47results about How to "Reduce hard agglomerates" patented technology

A synthetic method of a novel visible light photocatalyst Bi2MoO6 (bismuth molybdate) is provided. The method includes the following steps: weighing Bi(NO3)3*5H2O and (NH4)6Mo7O24*4H2O solids at the theoretical ratio by mass of 14:1, dispersing the weighed solids into an appropriate amount of deionized water, stirring to obtain white curdy precipitates, placing the precipitates in a magnetic stirrer and stirring at normal temperature for 30 minutes, subjecting to ultrasonic treatment with a ultrasonic generator for 30 minutes to allow intensively mixing, allowing reactions of the treated white precipitates at 150-200 DEG C under sealed conditions, filtering the reaction product to collect flavescent precipitates, washing, drying, and grinding to obtain Bi2MoO6 (bismuth molybdate) photocatalyst. The photocatalyst has good photodegradation effect on target pollutants; and when the temperature of hydrothermal synthesis is 160 DEG C, the removal rate of target pollutant 4BS after photodegradation for 90 minutes reaches 99.5%. The inventive synthetic method has the advantages of simple process and low requirement for equipment, and is suitable for the synthesis of highly-active visible light photocatalyst Bi2MoO6 (bismuth molybdate).

The invention discloses a method for preparing a nano-size catalyst of copper chromite and copper ferrite, and belongs to the technical field of nano-size catalyst preparation. The method of the invention comprises a sol-gel process and a vacuum freezing drying (VFD) process. Firstly, a mixed solution is prepared from a soluble copper salt and a soluble chromium salt or iron salt, added with a surface active agent, and mixed uniformly, and then the system is added with a precipitating agent to carry out precipitation reaction under the condition that the pH value is between 6.8 and 9.5, then is kept stand, aged, washed and melted in a water bath for 2 to 8 hours at a temperature of between 70 and 95 DEG C, thus sol is obtained; then the sol is subjected to freezing drying in a vacuum freezing dryer to obtain dried gel which is a precursor of the catalyst; finally, the dried gel is roasted to obtain the nano-size catalyst of copper chromite (CuCr2O4) or copper ferrite (CuFe2O4). The catalyst prepared by the method has the advantages of high purity, small grain diameter, good dispersivity, high catalytic activity, and the like.

The invention provides an aftertreatment method for doped nano-zirconia powder through spray freeze drying. The nano-powder prepared by the aftertreatment method has the advantages of regular shape, a few hard agglomerates, small particle size, low uniform sintering temperature and the like, and a nano-ceramic material which has the advantages of high density, strength, toughness, light-transmitting property and reliability and the like can be prepared. By the method, personalized nano-zirconia powder with small using amount can be prepared by introducing an additive in the aftertreatment process.

The invention discloses a preparation method of indium tin oxide composite powder, belonging to the technical field of preparation of indium tin oxide composite powder. The method comprises the following steps: preparation of mixed salt liquid: putting an InCl3 liquid and an SnCl4 liquid into a reaction kettle according to the In2O3:SnO2 weight ratio of 9:1, and uniformly mixing; addition of dispersing agents: adding polyvinylpyrrolidone, beta-alanine and ethanediol according to the weight ratio of 2:1:3, and adding more than 20% excessive of urea; coprecipitation reaction: gradually heating to 60-90 DEG C, keeping the temperature while continuously stirring until the In<3+> in the reaction solution is completely precipitated, carrying out ultrasonic treatment for 1 hour, continuing stirring, and aging to obtain an indium tin precipitate; and washing, drying, grinding, screening and carrying out high-temperature calcination to obtain the high-sintering-activity nano indium tin oxide composite powder. The indium tin oxide composite powder prepared by the method has the advantages of less hard aggregation and favorable flowability, and is easy for pressure molding.

The invention discloses a preparation method of a mesoporous SnO2 material. The preparation method comprises the following steps of dissolving 3.1g of CTAB (Cetyl Trimethyl Ammonium Bromide) into 40mL of water to obtain a surfactant solution; adding 0.11g of dodecylamine into the surfactant solution; adding a prepared ammonia water solution into a mixed solution to obtain a template agent solution; dissolving 10.5g of SnCl4.5H2O into 80mL of water and adding the prepared solution into the template agent solution to obtain a white slurry-like solution; performing reaction on the white slurry-like solution at the temperature of 160 DEG C for 12h, roasting the treated white slurry-like solution in air atmosphere, and preserving heat for 1h to prepare the mesoporous SnO2 material. The invention further discloses a high-sensitivity alcohol-sensitive gas sensor and a preparation method thereof. Impurities and structural defects caused by after-treatment such as high-temperature calcination or ball milling can be avoided, high-temperature roasting crystallization is not needed, and hard powder agglomeration which is difficult to avoid in the high-temperature roasting process is reduced.

The invention discloses a preparation method of high-dispersibility ITO powder and belongs to the technical field of preparation of indium tin oxide composite powder. The method comprises the steps of adding metal In to a HNO3 solution for completely dissolving; weighing SnCl4.5H2O white crystal at the mass ratio of In2O3 to SnO2 being 9:1, adding the SnCl4.5H2O white crystal to an indium salt solution and stirring evenly to prepare a mixed salt solution; adding a composite dispersing agent to a NH4AC buffer solution; dropwise adding ammonia water and a mixed salt solution to the buffer solution at the same time, thereby generating a indium-tin hydroxide precursor; reacting completely, ageing and carrying out suction filtration, washing the obtained indium-tin hydroxide precursor with water and an organic solvent separately; standing the washed indium-tin hydroxide precursor at room temperature and naturally airing; and calcining at a high temperature for 4h to obtain yellow ITO powder. The ITO powder prepared by adopting the preparation method has few hard agglomerates, and is good in mobility and easy to shape by pressing.

The invention discloses a high-sintering active indium tin oxide mixed powder preparation method. The method particularly comprises the steps that high-activity nano SnO2 powder is prepared, wherein a compound dispersing agent is dissolved into water, an appropriate amount of SnCl4 is added, stirring is conducted till the mixture is completely transparent, and clarification is conducted; stirring is kept, an appropriate amount of ammonium hydroxide is added, a tin-containing precursor is obtained, after the precursor is placed in a high pressure reaction kettle to be subjected to hydrothermal treatment, sediment is taken out to be washed repeatedly, dried and subjected to low temperature thermal treatment, and nano SnO2 powder is obtained; metal indium is dissolved into hydrochloric acid, a InCl3 aqueous solution is generated, and a method similar to the method for synthesizing SnO2 powder is used for preparing nano In2O3 powder; the prepared InCl3 is mixed with SnO2 in proportion, PVA is added, by means of a spray drying technology, mixed indium tin oxide granulation powder which is less in aggregation, good in liquidity and prone to pressure molding is obtained, and the preparation method can be suitable for preparing high-end ITO target materials.

The invention discloses a preparation method of a low-cost and high-densification ITO target material. The preparation method comprises the following steps: weighing metal In, adding into an HNO3 solution for complete dissolving, weighing SnCl4.5H2O white crystals, and adding into an indium salt solution, so as to prepare a mixed salt solution; preparing a NH4AC buffer solution, and adding a compound dispersing agent into the buffer solution; simultaneously dropwise adding ammonia water and the mixed salt solution into the buffer solution, so as to generate an indium-tin hydroxide precursor; after the reaction is complete, ageing, carrying out suction filtration, and respectively washing with water and an organic solvent; standing at room temperature for naturally airing; calcining at a high temperature for 4 hours, so as to obtain yellow ITO powder; and granulating the ITO powder, carrying out prepressing formation, so as to obtain a green body, and carrying out degreasing and sintering, so as to obtain the high-purity and high-density ITO target material. The ITO powder prepared in a preparation process of the preparation method has the characteristics of low sintering temperature and short time under a pressureless sintering condition and can be used for preparing the ITO target material which approaches to theoretical density and has relatively low porosity.

The invention provides a diamond polishing solution for rough polishing of a silicon carbide wafer and a preparation method. The diamond polishing solution comprises the following components in percentage by weight: 0.1-1% of a diamond abrasive, 3-10% of an oiliness agent, 0.1-0.4% of a dispersing agent, 0.1-0.5% of modified urea solution, 0.1-0.5% of an activating agent and the balance of basic solvent. By adopting the abrasive two-step treatment method, the utilization rate of the polycrystalline diamond powder can be effectively increased, and meanwhile, the problem of scratching caused byoversize particles and hard aggregates in the polishing solution is effectively reduced; the modified urea solution is adopted as an organic suspending agent, the polishing solution has no obvious layering phenomenon after being placed for a long time, and compared with inorganic suspending agents such as hydrophobic modified fumed silica and organic bentonite, polishing scraps are not prone to adhering to a polishing disc and are easy to clean.

The invention relates to the field of zirconium oxide ceramic powder preparation, in particular to a method for removing Cl <-> in zirconium oxide powder, which is characterized by comprising the following steps: S1, putting zirconium salt into water, stirring and heating to prepare a zirconium salt solution; s2, mixing the zirconium salt solution and ammonia water, adjusting the pH value to 7-7.5, continuously adding the ammonia water solution, adjusting the pH value of the solution to 9-10, and stirring the mixture to prepare slurry; s3, washing the slurry until the content of Cl <-> in the slurry is lower than 300ppm, and then carrying out filter pressing to obtain a filter cake; s4, calcining the filter cake to obtain calcined powder; and S5, mixing the calcined powder with a hot acid solution, carrying out ball milling and sand milling, carrying out spray granulation, and sieving the granules to obtain the zirconium oxide powder. According to the method, hot acid is added during ball milling of the calcined powder to break the acid-base balance of a solution, so that the powder is further cleaned, the content of Cl <-> in the powder is reduced, and hard agglomeration of the powder can be obviously reduced; therefore, the purity, sintering activity and the like of the powder can be improved, the permeability probability of parts made of the powder can be obviously improved, the sintering temperature can be reduced, and the cost can be saved.

The invention discloses a particle size control method of ceramic powder prepared by a wet chemical method. The particle size control method comprises the following steps: adding a combustible to initial powder prepared by a wet chemical method, uniformly mixing, drying, and calcining so as to obtain the ceramic powder, wherein the combustible is a solid particle combustible which can be completely burned off at a temperature which is below calcination temperature and is free of fusion and remained ash. The particle size control method is simple, convenient, easy to operate, economical and practicable; and the sintering degree among nano-powder particles in a calcination process can be controlled by adding the combustible, so as to reduce and control agglomeration particle sizes of nano-powder, so that the nanometer ceramic powder with uniform compositions and controlled particle sizes is realistically and effectively obtained.

The invention discloses yttrium-stabilized zirconium oxide hafnium powder for thermal spraying and a preparation method of the yttrium-stabilized zirconium oxide hafnium powder. The preparation method comprises the following steps: firstly, preparing a yttrium-stabilized zirconium oxide hafnium precursor, then carrying out primary calcination, ball milling, sanding and spray granulation to prepare yttrium-stabilized zirconium oxide hafnium granulated powder, and finally, carrying out secondary calcination and screening to prepare the yttrium-stabilized zirconium oxide hafnium powder for thermal spraying. The yttrium-stabilized zirconium oxide hafnium powder is prepared by using ammonium bicarbonate as a precipitator, so that hard agglomeration during calcination is reduced; the yttrium-stabilized zirconium oxide hafnium powder is used as a thermal barrier coating material, and compared with traditional yttrium-stabilized zirconium oxide powder, the service temperature of the coating is increased; the content proportion of zirconium and hafnium in the yttrium-stabilized zirconium oxide hafnium powder for thermal spraying is controllable, and compared with yttrium-stabilized hafnium oxide powder, the raw material cost is reduced.

The invention discloses an antibacterial toughening type polyethylene film and a preparation method thereof, the antibacterial toughening type polyethylene film comprises the following components in parts by weight: 45-50 parts of high density polyethylene particles, 15-20 parts of low density polyethylene particles, 0.5-0.75 part of an antioxidant, and 6-8 parts of antibacterial toughening particles; the antibacterial toughening particles are hydrotalcite particles prepared by metal oxide sol intercalation; and the preparation method comprises the following steps: stirring and mixing the low-density polyethylene particles, the antioxidant and the antibacterial toughening particles according to a formula, and collecting a mixed material; s2, extruding and granulating the mixed material, and collecting extruded particles; and S3, stirring and mixing the extruded particles and high-density polyethylene particles, extruding, blowing a film, and rolling to prepare the antibacterial toughened polyethylene film. The antibacterial toughening type polyethylene film can be used for fresh-keeping packaging and has excellent antibacterial performance and mechanical strength, and the mechanical strength of a polyethylene film fresh-keeping packaging material is improved.

The invention discloses a preparation method of submicron small primary crystal alpha aluminum oxide for a CMP (chemical mechanical polishing) solution, which adopts a two-stage decomposition method to directly decompose aluminum hydroxide with the average particle size D50 of 0.5-1.2 mu m and the purity of more than 99.6%, the aluminum hydroxide is small in particle size and high in purity, and the difficulty of subsequent grinding and impurity removal is reduced; the preparation method comprises the following steps: adding a composite activator into prepared aluminum hydroxide slurry, grinding by a sand mill until the average particle size D50 is 0.3-1.0 [mu] m, activating, and carrying out spray granulation on the activated aluminum hydroxide slurry to obtain false agglomerated large particles with the average particle size D50 being 35-55 [mu] m, so that the aluminum hydroxide granulated powder and the activator can fully react in the calcining process; and hard agglomeration is reduced, so that the difficulty of airflow crushing of the alpha alumina powder after subsequent calcination is reduced. By adjusting a calcining process, the aluminum hydroxide powder after spray granulation is fed into a pushed slab kiln to be calcined at the temperature of 1100-1300 DEG C, so that the purity of the calcined aluminum oxide is greater than 99.9%, the alpha conversion rate is greater than 95%, the original grain size is 0.2-0.4 mu m, and the growth of the original crystal of the aluminum oxide can be effectively inhibited.