1206 results about "Sodium oxide" patented technology

A fireproof magnesium oxide board is prepared by mixing the following raw materials, the raw material names and weight parts are as follows: 80-100 parts of magnesium oxide; 20-30 parts of anhydrous magnesium chloride; 10-20 parts of modified expanded vermiculite foaming agent; 20-30 parts of aluminum silicate fiber; 5-10 parts of sawdust; 10-15 parts of fly ash; 8-12 parts of glass magnesium board crushed powder; 1.5-5 parts of non-woven fabric; 10-20 parts of water; wherein the modified expanded vermiculite is prepared by the following steps: (1) Vermiculite is incompletely expanded and calcined; (2) acrylic acid monomer, sodium hydroxide, acrylamide monomer, initiator potassium persulfate, crosslinking aid pentaerythritol polyglycidyl ether, incompletely expanded vermiculite, and water are taken, stirred evenly and ultrasonically dispersed to obtain a first reaction solution, which is placed in a reactor for reaction to obtain a gel material; (3) the gel material is preliminarily crushed and dried, and then further crushed in a ball mill to obtain a fire-resistant expanded vermiculite with water absorption performance.

The invention discloses a method for recovering lithium phosphate from lithium iron phosphate black powder. The method comprises the following steps: mixing black powder recovered from waste lithium iron phosphate batteries with sodium persulfate, and calcining; adding water into the obtained calcined product, dissolving, filtering to obtain water extract A and leaching residues, washing the leaching residues with water, and calcining at high temperature to obtain battery-grade iron phosphate; adding a sodium hydroxide solution into the water extract A, and reacting to obtain a water extract B; adding a trisodium phosphate solution into the water immersion liquid B, fully reacting, performing suction filtration to obtain lithium phosphate and filtrate, and cleaning and drying the lithium phosphate to obtain battery-grade lithium phosphate; and freezing and denitrifying the filtrate to obtain a denitrified solution, and adding the denitrified solution into the sodium hydroxide solution for recycling. The method does not generate wastes, recycles the filtrate in the whole process, theoretically realizes zero loss of the lithium element, prevents the iron element from entering the solution, simplifies the preparation steps of the lithium phosphate, and has the advantages of cost reduction and environmental protection.

The invention belongs to the field of coal gangue resource utilization, and particularly discloses a method for preparing fiber-reinforced coal gangue-based composite functional aerogel. After being activated, the coal gangue is put into an acid leaching solution to be leached, and an aluminum-rich solution is obtained; adding ammonia water into the aluminum-rich solution to adjust the pH to obtain hydroxide precipitate; adding a sodium hydroxide solution into the precipitate to react to obtain a sodium aluminate solution; neutralizing the sodium aluminate solution with hydrochloric acid to obtain an aluminum chloride solution, stirring to obtain aluminum sol, and adding ceramic fibers into the aluminum sol; violently stirring the sol, and adding epoxypropane to obtain wet gel; after aging the wet gel, carrying out surface modification to obtain hydrophobic coal gangue-based aluminum oxide and composite wet gel of the hydrophobic coal gangue-based aluminum oxide; and drying the modified wet gel at normal pressure to obtain the hydrophobic coal gangue-based aluminum oxide and the composite aerogel thereof. Ceramic fibers are introduced as a reinforcing phase, so that the compressive strength and toughness of the material are improved; the composite aerogel is subjected to surface modification, uniform modification is ensured, the contact angle is remarkably increased, the hygroscopicity is reduced, and the stability of the material is enhanced.

The invention discloses high-toughness ultrathin flexible glass and a preparation method thereof, and relates to the technical field of glass manufacturing. The ultrathin flexible glass is prepared from the following raw materials: silicon dioxide, aluminum oxide, lithium oxide, sodium oxide, magnesium oxide, a modified nano reinforced phase, a high-temperature melting regulator and cerium dioxide. The modified nano reinforced phase is prepared by the following steps: pre-treating silicon carbide and silicon nitride with hydrochloric acid, and mixing with nano zirconium oxide to obtain a mixture; and modifying the mixture with a silane coupling agent to obtain the modified nano reinforced phase. The high-temperature melting regulator is a mixture of lithium borate, sodium sulfate and lithium fluoride. The preparation method of the ultra-thin flexible glass comprises the following steps: preparing the modified nano reinforced phase, melting and homogenizing the glass, forming the glass substrate, and preparing the ultra-thin flexible glass. The ultra-thin flexible glass prepared by the invention has relatively high fracture toughness and structural rigidity, excellent flexibility and bending fatigue durability, and excellent thermal shock resistance.

The invention discloses a gas-sensitive material for monitoring an environment-friendly gas characteristic substance CO as well as a preparation method and application thereof, and relates to the technical field of gas-sensitive materials. The preparation method comprises the following steps: dissolving tin tetrachloride pentahydrate, sodium hydroxide and polyvinylpyrrolidone, adding ammonium fluoride, reacting at 155-165 DEG C, drying the product, and calcining at 295-305 DEG C to obtain SnO2 nanoparticles; the preparation method comprises the following steps: performing ultrasonic mixing on SnO2 deionized water dispersion liquid and MoS2 nanosheet ethylene glycol dispersion liquid, and then drying to obtain the MoS2 / SnO2 composite material with a mesoporous hollow nanotube structure, and the volume ratio of ethylene glycol to deionized water is (0.9-1.1): 1. The MoS2 / SnO2 gas sensitive material has the advantages of low density, high pore volume, large specific surface area, high structural stability and the like. And when applied to a CO resistive sensor, the catalyst has good CO selectivity, high sensitivity and good long-term stability.

The invention belongs to the technical field of glass materials, and discloses thermal shock resistant transparent high borosilicate glass which comprises the following components in percentage by weight: 60-70% of silicon dioxide, 18-22% of diboron trioxide, 4-7% of aluminum oxide, 3-5% of magnesium oxide, 2-4% of alkali metal oxide, 0.5-1.5% of nano silicon nitride and 0.5-1% of nano aluminum titanate. The thermal shock temperature difference of the glass within the temperature change range of 20-200 DEG C is larger than or equal to 180 DEG C, the light transmittance within the visible light range of 400-760 nm is larger than or equal to 85%, the alkali metal oxide is composed of sodium oxide and potassium oxide, the weight ratio of the sodium oxide to the potassium oxide is 1: 1-3: 1, the average particle size of the nanometer silicon nitride is smaller than or equal to 100 nm, and the nanometer silicon nitride is evenly dispersed in the glass matrix; according to the thermal-shock-resistant transparent high borosilicate glass and the preparation method thereof, the thermal shock resistance and light transmittance of the glass are improved by optimizing the chemical components of the glass and adding the special nanoparticles in cooperation with a specific preparation process, and the thermal shock resistance of the glass is improved. The problems that existing high borosilicate glass is insufficient in thermal shock resistance and low in light transmittance in a high-temperature environment are solved.

The invention discloses an optical-grade PET release film and a preparation method and application thereof, and belongs to the technical field of PET release liners.The preparation method comprises the steps that organic silicon resin, polyacrylate and functional silicone oil serve as raw materials, hexadecafluorophthalocyanine copper serves as a catalyst, sodium hydroxide provides hydroxyl anions, and hydroxyl-containing fluorinated hydroxyaniline is obtained; amino groups on the surface of fluorinated hydroxyaniline react with carboxyl groups of graphene oxide and are grafted on the surface of graphene oxide, then hydroxyl groups in the fluorinated hydroxyaniline and carboxyl groups of acrylic acid are subjected to esterification reaction under the action of a catalyst, so that acrylic acid is grafted on fluorinated modified graphene oxide, and the fluorinated modified graphene oxide is obtained. Therefore, hydroxyl and epoxy functional groups on the surface of the graphene oxide are consumed, hindering of electron transmission is reduced, the conductivity of the release film is improved, and the antistatic requirement of the release film is met.

The invention relates to a method for synthesizing mordenite by using coal gangue as a raw material. The method comprises the following steps: firstly, carrying out acid treatment and activation on the coal gangue, extracting a silicon source and an aluminum source in the coal gangue as raw materials by accurately adjusting the use amount of sodium hydroxide, and finally preparing the pure-phase mordenite by accurately adjusting the content of acetic acid. The method for synthesizing the mordenite from the coal gangue is low in experiment cost, simple in process, good in repeatability and convenient for large-scale popularization to realize high value-added utilization of the coal gangue.

The present invention discloses a 3D three-dimensional glaze, which comprises the following components in percentage by weight: 45% - 60% of silicon dioxide, 17% - 25% of aluminum oxide, 1% - 2% of calcium oxide, 0.06% - 1.2% of magnesium oxide, 0.4% - 0.6% of sodium oxide, 1% - 3% of potassium oxide, 10% - 20% of zirconium oxide, 0.2% - 0.6% of zinc oxide, and 1% - 3% of boron oxide; the loss on ignition of the 3D three-dimensional glaze is 1.8% - 3.6%. The preparation method of the 3D three-dimensional glaze is to quantitatively weigh powders such as zirconium silicate, quartz powder, calcined alumina, potassium feldspar, ceramic frit powder, sodium carboxymethyl cellulose, and industrial tripolyphosphate, and then sequentially add the powders and emulsifying wax into water and stir to obtain a glaze slurry. After adjusting the viscosity of the glaze slurry, the 3D three-dimensional glaze is obtained by passing through an 80-mesh sieve. The present invention improves the adhesion of the 3D three-dimensional glaze on the surface of the green body, and when fired directly or in combination with other glazes, the three-dimensional glaze lines will not collapse, crack, have bubbles or breakpoints.

The invention belongs to the technical field of metallurgy, and particularly relates to a method for recovering valuable metals from smelting electric dust. The method comprises the following steps: S1, adding sulfuric acid, ferric sulfate and hydrogen peroxide into the smelting electric dust, and after reaction, carrying out solid-liquid separation to obtain an acidic leaching solution and acidic leaching residues; s2, sodium hydroxide is added into the acid leaching residues obtained in the step S1, the pH value of the acid leaching residues is adjusted to 13.5 or above, and alkaline leaching liquid and alkaline leaching residues are obtained after reaction; s3, sulfuric acid is added into the alkaline leachate obtained in the step S2, the pH value of the alkaline leachate is adjusted to 10.0-12.5, and neutralization liquid and lead slag are obtained after reaction; and S4, roasting the lead slag obtained in the step S3 to obtain lead oxide. According to the method, ferric sulfate is added in the acid leaching process of the smelting electric dust, leaching of arsenic can be effectively inhibited, and efficient separation and recovery of valuable metal can be effectively achieved by subsequently changing the acid-base environment of the reaction.

An ultra-thin flexible glass and its preparation method belong to the technical field of glass manufacturing. The raw materials of the ultra-thin flexible glass are composed of silicon dioxide, aluminum oxide, sodium oxide, boron trioxide, calcium oxide, lithium oxide, a composite toughening agent, a composite flux, and a composite fining agent. The ultra-thin flexible glass prepared by the present invention has an ultimate bending radius of 2-3 mm, a maximum number of bending times of 350,000-360,000 times, a surface compressive stress of 916-937 MPa, a Vickers hardness of 610-623 MPa, and an elastic modulus of 79-82 GPa.

The invention discloses a method for synthesizing a Mn0. 43Cd0. 57S / Cu2MoS4 photocatalyst by adopting a solvothermal method, and belongs to the technical field of catalysts. The preparation method comprises the following steps: preparing copper molybdenum sulfide by using cuprous oxide as a template, synthesizing copper molybdenum sulfide with high purity and good crystallinity by combining a solvothermal method, preparing manganese cadmium sulfide by using manganese acetate, cadmium acetate, sodium hydroxide and thioacetamide as raw materials, adding copper molybdenum sulfide before a hydrothermal reaction, successfully modifying the manganese cadmium sulfide by constructing a heterojunction, and preparing the copper molybdenum sulfide modified manganese cadmium sulfide. The Mn0. 43Cd0. 57S / Cu2MoS4 photocatalyst is synthesized, and the photocatalytic hydrogen production rate of the cadmium manganese sulfide is improved. Moreover, the hydrogen production rate of the Mn0. 43Cd0. 57S / Cu2MoS4 photocatalyst prepared by the invention can reach 8233 mu mol / (g.h), which is 2.08 times of the hydrogen production rate of pure cadmium manganese sulfide, and 1.24 times of the hydrogen production rate of cadmium manganese sulfide loaded with 1% platinum.

The invention discloses high-strength high-temperature-resistant fireproof industrial glass and a preparation method thereof, and relates to the technical field of glass manufacturing. The industrial glass is prepared from the following raw materials: silicon dioxide, boric oxide, aluminum oxide, sodium oxide, potassium oxide, niobium phosphate, a composite reinforcing component and a clarifying agent, the composite reinforcing component is prepared from hafnium oxide, gadolinium oxide and zinc oxide; the clarifying agent is obtained by mixing cerium dioxide and tin oxide. The preparation method of the industrial glass comprises the following steps: preparing functional components, melting glass, forming a glass substrate, and preparing the industrial glass. The prepared industrial glass is high in strength, good in high-temperature stability and excellent in fireproof performance.

The utility model relates to the technical field of carbon dioxide capture, in particular to a device for capturing carbon dioxide by using sodium hydroxide and sodium carbonate, which comprises a spray tower, a power box, a gas outlet pipe, a gas inlet mechanism and a spray mechanism, the gas inlet mechanism is arranged on the inner bottom wall of the spray tower and used for blowing flue gas into the spray tower, and the spray mechanism is arranged in the spray tower and used for spraying a sodium hydroxide solution to the flue gas entering the spray tower. And meanwhile, the spraying effect of the sodium hydroxide solution is improved through the spraying mechanism, so that the problem of relatively low spraying efficiency in the sodium hydroxide spraying process in the related technology is solved.

The invention belongs to the technical field of photocatalytic materials, and particularly relates to a manganese ferrite / bismuth tungstate heterojunction photocatalyst as well as a preparation method and application thereof. The preparation method comprises the following steps: 1) dissolving sodium tungstate dihydrate, bismuth nitrate pentahydrate and hexadecyl trimethyl ammonium bromide in deionized water, and obtaining bismuth tungstate by using a hydrothermal method; 2) dissolving ferric chloride hexahydrate and manganese chloride tetrahydrate in water, then adding a sodium hydroxide solution, and obtaining manganese ferrite by using a hydrothermal method; and 3) dissolving bismuth tungstate and manganese ferrite into a sodium hydroxide solution, stirring, and drying to obtain the manganese ferrite / bismuth tungstate heterojunction photocatalyst. The formation of the heterojunction can greatly improve the activity of the manganese ferrite / bismuth tungstate in photocatalytic reduction of carbon dioxide.

The invention provides a preparation method and application of graphene in-situ growth CNT composite conductive slurry. The preparation method comprises the following steps: adding a sodium hydroxide solution into a graphene oxide composite salt solution for reaction, and performing suction filtration after the reaction is completed to obtain a graphene oxide composite catalyst; repeatedly cleaning with deionized water, drying, firing at high temperature, and crushing to obtain a catalyst; the preparation method comprises the following steps: putting a catalyst into a CVD (Chemical Vapor Deposition) tubular furnace, carrying out high-temperature reaction under the protection of inert gas in the whole process, sequentially introducing reducing gas and carbon source gas to obtain coarse carbon nanotube powder, and then carrying out high-temperature oxidation purification in air to obtain high-purity CNT powder; the preparation method comprises the following steps: fully dissolving a dispersant in a solvent, adding high-purity CNT powder, stirring, and carrying out high-pressure homogeneous dispersion. The graphene oxide is selected as a carrier of the carbon nanotube catalyst, so that the activity of the catalyst and the growth multiple of the carbon nanotube are improved, and the carbon nanotube powder with good conductivity is prepared on the surface of the graphene.

The invention discloses low-carbon red-mud-based alkali-activated foam concrete and a preparation method thereof, and belongs to the field of low-carbon foam concrete. Specifically, the mix proportion and the preparation method of the low-carbon red-mud-based alkali-activated foam concrete are as follows: P.O42.5 ordinary Portland cement provided by building materials in Qingdao Weidong macro, the I-grade fly ash is S95-grade granulated blast-furnace slag produced by Henan Province Platinon Casting Material Co., Ltd., and Jinshu New Material Co., Ltd., the I-grade fly ash is S95-grade granulated blast-furnace slag produced by Henan Province Platinon Casting Material Co., Ltd. The Bayer process red mud powder is produced by Hebei Province Shihozhuangfei Mine Product Co., Ltd. The exciting agent is selected from an industrial liquid sodium silicate solution produced by Henan Jinmoistening New Material Co., Ltd. And solid sodium hydroxide particles with AR analytical purity of 96%; the admixture is selected from a TR-26C type polycarboxylate superplasticizer produced by Henan Fuhua Information Science and Technology Co., Ltd. And the foaming agent is a TR-E type animal protein foaming agent produced by Henan Zhuichun Information Science and Technology Co., Ltd. Compared with existing foam concrete, the low-carbon alkali-activated foam concrete provided by the invention uses a large amount of industrial solid waste, reduces the use cost, reduces the use amount of cement under the condition of ensuring the compressive strength, and is simple and convenient to operate, reasonable in process, low-carbon, environment-friendly, rapid in cement setting and hardening, and suitable for large-scale use.

The invention discloses a cellulose / chitosan / lanthanum oxide composite material for efficiently removing nitrogen and phosphorus from a water body. The composite material is mainly prepared from the following raw materials: bacterial cellulose, chitosan, lanthanum nitrate hexahydrate and sodium hydroxide. By regulating and controlling the dosage of raw materials such as chitosan, lanthanum nitrate hexahydrate, sodium hydroxide and the like in the synthesis process of the material, the process parameters of material preparation are optimized, so that the optimal nitrogen and phosphorus removal performance is achieved. The practical application capability of the material is verified by evaluating the nitrogen and phosphorus removal performance, the application stability and the environmental factor influence of the material. The development of the material solves the problems that an environmental functional material is high in preparation cost, low in adsorption capacity, poor in selectivity and incapable of removing nitrogen and phosphorus at the same time. Theoretical support is provided for preparation of the nitrogen and phosphorus removal adsorption composite material for the water body, and meanwhile, the composite material has a wide practical application prospect.

The invention relates to the technical field of electronic glass fiber materials, and particularly discloses a corrosion-resistant low-dielectric glass fiber and a preparation process thereof. A preparation process of corrosion-resistant low-dielectric glass fibers comprises the following steps: S1, uniformly mixing glass fiber raw materials, melting, clarifying, homogenizing, cooling, and carrying out wiredrawing treatment to obtain glass fiber precursors; and S2, sequentially carrying out plasma treatment and impregnating compound treatment on the glass fiber precursor, drying and curing to obtain the corrosion-resistant low-dielectric glass fiber, silicon dioxide, aluminum oxide, magnesium oxide, boric oxide, calcium fluoride, tin oxide, sodium oxide, potassium oxide and rare earth oxide are used as glass fiber raw materials, and the rare earth oxide is a mixture of gadolinium oxide, cerium oxide and samarium oxide. The obtained glass fiber has excellent low dielectric property and corrosion resistance, and has a wide market prospect.

The invention discloses high-performance asphalt-based porous carbon and a preparation method and application thereof.The preparation method comprises the following steps that refined asphalt is heated and stirred, then oxygen-containing gas is introduced, and oxygen-containing modified pre-oxidized refined asphalt is obtained through segmented heating oxidation treatment; heating the pre-oxidized asphalt to different temperatures in different stages in an inert atmosphere for pre-carbonization; placing the pre-carbonized product in a hydrogen-containing mixed atmosphere, and dynamically regulating and controlling the carbonization process according to asphalt components; and mixing the carbonized product with potassium hydroxide and sodium hydroxide mixed alkali, carrying out multi-temperature-zone stepped activation, washing, and drying to obtain the asphalt-based porous carbon. According to the invention, refined pitch is directly used as a carbon source raw material, pre-oxidation is carried out to obtain a partial oxygen-containing hard carbon structure, low-temperature pre-carbonization is carried out to obtain a carbonized precursor with very few volatile components, porous carbon is subjected to moderate graphitization through carbonization, the conductivity of a skeleton is improved, the skeleton is further subjected to pore forming through activation, and the high-performance porous carbon material is obtained.

The invention discloses a high-aluminum wear-resistant ceramic grinding ball and a preparation method thereof. The grinding ball comprises the following raw materials in percentage by weight: 85%-95% of aluminum oxide, 2%-10% of silicon dioxide, 1%-3% of calcium carbonate, 0.2%-0.5% of magnesium carbonate, 0.03%-0.05% of titanium dioxide, 0.01%-0.03% of sodium oxide and 1%-5% of modified zirconium dioxide. The preparation method of the modified zirconium dioxide comprises the following steps: adding hydrogen peroxide into a mixed solution of soluble cerium salt and soluble zirconium salt to obtain a reaction system; adding the reaction system into an alkaline solution for reaction, and collecting an insoluble substance after the reaction is finished; and calcining the insoluble substance to obtain the modified zirconium dioxide. The ceramic ball is simple in formula, rich in raw materials, low in price and low in production cost, the operation stability of the ceramic ball is improved, and the service life is prolonged.

This application relates to the field of metal surface treatment materials, specifically disclosing a silicon-integrated inorganic supercrystalline thermal energy powder and its preparation and application methods. The silicon-integrated inorganic supercrystalline thermal energy powder comprises raw material A and raw material B. Raw material A includes the following: magnesium oxide, sodium fluoroaluminate, sodium polyphosphate, zinc oxide, crystalline tin tetrachloride, silicon dioxide, and boric acid. Raw material B includes the following raw materials in parts by weight: spodumene, lithium carbonate, titanium dioxide, zinc silicate, sodium carbonate, antimony trioxide, albite, fluorite, boric acid, sodium hydroxide, and yttrium oxide. The inorganic supercrystalline thermal energy powder of this application has advantages such as corrosion resistance and oxidation resistance, good thermal stability, no damage from thermal cycling, high hardness, wear resistance and high temperature resistance, energy saving, water scale reduction, and the ability to replace organosilicon high-temperature resistant special coatings, baking paints, enamel paints, and ceramic floor glazes.

The invention provides a preparation method of low-sodium high-temperature alpha-phase alumina micro powder, and belongs to the technical field of alumina powder. The preparation method comprises the steps of acid leaching, coating and post-treatment. The coating step comprises the following steps: adding a silica sol solution into an acid-leached aluminum oxide suspension for the first time, stirring at 74-78 DEG C for 1.0-1.4 hours, then adding the silica sol solution for the second time, stirring for 1.0-1.5 hours while keeping the temperature, then adding the silica sol solution for the third time, and stirring for 0.8-1.2 hours at 62-65 DEG C to obtain silica sol-coated aluminum oxide; the alpha-phase alumina micropowder prepared by the preparation method disclosed by the invention is uniform in particle size, low in sodium oxide content, high in alpha-phase conversion rate and good in powder fluidity.

The invention relates to the technical field of preparation of magnesium sulfate heptahydrate, in particular to a method for preparing magnesium sulfate heptahydrate from magnesite flotation tailings, which comprises the following steps: 1) crushing the magnesite flotation tailings until the granularity is less than or equal to 0.074 mm to obtain tailings powder; 2) mixing and stirring the tailing powder and sulfuric acid, and then filtering to obtain a crude magnesium sulfate solution; 3) adding sodium hydroxide into the crude magnesium sulfate solution, adjusting the pH value of the solution to 6, and filtering; 4) concentrating the concentration of magnesium sulfate to 30%-40%; (5) cooling the concentrated solution to 0-10 DEG C, and controlling the cooling speed to be 1-5 DEG C / h, so that magnesium sulfate heptahydrate is fully crystallized and separated out; 6) filtering the crystallized mixture, and separating out magnesium sulfate heptahydrate crystals; and 7) finally drying the filtered magnesium sulfate heptahydrate crystal to obtain a magnesium sulfate heptahydrate finished product. According to the method, high-purity magnesium sulfate heptahydrate can be obtained, so that the influence of tailings on the environment is solved.

Described herein are techniques that may be performed in an Integrated Energy System (IES). The IES may include a clean water production plant, a supercritical water source, a waste source, a Sodium Hydroxide source, and a reaction chamber. The reaction chamber may be configured to receive supercritical water from the supercritical water source, waste from the waste source, and Sodium Hydroxide from the Sodium Hydroxide source to an interior of the reaction chamber. The reaction chamber may be configured to maintain a supercritical temperature and pressure within the interior of the reaction chamber and to convert the waste into Carbon Dioxide and Water in a Super Critical Water Oxidation (SCWO) reaction.

The invention discloses a hard carbon negative electrode composite material as well as a preparation method and application thereof, and relates to the technical field of sodium ion batteries. The hard carbon negative electrode composite material comprises an inner core and a shell coating at least part of the outer surface of the inner core, wherein the material of the inner core comprises graphite, and a metal oxide and a heteroatom which are doped in the graphite; the metal oxide at least comprises sodium oxide, and the metal oxide can react with sodium to form a sodium alloy material; the shell is made of amorphous carbon. The hard carbon negative electrode composite material disclosed by the invention has relatively high electronic conductivity and first charge-discharge efficiency, and also has relatively good low-temperature performance.

The invention discloses a preparation method and application of a layered positive electrode material with a self-sodium pre-modification function. The chemical general formula of the layered positive electrode material is Na < x > [Li < y > A < z > M < w > Mn < 1-y-z-w >] O < 2 >, wherein A is a vacancy, M is a transition metal element, x is 0.5-1, y is less than or equal to 0.2, z is less than or equal to 0.1, and w is less than or equal to 0.3; li, M and Mn respectively form transition metal oxide octahedrons with O, a plurality of transition metal oxide octahedrons are arranged in a common edge manner to form a transition metal layer, and unoccupied vacancies A exist in the transition metal layer; na and O form a sodium oxide octahedron, and the sodium oxide octahedron is located between every two transition metal layers. By designing the chemical general formula of the layered positive electrode material, material lattice regulation and control can be realized, so that irreversible lattice oxygen capacity is activated to provide compensation capacity, spontaneous sodium supplementation can be realized without an additional sodium pre-modification step, and the material has good air stability, rate capability and cycle stability.

The invention discloses a method for preparing an hBN ceramic coating on the surface of a SiCp / 2024Al substrate, and belongs to the technical field of surface treatment. The invention discloses a method for preparing an hBN ceramic coating on the surface of a SiCp / 2024Al substrate. The method comprises the steps that the SiCp / 2024Al substrate is polished and ground and then dried after being subjected to ultrasonic cleaning; adding sodium silicate, sodium hydroxide, the hexagonal boron nitride nano-powder and a surface active component into deionized water, and performing ultrasonic dispersion to obtain a composite electrolyte; placing the composite electrolyte in a stainless steel electrolytic bath, and connecting the stainless steel electrolytic bath to a power supply cathode of a plasma discharge system; the pretreated SiCp / 2024Al substrate is connected to the positive electrode of a power source of a plasma discharge system and immersed in the composite electrolyte; and the plasma discharge system operates, under the action of positive and negative pulses, the nano-particles are driven to migrate to the surface of the SiCp / 2024Al substrate and participate in reaction co-deposition, and the compact and uniform large-thickness high-electrical-insulation hBN ceramic coating grows on the surface of the substrate.

The invention provides a water-resistant building gypsum-based material and a preparation method thereof. The material comprises a building gypsum base body, a hydrophobic film is cured on the surface of the building gypsum base body, and the hydrophobic film is formed by curing waterproof liquid; the building gypsum base body is prepared from four components including desulfurized building gypsum, blast furnace slag, calcium oxide and water, the water-binder ratio is 0.5-0.6, the mass ratio of the blast furnace slag to the desulfurized building gypsum is (1-5): (5-9), and the mass of the calcium oxide is 2%-10% of that of the blast furnace slag; the waterproof liquid comprises water, sodium methyl silicate, tetraethoxysilane, dimethyl silicone oil, sodium hydroxide and sodium silicate. According to the preparation method, a proper waterproof treatment mode is selected according to the size of a workpiece. The blast furnace slag and the calcium oxide are introduced into the desulfurized building gypsum formula, the calcium oxide can effectively excite the activity of the blast furnace slag in a building gypsum matrix, so that the water resistance of a building gypsum-based material is improved, the water resistance of the material is further improved by the waterproof liquid, and meanwhile, the material is endowed with hydrophobicity.

The invention provides a method for synergistically preparing calcium fluoride and a molecular sieve based on multi-element industrial waste, and belongs to the technical field of industrial waste recycling. The method comprises the following steps: respectively taking an electrolytic aluminum industry byproduct fluorine-containing waste electrolyte cryolite and lithium slag after lithium extraction of lithium ore as raw materials, performing acid leaching on the electrolyte cryolite, adding a calcium compound, separating to obtain calcium fluoride solid and a mixed solution containing aluminum chloride and sodium chloride, and adding an alkaline solution into the mixed solution to obtain an aluminum hydroxide product. And carrying out alkaline leaching on the lithium slag to obtain a mixed solution containing sodium silicate and sodium metaaluminate, and proportionally synthesizing the mixed solution with the obtained aluminum hydroxide and sodium hydroxide solution to obtain the 4A zeolite molecular sieve product. The calcium fluoride and the zeolite molecular sieve are cooperatively prepared by adopting multi-element industrial waste, and the problems that electrolyte cryolite cannot be completely applied to the aluminum electrolysis process, the lithium slag treatment cost is high and the like in the prior art are solved.