225 results about "Magnesium nitrate" patented technology

The invention relates to the technical field of high-performance polyester fibers, particularly belongs to the patent classification number D01F6 / 00, and discloses a high-moisture-permeability polyester fiber and a preparation method thereof. Comprising the following steps: carrying out hydrothermal reaction on magnesium nitrate hexahydrate and aluminum nitrate nonahydrate to prepare layered double hydroxide nanosheets; then, sodium alginate is prepared into a solution, and the solution is cross-linked with calcium chloride to obtain alginic acid aerogel powder; then, carrying out ultrasonic oscillation dispersion on the two substances in deionized water, and cooling and drying to obtain composite aerogel; then, the composite aerogel and polyethylene glycol 4000 are subjected to melt blending and granulation in a double-screw extruder, and functional master batches are obtained; and finally, mixing the functional master batch with polyethylene glycol terephthalate slices, performing melt spinning at a specific spinning temperature and speed, and performing cooling forming and drafting to obtain the high-moisture-permeability polyester fiber. According to the method, through material compounding and process control, the moisture permeability of the polyester fiber is effectively improved, and the method has a good application prospect in the textile field.

The invention discloses a super-strong mute building drainage pipe and a preparation method thereof, and relates to the technical field of high polymer materials. Comprising the following raw materials in parts by mass: 100 parts of high-density polyethylene, 5-7 parts of a cold-resistant toughening agent, 8-12 parts of a synergist, 8-10 parts of a sound insulation filler and 0.3-0.5 part of an antioxidant. By introducing the synergist prepared from the components such as polyamine polyether methylene phosphonic acid, zinc nitrate hexahydrate, magnesium nitrate hexahydrate and the like, the sound insulation, flame retardance and smoke suppression capabilities of the drainage pipe can be effectively improved; by introducing the sound insulation filler prepared from the modified halloysite nanotubes, hydroxyl-terminated polydimethylsiloxane, aziridine cross-linking agent and the like, the sound insulation, flame retardance and smoke suppression capabilities of the drain pipe are further improved. Therefore, the drainage pipe prepared by the invention has a wider application prospect.

The invention provides a catalyst for preparing phenol through catalytic hydrogenation of guaiacol as well as a preparation method and application of the catalyst. The preparation method of the catalyst comprises the following steps: fully dissolving magnesium nitrate, P123 and urea in deionized water, carrying out hydrothermal reaction, filtering, washing, drying and roasting to obtain an MgO carrier; immersing the MgO carrier in an alkali metal nitrate aqueous solution, drying and roasting to obtain an alkali metal element loaded MgO carrier; the alkali metal is selected from one of Li, Na, K or Cs; and immersing the alkali metal element loaded MgO carrier in a methanol solution of chloroplatinic acid, removing methanol, drying, and then carrying out reduction treatment to obtain the catalyst. The catalyst disclosed by the invention is applied to catalytic hydrodeoxygenation of guaiacol and shows excellent catalytic performance, the hydrodeoxygenation reaction conditions are mild, and the target product phenol can be obtained with high selectivity and high yield.

The invention provides a preparation method of a porous carbon-loaded magnesium oxide adsorbent, and relates to the technical field of gas purification material preparation, and the preparation method comprises the following steps: S1, taking magnesium nitrate, dichromate, concentrated sulfuric acid, glucose and fuel as raw materials, forming a homogeneous solution, heating the solution at a certain temperature to form gel, and further carrying out a combustion reaction to obtain a porous carbon-loaded magnesium oxide adsorbent; fluffy precursor powder is obtained; s2, performing high-temperature calcination on the precursor powder in air to obtain a carbon-loaded intermediate product; and S3, placing the carbon-loaded intermediate product in a sodium hydroxide solution, carrying out a heating reaction, separating the solid obtained after the reaction, and drying to obtain the porous carbon-loaded magnesium oxide adsorbent. The invention provides a simple and extensible synthesis method for developing a CO2 adsorbent with large working capacity and high selectivity, the production process is environment-friendly and pollution-free, the operation cost is low, the economic benefit is high, and the method has a better industrial application prospect.

The invention relates to pickling paste, a preparation method thereof and application of the pickling paste to removal of an alpha layer on the surface of titanium alloy, and belongs to the technical field of alloy surface treatment. Based on 100 parts by mass, the pickling paste is prepared from the following raw materials in parts by mass: 10-20 parts of nitric acid; 30-40 parts of hydrofluoric acid; 10 to 20 parts of magnesium nitrate; 2 to 5 parts of an associative polyurethane emulsion; and the balance of solvent. The invention further discloses a preparation method of the titanium alloy pickling paste and application of the titanium alloy pickling paste to removal of an alpha layer on the surface of titanium alloy. The titanium alloy pickling paste is used for treating the titanium alloy surface, the removal rate of an alpha layer on the titanium alloy surface is 100%, the harmful surface layer on the titanium alloy surface can be effectively removed in time, and the product quality and the production schedule are guaranteed.

The invention relates to the technical field of precious metal detection, in particular to a molybdenum detection reagent, a preparation method and a use method thereof, and the molybdenum detection reagent comprises 20%-38% of hydrochloric acid, 20%-27% of nitrate and water. The 316 stainless steel and the 2205 stainless steel both contain more than 2% of molybdenum, the 316 stainless steel and the 2205 stainless steel can be distinguished through magnetism, and the 2205 stainless steel has strong magnetism. The molybdenum detection reagent can be used for detecting molybdenum ions in stainless steel so as to distinguish 316 stainless steel from 304 stainless steel. The nitrate can make the 316 stainless steel and the 304 stainless steel show different colors, so that the 316 stainless steel and the 304 stainless steel can be accurately distinguished. The reagent of the magnesium nitrate can make the reagent on the 316 stainless steel yellow, the reagent of the aluminum nitrate can make the reagent on the 316 stainless steel light yellow, and the reagent of the ferric nitrate can make the reagent on the 316 stainless steel brown. The molybdenum detection reagent can accurately and rapidly detect and identify 316 stainless steel, and is low in cost, convenient to operate and convenient to carry.

The invention provides a catalyst for methane and carbon dioxide dry reforming reaction as well as a preparation method and application thereof, and relates to the technical field of catalyst preparation. The catalyst for the methane and carbon dioxide dry reforming reaction is prepared by the following steps: taking boric acid, nickel nitrate, magnesium nitrate and aluminum nitrate as raw materials, dissolving the raw materials in water, and stirring until the raw materials are clear and transparent to obtain a mixed solution; adding an ammonia water solution into the mixed solution and stirring to obtain a precipitate mixture; placing the precipitate mixture in a hydrothermal reactor for hydrothermal reaction, and obtaining a catalyst precursor after the hydrothermal reaction is finished; filtering, washing and drying the catalyst precursor to obtain a dried product; and the dried product is calcined and cooled, and the Ni-B / MgAl2O4 catalyst is obtained. The catalyst prepared by the method provided by the invention can overcome inactivation caused by easy generation of carbon deposition in the existing Ni catalyst, and provides high methane and carbon dioxide dry reforming reaction activity and stability at the same time.

The invention relates to the technical field of preparation methods of nano precursor powder, in particular to a synthesis method of Cr < 3 + > doped magnesium aluminum oxide nano powder, which comprises the following steps: weighing magnesium nitrate, aluminum nitrate and chromic nitrate according to the stoichiometric ratio of MgAl2-xO4: xCr < 3 + >; stirring and mixing the prepared magnesium nitrate solution, aluminum nitrate solution and chromic nitrate solution together to prepare a mixed solution I; ammonia water is dripped into the first mixed solution, then the first mixed solution dripped with the ammonia water is stirred and mixed, and a second mixed solution is prepared; pouring the mixed solution II into a high-pressure reaction kettle, and putting the high-pressure reaction kettle into a constant-temperature box for reaction to prepare a white precipitate; adding deionized water into the white precipitate for washing and precipitating, and centrifuging to obtain white precipitate powder; drying the white precipitate powder at a constant temperature; calcining the dried white precipitate powder to prepare nano precursor powder; the prepared nanometer precursor powder has the advantages of being high in purity and small in particle size.

The invention discloses alkali metal doped MOF-74, a gas-sensitive material, a gas-sensitive sensor and a preparation method and application of the gas-sensitive sensor, and belongs to the technical field of gas-sensitive sensors. Magnesium nitrate hexahydrate and 2, 5-dihydroxyterephthalic acid are used as raw materials, alkali metal salt is added in situ for doping, triethylamine (TEA) is used as a deprotonation agent, a reaction process is optimized, alkali metal doped MOF-74 is rapidly synthesized at room temperature, miniaturization of MOF-74 is realized on the premise that crystallinity and high porosity are not lost, and the preparation method is simple and easy to implement. The gas-sensitive property of the material is favorably improved. The alkali metal doped MOF-74 is used for the gas sensitive sensor, has excellent selectivity and high sensing response to CO2 gas, and can meet the requirements of CO2 gas detection. The preparation period is short, heating is not needed, and large-scale production is facilitated.

The invention discloses a preparation method and application of a hydrotalcite-like compound derivative magnesium-aluminum composite oxide with a coral spherical structure, magnesium nitrate is taken as a magnesium source, aluminum nitrate is taken as an aluminum source, a proper amount of citric acid and urea are introduced, and under the thermal action of an alcohol-water mixed solvent, a citric acid intercalated hydrotalcite-like compound is obtained in one pot; and further roasting to obtain the derived magnesium-aluminum composite oxide. The magnesium-aluminum composite oxide has a unique coral spherical structure, is endowed with a large specific surface area and a developed pore structure, contains rich alkalescence and moderately strong alkaline sites and oxygen vacancies, shows excellent activity and stability in a high-concentration COS system, and is suitable for being used as a catalyst for a COS hydrolysis reaction.

The invention relates to the technical field of battery materials, in particular to a para-aramid lithium battery diaphragm and a preparation method thereof. The para-aramid lithium battery diaphragm comprises para-aramid slurry and a base membrane, the para-aramid slurry is coated on the two sides of the base membrane to form para-aramid coatings, and the para-aramid slurry comprises the following raw materials in parts by weight: 20-40 parts of modified para-aramid polymer liquid, 10-20 parts of nano ceramic composite material powder and 10-18 parts of a solvent; the nano ceramic composite material powder is prepared from the following raw materials in parts by weight: 50 to 100 parts of nano aluminum oxide, 8 to 12 parts of nano zirconium dioxide, 0.3 to 0.8 part of yttrium oxide, 1 to 5 parts of magnesium nitrate hexahydrate, 0.1 to 1 part of polyacrylic acid, 1 to 2 parts of ammonia water, 1 to 3 parts of coupling agent and 20 to 30 parts of silicon dioxide; the nano ceramic composite material powder is added into the para-aramid slurry, so that the para-aramid diaphragm has better thermal stability, and the phenomenon of thermal shrinkage of the diaphragm at high temperature is reduced.

The invention provides a refractory ceramic-based material for a smelting furnace lining and a preparation method of the refractory ceramic-based material, and belongs to the technical field of ceramic refractory materials. The material comprises coated modified fused magnesite main aggregate, ceramic sand main aggregate, surface coated magnesium oxide fine powder, gamma-phase aluminum oxide micro powder, an aluminum dihydrogen phosphate solution, alkaline silica sol, a pre-reaction spinel precursor and zirconium boride micro powder. The coated modified fused magnesite main aggregate is prepared by mixing and sintering fused magnesite, silicon carbide composite powder, chromium sesquioxide powder and phenolic resin powder. And mixing the silicon carbide powder and the magnesium oxide powder, and depositing a silicon nitride layer on the particle surface to prepare the silicon carbide composite powder. The surface-coated magnesium oxide fine powder is formed by coating the surfaces of magnesium oxide fine powder particles with aluminum oxide. The pre-reaction spinel precursor is prepared by the following steps: preparing a mixed salt solution from magnesium nitrate hexahydrate and aluminum nitrate nonahydrate by using deionized water, reacting, aging and carrying out heat treatment. And the ceramic sand main aggregate is made of zirconium oxide. And all the layers are matched for use to realize balanced improvement of performance.

The invention discloses a high-ammonia-nitrogen wastewater treatment process, and belongs to the technical field of pyridine wastewater treatment, and the high-ammonia-nitrogen wastewater treatment process comprises the following steps: preparing hydrotalcite: weighing cobalt nitrate, magnesium nitrate and aluminum nitrate, adding distilled water, and stirring to obtain a salt solution; weighing sodium hydroxide and anhydrous sodium carbonate, adding distilled water, and stirring to obtain alkali liquor; pumping the salt solution and the alkali solution into a round-bottom flask, and heating and dispersing the round-bottom flask on an oil bath pan; putting the ground sample into a ceramic crucible, calcining in a muffle furnace, weighing a silver-ammonia solution and acetaldehyde, and pouring into a round-bottom flask; the pyridine wastewater is weighed, the hydrotalcite is added, stirring adsorption is performed for 20 min, the hydrogen peroxide is added, suction filtration is performed after the reaction, and the hydrotalcite is filtered and separated out for recycling. The problem that existing wastewater treatment is difficult is solved. The method has the advantages of high catalytic activity, easiness in recovery and reutilization of hydrotalcite, no need of adding any auxiliary chemical reagent, mild reaction conditions, low cost and convenience in operation, and can meet the requirements of industrial production.

The invention belongs to the technical field of soil conditioners, and particularly relates to a soil biological conditioner and a preparation method thereof. The biological soil improver comprises the following raw materials in parts by weight: 30-50 parts of soybean meal, 10-15 parts of modified diatomite, 1-5 parts of a microbial agent, 6-12 parts of urea, 0.5-3 parts of a Zostera marina extract and 0.01-0.03 part of sodium selenite. A preparation process of the modified diatomite comprises the following steps: adding pretreated diatomite into water, then adding sodium dodecyl benzene sulfonate, adjusting the pH value of a system, and stirring to obtain diatomite with the surface modified by sodium dodecyl benzene sulfonate; adding magnesium nitrate and ferric nitrate into deionized water to obtain a mixed solution A; under the stirring condition, the mixed solution A is added into a sodium hydroxide solution, then diatomite with the surface modified by sodium dodecyl benzene sulfonate is added, heating reaction is conducted, and the modified diatomite is obtained. The obtained soil biological improver can improve the property of acid soil and promote the growth of crops.

The invention provides porous alumina ceramic and a preparation method thereof, and relates to the technical field of ceramic materials. The invention relates to a preparation method of porous alumina ceramic. The preparation method comprises the following steps: dispersing alpha-cellulose powder in deionized water to form a cellulose suspension; stirring to fully swell the cellulose and form uniform gel, and freeze-drying to obtain a template; dissolving aluminum nitrate hexahydrate, magnesium nitrate hexahydrate and yttrium nitrate hexahydrate in absolute ethyl alcohol to obtain a precursor solution; putting gamma-Al2O3 micro powder and ammonium fluoride into a ball milling tank, adding the precursor solution and a dispersing agent, adding zirconium oxide balls and absolute ethyl alcohol into the ball milling tank, and performing ball milling to obtain ceramic slurry; dipping a template into the ceramic slurry, and performing dipping treatment under a vacuum condition to form a composite green body; and sintering to obtain the porous alumina ceramic. According to the porous aluminum oxide ceramic, the process stability is improved, and the problem that the strength is sharply reduced when the porosity is too high is solved.

The invention discloses a novel modified flame-retardant polyethylene material, and belongs to the technical field of flame-retardant materials.The novel modified flame-retardant polyethylene material is prepared by the steps that S1, cobalt nitrate hexahydrate, sodium molybdate and urea are added into deionized water, washed with water and ethyl alcohol respectively, separated and dried, and CoMo-L nanosheets are obtained; s2, the CoMo-L nanosheet is calcined in N2 / NH3 mixed gas, and a cobalt molybdenum nitride nanosheet is obtained; s3, adding the cobalt molybdenum nitride nanosheet into deionized water, stirring, adding magnesium nitrate hexahydrate, aluminum nitrate nonahydrate and urea, separating and drying to obtain a CoMoN / Mg-AlLDH heterojunction flame retardant; s4, adding a product prepared in S3 into the carbon nanotube dispersion liquid, stirring, filtering and drying to obtain a pretreated flame retardant; and S5, carrying out melt blending on the pretreated flame retardant, the antioxidant and the modified polyethylene, and carrying out extrusion granulation to obtain the novel modified flame-retardant polyethylene material. The flame-retardant material prepared by the invention has good flame retardant property and mechanical property.

The invention relates to an acrylic acid catalyst based on a spinel structure carrier and a preparation method and application thereof, and relates to the technical field of acrylic acid catalysts, the preparation method comprises the following steps: mixing pseudo-boehmite, magnesium nitrate and activated carbon powder, then adding vaseline, and continuing mixing to obtain a first mixture; adding ammonium fluoride and water into the first mixture, and mixing to obtain a second mixture; carrying out extrusion molding and grain-sized dicing on the second mixture, and then carrying out first drying and first roasting to obtain an Al2O3 carrier with a magnesium aluminate spinel structure; and dipping the Al2O3 carrier in a solution containing a metal active component, and then carrying out second drying and second roasting to obtain the acrylic acid catalyst. By using the carrier with the magnesium aluminate spinel structure and adopting an impregnation method, not only is the use efficiency of active metal improved, but also the strength of the carrier of the catalyst is improved, and the defects in the prior art are overcome.

The invention discloses a slope cropland soil solidifying material based on agricultural waste and a preparation method thereof, and the slope cropland soil solidifying material is prepared from the following raw materials in parts by weight: 150-200 parts of a calcium lignosulphonate solution, 150-200 parts of a vinasse urease bacterium solution, 15-20 parts of phosphogypsum, 3-5 parts of urea, 2-3 parts of magnesium nitrate, 2-3 parts of calcium hydrophosphate and 2-3 parts of potassium carbonate. Wherein the calcium lignosulphonate solution is obtained by alkali treatment of corncobs, and the vinasse urease bacterial liquid is obtained by two-stage fermentation of corn vinasse with bacillus amyloliquefaciens and bacillus pasteurii. The prepared slope cropland soil solidification material can effectively utilize agricultural wastes, and can improve the soil structure and soil fertility and promote the growth of slope cropland plants while reducing water and soil loss.

The invention discloses a preparation method of a magnesium-manganese modified carbide slag CO2 adsorbent, which comprises the following steps: step (1), respectively grinding, sieving and drying carbide slag and magnesium nitrate hexahydrate to obtain pretreated carbide slag powder and magnesium nitrate hexahydrate powder; (2) adding the pretreated carbide slag powder and magnesium nitrate hexahydrate powder into deionized water, and uniformly mixing to obtain a mixed dispersion liquid A; (3) sequentially adding a manganous nitrate solution and citric acid into the mixed dispersion liquid A, and uniformly mixing to obtain a mixed dispersion liquid B; (4) heating and stirring the mixed dispersion liquid B to obtain colloidal paste, placing the colloidal paste in a drying oven to volatilize moisture, and grinding to obtain a solid intermediate product; and (5) calcining the solid intermediate product to obtain the magnesium-manganese modified carbide slag CO2 adsorbent. When the composite material is used for carbon dioxide adsorption, relatively high anti-sintering capability and cycling stability are shown.

The invention relates to the technical field of alloy additives, and discloses a high-toughness corrosion-resistant manganese additive for aluminum alloy and a preparation and application method thereof.The additive is prepared from, by mass, 50-65 parts of nanometer manganese alloy powder, 10-18 parts of magnesium-zirconium composite modifier, 4-9 parts of titanate coupling agent, 3-6 parts of dispersing aid and 2-5 parts of high-temperature stabilizer; the magnesium-zirconium composite modifier is a compound system of magnesium nitrate and zirconium oxychloride, and the molar ratio of magnesium element to zirconium element in the magnesium-zirconium composite modifier is 3: 1-5: 1. The dispersion uniformity of the additive is larger than or equal to 96%, after the additive is added, the impact toughness of the aluminum alloy is improved by 45%, the salt spray corrosion resistance reaches 600 h or above, the high-temperature (300 DEG C) stability is improved by 30%, the additive is suitable for various aluminum alloy systems such as 2024 and 6063, the preparation cost is reduced by 22%, and the industrial prospect is wide.

The present application relates to the technical field of reverse water gas shift reaction, and discloses a preparation method of a catalyst for reverse water gas shift reaction, comprising the following steps: weighing magnesium nitrate and zinc acetate, so that the molar ratio of Mg atoms to Zn atoms is 1:1 to 1:10 or 3:1 to 10:1; dissolving the weighed magnesium nitrate and zinc acetate in water, adding urea, stirring and uniformly mixing at room temperature, and then increasing the temperature and stirring to promote the co-precipitation of metal ions; and obtaining the MgO-ZnO composite oxide catalyst by centrifugation, washing, drying and calcination of the obtained precipitate. The MgO-ZnO composite oxide catalyst is prepared by adopting the urea uniform precipitation method, using magnesium nitrate and zinc acetate as raw materials, and precisely controlling the molar ratio of Mg to Zn.

According to the ultrahigh-temperature low-viscosity shear strength improving agent for the water-based drilling fluid and the method, the ultrahigh-temperature low-viscosity shear strength improving agent is prepared from hexadecyl trimethyl ammonium bromide modified montmorillonite, magnesium nitrate hexahydrate and aluminum nitrate nonahydrate, and the obtained low-viscosity shear strength improving agent has good ultrahigh-temperature stability and can effectively stabilize rheological stability under the ultrahigh-temperature condition; and a net-shaped structure connected by polarized water chains is formed, so that the shearing force of the drilling fluid is improved, and the requirement of ultrahigh-temperature formation drilling is met.

The invention relates to the technical field of pharmaceutical chemicals, relates to metal-loaded mesoporous silica and application thereof in synthesis of cyclic acid, and particularly relates to preparation of mesoporous silica simultaneously loaded with Mg, Al and Ca and application of the mesoporous silica as a catalyst in aldol condensation reaction for preparation of cyclic acid. The metal-loaded mesoporous silica is prepared by adopting an excessive impregnation method. The metal is one or more of Mg, Al, Ca, Co and Cu. The metals are derived from their nitrates, hydrochlorides or sulfates. When the metal is a combination of Mg, Al and Ca, the corresponding concentrations of magnesium nitrate, aluminum nitrate and calcium nitrate are 3.5-6.5 g / L, 6.5-7.5 g / L and 2.4-4.0 g / L respectively. The metal-loaded silicon dioxide provided by the invention can be used as a catalyst, and especially can be used as a catalyst for aldol condensation reaction to catalyze and synthesize cyclic acid, so that the reaction cost is reduced, and the yield and purity of the product can be obviously improved.

The invention discloses an ion complexing generator anode catalyst and a preparation method thereof, and relates to the technical field of heavy metal wastewater treatment, the catalyst is used for treating complexing-state heavy metal industrial wastewater in the fields of electroplating industry, electronics factories, machinery factories, smelting plants and the like, and the catalyst comprises the following components in parts by mass: 2-5 parts of copper sulfate powder, 1-2 parts of sodium hydroxide, 1-2 parts of sodium hydroxide and the balance of water. The composite material comprises the following components in parts by weight: 5-8 parts of ferric nitrate powder, 9-12 parts of cobalt nitrate powder, 8-15 parts of nickel nitrate, 8-18 parts of potassium chloroplatinate, 1-5 parts of palladium nitrate, 0.5-1 part of rhodium chloride, 20-40 parts of graphene and 20-40 parts of magnesium nitrate.

The application provides an in-situ liquid gel-forming water-retaining agent and a preparation method and application thereof. The water-retaining agent is composed of A component and B component which are applied in steps. The A component contains an aqueous solution of a natural modified polymer, and the natural modified polymer is selected from one or two of carboxymethyl chitosan, carboxymethyl cellulose or a sodium salt thereof. The B component contains an aqueous solution of a cationic crosslinking agent, and the cationic crosslinking agent is selected from one or more cations of copper nitrate, iron nitrate, zinc nitrate, manganese nitrate, chitosan quaternary ammonium salt, calcium nitrate and magnesium nitrate. The water-retaining agent can realize the integrated functions of slow release of trace elements, water retention, soil improvement and precise nutrition supply. Furthermore, the water-retaining agent is applied to crop growth in combination with the "step-by-step drip irrigation and in-situ gel formation" technology, so that the agronomic characters of crops can be significantly improved.

The present invention discloses a method for preparing ultrafine particles of low-dielectric ceramic materials for 6G, relates to the technical field of dielectric ceramic materials, and belongs to patent classification number C04B35 / 00. The specific preparation method is to first prepare a sol using tetraethyl orthosilicate, calcium nitrate, magnesium nitrate, aluminum isopropylate, zirconium oxychloride and lithium nitrate, heat the sol and let it stand for gelation, then use supercritical CO2 to dry, obtain aerogel, heat and reduce calcination to obtain (Ca, Mg) SiO3-ZrO2 nanopowder, and use atomic layer deposition technology to coat a TiO2 layer on the surface of the nanopowder to obtain ultrafine particles of dielectric ceramic materials. The ceramic particles prepared by the present invention not only have a low dielectric constant, but also have a smaller particle size and a higher density under low-temperature sintering.

The invention belongs to the technical field of metal part surface corrosion protection, and relates to brush coating passivation paste for helicopter surface in-situ repair and a brush coating method. The passivation paste comprises the following components in percentage by mass: 10%-20% of citric acid, 3%-5% of acrylic resin, 3%-10% of a cellulose inorganic thickener, 3%-5% of magnesium nitrate, 0.5%-2% of urotropin, a flatting agent, 0.5%-2% of bentonite and the balance of deionized water. The problems that an existing brush coating passivation solution flows, and protective layers such as paint layers, plating layers and chemical conversion layers of peripheral parts of to-be-repaired parts are prone to being polluted or damaged during on-machine repairing are solved. And meanwhile, a needle tube type packaging and brushing tool is adopted, so that the operation during on-machine repair and the control on the dosage of the paste are facilitated.

The invention discloses a method for comprehensively utilizing fluorine-containing gypsum in the glass thinning industry. The method comprises eight procedures of low-temperature molten salt conversion, wet grinding leaching, wet grinding alkali conversion, neutralization, sodium fluoride evaporative crystallization, acid leaching, magnesium nitrate regeneration and magnesium nitrate evaporative crystallization. Compared with the prior art, the method for comprehensively utilizing the fluorine-containing gypsum in the glass thinning industry has the advantages that fluoride in the fluorine-containing gypsum is efficiently converted into sodium fluoride, and sustainable utilization of resources is realized.

The invention provides a supported composite catalyst for production of N-methyl o-fluoroaniline, a carrier is Al2O3, and active components are K2CO3, MgO and Cu. The invention discloses a preparation method of a supported composite catalyst. The preparation method comprises the following steps: step 1, dissolving potassium carbonate and magnesium nitrate with preset mass in absolute ethyl alcohol to obtain primary steeping liquor; dissolving cupric acetate in absolute ethyl alcohol to obtain a secondary steeping liquor; step 2, adding Al2O3 into the primary steeping liquor to be fully infiltrated, and drying to obtain a first precursor; step 3, adding the first precursor into the secondary impregnation liquid for full infiltration, and drying to obtain a second precursor; step 4, performing high-temperature roasting on the second precursor, and then cooling the second precursor to room temperature to obtain a K2CO3-MgO-CuO / Al2O3 intermediate; 5, the K2CO3-MgO-CuO / Al2O3 intermediate is subjected to hydrogen reduction at the high temperature, K2CO3-MgO-Cu / Al2O3 is obtained, and the supported composite catalyst is obtained. The catalyst provided by the invention can significantly increase the reaction speed, has less side reactions, and has high stability.

The invention relates to a carbitol-containing anti-caking water-soluble fertilizer and a preparation method thereof, and belongs to the field of water-soluble fertilizer production, the carbitol-containing anti-caking water-soluble fertilizer comprises the following substances by weight: 0.15-0.2% of carbitol, 20-28% of diammonium hydrogen phosphate, 22-28% of ammonium nitrate, 40-50% of potassium sulfate, 3-5% of magnesium nitrate, and 2-4% of ferric citrate. According to the invention, carbitol is applied to anti-caking of the water-soluble fertilizer for the first time, and integration of anti-caking, stability improvement and function synergism is realized; by adding carbitol, caking of the water-soluble fertilizer can be effectively avoided, a green and efficient technical scheme is provided for improving the quality of the water-soluble fertilizer, and the storage and use cost is reduced.