42 results about "Iron oxyhydroxide" patented technology

A method for making an iron-based oxide magnetic powder includes adding 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 to a reaction system to adjust the pH of the reaction system to 1.0 or higher and 3.0 or lower. Hydroxycarboxylic acid is added to the obtained reaction solution and thereafter the pH of the reaction system is neutralized to 7.0 or higher and 10.0 or lower. The obtained precipitate of a substituent metal element-containing iron oxyhydroxide is coated with silicon oxide and then heated, whereby an iron-based oxide magnetic powder is obtained with a reduced content of fine and coarse particles, a particle shape close to a perfect sphere, and particles of ε-iron oxide in which Fe sites are partially substituted by other metal elements.

A water treatment method for reducing the dissolved silica content thereof, the method being characterized in that it comprises at least one step of adsorbing the dissolved silica, the step consisting of passing the water through a reactor containing a granular adsorbent material consisting of iron(III) hydroxide and / or iron(III) oxyhydroxide grains, and at least one step of regenerating the adsorbent power of the granular material, the step consisting of bringing the granular material into contact with a base and at least one chloride.

The invention relates to the technical field of desulfurizing agents, in particular to a reusable iron oxyhydroxide desulfurizing agent and a preparation method thereof. The problem that the activity of a traditional material is reduced due to sulfate accumulation and compact layer formation in a vulcanization-regeneration cycle is solved. The preparation method comprises the following steps: dissolving ferric nitrate and urea, adjusting the pH value to 1.8, and adding cerous nitrate and citric acid; heating, introducing zirconium oxynitrate, controlling the pH value at 3.7-3.9 for 2-3 hours, heating to 7.2, adding samarium nitrate and zirconium acetylacetonate, aging, and mixing with bentonite and ammonium bicarbonate for molding; and finally, carrying out segmented activation in a nitrogen and low-oxygen mixed atmosphere. The desulfurizer has high specific surface area and pore volume, the breakthrough sulfur capacity reaches 148-160mgS / g, the 10-time circulating sulfur capacity retention rate is 88-91%, and the desulfurizer is high in particle compressive strength, low in abrasion rate and suitable for the industrial desulfurization process.

The invention discloses a rare earth doped iron oxyhydroxide / ferric oxide-three-dimensional graphene composite material and a preparation method thereof, the material is x% RE-FeOOH / Fe2O3 (at) 3D Gr, x is the molar ratio of rare earth ions to iron ions, the value range of x is 1-8.5, RE is one of rare earth elements Ce, La, Sm, Nd or Y, and RE is one of rare earth elements Fe, La, Sm, Nd or Y; the preparation method comprises the following steps: preparing a mixed solution A from an iron salt, a rare earth salt and an alkaline solution, adding a complexing agent into a graphene oxide solution to prepare a mixed solution B, performing ultrasonic treatment on the two solutions, mixing, adding a reducing agent, performing ultrasonic treatment again, and finally performing hydrothermal treatment, washing, freeze drying and low-temperature sintering. Rare earth ions can induce oxygen vacancies, increase active sites and promote ion transmission, the maximum mass specific capacitance of the material under 0.5 A / g reaches 1218.7 F / g, and the maximum capacitance retention rate of a flexible supercapacitor assembled by the material is 97% after 5000 times of charging and discharging.

Provided are: a novel complex capable of efficiently adsorbing and collecting arsenic (V) dissolved in water; and a novel arsenic adsorbent. This complex contains iron (III)-containing particles supported on microfibrous cellulose. At least a portion of the iron (III)-containing particles has an aspect ratio of 2 or more. The iron (III)-containing particles preferably contain at least one iron compound selected from iron oxides, iron hydroxides, and iron oxyhydroxides. This arsenic adsorbent contains the complex.

The invention relates to the technical field of desulfurizing agents, in particular to a ferric oxyhydroxide desulfurizing agent and a preparation method thereof. According to the iron oxyhydroxide desulfurizing agent, zinc oxide nanoparticles are doped on the surface of iron oxyhydroxide, then the zinc oxide nanoparticles and manganese dioxide form a core-shell structure with manganese dioxide as a shell and iron oxyhydroxide as a core, and finally the core-shell structure is loaded on carbon nanofibers to finally obtain the iron oxyhydroxide desulfurizing agent. The iron oxyhydroxide desulfurizer disclosed by the invention has excellent sulfur removal performance, can still keep relatively excellent sulfur removal performance under the condition that interfering ions such as PO4 < 3-> and SO3 < 2-> exist in water, and can be widely applied to the field of industrial sulfur removal.

This invention discloses a method for preparing lithium iron phosphate using iron hydroxyl oxide as an intermediate, belonging to the field of new energy battery materials. The method includes: removing impurities from a ferrous sulfate solution, adding ammonium bicarbonate and ammonium fluoride, heating and passing an oxidizing gas to react and generate the iron hydroxyl oxide intermediate; mixing and milling this intermediate with a phosphorus source, a lithium source, and a carbon source, spray drying, and sintering under an inert atmosphere to obtain lithium iron phosphate cathode material. This invention uses iron hydroxyl oxide as the sole iron source, eliminating the need for the iron phosphate intermediate throughout the entire process. In step two, ammonium fluoride is used for in-situ doping with fluorine, and combined with the structural template effect of the nanorod-shaped iron hydroxyl oxide, uniform nanoparticles are obtained with only one milling operation, forming microporous channels. This method simplifies the production process, reduces equipment investment and energy consumption, and the resulting material exhibits high capacity, high initial efficiency, and excellent rate performance.

The invention discloses a method for producing high-quality diamond by utilizing biochar, and belongs to the technical field of diamond production. The method comprises the following steps: performing drying, crushing, high-temperature deliming and pickling pretreatment on biochar to obtain refined biochar; under the protection of inert gas, mixing with a transition metal catalyst, carrying out high-temperature and high-pressure treatment to complete graphitization, and carrying out acid pickling to obtain high-purity graphite; briquetting graphite and a metal catalyst, and synthesizing diamond under high-temperature and high-pressure conditions; and finally, sequentially carrying out crushing, deep acid pickling and ultrasonic-assisted electrolytic treatment on the diamond synthetic block, adsorbing and removing trace metal impurities by adopting modified iron oxyhydroxide, and carrying out separation, washing, drying, cutting and polishing to obtain the high-quality diamond. According to the method disclosed by the invention, the biochar is used as a sustainable carbon source, and the problems of more biochar impurities, difficulty in graphitization, incomplete impurity removal by a traditional acid pickling method, serious environmental pollution and the like are solved by integrating graphitization, synthesis and green purification processes.

The present application aims to provide a sucrose hydroxyl ferric oxide tablet composition and a preparation method thereof. The present application belongs to the technical field of pharmaceutical preparations, and particularly relates to a sucrose hydroxyl ferric oxide tablet composition and a preparation method thereof. The sucrose hydroxyl ferric oxide is a particle with a certain particle size distribution, and the pharmaceutical composition is prepared by adding pharmaceutically acceptable pharmaceutical adjuvants, the preparation method is simple, the product has small friability, is easy to package, and is more conducive to commercial production.

The application provides a preparation method of a sucrose-hydroxyl iron oxide compound, relates to the field of compound preparation methods, and specifically comprises the following steps: (1) synthesis of hydroxyl iron oxide; (2) desalination; and (3) synthesis of the sucrose-hydroxyl iron oxide compound. In the process of removing the inorganic salt of the hydroxyl iron oxide in the preparation method of the sucrose-hydroxyl iron oxide compound, the hydroxyl iron oxide is first diluted with water and then filtered and desalted, so that the desalination efficiency is significantly improved, the overall production cycle is greatly shortened, the production efficiency is improved, and the production cost is saved.

Provided is a powder of iron oxyhydroxide in which the nanoparticle content is controlled. A powder of iron oxyhydroxide in which the minor axis diameter Dn50 is from 100-300 nm and the proportion of particles having a minor axis diameter of less than 100 nm is 3.0% or less is provided through a method that includes: adding a metal-carbonate-free and metal-bicarbonate-free alkali to an iron(II)-containing aqueous solution to adjust the iron(II) concentration to 0.10-0.35 mol / L; blowing in an oxygen-containing gas to achieve a flow rate of 0.02-0.13 L / min per 1.00 mol of iron(II) while maintaining a solution temperature of 20-35°C; adding iron(II) to satisfy 7.0 ≤ (p + q) / p ≤ 12.0, where p is the substance amount / mol of iron(III) in the resulting nuclei, and q is the substance amount / mol of iron(II) added; adjusting the concentration of iron(II) to 0.45-0.85 mol / L; and blowing in an oxygen-containing gas at a flow rate of 0.01-0.10 L / min per 1.00 mol of iron(II) in a first stage and 0.03-0.12 L / min in a second stage while maintaining a solution temperature of 50-80°C.

The invention discloses a water-eroded slope cropland composite modifier and a preparation method and application thereof, and belongs to the technical field of soil improvement and water and soil conservation. In order to solve the technical problems that traditional biochar is easy to wash off, short in lasting effect and poor in improvement effect in a slope cropland water-eroded environment, the invention provides a composite modifier for water-eroded slope cropland, and amorphous iron oxyhydroxide nanoparticles are accurately loaded on pores and surfaces of biochar through an in-situ synthesis method; by combining the biochar and the calcium chloride-attapulgite composite adhesive, a stable soil aggregate is formed through the cementation effect of the iron oxyhydroxide, the pore adsorption effect of the biochar and the consolidation effect of the calcium chloride-attapulgite composite adhesive, synergistic interaction is achieved, the corrosion resistance and the water binding capacity of the slope cropland are effectively improved, and water and soil synergistic treatment is achieved.

The application relates to a preparation method of a magnesium alloy surface super-hydrophobic coating, which comprises the following steps: (1) constructing a micro-arc porous magnesium oxide coating on the surface of the magnesium alloy through a micro-arc oxidation technology; (2) immersing the magnesium alloy with the micro-arc porous magnesium oxide coating on the surface in a ferrous ion solution, then carrying out hydrothermal treatment in pure water, and obtaining the magnesium alloy with Mg-Fe layered double hydroxide nanosheets on the surface; (3) immersing the magnesium alloy with the Mg-Fe layered double hydroxide nanosheets on the surface in the ferrous ion solution, self-assembling iron hydroxyl nanosheets on the Mg-Fe layered double hydroxide nanosheets, and obtaining the magnesium alloy with secondary micro-nano rough structures on the surface; and (4) carrying out thermal reduction treatment on the magnesium alloy with the secondary micro-nano rough structures on the surface in a reducing atmosphere, and obtaining the magnesium alloy with the super-hydrophobic coating on the surface.

[Problem] To provide: a method for producing precursor fine particles, the method being improved in productivity and quality stability of ε-type ferric oxide fine particles; a method for producing ε-type ferric oxide fine particles; and precursor fine particles. [Solution] This method for producing precursor fine particles can be used for the production of ε-type ferric oxide fine particles, and is characterized by including an irradiation step in which a ferric salt in a solvent 5 is irradiated with a femtosecond pulse laser to produce precursor fine particles P each containing iron hydroxide oxide. In the irradiation step, precursor fine particles P each containing ε-type iron hydroxide oxide may be produced. In the irradiation step, the ferric salt in the solvent 5 that contains an alcohol may be irradiated with the femtosecond pulse laser.

The invention relates to the technical field of high polymer materials, and particularly discloses a degradable antibacterial modified ABS material and a preparation method thereof.The degradable antibacterial modified ABS material is prepared from, by mass, ABS resin, auxiliaries, an initiator, a heat stabilizer, antioxidant particles, a dispersion compatilizer and a composite antibacterial agent; the composite antibacterial agent is mainly used for releasing zinc ions for bacteriostasis, added hemicellulose is treated to react with zinc phosphate and phosphite to form a stable zinc ion release channel while being used for bacteriostasis, and antistatic particles are treated and mixed with ferric oxyhydroxide to modify diatomite to adsorb and destroy a bacterial structure so as to play a role in bacteriostasis and antioxidation. The prepared modified ABS material is a green degradable material with effective antibacterial performance, the antibacterial rate of the modified ABS material on escherichia coli, staphylococcus aureus and other florae can reach 99% or above, and meanwhile the modified ABS material has good mechanical performance and flame retardant performance and is biodegradable.

The application discloses a kind of iron sulfide-phosphide catalyst for electrolysis water separation hydrogen isotope and preparation method thereof.The catalyst is with conductive carbon paper as substrate, by in-situ growth of iron oxyhydroxide precursor by hydrothermal method, then simultaneously introduce sulfur source and phosphorus source by chemical vapor deposition technology, to obtain the nano-structured catalyst with Fe-S-P active component.The catalyst not only shows excellent hydrogen evolution reaction activity in alkaline electrolyte, but also can realize efficient separation of hydrogen and deuterium by using kinetic isotope effect, with high hydrogen / deuterium separation factor.The application also provides the application of the catalyst in electrolysis water hydrogen production and hydrogen isotope separation, as well as the electrolysis separation method based on the catalyst.The application has simple process and low cost, provides efficient integrated material and process scheme for solving the green and low-cost extraction of deuterium resources.

The invention relates to a chloride ion modified beta-type iron oxyhydroxide material, a preparation method and a method for separating hexafluoropropylene / octafluoropropane mixed gas, and belongs to the technical field of fluorine special electron gas separation and purification. The preparation method comprises the following steps: dissolving chloride of iron into a mixed solvent of ethylene glycol and water to obtain an iron salt solution; adding oxalic acid into the ferric salt solution to obtain a mixed solution; and reacting the mixed solution at 100-180 DEG C for 6-24 hours to generate a precursor, heating the precursor in an inert atmosphere to 150-250 DEG C, and calcining for 1-6 hours to obtain the chloride ion modified beta-type iron oxyhydroxide material. A set amount of chloride ions are introduced into a beta-FeOOH structure, the pore size distribution of beta-FeOOH can be regulated and controlled, the pore size of beta-FeOOH can allow hexafluoropropylene with small dynamic size to enter, octafluoropropane with large dynamic size is prevented from entering, and the requirement for separating and purifying hexafluoropropylene / octafluoropropane mixed gas through an adsorption method is met.

This invention provides an iron-modified magnesium slag-based amorphous iron hydroxide composite material, its preparation method, and a method for synergistically removing iron and manganese from acidic mine water, belonging to the technical field of mine water treatment materials. The preparation method of the composite material includes: dissolving iron salt in water to obtain an iron salt solution; adding undisturbed magnesium slag to the iron salt solution for a co-precipitation reaction; after the co-precipitation reaction is complete, performing solid-liquid separation, washing, and drying to obtain the iron-modified magnesium slag-based amorphous iron hydroxide composite material; wherein the undisturbed magnesium slag serves as an alkali source and silicon source to provide OH... ‑ The active silicate ions and the hydrolysis products of iron salts co-precipitate to form silicon-doped amorphous iron hydroxyl oxide. This invention yields a highly stable amorphous composite material with a specific surface area more than 18 times higher than that of undisturbed magnesium slag, exhibiting both slow alkalinity release and efficient adsorption catalysis.

The present invention provides a method and apparatus for producing iron from an iron ore, together with an option for the onward conversion of that iron into steel. The iron may come from an iron ore in which the iron is present as at least one of the mineral and mineraloid forms of iron oxide and iron oxyhydroxide, such as hematite and limonite, as well as from red bauxite. The invention may also be used to produce elemental iron from other sources of iron oxide, such as from mill scale, whereby sources of waste iron oxide may be recycled. The method comprises comminuting the iron ore into fines, dehydrating the iron ore and dehydroxylating hydroxylated compounds in the ore. The ore thus treated is then reacted with an amount of liquid sodium in excess of the stoichiometric amount thereof required for a redox reaction between the liquid sodium and iron oxide(s) from the ore. This precipitates out from the liquid sodium both elemental iron and other insoluble products at least comprising sodium oxide. The redox reaction is conducted in an inert atmosphere and its temperature is controlled to remain below about 450 °Celsius to inhibit the production of ternary oxides like Na4FeO3. The method then comprises separating the iron from the other insoluble products, for example using magnetic and / or density-based separation, and separating the iron and the other insoluble products as a solid phase from the liquid sodium, in any order. Thus iron can be extracted from iron ore without producing any greenhouse gas emissions, and sodium oxide, which has a high affinity for carbon dioxide, is produced as a co-product. Since the iron is produced as a finely divided particulate, it may subsequently be converted into steel using a powder metallurgical technique with a considerable energy saving over prior art steelmaking techniques. If the sodium oxide is used to mineralize captured carbon dioxide, the invention can have a negative carbon footprint overall. If the iron ore comprises red bauxite, the other insoluble products may also be processed to extract alumina from them without creating environmentally hazardous red mud. In some embodiments, the other insoluble products may be used to produce an alkaline activator for an alkaline activated or geopolymer cement. The corresponding apparatus (3a) comprises a comminution device (2) (such as a rock crusher or grinder), a dryer (4) for dehydrating and dehydroxylating the iron ore, a gas-tight reaction vessel (130) for reacting the treated ore with the liquid sodium, a solid-species separator (180a) for separating the iron from the other insoluble products and a solid-liquid sodium phase separator (190a, 190b).

The application discloses a method for removing salt in papermaking wastewater by using modified double-ion exchange resin. The method comprises the following steps: taking 201x7 hydroxyl type anion exchange resin as raw material, mixing the raw material with a mixed solution of ferric citrate, ethanol and water, and fully reacting under acidic conditions; and loading hydroxyl iron oxide onto the surface of the resin by using a strong alkali solution to obtain modified 201x7 hydroxyl type ion exchange resin. The modified resin has the advantages of increased exchange capacity for sulfate, no introduction of other ions, excellent regeneration effect and no iron ion dissolution. The modified resin and 732 hydrogen type cation exchange resin are combined to effectively remove anions and cations in papermaking wastewater, control the dosage and proportion of the modified resin and the 732 hydrogen type cation exchange resin, control the salt content and pH of the effluent, and the method for combining the modified resin and the 732 hydrogen type cation exchange resin is a new method suitable for desalination of papermaking wastewater, plays an important role in recycling of wastewater, and has great application potential in the field of industrial wastewater desalination.

The invention relates to the technical field of hydrometallurgy and inorganic nano material preparation, and discloses a preparation method of iron oxyhydroxide and a preparation method of iron oxide red. The preparation method of the iron oxyhydroxide comprises the steps that acid leaching slurry is provided, the acid leaching slurry is composed of acid leaching liquid and a second solid material, the acid leaching liquid is a reaction product of an acid solution and a first solid material, and the first solid material and the second solid material are solid raw materials containing nickel and iron; introducing oxygen-containing gas into the acid leaching slurry, controlling the temperature of the acid leaching slurry to be 65-95 DEG C, carrying out oxidation precipitation reaction, stopping introducing the oxygen-containing gas after full reaction, and carrying out solid-liquid separation to obtain filter residues with iron oxyhydroxide as a main component and nickel-containing filtrate. The preparation method of the iron oxide red comprises the preparation method of the iron oxyhydroxide and also comprises the step of preparing the iron oxide red from the prepared iron oxyhydroxide. According to the method provided by the invention, effective separation of iron and nickel can be realized, and high-value recovery of iron is realized.

This invention provides a composite iron phosphate, its preparation method, and its application. The preparation method includes the following steps: (1) mixing an iron salt solution and hydrochloric acid, heating and stirring, adding phosphate, adjusting the pH to obtain a mixed solution, mixing the mixed solution with hydrogen peroxide, and then performing a hydrothermal reaction to obtain a mixture of iron phosphate and iron hydroxide; (2) placing the mixture of iron phosphate and iron hydroxide and sodium hypophosphite in different regions of the same device, and heating the device to obtain the composite iron phosphate. This invention prepares a composite iron phosphate uniformly doped with iron phosphate through a simple hydrothermal method. The lithium iron phosphate cathode material made from the composite iron phosphate has high ionic conductivity, and thus exhibits high cycle stability and rate capacity.

The invention relates to the technical field of sewage treatment, and discloses a composite treatment agent for domestic sewage and a preparation method thereof. The composite treatment agent comprises the following raw materials in parts by weight: 15-25 parts of ferric trichloride, 3-8 parts of polysilicate aluminum ferric, 5-8 parts of polyacrylamide, 4-8 parts of magnesium sulfate, 1-3 parts of sodium hydroxide, 15-20 parts of a modified chelating agent, 20-30 parts of a modified flocculant, 2-6 parts of iron oxyhydroxide, 15-20 parts of bentonite and 10-15 parts of mesoporous silica. The modified chelating agent can efficiently chelate free heavy metal ions such as lead, cadmium and copper in sewage, and secondary pollution caused by diffusion of the heavy metal ions along with effluent is avoided; the modified flocculant can quickly adsorb suspended matters, colloidal particles and soluble organic matters in sewage to form dense and easily-settled flocs, so that the contents of COD (Chemical Oxygen Demand), BOD (Biochemical Oxygen Demand), nitrogen phosphorus and suspended matters in the sewage are effectively reduced.

The invention relates to the technical field of desulfurizing agents, in particular to a ferric oxyhydroxide desulfurizing agent and a preparation method thereof. The invention aims to solve the problems of low particle mechanical strength, high probability of pulverization to cause increase of bed pressure drop and insufficient sulfur capacity release caused by unreasonable pore structure of the existing desulfurizer in deep purification of low-concentration hydrogen sulfide. The preparation method comprises the following steps: by taking ferric nitrate as an iron source, generating iron oxyhydroxide slurry through urea hydrolysis reaction, and constructing a surface anchoring site through complexing modification of sodium citrate; introducing cetyltrimethylammonium bromide and sodium salicylate micelle templates to directionally construct mesopores; kneading and forming, spraying a salt solution, wetting, heating and aging to strengthen the compactness of the surface layer, and finally treating with hydrogen peroxide to remove the template. The obtained desulfurizer has the advantages of high mechanical strength, low wear rate, excellent mesoporous structure and long low-concentration penetration life, and is suitable for low-concentration long-period scenes such as urban gas purification.

The invention relates to a carbonate intercalated core-shell structured electrolytic seawater catalyst as well as a preparation method and application thereof. A preparation method of a carbonate intercalation core-shell structure electrolytic seawater catalyst comprises the following steps: (1) immersing pretreated foamed nickel into an aqueous solution containing cobalt salt, urea and ammonium fluoride, and growing a basic cobalt carbonate nanowire array containing a carbonate intercalation on the surface of the foamed nickel through a hydrothermal reaction; and (2) by taking the basic cobalt carbonate nanowire array as a working electrode, coating the surface of the basic cobalt carbonate nanowire with an iron oxyhydroxide layer through electrochemical deposition in a ferrite solution to obtain the seawater electrolysis catalyst. According to the carbonate intercalated core-shell structured electrolytic seawater catalyst and the preparation method and application thereof, the prepared electrolytic seawater catalyst is of a core-shell heterostructure, and the iron oxyhydroxide shell effectively inhibits release of carbonate, so that the catalyst keeps long-term chlorine corrosion resistance.

This invention relates to the field of wastewater treatment materials technology, and discloses a bio-iron sulfide composite packing material, its preparation method, and its application. The raw materials for preparing the bio-iron sulfide composite packing material of this invention include limestone gravel, iron hydroxyl oxide, nutrient solution I, and sulfate-reduced sludge; wherein the limestone gravel contains 70%–80% limestone by mass. This composite packing material not only has a simple preparation process, low cost, and readily available raw materials, but also allows the immobilized and adsorbed sulfate to be recycled in the secondary bio-sulfidation stage, achieving sulfur recycling and effectively avoiding secondary pollution problems caused by excessive sulfate production.

The invention relates to a preparation method of a homogeneous-phase ferronickel-based oxygen evolution reaction catalyst based on a microcell. The method comprises the following steps: soaking a nickel-based metal substrate in an iron salt solution, and generating iron oxyhydroxide on the surface of the nickel-based metal substrate to construct a micro-area primary battery; the nickel-based metal substrate soaked in the ferric salt solution is placed in a mixed solution containing a chelating agent, nickel salt and ferric salt, the nickel-based metal substrate is taken out and dried after heating reaction, and the nickel-iron-based oxygen evolution reaction catalyst with the uniform phase is obtained. According to the preparation method, ferric iron hydroxide nanoparticles are generated in situ on a nickel-based metal substrate through hydrolysis of ferric iron salt, a micro-area primary battery system is constructed, the hydrolysis rate of the ferric iron salt is accurately regulated and controlled through a chelating agent, nickel substrate etching and NiFe hydroxide catalyst generation are synchronously achieved, an oxygen evolution reaction (OER) catalyst which is uniform in phase, high in activity and high in stability is synthesized, and the preparation method has the advantages of being simple in process, low in cost and the like. And a low-cost and green preparation scheme is provided for efficient hydrogen production by water electrolysis.

This invention discloses a method for preparing α-ferric oxide using the directional conversion of γ-hydroxy iron oxide, belonging to the field of iron oxide material preparation technology. This invention uses γ-FeOOH with a crystallinity ≥70% as raw material, and through Fe... 2+ The precise and coordinated control of concentration, pH, and reaction temperature enables the directional conversion of high-crystallinity γ-FeOOH to pure-phase α-Fe2O3 over a wide pH and temperature range. After the reaction, α-Fe2O3 product is obtained through solid-liquid separation. When the parameters exceed the limits defined in this invention or are not synergistically matched, α-FeOOH and / or Fe3O4 impurities and byproducts are easily generated. This method is suitable for high-crystallinity industrial byproducts of γ-FeOOH, eliminating the need for additional preparation of low-crystallinity precursors, reducing the consumption of alkaline reagents and the generation of high-salt wastewater. It has advantages such as simple process, environmental friendliness, no secondary pollution, and suitability for industrial implementation.

The invention provides a method and a device for deeply removing dissolved aluminum in water, and belongs to the technical field of water treatment. The method for deeply removing the dissolved aluminum in the water comprises the following steps: filling a filter material into a filter column, and enabling the inlet water to pass through the filter material so as to remove the dissolved aluminum in the inlet water; wherein the filter material comprises manganese oxide, and optionally comprises any one of iron oxide, iron oxyhydroxide and quartz sand; wherein in the presence of any one of the iron oxide, the iron oxyhydroxide and the quartz sand, the manganese oxide, the iron oxide, the iron oxyhydroxide or the quartz sand are arranged in a layered manner or in a mixture manner.