930 results about "Brown iron oxide" patented technology

The invention provides a production process for stably controlling adhesive force of a DP steel zinc layer. The production process comprises the following steps: step 1, setting a heating section 1, a heating section 2 and a furnace nose section in a total radiation heating annealing furnace; 2, according to the model and thickness of DP steel, target dew points of a first heating section, a second heating section and a furnace nose section are set; 3, according to the target dew points set in the first heating section, the second heating section and the furnace nose section in the step 2, water vapor is put into the protective gas for humidification, and the water vapor reacts with Si, Mn and Cr elements enriched on the surface of the steel plate to generate volatile oxides; the dew point of the annealing furnace is precisely controlled in a segmented mode, different humidification modes are adopted, and the surface state is controlled, so that surface oxide residues are reduced, cleanliness of a steel substrate is guaranteed, and the binding force of a zinc layer is improved; the iron oxide layer formed on the surface of the steel plate enters a reducing atmosphere annealing furnace containing hydrogen, the hydrogen can reduce the iron oxide layer on the surface of the steel plate to form a reduced iron layer, and the adhesive force of a zinc layer is improved.

The invention discloses a nuclear radiation resistant heat-insulating protective coating for steam pipelines and a preparation method thereof. The coating comprises a surface layer and a bottom layer; the surface layer comprises 30 to 50 parts of a surface layer base, 10 to 30 parts of pigments and fillers, 5-10 parts of metal powder, 18 to 20 parts of a curing agent and 18 to 20 parts of a diluent; the bottom layer comprises 10 to 30 parts of a bottom layer base, 30 to 50 parts of pigments and fillers, 5-10 parts of metal powder, 18 to 20 parts of a curing agent and 18 to 20 parts of a diluent; wherein the surface layer base comprises acrylic modified organic silicon resin; the bottom layer base comprises water glass; the pigments and fillers comprise enamel powder, ceramics and auxiliary fillers; the auxiliary fillers comprise one or more of mica, iron oxide, zinc titanate, fluoropolymer and borosilicate; the coating of the invention can effectively insulate and protect the steam pipeline in a high temperature and nuclear radiation environment, thereby extending the service life of the steam pipeline and improving the safety and reliability of the nuclear power plant.

The invention provides a lithium manganese iron phosphate positive electrode material and a preparation method and application thereof. The method comprises the following steps: mixing manganese metal and iron metal, heating, melting and uniformly mixing in an inert gas atmosphere, and grinding into powder; adding an ammonium salt solution, continuously adding the ground manganese-iron alloy powder under heating to form a suspension, introducing compressed air and stirring, reacting, filtering, washing, drying, crushing and grinding to obtain a manganese-iron oxide precursor, feeding the manganese-iron oxide precursor, a lithium source, a phosphorus source and doped metal elements into pure water, adding a carbon source, mixing to form a suspension, and grinding and drying to obtain the lithium-phosphorus-doped manganese-iron composite material. And carrying out carbon thermal reduction in an inert gas atmosphere, and crushing to obtain the lithium manganese iron phosphate positive electrode material. The ferromanganese oxide precursor prepared by heating the metal manganese and the metal iron to a molten state and mixing the metal manganese and the metal iron realizes uniform dispersion of the manganese and the iron at an atomic level, avoids the problems of nonuniform mixing of the manganese and the iron and dissolution of the manganese, and improves the conductivity and the electrochemical performance of the material.

The present invention provides a glass sheet having soda-lime-silica glass composition with a high visible light transmittance (LtC) of at least 89% with a dominant wavelength (DW) from about 490 to 505 nanometers and purity (Pe) of no more than 1% for control thickness of 5.66 mm and methods of making the same. The glass composition comprising a low iron raw material, a total iron oxide (Fe2O3) of 0.02 to 0.06 wt. %, ferrous (FeO) from 0.006 to 0.02 wt. %, redox (FeO / Fe2O3) from about 0.30 to 0.55, Cr2O3 from about 0.3 to 10 ppm, TiO2 from about 50 to 500 ppm, SnO2 from about 10 to 500 ppm, and a critical amount from about 0.10 to 0.25 wt. % of SO3. The low content of iron oxide is achieved by the partial substitution of regular raw materials by low iron raw materials, with a complete substitution of regular dolomite by a low iron dolomite with a maximum content of 0.020 wt. % Fe2O3.

The invention relates to the technical field of metal material hot working, and discloses a hot-rolled coiled plate production process which comprises the following steps: preparing a reaction type protective agent, the high-temperature-resistant coating is prepared from the following raw materials in parts by weight: 20 to 40 parts of tetraethoxysilane, 5 to 15 parts of triethyl phosphate, 1 to 5 parts of triethyl borate, 0.5 to 2.0 parts of cerous nitrate (III) hexahydrate, 0.1 to 1.0 part of lithium acetate and 0.01 to 0.05 part of vanadyl acetylacetonate (IV). Coating the surface of a hot-rolled plate blank with the protective agent; the coated plate blank is heated in a heating furnace, so that the protective agent forms a molten-state protective layer in situ; carrying out hot rolling on the plate blank with the molten protective layer; and cooling and coiling the hot-rolled steel strip. In the whole heating and hot rolling process, the molten protective layer isolates the contact between the steel and the oxidizing atmosphere, so that the generation of oxide scales is fundamentally inhibited, the production process is simplified, and the metal yield is increased.

The invention discloses a method for improving corrosion resistance of steel, and belongs to the technical field of metal protection. The method for improving the corrosion resistance of the steel comprises the following procedures of acid pickling, rinsing, drying, reduction, hot dipping, passivation, drying and packaging. Replacing a plating assisting process in the hot dipping process with a thermal reduction process; and in the thermal reduction process, hydrogen with the volume content of 3-25% is adopted for thermal reduction. A plating assisting technology in a traditional hot dipping technology is replaced with a reduction technology, the steel obtained after acid pickling is dried and then fed into the atmosphere box, a small amount of iron oxide remaining on the surface of the steel is reduced into sponge iron in the hydrogen reduction atmosphere, the surface of the steel keeps active, and then a zinc-based or zinc alloy plating layer can be better plated; therefore, the corrosion resistance of the steel is greatly improved, and the service life is prolonged.

The invention discloses a waterborne epoxy coating for heavy corrosion prevention and a preparation method of the waterborne epoxy coating, and relates to the technical field of coatings. The waterborne epoxy resin, the waterborne epoxy curing agent, the titanium dioxide, the barium sulfate, the superfine talcum powder, the mica powder, the zinc phosphate, the aluminum tripolyphosphate, the superfine mica iron oxide, the glass flakes and the like are used as raw materials for preparing the epoxy coating. Meanwhile, the sheet structures of the superfine mica iron oxide and the glass flakes prolong the time for water and a corrosive medium to reach the surface of the base material, and sufficient dissociation time is given to phosphate. The anticorrosive paint disclosed by the invention has good flexibility and corrosion resistance.

A raw material solution containing trivalent iron ions, or trivalent iron ions and ions of a metal element that partially substitutes Fe sites, and an alkaline aqueous solution for neutralizing the raw material solution are added to a reaction system to adjust the pH of the reaction system from 1.0 to 3.0 or lower. Hydroxycarboxylic acid is added to the obtained reaction solution and the pH of the reaction system is then neutralized from 7.0 to 10.0 or lower. The obtained precipitate of a substituent metal element-containing iron oxyhydroxide is coated with silicon oxide, followed by heating so as to form particles of ε-iron oxide in which Fe sites are partially substituted by other metal elements, and then, a slurry containing the particles is classified. The iron-based oxide magnetic powder has a particle shape close to a perfect sphere and is suitable for use in a magnetic recording medium.

The invention discloses a gas-sensitive material based on double noble metal doped holmium iron oxide and application of the gas-sensitive material to detection of hydrogen sulfide in a sulfur-containing ore body exploration environment, and relates to the technical field of gas-sensitive materials. HoFeO3 is used as a substrate material, and two elements of Au and Pt are used for doping modification of the HoFeO3 to prepare the gas sensitive material based on double noble metal doped holmium iron oxide. Au and Pt are combined to perform doping modification on HoFeO3, a synergistic effect is achieved on improving the temperature stability of the gas-sensitive material, the sensitivity of the gas-sensitive material in a high-humidity environment can be improved, in addition, due to the synergistic catalysis effect of Au and Pt, an energy barrier of H2S adsorption reaction can be remarkably reduced, surface electron transfer and reaction activity are promoted, and the sensitivity of the gas-sensitive material in a high-humidity environment is improved. Therefore, the working temperature is reduced, the response value is improved, and the method is suitable for detecting hydrogen sulfide gas in a sulfur ore body exploration environment.

The invention relates to a process for extracting iron from red mud by using hydrogen reduction and electrolysis technologies, the red mud is a by-product generated in the industrial production process of aluminum, the environmental burden caused by the by-product can be solved, the carbon emission can be reduced, and the development of a green metallurgical technology can be promoted. Comprising the following steps: conveying red mud serving as a raw material into a rotary furnace, conveying hydrogen serving as a reducing medium into the rotary furnace, enabling iron oxide in the red mud to form hydrogen reduced iron in a furnace heating state and a hydrogen reducing atmosphere, conveying the red mud containing the hydrogen reduced iron into a sulfuric acid solution, the hydrogen reduced iron is dissolved in the sulfuric acid solution to form a sulfuric acid solution containing iron ions, the sulfuric acid solution containing the iron ions serves as an electrolyte in an electrolysis device, and electrolytic pure iron formed by electrolytic deposition of the iron ions is obtained through the electrolysis device.

The invention aims to provide a device and method for extracting iron from red mud and preparing iron oxide red, and belongs to the technical field of resource utilization, hydrochloric acid is adopted to leach iron element in the red mud, and a ferric chloride solution is separated from leachate through an extraction process. And then, carrying out alkali precipitation, washing and firing to prepare the high-purity iron oxide red. By using the method disclosed by the invention, the iron resource in the red mud can be recycled, so that the dual purposes of resource utilization and environment-friendly treatment are achieved.

The invention belongs to the field of metal materials, and particularly relates to a hot-rolled pickled steel plate for an automobile chassis and a production method thereof. The steel plate is mainly suitable for manufacturing automobile chassis structural parts. The steel comprises the following chemical components: C, Si, Mn, Al, Ta, Ni, Cu, Cr, Pt and Y, P is limited to be less than or equal to 0.015%, S is limited to be less than or equal to 0.005%, N is limited to be less than or equal to 0.003%, and the balance is Fe and inevitable impurities. The yield strength of the steel plate is larger than or equal to 265 MPa, the tensile strength is larger than or equal to 378 MPa, the transverse elongation A is larger than or equal to 46%, transverse cold bending is conducted by 180 degrees, D = a, the steel plate is qualified, the surface quality is good, oxide scale stripes and chromatic aberration defects are avoided, the surface roughness Ra is 1.10-1.35 micrometers, and the steel plate has good corrosion resistance.

The invention provides a high-crystallinity modified iron oxide as well as a preparation method and application thereof, and relates to the technical field of organic solid waste treatment. The preparation method comprises the following steps: preparing a precursor MIL-88B by utilizing a hydrothermal method; the precursor MIL-88B is subjected to calcination treatment, and an iron oxide with the MIL-88B as the precursor is obtained; the temperature condition of the calcination treatment is 550-850 DEG C. The high-crystallinity modified iron oxide prepared by the preparation method improves methane production efficiency and stability, avoids competition of iron reducing bacteria, is stable in long-term operation and low in cost, and has both environmental and economic benefits.

The invention discloses a sulfur iron oxide composite denitrification filler, a preparation method and application, and relates to the technical field of sewage treatment, the sulfur iron oxide composite denitrification filler comprises sulfur powder, siderite, magnesite, magnesium oxide, metal manganese, metal aluminum, nano iron, boric sludge, magnetite and a binder; wherein the sum of the addition amounts of the metal manganese, the metal aluminum and the nano iron accounts for 8-16% of the mass of the sulfur-iron oxide composite denitrification filler. The technical problems that in the prior art, strength and abrasion resistance are insufficient, and denitrification efficiency is low are solved.

The invention provides a preparation method of a catalytic material for removing new pollutants in a complex water environment. The preparation method comprises the following steps: step 10, preparing a metal organic framework material; step 20, preparing iron oxide particles in the metal organic framework material to obtain the confined iron nano material; and step 30, vertically growing molybdenum disulfide nanosheets on the surface of the confined iron nanomaterial to obtain the catalytic material. According to the preparation method of the catalytic material for removing the new pollutants in the complex water environment, provided by the invention, the prepared catalytic material has excellent anti-interference capability in the complex water environment, and the reaction activity is improved.

The invention discloses porous chlorine dioxide slow-release preservative paper and a preparation method thereof.The porous chlorine dioxide slow-release preservative paper comprises a paper base, a porous carrier is fixed to the paper base through oxidized starch glue, and sodium chlorite, an activating agent and a stabilizing agent are loaded on the porous carrier; the porous carrier is one of aluminum oxide, titanium oxide, cobalt oxide, zinc oxide, copper oxide, iron oxide, cerium oxide, zirconium oxide, nickel oxide, manganese oxide, praseodymium oxide and lanthanum oxide with a porous structure. The slow release of chlorine dioxide can be stably and effectively realized, the release period of chlorine dioxide is prolonged, and long-acting stable sterilization and disinfection effects are realized.

The invention provides a positive electrode material, a preparation method thereof and a lithium ion battery, and belongs to the technical field of battery materials. Comprising the following steps: carrying out acid treatment on ferric oxide to obtain acid-modified ferric oxide; and mixing the acid-modified iron oxide, a second iron source, a lithium source and a phosphorus source to obtain a mixture, and then roasting the mixture to obtain the positive electrode material. By performing acid treatment on the ferric oxide, on one hand, impurities and a loose oxide layer on the surface of the ferric oxide can be removed, more active sites can be exposed, the reactivity of the ferric oxide is matched with that of the second iron source, the reaction process is carried out synergistically, and formation of a regular and uniform-size crystal structure is promoted; a foundation is laid for obtaining a positive electrode material with excellent electrochemical performance; on the other hand, the surfaces of the iron oxide particles can be regulated and controlled, so that agglomeration among the particles can be reduced when the iron oxide particles are mixed with the second iron source particles, the dispersity of the particles is improved, and the mixture forms more excellent gradation.

The invention relates to the technical field of material surface corrosion prevention, in particular to a spraying method for a heavy anti-corrosion coating of a port steel structure. The method comprises the following steps that (1) sand blasting derusting treatment is conducted on a steel structure base body, so that the cleanliness of the steel structure base body reaches the Sa2.5 level, and the roughness is controlled to range from 40 micrometers to 75 micrometers; 2) coating the treated substrate with epoxy zinc-rich primer, and doping graphene modified zinc powder accounting for 1-3% of the total mass of the primer to form a primer layer with a dry film thickness of 60-80 [mu] m; (3) after the primer layer is cured, the primer layer is coated with epoxy micaceous iron oxide intermediate paint, aluminum tripolyphosphate accounting for 2-5% of the total mass of the intermediate paint is further added into the epoxy micaceous iron oxide intermediate paint, and an intermediate paint layer with the dry film thickness being 150-200 microns is formed; 4, the middle paint layer is coated with weather-resistant finish paint, and a finish paint layer with the dry film thickness being 60-80 microns is obtained.According to the method, the adhesive force, chloride ion permeation resistance, salt fog resistance (larger than or equal to 3000 hours) and weather resistance of the coating are remarkably improved, the method is suitable for the harsh marine environment, and the service life of the steel structure can be prolonged to 20 years or above.

A nanocomposite material including iron sulfide (FeS2) nanoparticles, iron oxide (α-Fe2O3) nanoparticles, titanium dioxide (TiO2) nanoparticles, and graphitic carbon nitride (C3N4) nanosheets and a method of its preparation. The nanocomposite is used in a method of forming oxygen gas from water using an applied voltage and photoirradiation, a method of forming hydrogen gas from water using an applied voltage and photoirradiation, and a method of photodegrading organic pollutants using visible light photoirradiation.

The invention relates to a production method for improving a low-carbon cold heading steel oxide scale structure, and belongs to the technical field of steel rolling production processes in the metallurgical industry. According to the technical scheme, the heating temperature of a steel billet is 1180 + / -10 DEG C, the finish rolling temperature of the steel billet is 970 + / -15 DEG C, and the wire rod spinning temperature is 920-940 DEG C; the wire rod enters a Stelmor cooling line for slow cooling after spinning, and the roller speed of the Stelmor cooling line is 0.28-0.30 m / s; the low-carbon cold forging steel comprises the following chemical components in percentage by mass: 0.15-0.27% of C, less than or equal to 0.30% of Si, 0.50-1.20% of Mn, less than or equal to 0.030% of S, less than or equal to 0.035% of P, more than or equal to 0.02% of Al and the balance of Fe and impurities. The method has the beneficial effects that by optimizing process parameters and properly controlling the roller way speed of the Stelmor cooling line, the thickness of the oxide scale of the steel wire rod is increased, the oxide scale can be conveniently removed in the subsequent mechanical husking process, and the next mechanical processing of the steel wire rod is facilitated.

The invention relates to the technical field of pipe fitting shot blasting machining, in particular to a reinforced shot blasting machine for the surface of a metal pipe fitting, which comprises an operation box, a box door is arranged outside the operation box, two symmetrically arranged side plates are fixedly mounted in the middle of an inner cavity of the operation box, and sorting boxes which are distributed left and right are jointly mounted between the side plates on the two sides; according to the shot blasting device, when the pipe fitting rotates, the outer portion of the pipe fitting sequentially faces the shot blasting head, and therefore the shot blasting head can evenly act on the outer wall of the pipe fitting when the shot blasting head starts shot blasting, compared with an existing device, when shot blasting is conducted on the outer portion of the pipe fitting, the outer wall of the pipe fitting can be evenly subjected to shot blasting operation through rotation of the pipe fitting, and the shot blasting efficiency is improved. Steel shots thrown by the shot blasting head and metal impurities shot down on the outer wall of a steel pipe can be subjected to magnetic separation treatment through arrangement of the sorting unit, and the used steel shots can be washed through arrangement of the cleaning unit, so that iron oxide impurities and the like which cannot be adsorbed during magnetic separation are removed, and the used steel shots can be recycled after being cleaned.

The invention relates to the technical field of refractory materials, in particular to a preparation process of hydration-resistant synthetic magnesia-calcium sand. Comprising the following steps: 1) grinding dolomite and magnesite into fine powder with the granularity of 200 meshes; (2) adding the workmanship dolomite fine powder and the magnesite fine powder in the step (1) into a high-speed mixing mill, adding cerium oxide and iron oxide red powder, and fully mixing; 3) adding water accounting for 22-38% of the total weight of the mixed material, and mixing for 45-60 minutes to obtain uniform wet powder without dry powder; (4) pressing the uniform wet powder into wet green bricks by using a brick press; (5) putting the wet green bricks into a drying kiln, drying for 24-30 hours at the drying temperature of 50-80 DEG C, and sintering in a high-temperature sintering device; the firing temperature is 1600 to 1700 DEG C; and 6) crushing the sintered green brick to finally obtain the magnesia-calcium sand. The magnesia-calcium sand prepared by the invention has good hydration resistance and high-temperature usability.

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.

The invention discloses an aluminum tube coating process for OPC photosensitive drum production and preparation, and belongs to the technical field of OPC photosensitive drum processing and preparation, and the aluminum tube coating process comprises the following steps: S1, preparing an outsourcing aluminum alloy into an aluminum tube; s2, the aluminum pipe is cleaned; s3, the cleaned aluminum pipe is sequentially subjected to the dip-coating process for three times; s4, nanoscale silicon dioxide particles accounting for 0.5%-2% of the total weight of the mixture are added in the preparation process of the substrate coating; s5, the photosensitive coating is prepared by dissolving polyamide resin in a tetrahydrofuran solution; s6, the charge transport layer is prepared by dissolving polycarbonate resin in tetrahydrofuran, and adding iron oxide and iron oxide yellow; and S7, the horizontal sand mill inputs the solid-liquid phase mixed material into the barrel through a material pump, and the disperser rotating at a high speed makes solid particles in the material collide, rub and shear with the grinding medium. According to the invention, stronger physical crosslinking points can be formed in the coating, and the adhesive force between the coating and the surface of the aluminum pipe is obviously improved.

The invention discloses a high-aluminum limonite and specularite ore blending and sintering method which comprises the following steps: 1) preparing primary pre-blending powder: pre-blending high-aluminum limonite, specularite concentrate powder, iron oxide scale, limestone powder and anthracite powder to prepare the primary pre-blending powder with the water content of 6.5-7%; (2) preparing a uniformly mixed material: blending the primary pre-blended material powder obtained in the step (1) with high-silicon iron ore powder and hematite and limonite powder to prepare the uniformly mixed material; 3) sintering and burdening: burdening the uniformly mixed material obtained in the step 2) with limestone, dolomite powder, quicklime, solid fuel and return mine, and 4) controlling the components of the sintered ore as follows: 2.3-2.5% of Al2O3, 5.7-6.5% of SiO2, 8-8.5% of FeO and 1.85-2.5% of MgO. According to the invention, while 20-30% of the proportion of the discount ore silk road powder in the total uniformly mixed material is increased, the sintering cost is reduced by 20-42 yuan / ton, the drum strength of the sintered ore is greater than or equal to 78.5%, the return mine rate is less than or equal to 27%, and the RDI + 3.15 mm is greater than or equal to 63%.

The invention relates to the technical field of bolts, and provides a bolt special for stainless steel mechanical equipment and a preparation method thereof. A bolt special for stainless steel mechanical equipment comprises a bolt body and a surface coating, and the surface coating is prepared from, by weight, 100 parts of epoxy resin E-44, 50-55 parts of a curing agent, 1.5-2 parts of a curing accelerator, 20-25 parts of flaky iron oxide, 10-12 parts of modified boron nitride, 2-3 parts of an ultraviolet light absorber, 3-5 parts of silicon dioxide, 1-1.5 parts of a dispersing agent, 25-35 parts of butanone and 10-12 parts of xylene. According to the bolt special for the stainless steel mechanical equipment, the corrosion resistance of the stainless steel bolt in a high-concentration acid-base solution and high-temperature and high-pressure seawater is improved.

The invention relates to the technical field of sewage treatment, particularly discloses an iron oxide red wastewater treatment system and treatment method based on anaerobic ammonia oxidation coupled AI prediction, and solves the problems of insufficient prediction capability and high operation cost in the prior art. The system comprises a sewage treatment module and an AI control module, wherein the sewage treatment module adopts an integrated biofilm process anaerobic ammonia oxidation system, is equipped with a sensing equipment group to detect water quality parameters, and controls the equipment group to execute instructions; the AI control module receives water quality data through a real-time data interface, generates feature data in combination with a production plan and a scheduling table, predicts water quality by using a GRU-QR model and outputs an advanced control instruction, and then dynamically optimizes the model and triggers compensation control according to actually measured data to form double closed-loop control. The system has the advantages of stable effluent ammonia nitrogen, high efficiency, improvement of regulation and control precision, reduction of medicament dosage and the like, and can effectively reduce the cost and realize high-intelligence control.

The invention provides a high-added-value recycling method of silicon and iron elements in iron tailings, and relates to the technical field of high-value and resource utilization of metallurgical solid wastes. The method comprises the steps of iron tailing grinding, middle-stage magnetic separation, microwave roasting, water quenching, grinding, high-stage magnetic separation, first-stage hot-pressing acid leaching, vacuum roasting, water quenching, second-stage hot-pressing acid leaching, low-stage magnetic separation of weakly magnetic minerals, ultrasonic acid leaching for iron extraction, aging reaction, filtering, drying and roasting. And finally obtaining high-purity quartz powder of more than 4N grade and nano iron oxide of which the purity of Fe2O3 is more than 95%. According to the method, silicon and iron elements in the iron tailings are recycled in a layered and stepped manner, and the acid leaching filtrate generated in the preparation process of the high-purity quartz powder is subjected to closed treatment, so that valuable components of silicon and iron in the iron tailings are utilized at a high value to the maximum extent, and no secondary waste liquid is discharged; meanwhile, the problem of fluorine pollution in the traditional process is avoided in the process of preparing the high-purity quartz powder, and the method is low-carbon and green and has remarkable economic benefits.

The invention relates to a process for preparing pure iron by using red mud, which is characterized in that the red mud is Bayer process red mud, i.e., solid waste residue formed by solid-liquid separation after aluminum oxide is dissolved out from bauxite through high temperature, high pressure and strong alkali in the process of producing aluminum oxide by adopting a Bayer process, so that the environmental burden caused by the Bayer process red mud can be solved; the method is beneficial for reducing carbon emission in the aspect of iron element extraction and promoting development of a green metallurgical technology, and is characterized by comprising the following steps: taking Bayer process red mud as a raw material, carrying out acid leaching on the Bayer process red mud to obtain a ferrous oxalate extract, calcining the ferrous oxalate to obtain iron oxide, and recycling the iron oxide. And dissolving the ferric oxide into a sulfuric acid solution to obtain a ferric sulfate solution, taking the ferric sulfate solution as an electrolyte in an electrolysis device, and obtaining electrolytic iron through the electrolysis device, so that the pure iron is prepared from the red mud.

The invention belongs to the technical field of iron oxide preparation, and discloses a method for purifying iron oxide for soft magnetic ferrite from red mud and application of the method. The red mud is subjected to crushing and wet grinding, and red mud slurry is obtained; the red mud slurry is subjected to magnetic separation, drying and grinding into powder, and a magnetic product containing ferric oxide is obtained; the magnetic product is subjected to acid leaching and suction filtration with hydrochloric acid, and first filtrate is obtained; carrying out alkaline leaching treatment on the first filtrate by adopting sodium hydroxide, filtering and drying to obtain a red brown dry material; grinding the red brown dry material into powder, washing with deionized water, carrying out suction filtration, and drying to obtain a first dry material; and grinding the first dry material to a powder state, and carrying out aerobic sintering to obtain the reddish brown solid iron oxide. The iron oxide extracted through the method can replace existing high-purity commercial iron oxide and can be applied to preparation and development of soft magnetic materials, and various properties of the soft magnetic materials are indifferent or even higher.