298 results about "Feroxyhyte" patented technology

The invention belongs to the technical field of environmental protection and environmental water treatment and in particular relates to a heavy metal ion adsorbent ferrite hollow spheres MFe2O4 (M=Fe, Co, Mn or Zn) and a preparation method thereof. The preparation method of the ferrite hollow spheres MFe2O4 belongs to a hydrothermal synthesis method, and the prepared ferrite hollow spheres are 180nm-380nm in diameter and 20nm-45nm in shell layer thickness and are used for adsorbing heavy metal ions As (V) and/or Cr (VI). The preparation method provided by the invention is simple and feasible, environment-friendly, pollution-free, low in equipment requirement and high in controllable degree; the raw material source is wide and the production cost is low; compared with a compound prepared in the prior art, the prepared heavy metal ion adsorbent is relatively high in adsorption capacity, and the adsorption capacity aiming at arsenic and chromium heavy metal ions reaches up to 340mg/g and is far beyond that in the prior art, so that the heavy metal ion adsorbent has relatively good application and promotion values.

The invention provides a preparation method of a manganese ferrite nanoparticle (MnFe2O4)-graphene compound. The preparation method comprises the following steps of: obtaining a mixed solution of manganese ions and oxidized graphene in the process of preparing the oxidized graphene by using a potassium permanganate graphite oxidizing method; adding enough H2O2 in the mixed solution, and reducing the manganese element into divalent manganese ions; adding tervalent ferric salt and divalent manganese salt, uniformly stirring the mixture, then, adding an alkaline solution in the mixed solution, adjusting the pH value of the solution to 8-13, then, heating the mixed solution to 70-99 DEG C, adding a reducing agent, and stirring for 0.5-24h to obtain a suspension liquid; and magnetically separating the suspension liquid and drying to obtain the manganese ferrite nanoparticle-graphene compound. According to the preparation method of the manganese ferrite nanoparticle-graphene compound, potassium permanganate used when the oxidized graphene is prepared can be sufficiently utilized so that the potassium permanganate can be converted into a nanomaterial containing manganese ferrites; and the preparation method has the characteristics of simplicity, environment friendliness, low cost and the like.

The invention relates to the technical field of environmental protection and discloses a method for treating alkaline sludge containing heavy metal as resources; the method comprises the following steps: first, using sulfuric acid liquor to leach valuable metals in the alkaline sludge containing heavy metal, solid-liquid separating acid leached slag and acid leached liquor containing SiO2; treating the acid leached liquor by using ultrasonic waves, adding alkaline and controlling pH value of the solution to precipitate and separate CaSO4, carrying out solid-liquid separation to obtain the liquid part and the solid part containing SiO2 and CaSO4; first using ferrous sulphate to treat the liquid part and then adding alkaline to adjust pH value of the liquid part, injecting compressed air to oxidize the liquid part to form ferrite and prepare the ferrite into additives with multiple usages. The solid part is used as additives for producing cement. The method of the invention not only features good commonality but also treats various alkaline sludge containing heavy metal; in addition, the method features easily controlled process conditions, simple equipment, easy realization of large-scale production, reduction of treatment cost, thus being a technology featuring reduction and decontamination for treating heavy-metal-containing alkaline sludge waste residue as a usable resource.

The present invention is monodisperse silica coated hollow magnetic microsphere and its preparation process and belongs to the field of nanometer magnetic material technology. Superparamagnetic nanometer ferrite particle is first prepared in coprecipitatin method and monodisperse polymer microsphere with surface functional radical is synthesized in emulsion polymerization; the superparamagnetic nanometer ferrite particle and the monodisperse polymer microsphere is then compounded by means of coordination effect, and the compound is coated with silica; and the composition particle is finally calcined at 500-700 deg.c for 5-12 hr to produce the silica coated hollow magnetic microsphere. The present invention has simple preparation process and controllability of the granularity and cavity size of the magnetic microsphere, and the magnetic microsphere has high chemical and colloid stability and may be used in biological detection and other fields.

The present invention relates to ferrite material of NiZn and method for manufacturing, and belongs to manufacturing technology field of ferrite material. The main constituent is calculated by oxide with molar percentage: 48.5-52.5mol% Fe2O3,25-33mol%ZnO,0.5-8.0mol%CuO, allowance being NiO; doping agent is calculated by oxide with molar percentage 0.001-0.15wt%CaO, 0.01-0.12wt% MoO3, 0.01-0.08wt%Bi2O3, 0.01-0.20wt%Nb2O5, 0.01-0.20wt% SnO2, 0.01-0.16wt%V2O5. The beneficial effect of the present invention is, first, improving power density, implementing miniaturization; second, improving reliability of electric system.

The invention relates to a stress-resistant nickel zinc ferrite which has the initial permeability of 120 and is applicable to a power inductor and a preparation method of the stress-resistant nickel zinc ferrite. The stress-resistant nickel zinc ferrite comprises the main components based on respective reference substance: 46.5-50mol% of ferric oxide (Fe2O3), 20-25mol% of nickel oxide (NiO), 20-25mol% of zinc oxide (ZnO) and 9-12mol% of copper oxide (CuO); and the nickel zinc ferrite comprises the accessory ingredient by respective reference substance: 0.1-0.3wt% of calcium carbonate (CaCO3), 0.035-0.10wt% of cobalt oxide (Co2O3), 0.05-0.45wt% of bismuth oxide (Bi2O3), 0.1-1.0wt% of talcum powder and 0.1-1.0wt% of mica powder. The stress-resistant nickel zinc ferrite is prepared by an oxide method and is sintered under a certain condition. After sintering, the product has the crystallized grain size of 20-30mu m, has obvious crystal boundary, and has the characteristic of less inductance change under the stress action, thus meeting the requirement of the power inductor needed to be packaged by resin on the stress resistance of the ferrite material.

Belonging to the technical field of ferrite material preparation, the invention relates to a high Tc, wide temperature ultrahigh Bs MnZn ferrite material and a preparation method. The ferrite material provided in the invention is composed of main materials and doping agents. The ferrite material is characterized in that, the main materials include: 58.0-62.0mol% of Fe2O3, 10.0-15.0mol% of ZnO, 4.0-6.0mol% of NiO, and the balance MnO; and by weight percentage, with the pre-sintered main materials as reference and in terms of oxides, the doping agents include: 0.001-0.30wt% of MoO3, 0.01-0.40wt% of Bi2O3, 0.001-0.05wt% of SnO2, 0.001-0.05wt% of Nb2O5, and 0.001-0.20wt% of Ta2O5. The MnZn ferrite material provided in the invention has the characteristics of high Curie temperature (with Tc greater than or equal to 320DEG C), high wide temperature BBs (at 25DEG C, with BBs being greater than or equal to 600mT; at 100DEG C, with BBs being greater than or equal to 490mT), and low loss (100DEG C, 100kHz200mT, with PL being smaller than or equal to 800kW/m<3>), etc.

The method includes following steps: (1) crashing zinc-manganese cells, solving coarsely separated iron-zinc-manganese so as to obtain solution of reaction predecessor: ferrous sulfate, zinc sulfate and manganese sulfate; (2) preparing predecessor of ferrite by reaction between mixed predecessors according to proportion and ammonium oxalate; (3) baking predecessor of ferrite in high temperature so as to obtain product of ferrite. The method carries out innoxiousness treatment and changes matter in cells to resources. Features are simple, economical and practical.

The invention relates to high-Q value nickel and zinc ferrite with the initial permeability of 70 and a preparation method thereof, which are suitable for a power inductor. The nickel and zinc ferrite comprises the following main ingredients calculated by the oxide: 47.0-49.0mol% of Fe2O3, 25.1-28.5mol% of NiO, 16.3-20.5mol% of ZnO, 4.3-7.5mol% of CuO, and also comprises the following auxiliary components: 0.1-0.2wt% of CaCO3, 0.8-1.3wt% of SiO2, 2-7wt% of LiFe5O8, 0.3-0.6wt% of Co2O3 and 0.8-1.3wt% of Bi2O3. The high-Q value nickel and zinc ferrite is prepared with an oxide method and is sintered under certain condition. The sintered product has the characteristics of high Q value within the high-frequency range of 5-10MHz, and is suitable for the requirement of high frequency and low loss of the ferrite material by the power inductor.

The invention discloses a zirconium-doped barium ferrite wave-absorbing material having a chemical formula of BaFe12-xZrxO19, wherein x is 0.3-0.5, zirconium-doped barium ferrite is a polycrystalline powder, and Fe<3+> and Fe<2+> exist in the barium ferrite simultaneously. A preparation method comprises the preparation steps: mixing barium nitrate, iron nitrate and zirconium nitrate, adding deionized water, and dissolving into a nitrate solution; placing EDTA in deionized water, and dissolving into an EDTA solution; adding the nitrate solution into the EDTA solution, heating, drying, and thus obtaining a dry gel; and sintering the dry gel to obtain a zirconium-doped barium ferrite powder, then grinding, and thus obtaining the zirconium-doped barium ferrite wave-absorbing material. The wave-absorbing material has the characteristics of thin matching thickness and wide wave-absorbing frequency band, can be used for a wave-absorbing coating layer, and can have wide applications in the electromagnetic shielding and stealth fields.

The invention discloses Mn element and Zn element-doped super-paramagnetic ferrite nanoparticles and a preparation method thereof. Manganese element is added or manganese element and zinc element are simultaneously added into a face-centered cubic crystal structure of ferriferrous oxide nanoparticles by using a method of decomposing metal precursor compound at a high temperature; the magnetic performance of the prepared super-paramagnetic nanoparticles is improved by changing the doping amount and the distribution of the metal element; and primarily, the saturation magnetization is improved. The preparation method specifically comprises the following steps of: mixing acetylacetones of Fe and Mn as well as Zn with 1,2-hexadecanol; performing high-temperature decomposition in high-boiling-point solvent by taking oleic acid and oleylamine as surfactants; or performing high-temperature decomposition on composite oleate of Fe, Mn and Zn by taking the oleic acid as the surfactant; heating and preserving heat in stages in argon or nitrogen protective atmosphere to guarantee growth of nanoparticle nuclear; and cooling to room temperature after reaction is finished and settling and centrifuging to finally obtain the super-paramagnetic ferrite nanoparticles which are uniformly dispersed in normal hexane solution.

Flux compositions for sintering Ni—Zn ferrite material are disclosed in the present invention, each flux composition basically and selectively has zinc oxide (ZnO), silicon dioxide (SiO₂), boric oxide (B₂O₃), bismuth trioxide (Bi₂O₃), aluminum oxide (Al₂O₃), potassium trioxide (K₂O₃), barium oxide (BaO), sodium oxide (Na₂O), calcium oxide (CaO), and magnesium oxide (MgO). Each flux composition is added into a mixture of Ni—Zn ferrite material composed of ferric oxide (Fe₂O₃), nickel oxide (NiO), zinc oxide (ZnO), cupric oxide (CuO) and cobalt oxide (CoO) and ranges from 0.05 to 10 weight percent based on the total weight of the Ni—Zn ferrite material. The flux compositions of the present invention decrease sintering temperature when the ferrite material is sintered and contain no lead (Pb) element so as to reduce toxic pollutants.

The invention relates to a novel material for absorbing electromagnetic waves, and in particular relates to a preparation method of a graphene oxide/barium ferrite wave-absorbing material. The preparation method comprises the following steps: forming a sol from analytically pure barium nitrate Ba(NO3)2 and ferric nitrate Fe(NO3)3 with a graphene oxide water solution by taking citric acid and ethylene glycol as a compound complexing agent; continuously heating and stirring the sol to form a gel; and igniting the gel by virtue of microwave-assisted auto-combustion to further prepare the graphene oxide/barium ferrite wave-absorbing material. The preparation method disclosed by the invention is simple and controllable in process, uniform in temperature distribution of the entire system through microwave field heating, and meanwhile, the preparation method can be used for greatly shortening reaction time and greatly improving the wave-absorbing performance of a barium ferrite material with the doping of the graphene oxide.

The invention relates to an ultralow-high-frequency-loss-power MnZn ferrite and a preparation method thereof. The ultralow-high-frequency-loss-power MnZn ferrite is composed of a spinel-structure main crystal phase and a doping component in the grain boundary and crystal, wherein the chemical composition of the spinel-structure main crystal phase is [MnxZnyFe<2>]Fe2<3>O4. The microstructure is characterized in that the relative density of the sintered body is 99.2-99.6%, the average size of the crystal grains is 2.0 mu m@30mT/1MHz/100 DEG C and 145<=P[cv]<=160mW/cm<3>@10mT/3MHz/100 DEG C.

The invention discloses a manganese-zinc ferrite of which the outer diameter is more than or equal to phi79mm and a preparation method thereof, and belongs to the technical field of manganese-zinc ferrite. The manganese-zinc ferrite disclosed by the invention comprises a ferrite pre-sintering material, an auxiliary component, a bonding agent, a dispersant and a defoamer, wherein the ferrite pre-sintering material consists of the following substances in molar percentage content: 52.0-53.0mol% of Fe2O3, 23.0-25.5mol% of ZnO and 21.5-25.0mol% of MnO; and the auxiliary component comprises CaO, Bi2O3, MoO3, Nb2O5 and Ti2O5. The preparation method disclosed by the invention can be used for preparing a manganese-zinc ferrite big magnetic ring of which the outer diameter is more than or equal to phi79mm; the obtained manganese-zinc ferrite big magnetic ring does not have cracking and marco-crystalline phenomena; and under the condition that the temperature is 25 DEG C and B is less than or equal to 0.25mT, the measured 10kHz initial magnetic permeability reaches 9000-11000, and the 100kHz magnetic permeability reaches 7000.

The invention relates to a ferrite-nickel compound powder used for electromagnetic wave-absorption and a preparation method thereof. Metallic nickel powder is taken as a matrix; a chemical method is adopted to prepare a product required by cladding ferrites on the surface of the nickel powder; the mass ratio of the ferrites to the nickel compound powder is between 1 to 5 and 1 to 0.01; the grain diameter of the nickel powder is 0.5 to 5 microns; the ferrites are ferrites of spinel type or ferrites of magneto plumbite type. Any method of the citrate sol-gel method, the self-propagating method or the coprecipitation method is adopted to prepare the product required. A compound powder material prepared by the invention has electromagnetic wave-absorption performance with broad band and high efficiency and can be prepared into wave-absorption coatings that are widely applied to various civilian and military wave-absorption fields.

The invention relates to the technical field of production of MnZn power ferrite materials and particularly relates to a wide-temperature MnZn power ferrite material and a preparation method thereof. The wide-temperature MnZn power ferrite material consists of main components and auxiliary components, wherein the main components include 52.45-52.6 mol% of Fe2O3, 9.2-9.7mol% of ZnO and the balance of MnO; according to the total weight of the main components, the auxiliary components include 0.05-0.06% of CaCO3, 0.02-0.03% of ZrO2, 0.03-0.04% of Nb2O5 and 0.35-0.4% of Co2O3. The wide-temperature MnZn power ferrite material has low loss characteristic at the temperature ranges of 25 DEG C and 140 DEG C and also gives consideration to high Bs characteristic.

The invention discloses a zirconium and titanium-co-doped barium ferrite wave-absorbing powder material. The chemical formula is BaFe(12-x)ZrxTixO19, wherein x is equal to 0.2-0.4. The zirconium and titanium-co-doped barium ferrite is single-phase polycrystalline powder, and Fe<3+> and Fe<2+> exist in the barium ferrite at the same time. A preparation method comprises the following step of preparing the zirconium and titanium-co-doped barium ferrite wave-absorbing powder material by virtue of a self-propagating combustion method which is combined with ball-milling and a sequential secondary vacuum high-temperature thermal treatment process. The wave-absorbing material disclosed by the invention has the characteristics of being strong in absorption loss, wide in wave absorbing bandwidth, thin in match thickness and wide in modulated wave-absorbing frequency range. The effective wave absorbing bandwidth is controlled in a frequency range of 18-40GHz, double absorption peaks appear, the maximum absorbing bandwidth can reach 16GHz, the optimum match thickness is just about 1mm, and the optimum reflection loss RL value at the special frequency can reach about -48dB. The barium ferrite wave-absorbing powder material is simple in preparation process, can be used for a wave-absorbing coating, and can be widely applied to the fields of electromagnetic shielding and stealth.

The invention relates to a high-frequency manganese-zinc ferrite material. The main component of the material is composed of 53-62 mol% of Fe2O3, 0.5-10.0 mol% of ZnO and the balance of MnO. The accessory components I are composed of CaCO3, Nb2O5, SiO2, V2O5 and Li2CO3, and account for 0.02-0.15 wt% of the main component; the accessory components II are composed of ZrO2, Co2O3, TiO2 and SnO2, and account for 0.10-0.75 wt% of the main component; and the combination of the accessory components comprises at least one accessory component II. The high-frequency manganese-zinc ferrite material has low power loss and high working frequency range within the temperature range of 0-125 DEG C: the loss is 500kW/m<3> or below under the conditions of f<=5MHz and B<=30mT. The high-frequency manganese-zinc ferrite material has the advantages of small power loss change rate and stable performance, is used for manufacturing various inductors and transformers, and is applicable to the field of high frequency.

The invention discloses a method for preparing nano-powder of nano cobalt ferrite (CoFe2O4) with a spinel structure at a low temperature. The preparation method comprises the steps of weighing ferric trichloride and cobaltous chloride in proportion, and mixing to prepare water solution A; evenly mixing the prepared NaOH or HOK aqueous alkali, and then dropwise adding N2H4.H2O to obtain solution B; rapidly stirring the water solution A obtained in the step 1 at 20-40 DEG C, and slowly dropwise adding the mixed solution B prepared in the step 2 into the water solution A to react, so as to obtain cobalt ferrite (CoFe2O4) powder sediment with a black spinel structure.

The invention provides a manufacturing method for a thermoplastic compound macromolecule bonded magnet. The manufacturing method comprises the following steps: taking and uniformly mixing neodymium iron boron rare earth magnetic powder and ferrite magnetic powder; adding the mixed magnetic powder into an acetone solution dissolving a silane coupling agent and performing a coupling treatment; taking an epoxy resin binder, dissolving in acetone and forming a solid gum, and volatilizing the acetone; soaking the magnetic powder after the coupling treatment into a fixing glue solution, fully mixing for more than 12 hours and drying, thereby forming a mixture; adding a zinc stearate lubricating agent into the mixture , heating to 90-110 DEG C, keeping constant temperature, pressing and treating for a preset time duration under the pressure more than 1000MPa, thereby acquiring a blank; heating the blank to be at 180 DEG C under inert atmosphere, injecting and forming, and adding solidifying agent for solidifying. According to the manufacturing method provided by the invention, the liquidity of mixture slurry mixed by the bonding agent and the magnetic powder is promoted, the temperature range for causing the slurry to have the liquidity is widened, and the method is fit for the production of articles of various complex shapes.

The invention relates to a permanent magnetic strontium-ferrite material powder and a preparation method thereof. The technical scheme is as follows: the preparation method comprises the following steps of: based on an iron scale and strontium carbonate as raw materials, adding a dispersant accounting for 0.1-0.5wt% of the raw material and water accounting for 90-110wt% of the raw material to form a mixture, wherein the molar ratio of strontium carbonate and ferric oxide is 1:(5.5-6); then wet-milling the mixture in a steel ball milling jar according to the mass ratio of steel balls to the raw material being (7.5-10):1 until the granularity reaches 0.7-0.9 micrometers; then drying the ball-milled slurry material, placing into a ceramic vessel, keeping the temperature at 1050-1350 DEG C in a rotary kiln for 120-240 minutes and then naturally cooling with the kiln, so as to obtain the permanent magnetic strontium-ferrite material powder. The preparation method of the permanent magnetic strontium-ferrite material powder has the characteristics of of simple process and low cost; and the magnetic property of the permanent magnetic strontium-ferrite material powder prepared by the method is good.

The invention provides wide-temperature-range low-loss ferrite and a preparation method thereof, and relates to the technical field of ferrite processing. The wide-temperature-range low-loss ferrite is prepared from the following raw materials in parts by weight: 90-100 parts of ferric oxide, 12-18 parts of nano titanium dioxide, 18-22 parts of magnesium oxide, 6-12 parts of barium oxide, 52-60 parts of manganese dioxide, 6-8 parts of a first mixture and 0.8-1.2 parts of a second mixture, wherein the first mixture is a mixture of chromium sesquioxide, tungsten trioxide, copper oxide and zinc oxide in a mass ratio of 3: 1: 4: 12, and the second mixture is a mixture of lanthanum hexaboride, cerium oxide and ammonium tungstate in a mass ratio of 2: 1: 1. The preparation method overcomes the defects of the prior art, effectively solves the problem of high loss of the traditional ferrite under the conditions of wide temperature and high frequency, effectively saves energy, and is suitable for various environments and fields.

The invention discloses a biology-base carbon nanofiber loaded cobalt ferrite wave-absorbing material which is formed by biology-base carbon nanofibers absorbing cobalt ferrite and further discloses a preparation method of the biology-base carbon nanofiber loaded cobalt ferrite wave-absorbing material. The method includes the steps that biology-base nanofiber suspension liquid is heated and carbonized and then the biology-base carbon nanofibers are obtained; afterwards, the biology-base carbon nanofibers, iron nitrate nonahydrate and cobalt nitrate hexahydrate are mixed evenly, and then an ethylene glycol-sodium hydroxide solution is added for reacting so that a finished product can be obtained. According to the method, the biology-base nanofibers are used as the precursor, and the biology-base carbon nanofiber loaded cobalt ferrite wave-absorbing material is prepared through a solvothermal method. A system for organically combining the two wave-absorbing media of different properties of the biology-base carbon nanofibers and the cobalt ferrite is established, the electric conductivity of the cobalt ferrite is enhanced through the net-shaped structure of the carbon nanofibers, agglomeration increase of cobalt ferrite particles is prevented, and the wave-absorbing property of pure cobalt ferrite can be improved obviously.