49results about How to "Uniform size distribution" patented technology

The invention belongs to the technical field of wastewater treatment, and particularly relates to an efficient ozone micro-nano bubble preparation system and a process method thereof. The device further comprises an ozone preparing unit, a gas conveying pipeline, a jet flow unit, a spiral mixing unit, a Venturi tube, a microporous membrane unit and a reaction unit. The ozone producing unit is connected with the jet flow unit through a gas conveying pipeline, the ozone producing unit comprises an ozone generator, and the gas inlet pressure is regulated and controlled through a gas valve in the gas conveying pipeline; and the jet flow unit is used for generating and conveying a mixed solution with ozone microbubbles. The jet flow unit enables the mixed liquid to form ozone microbubbles based on a Venturi effect and a hydraulic shearing effect; by arranging the jet flow unit, the spiral mixing unit, the Venturi tube and the microporous membrane unit, ozone micro-nano bubbles with high concentration and uniform size distribution can be generated under relatively low energy consumption, so that the treatment efficiency of the ozone micro-nano bubbles in the technical fields of wastewater treatment and environmental protection is improved.

The invention provides a method for preparing porous iron phosphate through an emulsion reaction. The method comprises the following steps: (1) reacting an iron source and a phosphorus source according to a certain proportion to prepare an iron phosphate precursor; (2) reacting the iron phosphate precursor with a foaming agent to obtain emulsified iron phosphate dihydrate; (3) adding a cross-linking agent for further emulsification and dispersion, and adding a curing agent to obtain cured iron phosphate dihydrate; and (4) drying, calcining and crushing the iron phosphate dihydrate to obtain the porous iron phosphate. The method is specifically characterized in that the porous iron phosphate with the three-dimensional foam structure is finally obtained through the processes of emulsification foaming, curing reaction, calcination pore-forming and the like in sequence in the iron phosphate preparation process. The iron phosphate material prepared by the method has rich three-dimensional reticular porous structures, high specific surface area and high porosity. The lithium iron phosphate material prepared from the precursor material is high in electronic conductivity and can adapt to a high-rate lithium iron phosphate process. In addition, the raw materials used in the preparation process are cheap and easy to obtain, the preparation process is stable and controllable, and the iron phosphate prepared by the process has better application value and economic value.

The invention discloses a porous carbon microsphere material, a silicon-carbon composite material and a preparation method and application thereof, and the preparation method of the porous carbon microsphere material comprises the following steps: S1, mixing a polymer, a solvent and conductive carbon black to obtain a precursor solution; s2, preparing the precursor solution into a carbon microsphere precursor material by adopting an electrostatic spraying method; s3, sequentially carrying out pre-oxidation and heat treatment on the carbon microsphere precursor material to obtain a spherical carbon material; s4, performing supercritical hydrothermal activation on the spherical carbon material, and performing post-treatment to obtain a porous carbon microsphere material; the activation temperature is 300 to 600 DEG C; the activation pressure is 15 to 30 MPa; the activation time is 0.5 to 1 hour. The porous carbon microspheres prepared by the invention have a series of adjustable physical and chemical characteristics, highly developed pore structures, high mesoporosity and better mechanical strength, and can enable lithium ion batteries to have the characteristics of low pole piece expansion rate, high first coulombic efficiency, excellent cycling stability and the like when being further applied to the lithium ion batteries.

The invention relates to the technical field of inorganic non-metallic materials, in particular to an onion carbon preparation method based on a metal organic framework and onion carbon. The preparation method comprises the following steps: S1, synthesizing a metal organic framework precursor; s2, preliminary pyrolysis of the metal organic framework precursor; s3, etching and decomposing the formed metal particles; and S4, carrying out secondary pyrolysis on the primary pyrolytic carbon material. The carbon diameter of the prepared onion is 5-20 nm, and the carbon layer spacing is 0.34 nm. According to the preparation method, a metal organic framework is taken as a precursor, a two-step pyrolysis method is adopted, the precursor is carbonized at high temperature, a carbon material is etched again by ammonia gas and other gases released by thermal decomposition of melamine, and under the action, graphene is rearranged in the form of the same sphere center layer to form onion carbon particles with uniform sizes. The temperature and the reaction time in the preparation process can be accurately controlled, the preparation process is simple, the cost is low, the prepared onion carbon has relatively high purity and uniformity, and the oxygen reduction catalytic activity can be improved.

The utility model relates to the technical field of crushers, and provides a raw material crusher for producing furfural, which comprises a shell, a feed port is arranged at the top of the shell, a first discharge port is arranged at the bottom of the shell, mounting grooves are arranged on two sides of the feed port, dustproof mechanisms for dust prevention are arranged in the mounting grooves, and the first discharge port is arranged at the bottom of the shell. A smashing cavity, a smashing cavity and a filtering cavity are sequentially formed in the shell, a plurality of smashing mechanisms used for smashing raw materials are arranged in the smashing cavity, a smashing mechanism used for smashing the raw materials is arranged in the smashing cavity, a filtering mechanism used for filtering the raw materials is arranged in the filtering cavity, and a transmission mechanism is arranged on the side face of the shell. The crushing mechanism and the plurality of smashing mechanisms are all linked with the transmission mechanism, each smashing mechanism is linked with the rotating motor, and by means of the technical scheme, the problems that in the related technology, the complexity of a system is increased, resource waste is caused, and the stability and quality of a final product are affected are solved.

The invention discloses a high-work-function metal oxide target material and a preparation method thereof. The preparation method comprises the following steps: mixing high-work-function metal oxide powder, indium oxide powder and zinc oxide powder into mixed powder according to a set mass ratio; putting the mixed powder into deionized water, adding a dispersing agent, and blending to obtain slurry; the slurry is subjected to high-energy sanding, and a binder is added before sanding is finished; performing spray granulation on the slurry to obtain spherical granulation powder; carrying out compression molding on the spherical granulation powder, and carrying out cold isostatic pressing to obtain a target material biscuit; and the target biscuit is subjected to degreasing and sintering integrated treatment, and the high-work-function metal oxide target is obtained. The high-work-function metal oxide target material disclosed by the embodiment of the invention is small in grain size, uniform in distribution, high in target material density and excellent in electrical property, and can be used for preparing a flexible OLED anode layer thin film material, the device structure is simplified, and the cost is reduced and the efficiency is improved.

The invention provides a preparation method and application of a TEMP (Tetraethyl Methacrylate) Lip nano material, and the preparation materials of the TEMP Lip nano material comprise CH3CH2OH, CHCl3, THF (tetrahydrofuran), CH2Cl2, N (CH3) 3, NHS (N-Hydroxysuccinimide), 3-mercaptopropionic acid, 1, 3-dicyclohexylcarbodiimide, 4-amino-2, 2, 6, 6-tetramethylpiperidine, PBS (Phosphate Buffer Solution), alpha-GalCer, (2, 3-dioleoxy propyl) trimethyl ammonium chloride (DOTAP), 1, 2-dioleoyl-SN-glycerol-3-phosphorylethanolamine and dioleoyl phosphatidyl ethanolamine. The TEMP (at) Lip nano material is small in particle size and uniform in distribution, has negative potential, is good in corresponding biological solubility, is relatively stable in property after entering a living body, can safely transport an iNKT cell agonist, activates iNKT to improve the autoimmunity of the living body, and realizes the aim of treating tumors by using an autoimmune system.

The invention discloses an industrial preparation method of nano yttrium oxide for electronic ceramics, belonging to the field of rare earth hydrometallurgy technology. The invention first dissolves yttrium oxide in nitric acid to remove anionic impurities in yttrium oxide, then removes impurities through (NH4)2S solution to obtain a high-purity yttrium nitrate solution, then precipitates yttrium carbonate crystals through ammonia water and ammonium bicarbonate solution, and finally calcines and decomposes to obtain nano yttrium oxide for electronic ceramics. The yttrium oxide obtained by the invention is nano-sized, has a high specific surface area, and is easy to disperse. It is suitable for the electronic ceramic industry, especially for industrial production, and has broad application prospects.

The present invention provides a method for preparing Pickering emulsion with esterified starch and its application in food preservation, belonging to the technical field of preparation of granular emulsifiers and their application. Corn starch is dissolved in dimethyl sulfoxide, 3,6-dimethylphthalic anhydride is added with stirring, reacted, eluted, dried, crushed and sieved to obtain esterified corn starch; esterified corn starch is used as a granular stabilizer to prepare an aqueous suspension, an oil phase is added, and homogenization is performed to obtain a Pickering emulsion that can remain stable after storage for 50 days, which can significantly reduce the particle size of starch particles, and provide a modification method for stabilizing Pickering emulsion with modified starch, which has a simple process, a wide source of raw materials, and a low cost, and the emulsion has good emulsification performance and high stability. In addition, the Pickering emulsion prepared with esterified starch is applied to food preservation, especially in food cling film or preservatives. The food cling film can extend the shelf life of fresh pork to 10 days at 4°C, which provides an effective prerequisite for food safety.

The invention discloses a ZrN tritium-resistant coating and a preparation method thereof, and relates to the technical field of coatings. According to the preparation method of the ZrN tritium-resistant coating, Zr serves as a target material, nitrogen serves as reaction gas, and the ZrN tritium-resistant coating is deposited on the surface of a base body through magnetron sputtering. The invention provides the preparation method of the ZrN coating with high crystallinity and good tritium blocking effect for the solid tritium breeding cladding.

The invention relates to a carbon nitride quantum dot with surface and core dual design and a preparation method thereof, and belongs to the technical field of nano materials. In order to achieve the first purpose, the carbon nitride quantum dot with the surface and inner core dual design comprises at least one of polyacrylic acid with the average particle size of 3-10 nm, the inner core co-doped with boron and phosphorus elements and the surface covalently modified with the average molecular weight of 2000-5000. The preparation method of the carbon nitride quantum dot with the double design of the surface structure and the core structure is simple, easy to operate and wide in large-scale production prospect. While the carbon nitride quantum dots are prepared, boron and phosphorus elements are doped in the cores, polyacrylic acid functional groups are covalently modified on the surfaces of the carbon nitride quantum dots, and the obtained carbon nitride quantum dots with double design of surface and core structures are uniform in size distribution and have good hydrophilicity.

The invention discloses a preparation method of an efficient light-emitting silver-indium-sulfur and silver-indium-zinc-sulfur composite nano material, and belongs to the technical field of light-emitting nano materials and preparation. The preparation method comprises the following steps: by taking silver dibutyl dithiocarbamate, indium dibutyl dithiocarbamate and zinc carboxylate as precursors, uniformly mixing at a dodecane neutralization pretreatment temperature to form a mixed solution A; naturally cooling, adding dodecanethiol, and uniformly stirring and mixing to obtain a mixed solution B; at the reaction temperature, decomposing part of silver dibutyldithiocarbamate in the mixed solution B to generate silver sulfide clusters; the activity of the silver sulfide cluster is closely related to the size, the silver sulfide cluster is used as a seed to induce growth of silver-indium-zinc-sulfur, meanwhile, silver sulfide is converted into silver-indium-sulfur, finally, the silver-indium-sulfur and silver-indium-zinc-sulfur composite nano material is obtained, the band gap is 2.0-2.8 eV, the luminous efficiency is 52% or above, and the luminous efficiency can still be kept at 78% or above after five months. The preparation process disclosed by the invention is low in raw material cost and good in process controllability.

According to the mixing equipment with the automatic feeding mechanism, a material hopper is connected to the top of a supporting frame, and a conveying device is installed in the middle of the supporting frame; a first discharging opening of the material hopper is aligned to the feeding end of the conveying device, the discharging hopper is communicated with the interior of the mixing equipment, and the conveying device conveys materials into the mixing equipment through the discharging hopper; the mixing equipment comprises a mixing shell, a driving motor, a transmission assembly, a first mixing shaft and a second mixing shaft; the first mixing shaft and the second mixing shaft are arranged in the mixing shell side by side in a penetrating manner; the driving motor drives the first mixing shaft and the second mixing shaft to rotate through the transmission assembly; mixing fins are arranged on the first mixing shaft and the second mixing shaft in the axial direction. The whole structure is simple, and by arranging the material hopper, the conveying device, the discharging hopper and the mixing stirrer, it is ensured that plastic particles continuously and quantitatively enter the mixing stirrer to be pretreated.

The invention discloses cation modified nano graphene oxide and a preparation method thereof, the transverse size of the cation modified nano graphene oxide is 10-100 nm, the surface of the cation modified nano graphene oxide is non-covalently bound with organic quaternary ammonium salt cations through electrostatic interaction, and the organic quaternary ammonium salt cations are provided by a cationic surfactant. According to the invention, electrostatic interaction is combined with a quaternary ammonium salt cationic surfactant, and a hydrophobic long alkyl chain of the quaternary ammonium salt cationic surfactant is exposed outwards, so that the product can be stably dispersed in various organic solvents such as methanol, ethanol, acetone, ethyl acetate, N-methyl pyrrolidone (NMP), N, N-dimethylformamide (DMF), dichloromethane and the like; the limitation that traditional nano graphene oxide is only limited to a water phase is avoided, and the compatibility and application potential in the fields of polymer composite materials, oil paint, high-performance resin and the like are improved.

A hydrophilic gadolinium hydroxide nanosheet and a preparation method thereof. The hydrophilic gadolinium hydroxide nanosheet comprises, by mass percentage, 32.0%-40.0% of gadolinium oxide nanoparticles and 60.0%-68.0% of a silane coupling agent. The preparation method comprises: dissolving gadolinium oxide nanoparticles in deionized water to obtain a milky white dispersion A, reacting the milky white dispersion A with a diluted silane coupling agent with a pH adjusted to obtain a liquid B, and reacting the liquid B with a pretreated cation exchange resin to obtain clarified hydrophilic gadolinium hydroxide nanosheets. The hydrophilic gadolinium hydroxide nanosheets have uniform size distribution, stable crystal structure, good dispersibility, and are characterized by simple preparation process, mild reaction conditions, less by-products, high yield, low equipment requirements and short preparation cycle.

The invention discloses a method for continuously preparing a chiral enriched single-walled carbon nanotube by adopting a fluidized bed, and belongs to the technical field of carbon nanotubes. The method comprises the following steps: preparing a fluidized catalyst by a sol-gel method, mixing a metal catalyst salt, an inorganic sol carrier, a pore-forming template agent and an electrolyte gel to form gel, and drying and annealing to form the fluidized catalyst with the particle size of 50-200 microns and rich mesopores; the method comprises the following steps: reducing and activating a catalyst in a pretreatment reactor, introducing into a main reactor, introducing a carbon source gas and a carrier gas, and cracking and depositing a carbon source at an active center of the catalyst to grow a single-walled carbon nanotube; after the growth is finished, increasing the carrier gas flow and conveying a product to a cooling separator for collection; and after the main reactor is empty, the next batch of catalyst can be introduced without cooling to realize continuous preparation. According to the method, the catalyst metal is uniformly dispersed, the fluidization performance is excellent, the growth of multi-wall and large-diameter carbon nanotubes can be effectively inhibited, and the efficient and continuous preparation of the chiral enriched single-wall carbon nanotubes is realized.

The present invention provides a propylene ammoxidation catalyst with high wear resistance and a preparation method thereof, and relates to the technical field of catalysts. The preparation method comprises: preparing a Mo precursor solution, other metal solutions and a carrier solution containing sodium dodecyl sulfate; dripping the Mo precursor solution into the carrier solution in batches, and then mixing the other metal solutions to obtain a propylene ammoxidation catalyst; in the propylene ammoxidation catalyst, the stoichiometric composition of the metal oxide is M O12 Bi a Fe b A c B d C e O x ; A is Re and Zr; B is selected from at least one of Cs, Be and Ca; C is selected from at least one of Al and Co; a is 0.8-1.6, b is 2-3, c is 0.1-0.5, d is 0.1-0.3, and e is 0.3-0.9; x is a charge balance value. The propylene ammoxidation catalyst of the present invention has high catalytic activity, high stability and wear resistance, and the wear rate is significantly reduced.

The present invention relates to a preparation method for a titanium-based lithium ion exchanger. The method includes the following steps: step 1, preparation of lithium metatitanate precursor, namely, uniformly mixing titanium source, lithium source and water in proportion by ball milling, adding an adjuvant, and allowing reaction by ultrasonic heating and stirring, so as to obtain the lithium metatitanate precursor powder; step 2, preparation of lithium metatitanate powder, including spray drying and microwave calcination with the lithium metatitanate precursor to obtain the lithium metatitanate powder; and step 3, elution and replacement, namely, leaching out Li with an eluent to obtain lithium ion exchanger. The preparation method is a solid-liquid phase contact reaction, the ratio of raw materials is easy to be accurately controlled. The synthesis reaction is strengthened by ultrasound, so as to accelerate the reaction, and the energy consumption is effectively reduced by microwave calcination. Titanium is controlled at a relatively excessive proportion, so as to prepare the lithium metatitanate powder with high porosity and good filterability. The prepared lithium ion exchanger has good lithium extraction performance and low solution loss of titanium, which satisfy the requirements for practical use.

The invention belongs to the technical field of biological medicines, and particularly relates to a CT (Computed Tomography) visual embolism microsphere based on iodine-containing nanoparticles as well as a preparation method and application of the CT visual embolism microsphere. The preparation method comprises the following steps: firstly, preparing iodine-containing organic silicon nanoparticles of which the surfaces are modified with active double bonds by using (3-iodopropyl) trimethoxysilane and 3-(methylacryloyloxy) propyl trimethoxysilane, and then adding methylacryloylated gelatin (GelMA) and a photoinitiator into the iodine-containing organic silicon nanoparticles to prepare a water phase capable of being photocured and cross-linked; the cross-shaped micro-fluidic chip is used as a dispersion phase in a micro-fluidic system, a mineral oil solution of Span 80 is prepared as a mobile phase in the micro-fluidic system, and the preparation of the microspheres is realized through the cross-shaped micro-fluidic chip. The embolism microsphere prepared by the method disclosed by the invention has relatively uniform size distribution, also has a good CT imaging effect, shows good biocompatibility, and has potential possibility of being applied to TAE therapy.

The invention provides a continuous drying and screening device for activated carbon preparation, and relates to the technical field of activated carbon manufacturing equipment.The continuous drying and screening device comprises a screening equipment base, a feeding supporting frame is fixedly installed at the upper end of the screening equipment base, and a feeding bin is fixedly installed at the upper end of the feeding supporting frame; the continuous drying and screening device comprises a screening equipment base, a protective shell is fixedly mounted at the upper end of the screening equipment base, and a closed side plate is fixedly mounted at the side end of the protective shell. And the number of screen holes of the drum screen is smaller than that of screen holes of the arc-shaped screen plate, so that continuous screening can be carried out when activated carbon is screened, the screening precision is improved, uniform particle size distribution is kept, the arc-shaped screen plate is matched with the drum screen for continuous screening, a large amount of activated carbon can be screened, and the production efficiency is effectively improved.

The invention provides a preparation method of an integrated platinum group metal gas diffusion catalyst layer, which comprises the following steps: (1) mixing a zinc-based organic metal framework, polyacrylonitrile and N, N-dimethylformamide to obtain an electrostatic spinning precursor solution; (2) spinning the electrostatic spinning precursor solution by using an electrostatic spinning machine, and collecting to obtain a Zn-MOF fiber layer; (3) the Zn-MOF fiber layer is placed in inert gas for high-temperature carbonization, the carbonization temperature is 700-1000 DEG C, and a Zn-containing N-doped carbon fiber layer is obtained; and (4) dipping the Zn-containing N-doped carbon fiber layer in a platinum group metal salt solution at 20-60 DEG C for 2-24 hours, taking out and drying to obtain the platinum group metal gas diffusion catalyst layer. According to the invention, a catalytic layer (CL) and a gas diffusion layer (GDL) are combined into a whole, and adjustment of a multi-stage pore channel is realized.

The present application discloses a preparation method and application of nanocellulose. The preparation method comprises at least the following steps: mixing a cellulose raw material with an organic acid and water, reacting, and high-pressure homogenizing to obtain the nanocellulose. The cellulose raw material is selected from sawdust or agricultural waste; the sawdust is selected from at least one of poplar sawdust, beech sawdust or birch sawdust; the agricultural waste is selected from at least one of corn stalks or sugarcane bagasse. The present application adopts a method combining low-concentration organic acid catalysis with high-pressure homogenization to prepare nanocellulose. The process is simple and green, and the situation of excessive acid concentration corroding equipment in traditional inorganic acid preparation is avoided, providing a new idea for the industrial production of nanocellulose.

The invention relates to a preparation method and application of a nano-drug for promoting liver cancer cell copper death and synergistic disulfiram (DSF) chemotherapy. At present, DSF in drugs for liver cancer cell copper death has huge potential, but the drugs are insufficient to cause liver cancer cell copper death. In order to overcome the defects, the invention provides a novel nano-drug which comprises inorganic nano-material hollow copper sulfide nano-particles (HCuS NPs) with near-infrared light (NIR) response, Au-Pt nano-enzyme with bimetallic catalytic activity, a photosensitizer indocyanine green (ICG), a diethyl dithiocarbamic acid-copper conjugate (Cu (DTC) 2) and peptide anchored with liver cancer targeting. The nano-drug HCuS / Au-Pt (at) DSF / ICG (at) 9R-P (HAPDI9P) capable of promoting liver cancer cell copper death and enhancing DSF chemotherapy is obtained, the nano-drug has an excellent combined treatment effect of chemotherapy, photothermal therapy, photodynamic therapy and chemical dynamic therapy, liver cancer cell immunogenicity death is induced, the immune response of liver cancer cells is enhanced, and the application prospect is wide. The important significance is realized on promoting liver cancer cell copper death.

This application discloses a bipolar molecularly co-modified perovskite nanocrystal and its preparation method. After nucleation of CsPbBr3 nanocrystals, zinc bromide and 1-naphthalenesulfonic acid (NSA) are introduced for post-treatment, resulting in dual passivation and physical coating of defect states on the nanocrystal surface. Zinc bromide provides excess Br. ‑ Zn fills surface halogen vacancies. 2+ Occupy Pb 2+ Vacancy suppression of deep-level defects; NSA's sulfonic acid group -SO3 ‑ As strong coordination sites, they replace and firmly anchor weakly bound oleic acid / oleylamine ligands to the surface, and their aromatic ring structure stabilizes the surface through cation-π interactions. Zinc bromide and NSA work synergistically to achieve efficient and deep passivation of surface defect states of CsPbBr3 nanocrystals. Perovskite nanocrystals exhibit high photoluminescence quantum yield, narrow fluorescence peak, and uniform size distribution, and are stably dispersed in organic solvents for a long time. The ligands on the nanocrystal surface are firmly bound, improving optical and structural stability, and the process is simple and efficient.

The invention relates to the technical field of crystallization, and provides a crystallization method of psicose. The method comprises the following steps: separating a psicose crude product solution by adopting a simulated moving bed method to obtain a psicose purified solution; evaporating the psicose purified liquid to constant weight to obtain a psicose concentrate; mixing the psicose concentrate, water and a psicose seed crystal to obtain a mixture; and cooling and crystallizing the mixture, and carrying out solid-liquid separation to obtain the psicose crystal. The method provided by the invention has the advantages of high crystallization yield, proper crystallization rate, full crystal form, simple preparation process, no use of organic reagents, environmental friendliness, economy, high efficiency, improvement of production efficiency and product quality, and low production cost, and brings innovation and improvement for the production process of psicose.

The invention relates to the technical field of metal surface treatment, in particular to a preparation method of a self-cleaning titanium and titanium alloy filter screen for filtering moxa smoke. The method comprises the steps that S1, direct current is introduced into the titanium and titanium alloy filter screen for heat treatment, and a high-activity metastable structure is formed on the surface of the titanium and titanium alloy filter screen; s2, the titanium and titanium alloy filter screen is subjected to anodic oxidation treatment, and a continuous multi-stage micro-nano rough structure is generated on the surface of the metastable structure to cover the surface of the titanium and titanium alloy filter screen; and S3, the surface of the titanium and titanium alloy filter screen is subjected to fluorosilane modification, and a uniform hydrophobic and oleophobic coating is formed on the surface of the multi-stage micro-nano rough structure. A metastable structure is formed on the surface of the titanium and titanium alloy filter screen, so that a continuous and multi-stage micro-nano rough structure is conveniently formed in subsequent anodic oxidation treatment. A firm and uniform hydrophobic and oleophobic coating is formed on a large surface area after fluorosilane modification, and the self-cleaning function is improved.

This invention belongs to the field of materials preparation and discloses a method for preparing plate-like zinc phosphate, comprising the following steps: (1) adding an inducing agent to a phosphoric acid solution; (2) adding the mixed solution from step (1) to a zinc oxide slurry, stirring the mixture at 60-90°C, and filtering and drying the reaction product after the reaction to obtain plate-like zinc phosphate. This invention directly controls the growth morphology of plate-like crystals through an aqueous synthesis reaction, eliminating the need for ultrafine grinding, reducing process flow and equipment investment, lowering energy consumption per unit product, and meeting the requirements of green manufacturing.

The invention belongs to the technical field of superfine powder preparation, and discloses a preparation method of nano zirconium oxide powder. The preparation method comprises the following steps: adding an oxalic acid solution into a zirconium oxychloride solution under a stirring condition to obtain sol; aging the obtained sol, and adding ammonia water to adjust the pH value to 7-9 to obtain gel; washing the obtained gel, and performing spray drying to obtain precursor powder; then carrying out calcination treatment at the temperature of 800-900 DEG C to obtain calcined powder; mixing the obtained calcined powder with water, and grinding to obtain slurry; and carrying out secondary spray drying on the obtained slurry to obtain the nano zirconium oxide powder. According to the preparation method, zirconium oxychloride is used as a raw material, oxalic acid is added as a complexing agent, ammonia water is used for adjusting the pH value to obtain a precursor, and the nano zirconium oxide powder is obtained through washing, spray drying, calcining, grinding and secondary spray drying. The preparation method is simple, and the obtained product has the advantages of small particle size, uniform distribution and difficulty in agglomeration.

The invention discloses a double-nano low-density thixotropic cement paste system, relates to the technical field of oil and gas well drilling engineering, and solves the problem that the existing cement paste system is difficult to adapt to stratums with low pore pressure and serious leakage. The cement paste system comprises the following components in parts by weight: 40-60 parts of G-grade oil well cement, 14-25 parts of a solid lightening agent, 20-45 parts of a solid admixture, 3-6 parts of a solid thixotropic agent, 0.5-2 parts of a nano stabilizer, 1-3 parts of a nano early strength agent, 1-3 parts of a fluid loss agent, 0.5-1 part of a dispersing agent and 70-100 parts of water. The double-nano low-density thixotropic cement paste system has the characteristics of lower density, high thixotropy and short setting waiting time, can enable a cement paste body to effectively reside in a shaft when a lower-density cement plug is achieved, is high in thixotropy and quickly forms a gelling structure, is controllable in compressive strength, is beneficial to plug drilling, shortens the setting waiting time and saves the production cost, and is suitable for popularization and application. Therefore, the production purposes of efficiently plugging and improving quality and efficiency are achieved.

The invention discloses a preparation method and application of cobalt hydroxide based on seed crystal circulation and special active magnesium oxide. Through cooperation of a seed crystal circulation technology and a special auxiliary agent, the generated cobalt hydroxide is converted into a core of subsequent crystal growth, uniform and thick growth of the cobalt hydroxide is guided, and the industry bottleneck that the underflow concentration of a thickener is low when high-activity magnesium oxide is adopted for cobalt precipitation is effectively solved. The average particle size (D50) of the product is increased from 16.81 [mu] m to 21.81 [mu] m or above, the underflow concentration is increased from 27% to 28-30%, and the sedimentation and compaction performance of ore pulp is remarkably improved. While excellent physical properties are obtained, the chemical quality of the product is excellent, the cobalt content reaches 40% or above, and the magnesium residue is lower than 5%. The process economy is outstanding, the cobalt precipitation rate is increased to 98% or above, and the unit consumption of magnesium oxide is reduced to 0.70-0.71 t / t Co. According to the method, the seed crystal derives from the process, parameter regulation and control are flexible, compatibility with an existing production line is good, and large-scale industrial application prospects are achieved.