501 results about "Flake graphite" patented technology

The present invention pertains to the technical field of phase-change temperature-reducing materials, and in particular, relates to a phase-change temperature-reducing polyurethane composite material, and a preparation method and application thereof, comprising the following parts by mass of raw materials: 50-80 parts of polyurethane material A+polyurethane material B, 1-3 parts of flake graphite powder with a particle size of 850-1200 meshes, 0.8-1.8 parts of vermicular graphite with a particle size of 10-40 meshes, 10-30 parts of phase-change paraffin, 1-3 parts of activated carbon, 0.5-2 parts of catalyst, and 0.2-1 parts of co-catalyst. The polyurethane composite material made in the present invention is rapid in phase-change temperature reduction, high in heat absorption and dispersion, and free of problems of phase-change paraffin leakage, crystallization, and frosting on the surface thereof. At the same time, it also has softness and high elasticity, and can be widely applied to objects in contact with human bodies. A temperature difference is formed by reducing the temperature of the surface in contact with skin, which can bring a comfortable sense of coolness and a temperature-reducing effect to consumers.

The invention discloses a low-carbon magnesia-carbon refractory material for clean steel smelting and a preparation method thereof, and relates to the technical field of magnesia-carbon refractory materials. The low-carbon magnesia-carbon refractory material comprises the following components: 40-50 wt% of fused magnesite with the particle size of 3-5 mm, 20-30 wt% of fused magnesite with the particle size of 1-3 mm, 10-20 wt% of fused magnesite with the particle size of less than or equal to 74 [mu] m, 8-12 wt% of silicon powder, 1-3 wt% of alumina powder and 3-5 wt% of crystalline flake graphite. 2-4 wt% of a composite additive and 4-6 wt% of phenolic resin are added; the composite additive comprises andalusite and mullite. The material has excellent mechanical properties, thermal shock resistance, oxidation resistance and erosion resistance; the preparation method has the characteristics of low cost and simple process, and the prepared low-carbon magnesia carbon refractory material has excellent oxidation resistance, thermal shock resistance and slag resistance by exerting the phase volume expansion effect and intergranular phase enhancement effect of the multiphase ceramic; the used graphite is low in content, graphite consumption and molten steel recarburization risk can be reduced, and the method is suitable for smelting clean steel.

The invention relates to a magnesia-carbon refractory material with high thermal shock resistance and erosion resistance and a preparation method thereof. The magnesia-carbon refractory material with high thermal shock resistance and erosion resistance is prepared from fused magnesia aggregate, fused magnesia fine powder, silicon powder, crystalline flake graphite, Al2O3-MgO-CaO core-shell structure raw materials and phenolic resin. The Al2O3-MgO-CaO core-shell structure raw materials are prepared by the following steps: uniformly mixing calcium carbonate, magnesium hydroxide and alumina micro powder by adopting a planetary ball mill, and then carrying out granulation treatment by adopting a disc granulator by taking polyvinyl alcohol as a binding agent, so as to obtain core particles; and mixing the inner core particles and the alumina micro powder by taking alumina sol as a binding agent, and further sintering to obtain the core-shell structure raw material. The Al2O3-MgO-CaO core-shell structure raw material is utilized to improve the comprehensive performance of the magnesia-carbon refractory material, and the prepared magnesia-carbon refractory material has excellent thermal shock resistance and slag corrosion resistance and can meet the requirements of the current steel industry for the magnesia-carbon refractory material.

The invention provides a high-temperature-resistant magnesia-carbon composite refractory brick and a preparation method thereof, and belongs to the technical field of magnesium oxide refractory wall bricks, the refractory brick comprises the following raw materials: double-layer modified magnesium oxide, modified crystalline flake graphite, zircon powder, modified liquid phenolic resin and a benzoxazine cross-linking agent; the double-layer modified magnesium oxide is obtained by firstly coating magnesium oxide with powder phenolic resin, aluminum oxide and zirconium oxide and then coating magnesium oxide with asphalt, micron magnesium oxide, zirconium oxide and calcium oxide; the modified crystalline flake graphite is obtained by coating crystalline flake graphite with strontium hydroxide, asphalt and boron carbide; the modified liquid phenolic resin is formed by mixing liquid phenolic resin with a silane coupling agent and a polyacrylate cross-linked polymer. Double-layer modified magnesium oxide, modified crystalline flake graphite and modified liquid phenolic resin are prepared by adopting special components and a method and are matched with zircon powder and a benzoxazine cross-linking agent for use, and a reasonable forming and sintering process is designed, so that the refractory brick has good high-temperature stability, oxidation resistance, thermal shock resistance and the like.

The invention belongs to the technical field of motor casing lost foam casting, and particularly relates to a special coating for a motor casing lost foam as well as a preparation method and application thereof. Through a quantitative formula design method, an aggregate proportion calculation formula based on thermal expansion coefficient matching and a grain size distribution correlation formula based on target air permeability, cooperative compounding of quartz powder and bauxite is achieved, and key functional components such as mullite, organic matter fibers and crystalline flake graphite are combined; the unification of high air permeability and excellent crack resistance of the motor shell lost foam coating is realized. The invention further provides a two-time coating gradient drying efficient process matched with the coating, and on the premise that the coating performance is guaranteed, the production efficiency is remarkably improved, and the energy consumption is reduced.

The invention relates to the technical field of electrode paste, in particular to a preparation method of high-pressure-resistant high-strength graphite enhanced electrode paste, which comprises the following steps: sequentially performing oxidation modification and silane modification on crystalline flake graphite powder, preparing silane modified graphite powder, and synchronously preparing a boron-nitrogen source precursor; coating the aminated carbon quantum dots with silicon to obtain silicon-coated carbon quantum dots; preparing a composite adhesive, a tungsten carbide-aluminum nitride composite reinforced phase and carbon-plated silicon powder; the preparation method comprises the following steps: blending and kneading silane modified graphite powder, a boron-nitrogen source precursor and other components, and pressing under gradient pressure to obtain a green body; and performing segmented roasting on the green body, and cooling to obtain the target electrode paste. According to the invention, crystalline flake graphite oxidation-silane modification is adopted to optimize interfacial compatibility, silicon-coated carbon quantum dots are adopted to reinforce a bonding system, a composite reinforcement phase is adopted to construct a mechanical support network, boron-nitrogen source in-situ doping supplemental reinforcement is adopted, and gradient pressure pressing and segmented roasting are combined to ensure that the structure is compact. The normal-temperature compressive strength, high-temperature mechanical stability and compactness of the electrode paste are improved through the synergistic effect of all links, and the electrode paste can stably adapt to the high-temperature and high-load working conditions.

The invention discloses a high-corrosion-resistance powder coating and a preparation method thereof, and belongs to the technical field of powder coatings. Through modification of the resin system, the ultraviolet absorbent modified epoxy resin and the weather-resistant polyester resin are compounded, so that the ultraviolet resistance and the weather resistance of the resin system are remarkably improved, and the corrosion resistance reduction caused by light aging is avoided; the flake graphene forms an excellent physical barrier to block corrosion medium permeation, then chemical passivation of zinc phosphate is combined to inhibit electrochemical corrosion, the synergistic effect is achieved, the corrosion resistance is synergistically enhanced from the physical and chemical angles, the path of the corrosion medium is further prolonged in combination with the laminated structure of the glass flakes, and the corrosion resistance is improved. And meanwhile, the filler A and the filler B can also play a role in enhancing the mechanical strength of the coating, so that the powder coating with high corrosion resistance can be obtained on the whole.

The invention relates to the field of graphene preparation, and discloses a layer number controllable graphene material preparation process which comprises the following steps: S1, substrate selection: selecting a copper surface or nickel surface substrate, and putting the copper surface or nickel surface substrate into a chemical vapor deposition reaction chamber; s2, raw material preparation: selecting ultra-high-purity natural flaky graphite, and putting the pretreated ultra-high-purity natural flaky graphite into a reaction chamber; s3, reaction precursor: introducing hydrogen and argon into the reaction chamber, and adjusting to preset conditions; s4, reaction condition adjustment: adjusting the temperature and atmosphere to gasify the graphite and deposit the graphite into graphene; and S5, cooling and transferring: spraying a protective layer after cooling, drying, and then transferring to a target substrate. Through the technical scheme of temperature staged regulation and control and hydrogen concentration dynamic regulation, the deposition process of carbon atoms on the substrate is more controlled, the number of growth layers is more stable, the carbon dissolution and precipitation rate is effectively balanced, random accumulation of a multi-layer structure is avoided, and the application of the multi-layer structure in a high-precision electronic device is more reliable.

The invention relates to the technical field of refractory materials, in particular to an antioxidant and application thereof in steel ladle slag line bricks, and the antioxidant comprises a Si / SiC multiphase material, modified nano Al2O3 and CaF2; the ladle slag line brick comprises an antioxidant, fused magnesite, crystalline flake graphite and phenolic resin. Si-SiC compound waste is subjected to magnetic separation and acid pickling, then a SiO2 passivation layer is formed through pre-oxidation, moisture and air in the storage period are isolated, and a titanate coupling agent is introduced to improve the wettability and compatibility with phenolic resin. P2O5 released by phosphate on the surface of the modified nano Al2O3 at a high temperature reacts with alkali (earth) metal migrated to a SiO2 oxide layer to prevent the alkali (earth) metal from forming a low-melting-point eutectic substance, CaF2 reacts with SiO2 along with temperature rise, a passivation layer is broken, internal Si and SiC are directly exposed, and boron oxide of the modified nano Al2O3 remarkably reduces activation energy and a temperature threshold value of the reaction of CaF2 and SiO2.

The invention relates to a preparation method of a refractory material, in particular to a preparation method of a high-corrosion-resistance low-carbon magnesia-carbon refractory material. The high-corrosion-resistance low-carbon magnesia-carbon refractory material is prepared from fused magnesite aggregate, fused magnesite fine powder, Ti3SiC2 powder, crystalline flake graphite, corundum slag and phenolic resin. The prepared low-carbon magnesia-carbon refractory material has excellent oxidation resistance and slag corrosion resistance, the service life of the magnesia-carbon refractory material under the large scrap ratio smelting condition can be prolonged, and the cost is reduced from the perspective of refractory raw materials, so that the low-carbon magnesia-carbon refractory material has high economic benefits, meanwhile, the carbon content of the refractory material is lower, and the cost is lower. And high-temperature industrial carbon emission can be reduced. The oxidation index of the magnesia-carbon refractory material is 20-30% after the magnesia-carbon refractory material is oxidized in an air atmosphere of 1600-1700 DEG C for 2-5 h; and after the magnesia-carbon refractory material is eroded for 1-3 hours under the dynamic slag condition of 1600-1700 DEG C, the erosion index of the magnesia-carbon refractory material is 0.5-4%.

The invention relates to a method for removing graphite metal-based impurities through surface activity and pressure oxygen method combined low-concentration hydrochloric acid, and aims to solve the problem that the use amount of hydrochloric acid and nitric acid is large in a process for removing natural flake graphite metal-based impurities by mixing high-concentration hydrochloric acid and nitric acid. The purification method comprises the following steps: 1, mixing natural spherical graphite, sodium hydroxide and industrial pure water, and carrying out heat preservation treatment at the temperature of 380-440 DEG C; 2, uniformly stirring the graphite subjected to alkali melting treatment and hydrochloric acid; 3, adding absolute ethyl alcohol and hydrogen peroxide into the graphite-hydrochloric acid material to obtain a mixed material; 4, introducing oxygen into the reaction kettle, and raising the temperature to 75-85 DEG C; 5, carrying out suction filtration, solid-liquid separation, washing and drying on the acid-leached material; and 6, carrying out demagnetization treatment. According to the method, hydrogen peroxide and high-pressure oxygen are added to replace low-concentration nitric acid to serve as oxidizing agents, a small amount of absolute ethyl alcohol and high pressure of 10 atmospheric pressure oxygen are added synchronously, and the content of purified spherical graphite iron-based impurities can be controlled within 0.002%.

The invention relates to the technical field of precision casting of turbine blades, in particular to a ceramic core for a nickel-based superalloy isometric crystal hollow turbine blade and a preparation method of the ceramic core. The ceramic core is prepared by mixing refractory powder and a paraffin-based plasticizer and then sintering the mixture at a high temperature, and the mass ratio of the refractory powder to the paraffin-based plasticizer is (75-85): (15-25); the refractory powder is composed of quartz glass powder, alumina powder and natural crystalline flake graphite, and the mass ratio of the quartz glass powder to the alumina powder to the natural crystalline flake graphite is (72-77): (20-25): (0.5-3); the paraffin-based plasticizer is prepared from refined paraffin, beewax and low-density polyethylene, and the mass ratio of the refined paraffin to the beewax to the low-density polyethylene is (40-50): (40-50): (5-10). The natural flake graphite is creatively added into the raw materials of the ceramic core, so that the flowability of slurry is improved, the high-temperature bending strength of the ceramic core is improved, and the depoling performance of the mold core is improved.

The invention discloses a cavitation-flotation method for purification and synchronous spheroidization of crystalline flake graphite, and belongs to the technical field of graphite purification and spheroidization. The method aims at solving the problems that an existing crystalline flake graphite flotation purification method is long in technological process, high in energy consumption and low in graphite purity, and the overall technological process is long and high in additional energy consumption due to the fact that additional spheroidizing treatment is needed. According to the invention, after first grinding and flotation treatment of graphite ore, graphite purification and synchronous spheroidization are realized through at least one coupling operation unit; one coupling operation unit comprises primary cavitation treatment, primary flotation treatment after the cavitation treatment and primary ore grinding treatment before the cavitation treatment, so that a spherical graphite product with high purity and high spheroidization rate can be obtained.

The invention discloses a carbon-coated surface modification method of granulated graphite powder, and belongs to the technical field of lithium ion battery negative electrode materials. The method comprises the following steps: mixing crystalline flake graphite and a hard carbon binder, granulating to obtain particles with d50 of 15-25 microns, adding a soft carbon coating agent, carbonizing, and screening to finally obtain the granulated graphite material. According to the method, two key links of granulation and carbon coating are comprehensively considered, the synergistic effect of a hard carbon binder and a soft carbon coating agent and the influence of different carbonization treatment modes such as gradient carbonization and co-carbonization on the performance of the granulated graphite powder are systematically studied, various parameters in the granulation and carbon coating processes are accurately regulated and controlled, and the performance of the granulated graphite powder is improved. Comprehensive optimization of granularity, structural stability, electrochemical performance and the like of the granulated graphite powder is realized, a brand new technical thought and method are expected to be provided for research, development and production of a lithium ion battery negative electrode material, and further development of a lithium ion battery technology is promoted; and the method has extremely important strategic significance and wide application prospect for promoting the progress of the new energy industry and optimizing the energy structure.

The invention relates to the technical field of refractory materials, in particular to a method for producing magnesia carbon bricks from low-carbon reduced magnesia. The method comprises the following steps: respectively weighing 80-90 parts by weight of magnesia, 3-5 parts by weight of a function enhancer, 1-3 parts by weight of aluminum powder, 0.3-1 part by weight of aluminum nitride, 2-3 parts by weight of carbon black, 3-5 parts by weight of crystalline flake graphite and 3-5 parts by weight of phenolic resin for later use; mixing the magnesite except the fine magnesite with phenolic resin, uniformly mixing, adding the rest raw materials, uniformly stirring at a low speed, adding the fine magnesite, and uniformly stirring at a high speed to obtain mixed slurry; and injecting the mixed slurry into a prepared mold, and sequentially carrying out compression molding and heat treatment to obtain the magnesia carbon brick. The magnesia carbon brick produced by the invention not only has excellent mechanical properties, but also has excellent thermal shock resistance stability and oxidation resistance; the quality of the produced magnesia carbon brick is effectively guaranteed, and meanwhile the service life of the magnesia carbon brick is prolonged to a certain degree.

The invention discloses a graphene aerogel modified elastic graphite material and a preparation method thereof, and the graphene aerogel modified elastic graphite material comprises the following components by mass: 50-80 parts of crystalline flake graphite; 8 to 15 parts of graphene aerogel; 3 to 8 parts of aminated modified boron-doped carbon nanotubes; 2 to 6 parts of hydroxyapatite-cerium oxide composite nano particles; 1 to 4 parts of a polyimide-montmorillonite nano composite material; 0.5 to 3 parts of titanate coupling agent modified nano silicon dioxide; 1-3 parts of a dispersant; 2-5 parts of a binder; the amination modified boron-doped carbon nanotubes can enhance the electrical conductivity and interface bonding force of the material, the hydroxyapatite-cerium oxide composite nanoparticles improve the high-temperature stability and mechanical toughness of the material, and the polyimide-montmorillonite nanocomposite improves the corrosion resistance and resilience durability of the material. And the titanate coupling agent modified nano silicon dioxide further optimizes the dispersion uniformity of all the components, and the comprehensive performance of the material is remarkably improved.

The invention discloses a submerged nozzle lining material for rare earth steel continuous casting and a preparation method thereof, and relates to the field of refractory materials. The high-strength wear-resistant ceramic material comprises the following components in percentage by weight: 40-65 wt% of fused white corundum, 8-20 wt% of quartz, 15-25 wt% of crystalline flake graphite, 1-2 wt% of metal silicon powder, 2-4 wt% of ferro-silicon nitride powder, 0.5-1 wt% of boron carbide powder and 8-12 wt% of thermosetting phenolic resin. The method has the beneficial effects that the raw materials are processed through the processes of mixing, drying and the like to prepare the pug, the pug is used for manufacturing the submersed nozzle lining, the submersed nozzle using the lining is used for rare earth steel pouring, the nodulation problem of an inner hole of the nozzle is remarkably relieved, the content of inclusions in molten steel is reduced, the quality of steel billets is improved, and meanwhile the production cost is reduced. And the service life of the submersed nozzle is prolonged, so that the submersed nozzle is more suitable for production of rare earth steel protective pouring.

The invention relates to the technical field of refractory brick production, and discloses a high-strength refractory brick for a garbage incinerator and a preparation method thereof.The high-strength refractory brick is prepared from, by mass, 32-45 parts of fly ash, 18-30 parts of kieselguhr, 6-10 parts of modified aluminum silicate fibers, 20-30 parts of nano zirconium silicate loaded crystalline flake graphite powder, 7-10 parts of metal oxide and 1-3 parts of auxiliary materials. Fly ash and diatomite are used as raw materials, modified aluminum silicate fiber, nano zirconium silicate loaded crystalline flake graphite powder, metal oxide and auxiliary materials are compounded, the prepared refractory brick has high mechanical strength, fire resistance and oxidation resistance, the product quality of the refractory brick is improved, the refractory brick is prevented from cracking in the waste incineration process, and the service life of the refractory brick is prolonged.

The invention belongs to the technical field of glass fibers, and discloses a glass fiber bundling wheel based on a graphite composite material and a preparation method of the glass fiber bundling wheel. The bundling wheel is made of a composite material comprising the following components: 50%-70% of polytetrafluoroethylene, 10%-25% of crystalline flake graphite, 1%-5% of antimony, 3%-10% of carbon nanotubes, 2%-8% of nano titanium dioxide and 5%-15% of chopped glass fibers; the preparation method comprises the following steps: mixing polytetrafluoroethylene, crystalline flake graphite, antimony, carbon nanotubes, nano titanium dioxide and chopped glass fibers step by step according to a ratio to obtain a mixed material; quantitatively weighing the mixed material, putting into a mold, carrying out hot press molding on the material by gradient pressurization and temperature increase, and then carrying out depressurization cooling to obtain a molded product; and polishing the surface of the formed product, and performing heat treatment to obtain the bundling wheel. According to the glass fiber bundling wheel, the bending strength, the impact strength and the abrasive resistance are effectively improved, the friction coefficient is reduced, zero particle falling can be achieved, the service life and the maintenance period are prolonged, and the production efficiency is improved.

The invention relates to the technical field of material science, and discloses an efficient preparation and functional modification method of graphene oxide, which comprises the following steps: carrying out nitric acid pretreatment on crystalline flake graphite powder to form pre-oxidized graphite, carrying out deep oxidation reaction on the pre-oxidized graphite, and carrying out centrifugal washing to obtain a graphene oxide crude product; the preparation method comprises the following steps: adding a crude product into boron nitride nanosheets and phosphotungstic acid, carrying out ultrasonic dispersion, carrying out a hydrothermal reaction to improve the performance of graphene oxide, carrying out dopamine functionalization on composite graphene oxide to form a polydopamine coating, grafting organosilane on the surface of the polydopamine coating, introducing an amino functional group, and carrying out drying treatment to obtain functionalized modified graphene oxide. According to the method, through dopamine functionalization, organosilane grafting and amino functional group introduction, active sites and chemical reactivity on the surface of the graphene oxide are increased, the dispersity of the graphene oxide in an organic phase and the compatibility of the graphene oxide with polylactic acid are improved, and the application performance and functionality of the graphene oxide in a composite material are enhanced.

The invention relates to the technical field of graphite materials, and provides a method for preparing expanded graphite with high expansion volume through activation or pretreatment. Natural crystalline flake graphite, potassium permanganate, concentrated sulfuric acid and an activating agent are mixed for an oxidation intercalation reaction, and then high-temperature expansion is performed to obtain high-expansion-volume graphite; or, the natural flake graphite is pretreated by adopting the pretreating agent, and then the oxidation intercalation reaction and high-temperature expansion are performed to obtain the high-expansion-volume graphite. Through activation or pretreatment, the expansion volume of the expanded graphite can be increased, especially when the pretreatment method is adopted, the expanded graphite with the expansion volume obviously increased can be prepared on the basis of reducing the usage amount of the oxidizing agent and the intercalator, and the expansion effect is more remarkable.

The invention discloses a lithium tantalate wafer with high electrical conductivity and a preparation method thereof, belonging to the technical field of crystal materials. The invention comprises the following steps: uniformly mixing an organic carbon source, an inorganic carbon source and spherical zinc powder to obtain a reducing agent; embedding the reducing agent on the surface of the lithium tantalate wafer, placing the wafer in a heat treatment furnace, introducing an inert gas for carbonization; introducing a reducing gas for heat treatment, taking the wafer out, and obtaining the lithium tantalate wafer with high electrical conductivity; the organic carbon source comprises at least one of sucrose and phenolic resin; the inorganic carbon source comprises at least one of flaky graphite and graphene; the invention uses an organic carbon source, an inorganic carbon source and spherical zinc powder in a mass ratio of 1: (0.3-0.6): (0.4-0.7) as a reducing agent, embeds the reducing agent on the surface of the lithium tantalate wafer, firstly undergoes carbonization, and then undergoes heat treatment, so as to effectively improve the electrical conductivity of the lithium tantalate wafer and has broad application prospects.

The application discloses a low-carbon magnesia carbon brick and a preparation method thereof, and relates to the technical field of weather-resistant magnesia carbon bricks. The low-carbon magnesia carbon brick comprises the following components in parts by mass: fused magnesia particles 80-90 parts, fused magnesia fine powder 15-25 parts, flake graphite 5-10 parts, nano carbon powder 1-5 parts, phenolic resin 10-20 parts, curing agent 0.2-1.5 parts, antioxidant 0.5-3 parts, and modifier 0-8 parts. The core lies in a triple synergistic protection mechanism of the antioxidant, which comprises the electron delocalization of a conjugated pi bond system to stabilize free radicals, the physical isolation of a tert-butyl group, and the formation of a high-temperature barrier layer of a silane group. This effectively delays the oxidation loss of graphite, strengthens the resistance to slag penetration, and improves the service performance of the material under extreme storage conditions.

The invention discloses a multi-stage circulating graphite flotation process which specifically comprises the following steps: S1, coarsely crushing a graphite mineral material containing crystalline flake graphite, then feeding the graphite mineral material into a screening machine for grading, separating out oversize coarse grain products and undersize fine grain concentrate, carrying out screening treatment on the oversize coarse grain products again through scavenging equipment, and screening the oversize coarse grain products to obtain oversize fine grain concentrate and undersize fine grain concentrate; then feeding undersize fine-grain concentrate and scavenged materials into a grinding machine for crushing and grinding treatment, and discharging the ground materials from a discharge port; s2, separation flotation; and S3, ore grinding and flotation. The invention relates to the technical field of purification of graphite in nonmetallic minerals. According to the multistage circulating graphite flotation process, the flotation efficiency can be greatly improved by simplifying the flotation process, the flotation effect can be greatly enhanced by adopting the flotation agent, and the graphite flotation process is simple in flotation procedure, good in flotation effect and high in practicability. Concentrate and tailings can be subjected to more sufficient flotation treatment by utilizing the flotation agent.

The invention discloses a carbonyl iron powder-graphite electromagnetic wave absorption composite material and a preparation method thereof. The carbonyl iron powder-graphite electromagnetic wave absorption composite material is composed of superfine spherical carbonyl iron powder and flake graphite. According to the method for preparing the carbonyl iron powder-graphite electromagnetic wave absorbing composite material, a room-temperature dry ball milling technology is utilized, various carbonyl iron powder-carbon composite wave absorbing materials can be flexibly prepared, the preparation process is simple, the condition is mild, consumed time is short, use of a large amount of solvent is avoided, and the method is economical and environmentally friendly. According to the method for preparing the carbonyl iron powder-graphite electromagnetic wave absorption composite material, cheap carbonyl iron powder and flake graphite are adopted as raw materials, the raw materials are cheap and easy to obtain, and the method is suitable for actual industrial application. The carbonyl iron powder-graphite electromagnetic wave absorption composite material provided by the invention has large reflection loss and absorption bandwidth under the condition of low thickness, and can effectively absorb electromagnetic waves.

The utility model relates to a crystalline flake graphite spheroidization processing device which comprises a processing outer roller, a processing roller piece, roller support frames, a front end cover and end cover fixing bolts, the roller support frames are fixed on the bottom sides of the two ends of the processing outer roller, the processing roller piece is arranged in the processing outer roller, and the front end cover is arranged on the front end cover. The front end cover is fixed to the side end of the machining outer roller through an end cover fixing bolt, and the side end of the machining roller piece is connected to the center of the front end cover in a penetrating mode. The graphite spheroidizing device optimizes the arrangement of graphite spheroidizing, changes the traditional machining mode, designs a roller type machining device, improves the machining speed, and is simple in structure, small in abrasion in the machining process and suitable for being used and popularized.

The invention discloses prime coat slurry for a positive electrode of a lithium battery and a preparation method of a prime coat coating. The prime coat slurry is prepared from the following components in percentage by mass: 4-5% of a conductive agent, 5-6% of a binder, 14-16% of an alcohol solvent and the balance of deionized water, wherein the conductive agent is composed of spherical conductive carbon black, flaky conductive graphite, carbon nanotubes and graphene. Through the innovative quaternary conductive agent combination and low-temperature plasma synergistic modification technology, the conductivity and binding force of a prime coat coating are remarkably improved, and meanwhile the pulping process and the aluminum foil pretreatment effect are optimized. The flake graphite is used as a micron-sized conductive agent, a main body frame of the conductive layer is built, the surface roughness is increased, and a good foundation is provided for subsequent attachment of the positive electrode active layer; gaps among the flake graphite are filled with the spherical carbon black, and a basic conductive network is constructed.

The invention relates to the technical field of electrode paste production, and provides an anti-oxidation high-electrical-stability electrode paste and a preparation method thereof, and the electrode paste is prepared from the following raw materials: BN thick-coated coarse SiC, BN thin-coated fine SiC, carbon-coated graphite, ZrO2-carbon composite microspheres, a filler and a binder in a mass ratio of (16-19): (11-14): (29-32): (7-10): (13-16): (15-18). BN thick coating and BN thin coating are respectively carried out on the coarse SiC particles and the fine SiC particles, so that the balance of oxidation resistance and conductivity is realized; the flake graphite is subjected to light oxidation and carbon coating modification, so that electron transfer is promoted while oxygen is isolated, and the problem of conductive phase isolation possibly caused by an antioxidant layer is avoided; zrO2 at carbon composite microspheres are prepared to improve the structural stability and form a complementary anti-oxygen barrier, so that the synergistic improvement of the oxidation resistance and the conductivity of the electrode paste is realized.

The invention discloses lignin-based hard carbon and a preparation method thereof.The preparation method comprises the steps that triethylene tetramine is grafted to the surface of lignin through Mannich reaction, then dithio-amino is grafted to the surface of the lignin through esterification reaction, and the lignin-based hard carbon is obtained by grafting dithio-amino groups to the surface of the lignin. On one hand, the adsorption capacity of the lignin to metal ions is improved, and on the other hand, the electrochemical performance of the lignin is improved by doping N and S elements into the lignin; the rate capability of the hard carbon is related to the electronic conductivity of the hard carbon and the transmission rate of Na < + > in the hard carbon, the carbonization material and the crystalline flake graphite powder are blended, the electronic conductivity is improved, meanwhile, the layered structure of the crystalline flake graphite powder is beneficial to the transmission of Na < + >, and the performance of the hard carbon is improved. Furthermore, the electrochemical performance of the lignin-based hard carbon is further improved.

The invention relates to a liquid metal composite material and a preparation method thereof.The method comprises the steps that firstly, a small amount of liquid metal is mixed with diamond particles till the diamond particles are completely wrapped by the liquid metal to form diamond liquid metal, then crystalline flake graphite is mixed with the diamond liquid metal, and the diamond liquid metal is formed; the crystalline flake graphite is used for forming bridging among diamond particles, finally, a certain amount of liquid metal is added to form the liquid metal composite material with the crystalline flake graphite bridging diamond particles, bridging is formed through a very small amount of the crystalline flake graphite, the heat-conducting property of the liquid metal is greatly enhanced, and the heat-conducting property of the liquid metal is greatly improved. Therefore, the composite material has advantages in the field of thermal management of high-power electronic products. Through experimental verification of the applicant, the heat conductivity of the crystalline flake graphite bridged diamond particle liquid metal composite material prepared through the method can reach 80-133W / mK.