. Because of the doping of the transition element, the pressure control adjustable rate of the M-Ba0.6Sr0.4TiO3/MgO composite ceramic is improved, the microwave dielectric loss is greatly reduced, and meanwhile the breakdown field strengths of ceramic blocks are more than 28 kV/mm and can meet the using requirements of microwave dielectric materials.

The invention particularly relates to a preparation method of alpha-alumina with narrow original grain size distribution, and belongs to the technical field of inorganic non-metallic materials. The preparation process comprises the following steps: taking aluminum hydroxide (Na2O content is 0.35-0.5%) as a raw material, adding a proper amount of seed crystals and a calcining aid, performing uniform mixing, performing calcining in a rotary kiln at 1,300-1,500 DEG C for 20-60 minutes, performing cooling, and performing ball-milling to a certain grain size, obtaining the original grain size narrow-distribution calcined alpha-alumina (D90/D10 < = 4), and finally packaging the calcined alpha-alumina into a finished product to be sold. The alpha-aluminum oxide is prepared through seed crystal induction, the phase change temperature of the alpha-aluminum oxide is reduced, powder agglomeration is reduced, the original grain size narrow distribution (D90/D10 < = 4) of the calcined alpha-aluminum oxide is controlled, and the re-sintering activity and the specific surface area of the alpha-aluminum oxide powder material and the mechanical performance, the compression resistance and the like of downstream products are remarkably improved.