424 results about "Iron(III) oxide" patented technology

The invention relates to a process for producing carburized directly reduced iron sponge from iron oxide material. Firstly, direct reduction is carried out by means of a reduction gas consisting at least predominantly of H2 and the carbon content in the iron sponge is then increased by means of a carburizing gas which is fed in, after which used carburizing gas is at least partly taken off while largely avoiding mixing with the reduction gas. The plant for producing carburized directly reduced iron sponge from iron oxide material comprises a reduction zone for directly reducing introduced iron oxide material to directly reduced product by means of reduction gas consisting predominantly of H2 and a reduction gas feed conduit opening into the reduction zone. It also comprises a carburization zone having a carburizing gas feed conduit opening into the carburization zone and a carburization offgas conduit.

The invention provides a composite granular desulfurizer and a preparation method thereof. The desulfurizer comprises the following components: zinc oxide, calcium oxide, iron oxide, coke, activated carbon, modified attapulgite, a pore-enlarging agent and aluminum oxide. The preparation method comprises the following steps: uniformly mixing the components, feeding into a calcining furnace, roasting at 350-450 DEG C for 2-4 hours to obtain a calcined material, crushing, extruding and forming, and screening by using a vibrating screen to obtain the desulfurizing agent. The desulfurizer is prepared by loading calcium oxide with aluminum oxide, and ferric oxide is added to further catalyze the desulfurization reaction, so that the desulfurization reaction process is changed, and the desulfurization efficiency is improved. The pore-enlarging agent is used for pore-forming of desulfurizer particles, the adsorption performance of the active substance calcium oxide in the desulfurizer is improved, meanwhile, the mechanical performance of the desulfurizer particles is changed, the desulfurizer particles can be repeatedly used, and the regeneration performance of the desulfurizer is improved.

The invention discloses a method for recovering lithium, nickel cobalt manganese composite hydroxide and aluminum copper powder from a waste ternary lithium ion battery pole piece. The method comprises the following steps: treating waste pole pieces of a ternary plant or a mixture of positive and negative pole pieces by using a Fenton technology, leaching by using a mixed ferric salt solution, and filtering to obtain lithium-containing leachate and slag; adjusting the pH value of the leachate, oxidizing and filtering to obtain a purified solution and ferric hydroxide precipitate, and adding the purified solution and a lithium hydroxide solution into a reactor for coprecipitation to obtain a deeply purified solution and the nickel-cobalt-manganese composite hydroxide. And dissolving the ferric hydroxide precipitate with dilute acid, adding a reducing agent to generate a ferrous salt solution, and returning the ferrous salt solution for Fenton reaction and leaching reaction. And adding the sodium carbonate saturated solution into the deep purification solution, and crystallizing and precipitating to obtain the battery-grade lithium carbonate. And performing hydrodynamic screening on the leaching residues to obtain an aluminum-copper mixture and graphite residues, and performing grinding and specific gravity separation on the aluminum-copper mixture to obtain high-purity aluminum powder and copper powder. According to the method, the iron salt is directly leached from the pole piece, the used iron salt can be recycled, and the method is suitable for large-scale recovery of the waste ternary lithium ion battery.

The invention discloses a metal soft magnetic powder core and a preparation method thereof.The preparation method comprises the steps that cold sintering is conducted, under the ultrasonic-assisted condition, warm-pressing is conducted on mixed powder containing modified iron powder and a release agent, and a metal soft magnetic powder core green body is obtained; wherein the modified iron powder comprises iron powder and a coating layer, the surface of the iron powder is coated with the coating layer, and the coating layer comprises copper, hydrated ferric oxalate, hydrated cupric oxalate and iron oxide; and heat treatment is conducted, specifically, the metal soft magnetic powder core green body is subjected to heat treatment under the oxygen-containing condition, and the metal soft magnetic powder core is obtained. Ultrasonic assistance is introduced when the modified iron powder is subjected to cold sintering, and a mixed insulation coating layer of ferric oxide and copper oxide can be generated on the surfaces of powder particles in situ during heat treatment, so that the compactness, the strength, the resistivity and the magnetic conductivity of the magnetic core are improved while the pressing force is reduced and the pressing efficiency is improved.

The invention relates to a method for solving strip-shaped defects on the surface of a cold-rolled coil. The method comprises the steps of redesigning components and hardness of a product, adjusting the hot rolling tapping temperature, increasing the cooling water amount during laminar cooling after hot rolling, reducing the coiling temperature and the like. According to the method for solving the strip-shaped defects on the surface of the cold-rolled coil, the hardness of a low-carbon steel material is improved, the compactness of a material structure is improved, oxide scale cannot be pressed into the surface of the hot-rolled coil, the slab heating tapping temperature is reduced, the coiling temperature of the hot-rolled coil is reduced, and therefore the problem that the oxide scale of the hot-rolled coil is pressed in is solved; and strip-shaped defects cannot be generated when the hot-rolled coil is further cold-rolled.

The invention belongs to the technical field of angle steel bending, and discloses an angle steel bending device for steel structure construction, which comprises a bending table, an L-shaped heating plate is arranged on one side of the top of the bending table, a heating rod is fixedly connected to one side of the L-shaped heating plate, a guide plate is fixedly connected to one side of the top of the bending table, and first angle steel is arranged in the guide plate. By starting a first driving motor, the first driving motor is started to drive a first rotating shaft to rotate to drive a grinding wheel to rotate, meanwhile, the first rotating shaft rotates to drive a rotating disc to do 45-degree reciprocating swing motion, and at the moment, the rotating disc reciprocates to drive a first shaft sleeve, a dustproof shell, a fourth rotating shaft and the grinding wheel to do reciprocating swing; and therefore, the grinding wheel can be attached to the bending angle of the first angle steel to conduct grinding, ferric oxide formed on the surface is better removed, the product quality is improved, and meanwhile equipment abrasion and the failure rate are reduced.

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 relates to the technical field of iron ore tailing resource utilization, in particular to a method for preparing iron oxide yellow by leaching iron ore tailings through an advanced oxidation technology, which comprises the following steps: adding a required amount of iron ore tailing powder into a persulfate solution, stirring to react, adding a reducing agent, boiling, filtering, adding alkali liquor to adjust the pH value, and filtering, thereby obtaining the iron oxide yellow. Pure liquid containing ferrous ions is obtained; taking part of the pure solution containing ferrous ions, and adding a potassium hydroxide solution to obtain an iron oxide yellow seed crystal solution; adding a pure solution containing ferrous ions into the iron oxide yellow seed crystal solution, adding an alkali solution to adjust the pH value, reacting, and separating and drying a product to obtain the iron oxide yellow. According to the method, the persulfate is adopted to leach iron from the iron ore tailings, and the iron oxide yellow is prepared from the leachate; harmless treatment of the iron ore tailings and value-added utilization of valuable resources are achieved, the raw material source of the iron oxide yellow industry is widened, and a wider prospect is provided for development of iron oxide yellow.

The invention belongs to the technical field of environmental rock soil, and particularly relates to a preparation method of zeolite-magnetic iron oxide and application of the zeolite-magnetic iron oxide in catalyzing sodium percarbonate to repair petroleum hydrocarbon polluted soil. The specific method comprises the following steps: carrying out alkali treatment on zeolite, and then carrying out heat treatment to obtain alkali-heat combined modified zeolite; extracting an iron element in the iron-containing by-product with acid and preparing ferric hydroxide colloid; and uniformly mixing the alkali-heat combined modified zeolite with the ferric hydroxide colloid, carrying out solid-liquid separation, and then carrying out heat treatment and hydrogen reduction treatment to obtain the zeolite-magnetic iron oxide, the application specifically comprises the following steps: uniformly mixing sodium percarbonate, tween-80, silica sol and water to prepare a turbid solution A; uniformly mixing zeolite-magnetic iron oxide, organic acid, silica sol and water to prepare a turbid solution B; and uniformly mixing the turbid liquid B with the petroleum hydrocarbon polluted soil, then adding the turbid liquid A, uniformly mixing, and maintaining for 12-15 days to finish the remediation.

The invention provides a manganese zinc ferrite material as well as a preparation method and application thereof. The manganese zinc ferrite material is prepared from main components and auxiliary components, the main component is prepared from the following components in molar ratio: 51.5 to 53.0 mol percent of ferric oxide, 17.0 to 18.5 mol percent of zinc oxide and 29.0 to 30.0 mol percent of manganese oxide; the auxiliary components comprise the following components according to the total weight of the main components: 200 to 2000 ppm of nano-scale bismuth oxide, 200 to 2000 ppm of nano-scale calcium carbonate, 200 to 2000 ppm of nano-scale molybdenum oxide, and 0 to 4000 ppm of nano-scale cobalt oxide. By optimizing the components and the proportion of the ferrite material, improving the preparation process and organically combining the formula and the process, the ferrite material with high magnetic conductivity, high Curie temperature, wide frequency and wide temperature is finally prepared, and large-scale popularization and application are facilitated.

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 relates to the technical field of preparation of a lithium ion battery negative electrode material, in particular to a metal organic framework coating for improving the performance of an iron oxide negative electrode lithium ion battery and a preparation method of the metal organic framework coating. The metal organic framework coating mainly comprises the step of coating the iron oxide by growing a metal organic framework on the surface of the iron oxide in situ. According to the invention, in-situ synthesis of a metal organic framework material on the surface of iron oxide is innovatively proposed, and the iron oxide material is coated in a hollow structure through a structure provided by an organic framework, so that volume expansion and shrinkage of iron oxide in charge and discharge processes are effectively buffered. By regulating and controlling the mass ratio of the organic framework to the ferric oxide, the high-rate discharge performance and the specific discharge capacity of the ferric oxide negative electrode are improved.

The invention provides a method for preparing H2-CO energy gas from steel slag, and belongs to the field of metallurgy and solid waste treatment. The preparation method comprises the following specific preparation steps: step 1, blowing weak oxidizing gas to the liquid level of the steel slag in a molten state to oxidize FeO in the steel slag, so that hydrogen and carbon monoxide gas are generated while ferric oxide is converted into a magnetic phase which is easy to separate; and 2, separating and collecting the reacted gas. After the steps, the energy gas containing H2 and CO is finally generated for recycling. Through the treatment steps provided by the invention, (1) CO2 is absorbed and converted into CO energy gas, and carbon emission is reduced; (2) waste heat of the steel slag is utilized, water vapor is converted into clean energy H2, and the hydrogen production cost is remarkably reduced; and (3) the injection proportion of H2O-CO2 gas is regulated and controlled, and the generation rate of H2-CO is remarkably increased.

The invention relates to the technical field of fire coal additives, in particular to a high-efficiency coal saving agent and a preparation method thereof. The coal saving agent is prepared from the following raw materials in percentage by mass: 7-14% of an oxygen supply agent, 5-12% of a combustion improver, 5-13% of a catalyst, 0.1-1% of industrial waste residues, 1-3% of a desulfurization additive, 1-2% of a dispersing agent and the balance of deionized water, wherein the catalyst is a Ce-Mn / TiO2 catalyst, and the catalyst is a TiO2 catalyst; the industrial waste slag is selected from at least one of cold-rolled iron oxide slag, nickel slag or steel slag; the desulfurization additive is selected from at least one of calcium acetate, calcium oxide or calcium carbonate. The coal-saving agent can effectively improve the combustion characteristic of coal, improve the combustion efficiency and the combustion effect, and realize the efficient coal-saving effect under the condition of low mixing amount; meanwhile, desulfurization and denitrification can be achieved, emission of sulfide and nitric oxide is reduced, and environmental pollution can be prevented and controlled.

The present invention relates to the technical field of steel slag solid waste utilization, and in particular to a method for selective extraction of calcium and secondary magnetic separation of iron from steel slag, comprising the following steps: adding a leaching agent into steel slag, controlling the leaching temperature to be 95-125℃ and the pH of a leaching system to 5.5-8, and continuously leaching calcium for 0.5-2 h; in the process of leaching the calcium or after the leaching of the calcium is finished, adding an oxidizing agent into a reaction system, and oxidizing part of the original non-magnetic ferrous oxide in the steel slag into magnetic ferroferric oxide; and performing magnetic separation on residues obtained after leaching to obtain magnetically separated powder having a total iron content of greater than 40% and tailing powder having an iron oxide content of greater than 40%. According to the method, calcium in the steel slag can be efficiently and selectively extracted, and a steel slag ore phase can be changed while the calcium is extracted, so that most of iron in the residues obtained after leaching can be enriched by magnetic separation again, thereby realizing grading and efficient utilization of calcium and iron elements in the steel slag, and improving the recycling rate of the iron.

The invention relates to the technical field of ceramics, in particular to mottle crack glazed ceramic and a preparation method thereof.The ceramic comprises a green body, ground glaze and cover glaze, and the ground glaze is prepared from, by weight, 30-35 parts of kaolin, 25-30 parts of quartz, 20-25 parts of feldspar, 8-12 parts of ferric oxide, 5-8 parts of calcium carbonate and 3-5 parts of borax; the cover glaze is prepared from the following raw materials in parts by weight: 35 to 40 parts of feldspar, 25 to 30 parts of quartz, 6 to 10 parts of copper oxide, 5 to 8 parts of granular rock powder, 8 to 12 parts of borax and 5 to 8 parts of clay. Embedding porous particles into the green body to initiate explosion cracks, and fusing interlayer stress cracks and devitrification cracks to form a multi-stage composite crack network; iron ions in the ground glaze and copper ions in the cover glaze form ion gradient migration through the iron axe stone powder in the middle layer to generate red and green blended stripes; the microcapsule carbon powder regulates and controls the pores and texture of the glaze, and copper foil fragments are oxidized and reduced to form gilding-brown mottles.

The invention provides coal gangue-based artificial soil as well as a preparation method and application thereof. The preparation method of the coal gangue-based artificial soil comprises the following steps: S1, modifying coal gangue by adopting a solution containing citric acid and ethylenediamine tetraacetic acid to obtain modified coal gangue; s2, preparing the modified coal gangue into artificial soil. According to the invention, the citric acid can dissolve carbonate in the coal gangue, the released carbonate can be combined with heavy metals, and citrate ions and ferric ions can form a complex to destroy the outer layer of ferric oxide of the heavy metals; ethylenediamine tetraacetic acid can permeate into mineral lattices of the coal gangue, lattice bound state heavy metal is released through octahedral Al-O bond breakage, the ethylenediamine tetraacetic acid can capture heavy metal combined with citric acid, a more stable heavy metal complex is formed, the heavy metal complex carries strong negative charges, and the heavy metal complex can be separated from the coal gangue. And electrostatic repulsion can be generated on the surface of the coal gangue with negative electricity, so that the heavy metal removal effect is improved.

The invention discloses an iron oxide-iron cluster catalyst for a reverse water gas shift reaction and preparation of the iron oxide-iron cluster catalyst. The catalyst is a double-site material Fe2O3-Fe4 / C of carbon-loaded iron oxide particles and iron clusters. The preparation method comprises the following steps: firstly, synthesizing an NH2-MIL-88B (Fe) material through a solvothermal method, then grinding and uniformly mixing the NH2-MIL-88B (Fe) material with KCl, feeding the mixture into a tubular furnace for high-temperature calcination, and washing after cooling to obtain the MOFs-derived double-site catalyst, namely Fe2O3-Fe4 / C. The MOFs-derived Fe2O3-Fe4 / C double-site catalyst prepared by the invention is low in cost and simple and convenient in process, and when the MOFs-derived Fe2O3-Fe4 / C double-site catalyst is applied to a low-temperature catalytic reverse water-gas shift reaction, the CO2 conversion rate and the CO space-time yield are greatly improved, and the industrial application potential is huge.

According to the production method, an extremely-cold fine grain layer with the thickness being 10 mm or above and a large-size rectangular blank are obtained by means of the large specific water flow of primary cooling water, and the two-phase region controlled rolling, rapid cooling and isothermal slow cooling processes are matched, so that the low-carbon free-cutting steel wire rod capable of being subjected to large-deformation cold heading is obtained. And a structure of fine grain ferrite with large deformability and a very small amount of sorbite is obtained, and the 1 / 3 cold upsetting non-cracking requirement is met. After the produced free-cutting steel wire rod is subjected to oxide scale removal, drawing sizing and blanking, direct large-deformation cold heading and punching machining can be achieved, and the requirement for high-speed cutting machining is met.

According to the red mud-based composite material and the preparation method and application thereof, bentonite, red mud and biomass are mixed in a proper amount of water according to the mass ratio of 1: 1: (1-10), and first suspension liquid is formed; drying the first suspension to obtain a precursor of the red mud-based composite material; the precursor is subjected to a carbon thermal reaction at 300-700 DEG C, ferric oxide in the red mud is converted into zero-valent iron, and the red mud-based composite material is obtained. The red mud is alkaline and promotes manganese ions to form insoluble precipitates, the unique structure and ion exchange capacity of the bentonite can effectively solidify the manganese ions, the biomass has a high specific surface area and a developed pore structure, and the manganese ions are physically adsorbed through Van der Waals' force and pore interception; ferric oxide in the red mud is converted into zero-valent iron in the carbothermal reaction process, and the zero-valent iron can catalytically oxidize ammonia nitrogen, so that the red mud-based composite material synchronously solves the problem of combined pollution of manganese and ammonia nitrogen in the soil.

The invention provides a coal-based solid waste foamed cement material for filling a coal mine tunnel and a preparation method of the coal-based solid waste foamed cement material. The coal-based solid waste foamed cement material comprises 10-30 parts of coal gasification coarse slag micro powder, 0-30 parts of first-grade fly ash, 70-90 parts of cement, 0.3-0.8 part of a foam stabilizer and 0.1-0.5 part of an additive, the coal-based solid waste foamed cement material is further doped with foam, the mixing amount of the foam is 2-5 times of the volume of the cement slurry, the coal gasification coarse slag micro powder is coal water slurry furnace gasification coarse slag, and the coal gasification coarse slag micro powder is prepared from, by mass, 40% of silicon dioxide, 19% of aluminum oxide, 15% of ferric oxide, 16% of calcium oxide, 3% of sulfur trioxide, 3% of sodium oxide, 1% of magnesium oxide and 0.5% of titanium oxide. And 0.5% of potassium oxide. According to the invention, a physical foaming method is utilized, coal-based solid waste is used as a raw material to replace part of cement, and the foamed cement material with light weight and high strength is prepared, so that the foamed cement material meets the use requirements of underground roadway filling.

The invention discloses a method for preparing iron oxide and calcium chloride by electrochemically recovering iron-containing waste hydrochloric acid, and belongs to the technical field of waste acid treatment. The method comprises the following steps: S1, respectively putting a cathode and an anode at two ends of an electrolytic cell, putting a diaphragm to separate the cathode and the anode, filtering the iron-containing waste hydrochloric acid, removing suspended matters and solid residues, and introducing the iron-containing waste hydrochloric acid into the electrolytic cell; s2, measuring the content of iron element and the content of free acid in the iron-containing waste hydrochloric acid, and adding a neutralizing agent to neutralize redundant free acid; s3, applying voltage between the cathode and the anode according to the content of the iron element, performing electrolytic reaction to generate an oxidation intermediate, and oxidizing the iron element by using the oxidation intermediate to obtain a precipitate iron oxide and a calcium chloride solution; and S4, adding a proper amount of water into the reaction solution for dilution, filtering to obtain iron oxide, and concentrating the filtrate to obtain calcium chloride. According to the method, the oxidation intermediate generated by waste hydrochloric acid electrolysis is used as the oxidizing agent, the ferrous ions in the waste hydrochloric acid are selectively oxidized, other oxidizing agents do not need to be additionally added, new impurities cannot be generated in the oxidation process, the treatment time is short, the product is controllable, and remarkable economic benefits and social benefits are achieved.

Separating the specific gravity gt of the solid-liquid mixture type underflow red mud discharged in aluminum oxide production from liquid; continuously grading and separating out ferric oxide, trace heavy metal minerals and rare earth from the 5 g / cm < 3 > material, and carrying out solid-liquid separation treatment; the separated materials with the specific gravity smaller than or equal to 5 g / cm < 3 > are atomized and dispersed into particles and liquid drops, the particles and the liquid drops are quickly freeze-dried to prepare fine particles, and the fine particles are divided into sodium aluminosilicate and silicon oxide mixed particles, calcium compound mixed particles and crystallized sodium hydroxide, sodium aluminate and ice crystal particles through multi-stage specific gravity classification in the environment with the temperature smaller than-5 DEG C; and sublimating and dehydrating the separated sodium aluminosilicate and silicon oxide mixed particles and calcium compound mixed particles to form powder materials, and melting sodium hydroxide, sodium aluminate and ice crystal particles at normal temperature to form a solution containing sodium aluminate and sodium hydroxide.

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 discloses a clean production process for contaminated acid treatment, which comprises the following steps: (1) after contaminated acid is subjected to heavy metal removal pretreatment, adding iron oxide / iron and copper oxide / copper into the contaminated acid to carry out neutralization reaction, and carrying out solid-liquid separation to obtain a ferric sulfate / ferrous sulfate solution and a copper sulfate solution; (2) concentrating and crystallizing the ferric sulfate / ferrous sulfate solution and the copper sulfate solution which are generated by neutralizing the waste acid; (3) roasting the ferric sulfate / ferrous sulfate and copper sulfate crystals step by step to remove crystal water; (4) carrying out high-temperature roasting on the ferric sulfate / ferrous sulfate or copper sulfate after the crystal water is removed, and decomposing into ferric oxide, copper sulfate, sulfur dioxide or sulfur trioxide; the obtained ferric oxide and copper oxide are recycled for neutralization treatment of waste acid after being recycled, and the obtained sulfur dioxide and sulfur trioxide can be recycled for sulfuric acid production. The waste acid is subjected to circulating neutralization treatment, so that the generation of traditional waste acid neutralization slag is avoided, and the resource utilization of sulfur is also realized.

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.

The invention relates to a treatment method for red mud dissolved out of gibbsite, the red mud dissolved out of gibbsite contains sodium-silicon slag and ferric oxide, the method comprises the following steps: under the condition of set temperature, mixing the red mud dissolved out of gibbsite with alkali liquor with set concentration and degassed carbide slag for chemical reaction, the red mud is dissolved out from the gibbsite to be converted into molten garnet, and dissolved-out slurry is obtained. According to the method, sodium oxide and aluminum oxide in the red mud dissolved out of gibbsite are effectively recycled.

The invention discloses a preparation method of a medium-high carbon steel hot-rolled coil and medium-high carbon steel. The preparation method of the medium-high carbon steel hot-rolled coil comprises the steps that slab continuous casting is conducted, specifically, molten medium-high carbon steel is subjected to casting and drawing to obtain a slab, the slab is subjected to pre-descaling treatment to reduce oxide on the surface of the slab, and a pretreated slab is obtained; plate blank heating, specifically, the pretreated plate blank is subjected to heating treatment, high-pressure water descaling treatment is conducted after heating treatment is finished, and a to-be-machined plate blank is obtained; and rolling is conducted, specifically, the to-be-machined plate blank is rolled, and strip steel is obtained. According to the preparation method disclosed by the embodiment of the invention, the slab subjected to slab continuous casting is subjected to pre-descaling treatment before being put into a furnace to be heated, and is subjected to high-pressure water descaling treatment before being rolled after being heated, so that the initial thicker oxide scale on the surface of the slab is removed, and the uniformity of the oxide scale formed on the surface of the slab during hot rolling is ensured to be good.

The invention provides a collaborative recovery method for directionally converting SO2 into waste tire cord steel wires, and belongs to the technical field of solid waste recycling. According to the collaborative recovery method provided by the invention, the granular waste tire cord steel is roasted in an SO2 / O2 / N2 mixed atmosphere and an air atmosphere in sequence, and then the valuable metal components copper, zinc and iron in the waste tire cord steel wire are directionally converted into copper sulfate, zinc sulfate and iron oxide through further leaching and magnetic separation processes. According to the method, efficient recovery and resource utilization of valuable metal components of copper, zinc and iron in the waste tire cord steel wires are achieved, an innovative solution is provided for high-value utilization of the waste tire cord steel wires, and the method has good application prospects and social and ecological benefits.