472results about "Ferric oxides" patented technology

The invention discloses a method for comprehensively recovering valuable elements from a waste lithium iron phosphate battery material. The method comprises the following steps: carrying out alkali leaching on black powder and / or pole piece materials of the waste lithium iron phosphate batteries, and then carrying out solid-liquid separation to obtain alkali leaching residues and an alkali leaching solution; carrying out acid leaching on the alkaline leaching residues, and then carrying out solid-liquid separation to obtain an iron oxide powder product and an acid leaching solution; the alkali leaching liquid is cooled and crystallized to obtain a sodium phosphate product and crystallization mother liquor, and the crystallization mother liquor can be circularly used for the alkali leaching process; adjusting the pH value of the acid leaching solution, precipitating and separating to obtain a lithium phosphate product and a lithium precipitation mother solution, wherein the lithium precipitation mother solution can be used for preparing a sodium sulfate product. The method can effectively separate iron, phosphorus and lithium products, and is high in recovery rate, simple, short in process, low in cost and suitable for industrial application.

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 discloses a Fe-Beta molecular sieve for N2O catalytic decomposition and a preparation method of the Fe-Beta molecular sieve. According to the method, chitosan and metal Fe < 3 + > ions are complexed to form a chitosan Fe < 3 + > complex, and then the complex, a silicon source, an aluminum source and a template agent are used as raw materials to prepare the Fe-Beta molecular sieve in one step through a hydrothermal method. Hydroxyl, amino and other groups rich in a chitosan molecular chain can effectively complex metal Fe < 3 + > ions to form a stable chitosan Fe < 3 + > complex, and the stable chitosan Fe < 3 + > complex is used as a Fe source to realize uniform dispersion of Fe species in the molecular sieve and effectively reduce formation of FexOy clusters and Fe2O3 nanoparticles, so that the N2O decomposition catalytic performance of the Fe-Beta molecular sieve is improved. Inorganic alkali metal ions are not introduced, so that a large amount of ammonia-nitrogen wastewater generated in a subsequent tedious ammonium exchange process can be avoided, the synthesis period is effectively shortened, and energy consumption, material consumption and environmental pollution are reduced.

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.

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 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 provides a graphene-based hydrogen sulfide gas sensor and a preparation method thereof, and relates to the technical field of gas sensors. The preparation method of the graphene-based hydrogen sulfide gas sensor comprises the following steps: soaking the wood substrate in a mixed metal salt solution containing a water-soluble silver salt and a water-soluble transition metal salt; irradiating the soaked wood substrate by using a laser beam at room temperature under the condition of no shielding gas, so that lignin and cellulose in the wood substrate are cracked and reconstructed to form graphene; meanwhile, the mixed metal salt immersed in the wood substrate is decomposed to form bimetallic oxide nanoparticles including silver oxide nanoparticles and transition metal oxide nanoparticles, and the bimetallic oxide nanoparticles are dispersed on the surface of each layer of graphene to obtain a sensitive layer; and coating conductive materials on the wooden substrate and on the two sides of the sensitive layer to form a connecting electrode in contact with the sensitive layer, thereby obtaining the graphene-based hydrogen sulfide gas sensor.

4, 4 '-bipyridine (Bpy), 2, 5-thiophenedicarboxylic acid (Tdc), FeCl3. 6H2O, NiCl2. 6H2O, urea and tetrabutylammonium bromide are used as raw materials, a simple hydrothermal-calcination method is adopted to prepare the Fe2O3-coated Ni-MOF composite nanomaterial catalyst, X-ray diffraction (XRD), a scanning electron microscope (SEM) and a N2 adsorption and desorption technology are adopted to characterize a prepared sample, and the electro-catalytic oxygen evolution reaction (OER) activity of the Fe2O3-coated Ni-MOF composite nanomaterial catalyst is tested. Results show that compared with a single component, the activity of the composite nano-material catalyst is greatly improved, especially the composition-optimized Fe2O3-coated Ni-MOF-1 composite nano-material catalyst shows the highest catalytic activity, the composite nano-material catalyst catalyzes OER in 1M KOH, and the overpotential (eta 10) is only 330mV when the current density is 10mA / cm < 2 > and is close to the overpotential 291mV of a noble metal catalyst RuO2.

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 spodumene concentrate resourceful treatment method which comprises the following steps: carrying out wet treatment on spodumene acid clinker to prepare lithium-removed filter residues and leachate; carrying out neutralization treatment and desulfurization treatment on the leachate to obtain a lithium-containing purified solution, gypsum and iron oxide red, and carrying out lithium extraction treatment on the lithium-containing purified solution to obtain a lithium salt and mirabilite; the lithium-removed filter residues are treated through a process combining a beneficiation method and a chemical method, and water glass, nano kaolinite, ceramsite aggregate and tantalum-niobium concentrate are obtained. According to the method, whole-process slag-free production of the spodumene concentrate is achieved, and meanwhile the lithium-containing compound with the high purity and the high quality is obtained; and various valuable products can be obtained.

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 a striker type micro-nano robot for cell membrane breakthrough and a preparation process of the striker type micro-nano robot, in particular to a striker type micro-nano robot driving control method based on a photomagnetic coupling field and a rotary blasting type cell membrane breakthrough method. The invention discloses a striker type micro-nano robot for cell membrane breakthrough. The striker type micro-nano robot consists of a magnetic iron oxide core and a silicon dioxide needle handle, wherein the surface of one side of the magnetic iron oxide core is coated with a gold layer. The invention discloses a preparation process of a firing pin type micro-nano robot. The preparation process of the firing pin type micro-nano robot comprises the steps of sol-gel core preparation, magnetron sputtering and chemical precipitation needle handle preparation. Under the cooperative driving of an external magnetic field and a near-infrared light field, rotary blasting type breakthrough can be performed on a mononuclear membrane through the tip end of the needle handle.

A method and equipment for recycling alumina red mud. First, the alumina red mud is added to a mixed acid of hydrochloric acid and sulfuric acid for reaction to dissolve metals such as iron, aluminum, calcium, sodium, and a small amount of zinc, copper, magnesium, etc., and the solid silicon dioxide is left to be separated as building materials or glass raw materials; after the solution is collected, ammonium bicarbonate is added to obtain aluminum, calcium, and some metal precipitates and separated. Iron and sodium remain in the solution and continue to react with sodium hydroxide to obtain iron hydroxide precipitate and separate out sodium salts. After evaporation of the concentrated solution, iron oxide is obtained as a raw material for steel production; the aluminum, calcium, and other metal precipitates are added to sulfuric acid with a concentration of 90-98% for reaction. After all are dissolved, the solution is subjected to membrane separation and then carbonates are added to obtain calcium carbonate precipitate as a raw material for cement production; after evaporation of the concentrated solution, high-purity alumina is obtained and sent to an aluminum processing plant to produce pure aluminum or aluminum alloy products; the separated sodium salt solution is evaporated to be used as industrial and agricultural salt; the acid mist and harmful gases in the reactor process are treated by an absorption tower and then discharged. The present invention can make full use of the iron oxide, alumina, and effective components of alumina red mud, solves the problem of environmental pollution caused by the large amount of piled-up alumina red mud at present, has a low cost, and is suitable for the current alumina production plants.

The invention belongs to the technical field of lithium batteries, and particularly relates to a preparation method of a positive electrode material, the positive electrode material, a positive electrode plate, a battery and an electric device. The method comprises the following steps: mixing nitrate and a precursor in a solvent, and roasting to obtain the positive electrode material, wherein the precursor comprises LiFe (1-y) MyPO4, M comprises one or more metal elements in IVB family, VB family, VIII family, IIA family, IIIA family, IVA family and VA family, and y is 0-0.1. According to the method, the electronic conductivity of the positive electrode material is improved, and the specific capacity and cycling stability of the battery are improved.

The invention provides an oxidation intermediate and application thereof. The oxidation intermediate is obtained by oxidizing and calcining a waste lithium iron phosphate positive electrode material; primary particles (D90-D10) / D50 in the oxidation intermediate are less than or equal to 3. According to the method, the oxidation intermediate with specific particle size distribution is obtained by oxidizing and calcining the waste lithium iron phosphate positive electrode material, the sizes of particles in the oxidation intermediate are relatively consistent, and relatively high compaction density can be realized when the oxidation intermediate and other small-particle materials form size grading. On the basis that the oxidation intermediate and an iron source with small granularity are ground, large and small particles are compounded, the compaction density and the battery energy density of the recycled lithium iron phosphate positive electrode material are greatly improved, and double excellent effects are achieved.

The invention discloses lithium sulfide and a preparation method thereof. The preparation method comprises the following steps: (1) carrying out ball-milling mixing on iron powder, sodium sulfide and lithium sulfate in a first inert atmosphere to obtain a mixture; (2) calcining the mixture in a second inert atmosphere for the first time to obtain a reaction material; (3) stirring and washing the reaction material with an alcohol solvent in a third inert atmosphere, filtering to obtain filtrate and a filter cake, performing reduced pressure distillation on the filtrate to obtain a lithium sulfide crude product, washing the filter cake with deionized water, and filtering to obtain a solid by-product; and (4) carrying out secondary calcination on the lithium sulfide crude product in a fourth inert atmosphere to obtain lithium sulfide. The preparation method provided by the invention has the advantages of few synthesis steps, simple product purification and environmental protection.

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 provides a method for extracting gallium and iron from neodymium iron boron waste, which is a method for efficiently extracting gallium and recovering iron from hydrochloric acid leachate of the neodymium iron boron waste based on a solvent extraction method. The method is short in technological process and good in separation effect, compared with the prior art, the dosage of reagents such as alkali liquor is obviously reduced, generation of waste residues is reduced, additional reagents such as an iron masking agent and a reducing agent do not need to be used, the follow-up recovery process is prevented from being complicated, and the recovery rate and purity of gallium and iron are greatly improved. The method can be directly and effectively combined with an existing process for recycling rare earth elements from waste neodymium iron boron, is stable in process and low in cost, and is a gallium extraction process with a very promising prospect.

The invention introduces a method for preparing artificial rutile by using reduced ilmenite, which comprises the following steps: S1, adding reduced ilmenite into a corrosion tank, introducing oxidizing gas to carry out corrosion reaction, and washing and separating the reaction product through a cyclone and a high-frequency sieve to obtain primary artificial rutile and hydrated iron oxide slurry; s2, carrying out filter pressing on the hydrated iron oxide slurry obtained in the step S1 by using a filter press, and preparing refined iron oxide from the obtained iron oxide slurry; s3, the primary artificial rutile obtained in the step S1 is washed and then subjected to a hydrochloric acid leaching reaction, a mixed material obtained after acid leaching enters a thickener, and supernatant returns to prepare an acid leaching solution; feeding lower-layer ore grains into a belt filter for deacidification and washing; and S4, drying the cleaned primary artificial rutile obtained in the step S3 through a drying cylinder to obtain the finished artificial rutile. Industrial hydrochloric acid is used as a rusting agent, and compared with ammonium chloride, the product Fe (OH) 3 can be separated more easily. Oxidizing gas used for rusting is mixed gas of air and pure oxygen, and the mixing proportion of the air and the pure oxygen can be dynamically adjusted according to different rusting raw materials, so that the reaction condition is in an optimal state. In the corrosion and acid leaching processes, the recycling efficiency of the liquid raw material is extremely high, and the prepared artificial rutile meets the requirements of a chlorination process titanium dioxide raw material. The whole process flow is reasonable in design, simple to operate, free of environmental pollution and easy for industrial production.

Systems and methods for generating hydrogen through serpentinization of iron-bearing rock, including mafic rock, ultramafic rock and banded iron formations is presented herein. The systems and methods use geothermally-heated and / or surface-heated fluid circulating through one or more fluidically-communicative wellbores to accelerate the production of hydrogen. A geothermal-injector wellbore is formed in a geothermal rock layer, and is communicative with a separate geothermal-collection wellbore, also formed in the geothermal layer. Fluid is pumped through the geothermal-injector wellbore, geothermally heated, collected by the geothermal-collection wellbore, and injected into a targeted rock layer that includes iron-bearing rock. The heated fluid increases the rate of hydrogen production though serpentinization of the rock, which is then collected through a separate producer wellbore. In some cases, a serpentinization-injector wellbore is used to circulate surface-heated and / or chemically-treated fluid to the targeted rock layer to accelerate hydrogen production.

The present invention provides a method of producing hydrochloric acid, comprising reacting high-temperature gaseous chlorine and water vapour in a carbon-free reverse Deacon reaction (RDR) at a temperature of from about 450 to about 750 °Celsius to produce a mixture of gases comprising hydrogen chloride and oxygen. The chlorine is produced by fusing and electrolysing sodium or magnesium chloride in solid phase. The water vapour comes from thermally decomposing a hydroxide of at least one of calcium, magnesium and iron in the absence of oxygen to produce the water vapour without any admixture of oxygen (e.g., from atmospheric air). The mixture of gases produced by the RDR is immediately contacted with liquid water to dissolve the hydrogen chloride therein, thereby producing hydrochloric acid and a stream of tail gases. Heat is extracted from the hydrochloric acid to maintain its temperature substantially constant until the stream of tail gases is no longer in contact therewith. Thus the chlorine and water vapour are both supplied to the RDR at high purity and require little, if any, preheating. Heat extracted from contacting the mixture of gases with liquid water may be used to keep the RDR within its range of operating temperatures. Oxygen can be separated from the stream of tail gases, and the oxygen-depleted stream can be recycled back to the RDR to give a high percentage conversion of chlorine to hydrogen chloride. The RDR may be uncatalysed and kept within its operating temperature range by radio-frequency volumetric heating in at least one of the IEEE Ku-, K- and Ka-bands. The invention also provides a corresponding apparatus (1h) for producing hydrochloric acid, comprising an electrolytic cell (10) for the electrolysis, a gas-tight kiln (20) for the thermal decomposition, a gas-phase reactor (30) for the RDR, and an absorber (40) for dissolving the hydrogen chloride in the liquid water. The apparatus (1h) may further comprise a separator (80) for separating the stream of tail gases into the oxygen-depleted stream and a stream of oxygen, which may be fed to a steelmaking apparatus (90), for example. The liquid water for dissolving the hydrogen chloride can come from condensing water vapour obtained by drying an aqueous solution of sodium or magnesium chloride or of sodium hydroxide. The apparatus (1h) may therefore also comprise a dryer (60) for drying this aqueous solution, and a condenser (70) for condensing the water vapour thus obtained. Sodium chloride or magnesium chloride in solid phase derived from drying the aqueous solution may be recycled back to the electrolytic cell (10). Electricity for the electrolysis can come from a renewable resource. At least some of the heat for the thermal decomposition may come from the liquid metal which is a co-product of the electrolysis. The invention is therefore highly energy efficient and requires little, if any, extra energy, apart from the electricity required for the electrolysis. The invention also uses commonly available ingredients and produces no greenhouse gases.

The application discloses an oxygen reduction catalyst and a preparation method and application thereof. The preparation method of the oxygen reduction catalyst comprises the following steps: S1: mixing mycelia of filamentous fungi, ferrocene and a nitrogen source, and performing first calcination to obtain a mixture A; and S2: mixing the mixture A and a ZnCl2 solution, and performing activation and carbonization reaction to obtain the oxygen reduction catalyst. The preparation method can realize environmental management through waste recycling, and has the advantages of easy preparation of raw materials, low cost, simple preparation method, and suitability for large-scale preparation and application. Meanwhile, the oxygen reduction catalyst has the advantages of obvious three-dimensional porous structure, large specific surface area, rich active sites, good catalytic activity and stability.

The invention discloses a method and equipment for in-situ synthesis of food-grade nano iron oxide from a donkey-hide gelatin medium, and the method comprises the following steps: dissolving enzymolysis donkey-hide gelatin peptide at 75-82 DEG C by using an interlayer heating type gelatin boiling tank to form a reaction medium, applying 40-60kHz ultrasonic waves through a piezoelectric ceramic ultrasonic vibrator array integrated at the bottom of the tank, and generating a 0.3-0.5 T magnetic field through a Helmholtz coil surrounding the tank, the uniform dispersion and directional crystallization of Fe < 3 + > / Fe < 2 + > (the molar ratio is 2: 1) in a donkey-hide gelatin matrix are synergistically promoted; the preparation method comprises the following steps: accurately regulating the pH value to 8.5-9.5 by utilizing an ammonia water pulse quantitative injection device, combining citric acid-ascorbic acid dual modification, and finally carrying out magnetic separation, ceramic membrane filtration and freeze drying to obtain the high-purity beta-cyclodextrin with the average particle size of 38.5 + / -4.2 nm (PDilt; 0.2) of nano iron oxide; the bioavailability is more than two times that of a traditional iron agent, and no organic solvent is left; according to the method, safe, efficient and large-scale preparation of the nano iron oxide is realized through equipment-process collaborative innovation.

The application discloses a kind of iron oxide / nickel ferrite composite nanorods and synthesis method thereof, belong to nanometer material technical field.The obtained composite nanorod is polycrystalline structure, and is composed of rhombohedral Fe2O3 and cubic NiFe2O4 crystal phase.The diameter of the composite nanorod is 10-100nm, and the length is greater than 500nm.The synthesis method is that iron acetate and nickel acetate are dissolved in deionized water, heated to temperature 80-100 DEG C, and kept for 1-5h, and iron oxide / nickel ferrite precursor is obtained after cooling and drying;iron oxide / nickel ferrite precursor is mixed with calcium chloride and sodium chloride, then the mixture is loaded into corundum crucible, the crucible is placed in reaction furnace, at temperature 800-1000 DEG C, and kept for 5-10h.The synthesis process of the application is simple, does not need complex equipment, and is easy to control.Iron oxide / nickel ferrite composite nanorod has a large number of catalytic active sites, and is expected to have good interface performance, catalytic activity, electrical and magnetic properties, and has good application prospect in catalysts, electrical devices and magnetic devices.

This invention belongs to the field of lithium-ion battery technology, specifically relating to a composite cathode material for lithium-ion batteries and its preparation method. The composite cathode material consists of three parts: a cathode matrix material, a lithium replenishment material, and a catalyst material. The preparation method is as follows: (1) preparing a composite material of the cathode matrix material and the lithium replenishment material in situ; (2) dispersing the catalyst material on the surface of the composite material and forming a stable interface layer between the catalyst material and the lithium replenishment material. Through the method of this invention: the lithium replenishment material has both surface modification of the cathode matrix material and lithium replenishment of the negative electrode, simultaneously improving the battery's initial efficiency and cycle stability; introducing the catalyst material onto the surface of the lithium replenishment material in situ fixes the free O generated by the Li release from the lithium replenishment material, alleviating the battery swelling phenomenon and further improving the battery's cycle stability and safety; moreover, the preparation process is simple, the raw materials are cheap and readily available, the production cost is low, and it is easy to promote industrial production.

The invention relates to the technical field of lithium ion batteries, and discloses a lithium supplement agent precursor and a preparation method thereof, a lithium supplement agent, a lithium ion battery and electric equipment. The chemical formula of the lithium supplementing agent precursor is Fe2-x-yAlxMeyO3 + / -delta, the value of x, the value of y and the value of delta enable the chemical formula to keep valence equilibrium, x is larger than or equal to 0 and smaller than or equal to 0.4, y is larger than or equal to 0 and smaller than or equal to 0.1, and Me is selected from at least one of Ni, Co, Cr, Mn, Ti and Zr. After the lithium supplement agent precursor is mixed with lithium and sintered into the lithium supplement agent, the morphology has inheritance, the mechanical strength is higher than that of an irregular morphology, the specific surface area of the lithium supplement agent can be reduced, the side reaction with an electrolyte is reduced, the cycle performance of a battery is improved, the compaction density of the material can be improved, and the service life of the battery is prolonged. And the material has a good application prospect in lithium ion batteries.

The invention discloses a preparation method and application of a Fe2O3 catalyst, and the preparation method of the Fe2O3 catalyst comprises the following steps: (1) dissolving a first ferric salt and a second ferric salt in water to form a solution, adding an organic solvent, adding alkali to adjust the pH value to 8-10, and placing at 150-170 DEG C for hydrothermal reaction; and (2) separating the solid in the step (1), and calcining the solid intermediate at 490-510 DEG C to obtain the Fe2O3 catalyst. According to the invention, two iron salts are adopted to form a precursor with a specific structure in a high-temperature and high-pressure water-organic solvent environment, and then the precursor is calcined at a specific temperature to obtain the Fe2O3 catalyst with high medium and low temperature activity and a wider active temperature window, and the Fe2O3 catalyst is suitable for flue gas denitration of glass furnaces, cement furnaces and the like.

The invention discloses a method for recycling and regenerating a positive electrode material of a waste lithium iron phosphate battery, and relates to the technical field of positive electrode materials of lithium iron phosphate batteries. When the lithium iron phosphate battery positive electrode material is prepared, recycled lithium carbonate, recycled iron oxide red, ammonium dihydrogen phosphate, lithium fluoride, cerium nitrate hexahydrate, lanthanum nitrate hexahydrate and glucose are mixed and calcined to prepare doped modified lithium iron phosphate; coating the surface of the doped modified lithium iron phosphate with polyaniline to prepare polyaniline-coated lithium iron phosphate; and mixing the polyaniline-coated lithium iron phosphate, a conductive agent and a binder, and coating an aluminum foil with the mixture to prepare the positive electrode material of the lithium iron phosphate battery. The lithium iron phosphate battery positive electrode material prepared by the invention has good cycle performance.

The invention discloses a method and a system for separating and recovering phosphorus and iron in a phosphorus-containing iron compound, and relates to the technical field of solid waste utilization. The method comprises the following steps: obtaining a crushed phosphorus-containing iron compound and a solid alkaline substance; the crushed ferrophosphorus-containing compound and the crushed solid alkaline substance are taken and placed in a reaction furnace, the ferrophosphorus-containing compound and the solid alkaline substance are fused and react to obtain a first mixed material, and the dosage of the solid alkaline substance is 1-1.2 times of the theoretical molar dosage; adding water into the first mixed material for leaching to obtain a first solid-liquid mixture, and performing solid-liquid separation on the first solid-liquid mixture to obtain a first filter cake and first filtrate; washing and drying the first filter cake to obtain a ferric oxide product; evaporating, concentrating, crystallizing and drying the first filtrate to obtain a phosphate finished product. The method provided by the invention has the advantages of environmental protection and high product quality.

This invention belongs to the field of aerogel technology, and relates to a silicon-based aerogel composite material, its preparation method, and its application. The preparation method of the silicon-based aerogel composite material is as follows: An active component precursor is added to a solvent and stirred until homogeneous, forming an active component precursor solution; ethanol and acid are added to the silicon-based precursor, stirred until homogeneous, and cooled to room temperature to form a silicon-based precursor solution; the active component precursor solution is added to form a precursor-silica sol mixed solution; an alkaline solution is added and stirred until homogeneous, forming a mixed solution; a stepped hot melt-gel treatment is performed, followed by standing to form a silicon-based composite wet gel; solvent replacement and drying yield silicon; the stepped hot melt-gel reaction includes 2-5 temperature stages, each lasting 10-80 minutes at 50-100°C. This invention employs a controllable stepped hot melt-gel process to obtain a silicon-based aerogel composite material with both high specific surface area and excellent mechanical properties.