185 results about "Feroxyhyte" patented technology

The present invention relates to a steel sheet and a plated steel sheet, each of which has high LME resistance. The steel sheet according to the present invention is characterized in that: the steel sheet has a tensile strength of 780 MPa or more; the steel sheet has a specific chemical component; the depth, at which the C concentration as measured by GDS is 0.05% or less, from the surface of the steel sheet in the thickness direction of the steel sheet is 8 μm or more; the thickness of a layer, in which the area ratio of the ferrite phase is 90% or more, in the thickness direction of the steel sheet from the surface of the steel sheet is 8 μm or more; and the solid solution amount of Si metal and Al metal in the ferrite phase is 0.3% or more in total at the position of 4 μm from the surface of the steel sheet in the thickness direction of the steel sheet.

Methods of forming spinel ferrite nanoparticles containing a chromium-substituted copper ferrite as well as properties (e.g. particle size, crystallite size, pore size, surface area) of these spinel ferrite nanoparticles are described. Methods of preventing or reducing microbe growth on a surface by applying these spinel ferrite nanoparticles onto the surface in the form of a suspension or an antimicrobial product are also described.

The invention discloses a neodymium-zirconium co-substituted M-type strontium ferrite wave-absorbing material and a preparation method thereof, the chemical formula of the neodymium-zirconium co-substituted M-type strontium ferrite wave-absorbing material is Sr1-xNdxZr0. 2Fe11.8 O19, and x is more than or equal to 0.1 and less than or equal to 0.4. The method comprises the following steps: (1) mixing strontium nitrate, ferric nitrate nonahydrate, neodymium nitrate hexahydrate, zirconium nitrate pentahydrate, citric acid monohydrate and deionized water, stirring and dissolving to obtain sol; (2) adjusting the pH value of the sol to 6.5-7.5, and then heating to carry out sol-gel reaction to obtain wet gel; (3) drying and grinding the wet gel to obtain precursor powder; and (4) performing heat treatment on the precursor powder in a box-type furnace, cooling and grinding to obtain the neodymium-zirconium co-substituted M-type strontium ferrite wave-absorbing material. According to the material, effective wave-absorbing frequency band broadening is achieved, the matching thickness corresponding to the effective wave-absorbing bandwidth is as thin as 0.55-0.7 mm, and meanwhile, the performance requirements of thinness, width and strength in the field of electromagnetic compatibility are met.

Provided are cobalt ferrite particles having a micrometer-order average particle diameter and similar particle diameters. The cobalt ferrite particles are obtained by a method for producing cobalt ferrite particles, including performing a thermal treatment on an aqueous solution containing a divalent iron salt and a divalent cobalt salt stabilized by a complexing agent (ferrite precursor).

The invention discloses a ferrite nanoparticle-loaded biochar adsorption material and a preparation method thereof, and the ferrite nanoparticle-loaded biochar adsorption material is prepared by the following steps: S1, sieving biochar, cleaning and drying to obtain pretreated biochar; s2, adding the pretreated biochar into a nitric acid solution, mixing, cleaning, filtering and drying to obtain a material A; s3, respectively dissolving a water-soluble ferric salt and a water-soluble sodium salt in water to obtain a ferric salt solution and a sodium salt solution, and mixing the ferric salt solution and the sodium salt solution to obtain a solution a; and S4, adding the material A into the solution a, mixing, cleaning, and drying to obtain the ferrite nanoparticle-loaded biochar adsorption material. By controlling the proportion of the components and the proper raw material ratio, the ferrite nanoparticle-loaded biochar adsorption material for the permeable reactive barrier, which is relatively strong in adsorption catalysis capability, can be prepared, and arsenic ions in pollutants can be efficiently adsorbed.

The invention discloses a sodium alginate embedded iron-carbon microcapsule material for repairing cadmium and arsenic polluted soil and a preparation method of the sodium alginate embedded iron-carbon microcapsule material, and belongs to the technical field of soil heavy metal pollution repairing materials. The material comprises straw biochar, high-iron steel slag powder, a sulfydryl acetylated chitosan-iron monatomic cluster compound, a boron-doped graphitized carbon coated cobalt ferrite nanosheet, sodium alginate, calcium chloride and sodium carbonate. Wherein the sulfydryl acetylated chitosan is prepared by reacting chitosan with sulfydryl acetic anhydride, dialyzing and drying, and performing solvothermal reaction with ferric nitrate under high pressure. The preparation method comprises the following steps: pyrolyzing and drying the straw biochar, reacting the high-iron steel slag with sulfuric acid, adding the biochar, adjusting the pH value, adding sodium carbonate, mixing to obtain an iron-carbon-based passivation material, mixing with two modified compounds, mixing with a sodium alginate solution, dropwise adding a calcium chloride solution, and stirring and curing. The material can be applied to remediation of cadmium and arsenic polluted soil.

The invention provides a composite wave-absorbing material as well as a preparation method and application thereof, and relates to the technical field of wave-absorbing materials. The composite wave-absorbing material provided by the invention has high-entropy ferrite with a spinel structure and high-entropy iron alloy with a body-centered cubic structure, the chemical formula of the high-entropy ferrite is (CoxNiyCuzMnaZnbMgcCrd) Fe2O4, x + y + z + a + b + c + d = 1, x, y and z are real numbers greater than 0 and less than 1, a, b, c and d are real numbers greater than or equal to 0 and less than 1, and two or three of a, b, c and d are equal to 0. The composite wave-absorbing material provided by the invention has the advantages of thin matching thickness, strong wave-absorbing performance and wide absorption frequency band.

A hot rolled steel sheet having a composition comprising of the following elements, 0.03% ≤ Carbon ≤ 0.07 %,0.8 % ≤ Manganese ≤ 1.3%, 0.01% ≤ Aluminum ≤ 0.07 %, 0.01% ≤ Niobium ≤ 0.07%, 0.05 % ≤ Titanium ≤ 0.15%, 0.0005% ≤ Calcium ≤ 0.005%, 0% ≤ Phosphorus ≤ 0.03 %, 0 % ≤ Sulfur ≤ 0.015 %, 0 % ≤ Nitrogen ≤ 0.02%, 0.001% ≤ Silicon ≤ 0.09%, 0% ≤ Chromium ≤ 0.2%, 0.03% ≤ Copper ≤ 0.25%, 0% ≤ Nickel ≤ 0.2%, 0% ≤ Molybdenum ≤ 0.2%, 0% ≤ Vanadium ≤ 0.1%, 0 % ≤ Boron ≤ 0.003%, 0 % ≤ Magnesium ≤ 0.010%, 0% ≤ Cerium≤ 0.1%, 0% ≤ Zirconium ≤ 0.010%,,the remainder composition being composed of iron and unavoidable impurities caused by processing, the microstructure of said steel sheet comprising in area fraction, 40% to 75% Bainite, 25% to 60% Ferrite, Pearlite from 0% to 2% and Martensite-Residual Islands from 0% to 2% wherein the said hot rolled steel sheet has an inclusion density of 200 inclusions per square micro-meter, the inclusions having a size of 2 microns or more being 15% or less of the total number of inclusions.

The invention provides a W-type ferrite wave-absorbing agent as well as a preparation method and application thereof, and relates to the technical field of ferrite wave-absorbing agents. Specifically, the W-type ferrite wave-absorbing agent disclosed by the invention is of a sheet-shaped core-shell structure; the molecular formula of the core material comprises AxMe < 2 > Fe < 16 > O < 27 >; the molecular formula of the shell material comprises REmC1-m-nDn; a comprises at least one of Sr, Ba, Ca, Mg or Pb, Me comprises at least one of Zn, Co, Ni or Cu, C comprises at least one of Fe, Co or Ni, and D comprises at least one of Cu, Al, Zn, Bi, Sn or Pb. The invention provides a formula system with high universality, and the material has a good sheet-shaped structure, high impedance matching performance and good wave-absorbing performance, and has a good application prospect in preparation of wave-absorbing materials.

The invention discloses a method for extracting copper fine powder by flotation of copper-containing ore, which belongs to the technical field of mineral processing, and comprises the following steps: after copper-containing raw ore is crushed, ground and classified by a cyclone, overflow enters flotation, and settled sand is returned for regrinding; sodium carbonate is added into graded overflow to adjust the pH, a sodium hexametaphosphate-polyacrylamide composite dispersant is added, and copper sulfate is added and stirred after low-temperature microwave heating; gradient flotation is conducted, specifically, copper sulfide is roughly selected, the pH is adjusted, an amino-sulfonic acid group synergistic modified layered double metal hydroxide / cobalt ferrite composite collecting agent is added, and rough concentrate 1 is obtained through high-frequency pulse air inflation flotation; copper oxide roughing is conducted, clear water is supplemented to adjust the pH, and a collecting agent is supplemented to obtain rough concentrate 2; scavenging is performed for three times, a collecting agent is added for flotation, and concentrate returns to the previous stage; the rough concentrates are combined, and magnetic impurities are removed through high-gradient magnetic separation to obtain magnetic concentrates; and carrying out microbiological leaching on tailings to recover copper. The composite collecting agent is prepared through layered double hydroxide carrier synthesis, amino modification, sulfonic acid group grafting and cobalt ferrite anchoring.

A hot rolled steel sheet having a composition comprising of the following elements,0.02 % ≤ Carbon ≤ 0.06 %, 1.1 % ≤ Manganese ≤ 1.60%,0.01% ≤ Aluminum ≤ 0.08 %, 0.01% ≤ Niobium ≤ 0.07%, 0.05 % ≤ Titanium ≤ 0.15%, 0.0005% ≤ Calcium ≤ 0.005%, 0% ≤ Phosphorus ≤ 0.03 %, 0 % ≤ Sulfur ≤ 0.015 %, 0 % ≤ Nitrogen ≤ 0.02%,and can contain one or more of the following optional elements 0.001% ≤ Silicon ≤ 0.09%, 0% ≤ Chromium ≤ 0.2%, 0 ≤ Copper ≤ 0.25%, 0% ≤ Nickel ≤ 0.2%,0% ≤ Vanadium ≤ 0.1%, 0 % ≤ Boron ≤ 0.003%, 0 % ≤ Magnesium ≤ 0.010%, 0% ≤ Cerium≤ 0.1%, 0% ≤ Zirconium ≤ 0.010%,the remainder composition being composed of iron and unavoidable impurities caused by processing, the microstructure of said steel sheet comprising in area fraction, 35% to 75% Bainite, 25% to 65% ferrite, from 0% to 2% Pearlite and Martensite­Residual Islands from 0% to 2% wherein said hot rolled steel sheet has an inclusion density of 200 inclusions per square micro­meter, the inclusions having size of 2 microns or more being 25% or less of the total number of inclusions.

The invention discloses a treatment method of strong complexing copper wastewater, which comprises the following steps: adjusting the pH value of the strong complexing copper wastewater, adding a complexing breaking agent, stirring and reacting until the color of the solution becomes brownish black, then adding ferric chloride for deep purification, and finally adjusting the pH value back for flocculating settling and solid-liquid separation. And finally, obtaining clear liquid with the effluent copper ion concentration stably lower than 0.5 mg / L and ferrite precipitate-sludge with stable chemical properties. The method is simple and low in cost, secondary pollution is avoided, the treatment difficulty and environmental risks of the strong complexing copper wastewater and the sludge obtained through treatment are greatly reduced, and the method has wide application prospects.

The application discloses a kind of microspheroidal high-entropy spinel type ferrite wave-absorbing materials and preparation method thereof, belong to electromagnetic wave absorbing material technical field, the preparation method includes with the designed molar ratio six metal nitrate is weighed and dissolved in deionized water, then add ammonium fluoride, urea, after stirring, the obtained solution is hydrothermal reaction at a certain temperature for a certain time to obtain precursor, the precursor is calcined to obtain microspheroidal high-entropy spinel type ferrite.The obtained wave-absorbing material is single-phase spinel structure, micron-sized spherical morphology, its chemical formula is MFe2O4;Wherein M=Co, Ni, Cu, Zn, Cr.The microspheroidal high-entropy spinel type ferrite wave-absorbing material and preparation method thereof are used, and the performance of pure ferrite wave-absorbing material can be effectively improved, with the characteristics of simple preparation, strong absorption performance, absorption frequency bandwidth.

A hot rolled steel sheet having a composition comprising of the following elements 0.03% ≤ Carbon ≤ 0.070 %, 0.4 % ≤ Manganese ≤ 0.9%, 0.01% ≤ Aluminum ≤ 0.08 %, 0.01% ≤ Niobium ≤ 0.08%, 0.05 % ≤ Titanium ≤ 0.15%, 0.0005% ≤ Calcium ≤ 0.005%, 0% ≤ Phosphorus ≤ 0.03 %, 0 % ≤ Sulfur ≤ 0.015 %, 0 % ≤ Nitrogen ≤ 0.02%, 0.001% ≤ Silicon ≤ 0.09%,0% ≤ Chromium ≤ 0.2%, 0.% ≤ Copper ≤ 0.25%, 0% ≤ Nickel ≤ 0.2%, 0% ≤ Molybdenum ≤ 0.2%, 0% ≤ Vanadium ≤ 0.1%, 0 % ≤ Boron ≤ 0.003%, 0 % ≤ Magnesium ≤ 0.010%, 0% ≤ Cerium≤ 0.1%,0% ≤ Zirconium ≤ 0.010%, the remainder composition being composed of iron and unavoidable impurities caused by processing, the microstructure of said steel sheet comprising in area fraction, 35% to 70% Bainite, 30% to 60% Ferrite, Pearlite from 1% to 5% wherein the said hot rolled steel sheet has an inclusion density of 110 inclusions per square micro-meter and the inclusions having a size of 2 microns or more being 22% or less of the total number of inclusions.

The invention relates to the technical field of extremely high vacuum acquisition, in particular to a process for reducing the surface air output rate of ferrite. The process comprises the steps of S1, pretreatment, S2, high-temperature degassing and S3, aftertreatment. Wherein the step S2 of high-temperature degassing comprises the following steps: placing the ferrite in a degassing furnace; vacuumizing the degassing furnace; starting a heating system of the degassing furnace, heating the ferrite to 500-600 DEG C at the heating rate of 1-2 DEG C / min, preserving heat for 0.5-1 hour, heating to 850-900 DEG C at the heating rate of 1-2 DEG C / min, preserving heat for 1-2 hours, cooling to 300-500 DEG C at the cooling rate of 1-2 DEG C / min, closing the heating system, and cooling the ferrite along with the furnace. According to the process, the surface gas outlet rate of the ferrite can be effectively reduced, the ferrite can be used for an extremely high vacuum system of 10 <-10 > Pa, and meanwhile, the situation that the ferrite is cracked and damaged in the degassing process can be avoided.

The invention relates to the technical field of metal material surface treatment, and discloses an efficient anti-radiation treatment agent for magnesium alloy and a preparation method thereof.The surface treatment agent is prepared from, by weight, 8-15 parts of polydimethylsiloxane, 5-9 parts of graphene oxide, 3-6 parts of fly ash, 2-5 parts of magnetic nanoparticles, 1-3 parts of dispersing agent and 4-8 parts of nano cobalt ferrite. 2-4 parts of rare earth salt, 7-14 parts of polyaniline and 100 parts of absolute ethyl alcohol. In the treating agent, the electromagnetic shielding effect of the magnesium alloy is improved through multiple effects of polydimethylsiloxane, multi-layer graphene oxide, hollow fly ash and magnetic nanoparticles, and the absorption capacity of the magnesium alloy to electromagnetic waves is comprehensively improved by adding nano cobalt ferrite, rare earth salt and polyaniline; the electromagnetic shielding effectiveness of four different brands of magnesium alloys treated by the treatment agent under the frequency of 30-1500MHZ is more than 90dB, and excellent anti-radiation performance is realized.

Provided are: a steel sheet that exhibits excellent toughness in a joint after high heat input welding, while also exhibiting low temperature toughness and a strength range required for a liquefied gas storage tank; and a method for manufacturing the steel sheet. A steel sheet according to the present invention has a prescribed component composition that includes Ti / N of 2.00 to 4.00, a carbon equivalent Ceq of 380 or less, and satisfies 169 ≤ 5158 × Ti + 25563 × N ≤ 360. The steel sheet has a hardness at a depth position of 1 mm from the surface of 210 HV or less, and has a microstructure in which the volume ratio of each of ferrite and bainite is 20% or more at a depth position of 1 / 4 of the sheet thickness, the volume ratio of the total of ferrite and bainite is 80% or more, and the volume ratio of martensite islands is 5% or less. The steel sheet has a yield strength of 440 MPa or less and a ductility-brittleness fracture surface transition temperature vTrs of -60°C or less.

The present invention relates to scandium-doped nickel-zinc-cobalt ferrite and a preparation method thereof, belonging to the technical field of soft ferrite materials. The scandium-doped nickel-zinc-cobalt ferrite has a molecular formula of: Ni 0.5 Zn 0.4 Co 0.1 Sc x Fe 2‑x O4; wherein 0<x≤0.1. The scandium-doped nickel-zinc-cobalt ferrite prepared by the present invention has higher saturation magnetization intensity and higher initial magnetic permeability.

The present invention relates to a process for recovering zinc and iron products from zinc-containing waste materials obtained from the zinc or steel industry, or both, by first treating the waste material(s) with strong acid, to convert any zinc ferrites into leachable compounds, and then leaching the acid-treated material, neutralizing the acid of the leach solution, recovering zinc from the neutralized ferrous iron-containing solution, recovering iron from the thus obtained solution, and circulating at least a fraction of the raffinate solution obtained from the iron recovery back to the leaching step.

The application relates to a preparation method of high-intermediate low-loss garnet ferrite with high bismuth substitution, and belongs to the field of microwave ferrite materials. 3+ The application reduces the volatilization of Bi by adding a small amount of H3BO3 and Bi2O3 as additives in the two-milling process, accelerates the growth of the crystal under the driving of the low-melting-point Bi2O3 additive in the sintering process, and accelerates the growth of the crystal under the driving of the low-melting-point Bi2O3 additive in the sintering process. 3+ The volatilization of Bi in the pre-sintering process is reduced by using a lower pre-sintering temperature, the optimal sintering temperature is wider, and the microstructure of the material is effectively improved. 3+ The volatilization of Bi in the sintering process is compensated by using a three-stage progressive holding sintering method in the high-temperature section of the final sintering, the sintering temperature and the holding time are controlled, the crystal grain growth is reduced after the continuous growth of the crystal grain, and the uniformity of the solid-phase reaction is improved.

The invention relates to the technical field of photocatalysts, in particular to a magnetic composite photocatalyst for removing antibiotics as well as a preparation method and application of the magnetic composite photocatalyst. The preparation method comprises the following steps: mixing choline chloride, glycerol, ethanol, a magnesium source, an iron source and citric acid, and carrying out complex reaction to obtain sol; adjusting the pH value of the sol, and then heating to form gel; igniting the gel to obtain a precursor; calcining the precursor to obtain the magnetic composite photocatalyst; in the mixing process, the molar ratio of the magnesium element in the magnesium source to the iron element in the iron source is (1-1.6): (1.8-2.4); the molar ratio of choline chloride to glycerol to ethanol is (0.5-1.5): (1.5-2.5): (0.1-0.3). By adopting the method, the magnetic composite photocatalyst composed of magnesium ferrite, magnesium oxide and ferric oxide can be prepared, and the magnetic composite photocatalyst has a relatively good treatment effect on antibiotics, and is high in removal rate and relatively short in removal time.

The present invention generally relates to a method for synthesizing dysprosium-doped copper-zinc ferrite nanomaterials with enhanced structural and functional properties. The method comprises dissolving stoichiometric quantities of copper nitrate trihydrate, zinc nitrate hexahydrate, iron nitrate nonahydrate, and dysprosium nitrate hexahydrate in distilled water to prepare an oxidizer solution. A fuel mixture is separately prepared using urea and glucose in equal proportions by weight. The oxidizer and fuel mixtures are combined in 1:1 ratio, calculated based on their respective oxidizing and reducing valencies, to form a homogeneous precursor solution. This solution is stirred thoroughly for about one hour and subsequently transferred to a Pyrex dish. The dish is placed in a muffle furnace preheated to approximately 450° C., where the solution undergoes a self-sustained combustion reaction, yielding a fine, porous Cu0.5Zn0.5DyxFe2-xO4 ferrite powder within 20 minutes. The resultant powder is ground to achieve uniform particle distribution suitable for advanced applications.

The invention relates to the technical field of preparation of manganese zinc ferrite powder, and discloses a preparation process of manganese zinc ferrite powder, which comprises the following steps: S1, adding raw materials, proportioning and mixing the raw materials; s2, cutting: cutting the mixed raw materials in a cutting device; s3, sanding is conducted, specifically, sanding granulation is conducted on the cut materials in a sanding device; s4, pre-sintering: pre-sintering the sprayed raw materials; the cutting structure is used for cutting the raw materials in the inner barrels, and in the process that the cutting structure moves upwards, is pulled out of the corresponding inner barrel and moves downwards again, the next inner barrel containing the raw materials can be automatically switched in the cutting barrel to continue switching, and meanwhile, the cutting structure can be used for cutting the raw materials. When the raw materials are cut, the inner barrel filled with the cut raw materials can be switched to the fifth discharging opening of the sanding barrel to be automatically discharged, sanding work is carried out in the sanding barrel, and therefore the raw material ratio cannot be changed, the preparation quality is improved, and meanwhile the preparation work efficiency is improved.

The present invention developed a composite having a novel structure containing, in a high content, a powder having a radiation-shielding function.　Provided is a composite having a radiation-shielding function and a method for producing the same. The composite comprises a preform made from a mixture containing a liquid silica-based binder and one or more radiation-shielding powders selected from gadolinium oxide, boron carbide, boron oxide, boron, barium sulfate, strontium oxide, tungsten, tungsten oxide, tungsten carbide, molybdenum, molybdenum oxide, iron powder, iron oxide powder, and ferrite powder, the radiation-shielding powder(s) being contained in the range from 3% to 85% in total. All of the voids in the preform are impregnated and filled with molten aluminum and solidification is allowed to occur to form a composite, or 25% or more of the voids in the preform are impregnated with a liquid organic / inorganic sealing agent and solidification is allowed to occur to form a composite. The liquid silica-based binder has properties that allow the preform to be formed at a temperature at which the radiation-shielding powder(s) does not decompose.

To provide a steel sheet excellent also in low temperature toughness, which not only secures ammonia stress corrosion crack resistance but also can be used without passing through another correction process step, for supplying to a tank of a liquefied gas carrier or a liquefied gas storage.SOLUTION: A steel sheet has a specified component composition, with a volume fraction of bainite at 0.5 mm from the surface of the steel sheet being 20% or less, and at a position 1 / 4 of the plate thickness, the volume fraction of ferrite being between 50% and 90%, additionally, the proportion of ferrite with an equivalent circle diameter of less than 10 μm among the total number of ferrite with an equivalent circle diameter of 2 μm or more should be between 80% and 95%, the proportion of number of ferrite with an equivalent circle diameter between 10 and 20 μm should be between 4% and 20%, and the proportion of ferrite with an equivalent circle diameter exceeding 20 μm should be 1% or less.SELECTED DRAWING: Figure 1

The invention discloses a cerium-doped modified pre-sintered material, ferrite prepared by using the pre-sintered material and a preparation method and application of the ferrite, and belongs to the technical field of permanent magnetic ferrites.The cerium-doped modified pre-sintered material is prepared by adopting a hydrothermal method, the dielectric constant of water is reduced and the ion product is increased at high temperature and high pressure, Fe < 3 + > can be promoted to be hydrolyzed to generate oxyhydroxide (alpha-FeOOH), and the performance of the ferrite is improved. Under the hydrothermal condition, alpha-FeOOH is converted into alpha-Fe2O3 after being dehydrated, Sr < 2 + > and Ce < 3 + > are diffused along alpha-Fe2O3 crystal lattice gaps through a solid-liquid interface diffusion mechanism, and finally the cerium-doped modified strontium ferrite is formed. Tiny crystal nucleuses obtained through the hydrothermal reaction can be deposited on the surfaces of large crystal grains, and stable nano-particles with the uniform size are formed.

Copper-boron-ferrite (Cu—B—Fe) composites may be prepared and immobilized on graphite electrodes in a silica-based sol-gel, e.g., from rice husks. Different bimetallic loading ratios can produce fast in-situ electrogeneration of reactive oxygen species, H2O2 and ·OH, e.g., via droplet flow-assisted heterogeneous electro-Fenton reactor system. Loading ratios of, e.g., 10 to 30 wt. % Fe3+ and 5 to 15% wt. Cu2+, can improve the catalytic activities towards pharmaceutical beta blockers (atenolol and propranolol) degradation in water. Degradation efficiencies of at least 99.9% for both propranolol and atenolol in hospital wastewater were demonstrated. Radicals of ·OH in degradation indicate a surface mechanism at inventive cathodes with correlated contributions of iron and copper. Copper and iron can be embedded in porous graphite electrode surface and catalyze the conversion of H2O2 to ·OH to enhance the degradation. Inventive cathodes can be stable catalytically after 20 or more cycles under neutral and acidic conditions.

The present invention relates to a ferrite particle containing a crystal phase component containing a perovskite crystal represented by a compositional formula: RZrO3 (provided that R represents an alkaline earth metal element), having a surface roughness Rz of 2.0 μm or more and 4.5 μm or less, and satisfying the following formulas: 6.5≤log H1000≤8.5 and 0.80≤log H1000 / log H100≤1.00. The ferrite particle can be used as an electrophotographic developer carrier core material. In addition, an electrophotographic developer carrier and an electrophotographic developer can be obtained.

The invention provides a MnZn ferrite material as well as a preparation method and application thereof, and belongs to the field of ferrite materials. The preparation raw materials of the MnZn ferrite material provided by the invention comprise main materials and auxiliary materials, wherein the main materials comprise the following components in percentage by mass: 71-73% of Fe2O3, 3-4.5% of ZnO and the balance of Mn3O4; the auxiliary materials are prepared from the following components in percentage by mass: 50 to 200 ppm of SiO2, 150 to 300 ppm of CaCO3, 200 to 300 ppm of Nb2O5, 1500 to 2500 ppm of Co2O3, 200 to 300 ppm of Cr2O3, 200 to 400 ppm of V2O5, 50 to 300 ppm of ZrO2, 100 to 400 ppm of La2O3, 100 to 300 ppm of Bi2O5 and 100 to 300 ppm of MoO3, and the auxiliary materials are prepared from the following components in percentage by mass: 50 to 200 ppm of SiO2, 150 to 300 ppm of CaCO3, 200 to 300 ppm of Nb2O5, 1500 to 2500 ppm of Co2O3, 200 to 300 ppm of Cr2O3, 200 to 400 ppm of V2O5, 200 to 300 ppm of ZrO2, 100