291 results about "Ferrous salts" patented technology

The preparation method comprises the following steps: S1, preparing a phosphoric acid solution, a hydrogen peroxide solution, a Ti salt, a phosphor salt solution and a ferrite solution; s2, Ti salt and the ferrite solution are mixed, and a titanium iron salt solution is obtained; mixing the phosphoric acid solution and the phosphorus salt solution to obtain a phosphorus source solution; s3, adding the titanium iron salt solution into a reaction kettle, and adding the hydrogen peroxide solution; s4, adding the phosphorus salt solution into the reaction kettle to obtain yellow slurry; s5, after the color of the slurry is heated to be white, white slurry is obtained; s6, carrying out solid-liquid separation on the white slurry to obtain an iron phosphate dihydrate filter cake; and S7, drying and calcining the iron phosphate dihydrate filter cake to obtain the Ti-doped battery-grade anhydrous iron phosphate. The titanium-doped iron phosphate is firstly prepared by a one-step method, the pH value of the reaction system is controlled by controlling the molar ratio of the iron element to all phosphorus elements in total phosphorus, ammonium phosphate and phosphoric acid in the reaction system, and the retention of the Ti element in the finished product and the regulation and control of the iron-phosphorus ratio in a specified range are ensured.

The present invention relates to the technical field of ORR catalyst preparation, and in particular to an iron-nitrogen-carbon catalyst and its preparation method and application. The present invention provides a method for preparing an iron-nitrogen-carbon catalyst, characterized in that it comprises: dispersing a zinc salt and a ferrous salt in methanol to obtain a mixed solution A; under heating conditions, dispersing 2-methylimidazole and 1,4-terephthalonitrile in methanol to obtain a mixed solution B; stirring and mixing the mixed solution A and the mixed solution B to obtain a precursor powder, and calcining the precursor powder under an inert atmosphere to obtain an iron-nitrogen-carbon catalyst with a hierarchical porous structure. The present invention provides a new preparation method for preparing an iron-nitrogen-carbon catalyst with a hierarchical pore structure, which prepares the iron-nitrogen-carbon catalyst with a hierarchical pore structure by introducing a 1,4-terephthalonitrile molecular template.

The invention provides an oxytetracycline-containing organic pyrite micron column and a synthesis method thereof, the oxytetracycline-containing organic pyrite micron column is prepared by preparing a solution containing potassium salt and oxytetracycline, adding ferrous salt and KFeS2 and reacting under stirring, an organic pyrite material is synthesized under a mild condition, the morphology is uniform, and the preparation method is simple. The organic sulfur iron micron column shows the reduction coordination characteristic of an oxytetracycline-Fe / S ligand, the performance stability of a Fe / S structural material is enhanced, the applicable pH range is wide, and the complexing breaking and chromium removal efficiency on organic chromium under the action of an electric field is remarkably enhanced.

The present solution provides a preparation method for a three-dimensional structured ferrous phosphate pigment with corrosion early warning capability, including following steps: preparing a ferrous ion-containing solution for providing ferrous ions, where the ferrous ion-containing solution includes a soluble ferrous salt and a surfactant but no oxidizing ions, and the ferrous ion-containing solution is maintained in an acidic environment; preparing an initial mixed solution for providing phosphate ions and ammonium ions; and performing ultrasonic refinement, heating, and holding on the intermediate mixed solution using an auxiliary device with ultrasonic oscillation and microwave heating functions to obtain a final mixed solution; and filtering out precipitates from the final mixed solution, and then transferring the precipitates to a vacuum environment for high-temperature heating treatment to obtain a three-dimensional structured ferrous phosphate pigment with corrosion early warning capability.

The invention relates to a nickel-iron layered double hydroxide with flaky nanoflower morphology and a preparation method and application thereof. The preparation method of the nickel-iron layered double hydroxide comprises the following steps: S1, dissolving nickel acetate in an organic solvent or a mixed solvent of the organic solvent and water to prepare a first solution; dissolving ferrite in water to prepare a second solution; and S2, uniformly mixing the first solution and the second solution to obtain a mixed solution, and standing and aging to obtain the ferronickel layered double hydroxide. The method is simple to operate, mild in reaction condition, low in equipment cost and green and environment-friendly in synthesis process; the NiFe-LDH prepared by the method is of a three-dimensional nanoflower structure, is uniform in morphology, has a high specific surface area, can provide more active sites, shows excellent electro-catalytic performance when being used as a catalyst for oxygen evolution by electrolysis of water, and has a wide application prospect in the fields of electrochemical energy storage, electro-catalysis, catalytic oxidation and the like.

The present disclosure provides a method for preparing lithium iron phosphate and use thereof. The method comprises: adding a mixed solution of ferrous salt and ammonium dihydrogen phosphate, a citric acid solution and a pH adjusting agent in parallel into a first reactor for reaction, and simultaneously extracting the materials in the first reactor to a second reactor, and adding a copper salt solution and a sodium hydroxide solution to the second reactor for reaction, and refluxing the materials in the second reactor into the first reactor, mixing the solid material obtained in the reaction with a lithium source, and calcining the mixture in an ammonia gas stream to obtain lithium iron phosphate. This method can prepare a lithium iron phosphate precursor with a spherical structure, thereby improving the electrochemical performance of the subsequently prepared lithium iron phosphate material, which has a relatively high conductivity.

The invention discloses a vanadium iron-site doped iron phosphate material and a preparation method, and relates to the technical field of lithium ion battery positive electrode material preparation, pure water is used as a base solution, and a vanadium salt solution with the pH value of 2.0-3.0, a ferrite solution with the pH value of 1.0-2.5 and a phosphorus-oxygen mixed solution with the pH value of 5.0-7.0 are simultaneously added into a reaction kettle in a three-strand parallel flow mode for a co-precipitation reaction. By controlling the acid environment of a key solution system, reduction of metavanadate radicals or generation of ferric vanadate precipitates is effectively inhibited, and vanadium elements are successfully and uniformly doped to iron sites of iron phosphate crystal lattices; the mass ratio of iron to phosphorus in the obtained iron phosphate material is stabilized at 95-98%, the doping amount of vanadium is 100-10000 ppm, and the vanadium is uniformly distributed. Lithium iron phosphate prepared by taking the material as a precursor has higher discharge capacity and compaction density, and the electrochemical performance of a lithium ion battery is remarkably improved.

The invention provides continuous wastewater treatment equipment, which belongs to the technical field of wastewater treatment, and comprises a treatment tank and an observation window arranged in the middle of the treatment tank, and further comprises a multi-stage treatment assembly, a pollution discharge purification assembly and a stripping assembly, deep purification of the wastewater is realized through multi-stage treatment; the vertical spraying is combined with the stirring of the fan blades and the scrapers, strong water flow scouring force is formed above the elastic filter plate, meanwhile, the convex plates periodically extrude the elastic filter plate during rotation to enable the elastic filter plate to vibrate, suspended particles and impurities can be effectively prevented from being accumulated on the surface of the elastic filter plate, the risk of filter plate blockage is reduced, and meanwhile, the service life of the filter plate is prolonged. Ferric hydroxide colloid generated by ferrite reaction can more uniformly adsorb suspended particles under the driving of upper and lower water flows, and the precipitation separation of the suspended particles is accelerated; the connecting shaft rotates to drive the mounting cylinder, the arc-shaped groove of the trigger cavity is matched with the ball, the oxidation disc vibrates, the vibration strength is adjusted according to the descending amplitude of the oxidation disc, and the overall wastewater treatment efficiency is improved.

The present invention relates to a nickel-iron layered double hydroxide having a flaky nanoflower morphology and its preparation method and application. The preparation method of the nickel-iron layered double hydroxide comprises the following steps: S1, dissolving nickel acetate in an organic solvent or a mixed solvent of an organic solvent and water to prepare a first solution; dissolving a ferrous salt in water to prepare a second solution; S2, mixing the first solution and the second solution to obtain a mixed solution, and obtaining the nickel-iron layered double hydroxide through standing and aging. The method is simple to operate, has mild reaction conditions, low equipment cost, and a green synthesis process; and the NiFe-LDH prepared by the above method presents a three-dimensional nanoflower structure with uniform morphology and high specific surface area, which can provide more active sites. It exhibits excellent electrocatalytic performance as a catalyst for electrolysis of water and oxygen evolution, and has broad application prospects in the fields of electrochemical energy storage, electrocatalysis, and catalytic oxidation.

The invention provides a sodium-rich ferric sodium pyrophosphate positive electrode precursor and a preparation method and application thereof.The preparation method comprises the following steps that a ferrite solution, a phosphoric acid source solution, a pyrophosphoric acid source solution, an alkaline solution and a sodium persulfate solution are injected into a base solution in a parallel flow mode for a co-precipitation reaction, the sodium-rich ferric sodium pyrophosphate positive electrode precursor is obtained; wherein the base solution is pure water. The method disclosed by the invention is simple to operate, the sodium-rich ferric sodium pyrophosphate positive electrode precursor with high sodium content, uniform element distribution and uniform phase can be prepared, the sodium-rich ferric sodium pyrophosphate positive electrode precursor is low in gas production rate in the subsequent sintering process, and the sodium-rich ferric sodium pyrophosphate positive electrode material with high compaction density can be prepared.

The invention belongs to the technical field of adsorbents, and discloses a core-shell structure composite material as well as a preparation method and application thereof. Ferroferric oxide is loaded on biochar by coprecipitation of ferric salt, ferrous salt and biochar, amination modification is performed by using polyethyleneimine, and a COF shell layer is prepared in situ by using a magnetic core. The shell layer is chemically connected with the magnetic core, and is coated by the COF shell, so that the structural stability is improved, the porous structure of the biochar is not easy to collapse, and the magnetic particles are not easy to fall off; the shell contains sulfonic acid groups, has electronegativity, and is combined with metal ions through electrostatic interaction, so that the adsorption sites of the adsorbent are increased. Meanwhile, the COF shell is of a porous structure, the specific surface area is large, the COF shell has the adsorption effect on metal ions, more adsorption sites are provided for the metal ions through the multiple adsorption effects of the COF shell and the magnetic core, and the removal rate is effectively increased.

The invention discloses a treatment method of an electrolyte after wet crushing of a waste lithium ion battery. During crushing, an alkaline solution is sprayed out of a spraying opening located above a shearing opening to completely cover the waste lithium ion battery crushed material, a hydrolysis reaction is carried out under the cooperation of ultrasonic waves, and waste water, a pole piece mixture, a shell pile head, a diaphragm and the like are separated out through hydrodynamic force. The method comprises the following steps: adding dilute acid into wastewater to adjust the pH value, adding bivalent iron salt and hydrogen peroxide, performing Fenton oxidation and mineralization on an organic solvent in the wastewater under the synergism of ultrasonic waves, then adding an alkali metal salt solution to adjust the pH value, and filtering and separating to obtain filtrate and ferric hydroxide precipitate; adding alkali into the filtrate twice to adjust the pH value for precipitation, and filtering to separate valuable precipitate and filtrate; and adding dilute acid into the ferric hydroxide precipitate for dissolving, and then adding a reducing agent to obtain a ferrous salt solution which is circularly used for Fenton reaction. According to the method, hydrolysis, Fenton oxygenolysis, mineralization of the organic electrolyte and regeneration and recycling of the ferrous salt are adopted, and the method is suitable for large-scale and low-cost treatment of the electrolyte in the waste lithium ion battery.

The invention relates to the technical field of soil remediation, and discloses a soil remediation material for targeted adsorption of perfluoroalkyl acid organic pollutants and a preparation method of the soil remediation material. The soil remediation material is prepared from the following raw materials: microorganisms, a porous carrier, cationic gel, anionic gel and ferrite, wherein the microorganisms have the capability of driving a nitric acid reduction-ferrous oxidation process. According to the soil remediation material provided by the invention, the microorganisms with the capability of driving the nitric acid reduction-ferrous oxidation process, the porous carrier, the cationic gel, the anionic gel and the ferrite are used as raw materials, and the mechanical strength change of the material in different application stages is dynamically regulated and controlled through the valence change of iron ions and the mineralization process of the microorganisms; according to the soil remediation material disclosed by the invention, the miscibility of the soil remediation material and soil and the specific adsorption of the medium-short-chain perfluoroalkyl acid are enhanced, and meanwhile, the conversion of pollutants from an extractable state to a non-extractable state can be promoted, so that the deep fixation of the pollutants is realized, and the secondary release risk after fixation is reduced.

The invention belongs to the field of field remediation functional materials, and particularly relates to a preparation method and application of a chelating iron agent for remediation of organic contaminated soil. The preparation method comprises the following steps: firstly, preparing a chelating agent aqueous solution, adding ferrite under a continuous stirring condition to carry out chelation reaction, then adding organic acid to carry out stabilization treatment, finally adding an activating auxiliary agent fulvic acid, uniformly mixing, and adjusting the pH value of the solution to a required value to obtain the chelating iron agent. The chelating iron agent can be used for activating an oxidizing agent during in-situ / ex-situ remediation of an organic polluted site, and has the advantages that the chelating iron agent is environment-friendly, the ferrous ion stability is good, the contact reaction with the oxidizing agent is mild and controllable, iron precipitates are not easy to form, and the growth and metabolic activity of indigenous organisms are stimulated.

The invention discloses a treatment method of electroplating wastewater, and belongs to the technical field of electroplating wastewater treatment. The process comprises the following steps: electrically adjusting the pH value of the electroplating wastewater to 2.5-4.0, adding ferrite, adopting a Ti / PbO2 anode and a graphite cathode, controlling the current density to 15-30mA / cm, introducing air, reacting for 40-80 minutes, and adjusting the pH value to 6.0-7.0 after the reaction; introducing the wastewater into a chelating resin column, wherein the chelating resin is an amino phosphonic acid type or iminodiacetic acid type; the method comprises the following steps of: introducing into a built-in filter column, loading two layers of recrystallized silicon carbide honeycomb ceramic membranes in the filter column in parallel, performing cross-flow filtration under the conditions that the operation pressure is 0.8-2.0 MPa, the temperature is 25-40 DEG C and the cross-flow velocity is 1.5-3m / s, and collecting permeate; the permeate liquid is used for backwashing every 8-12 hours of operation. According to the method, heavy metal ions in the electroplating wastewater can be effectively removed, and the treatment efficiency of the electroplating wastewater is improved.

The invention provides a method for improving fermentation yield and sugar-acid conversion rate of 5-hydroxytryptophan, alpha-ketoglutaric acid ferrous salt, alpha-ketoglutaric acid zinc salt, alpha-ketoglutaric acid cobalt salt and alpha-ketoglutaric acid manganese salt are added into a fermentation culture medium according to a specific proportion, alpha-ketoglutaric acid directly participates in TCA circulation, circulation operation can be accelerated, generation of NADH and FADH2 is increased, the yield of 5-hydroxytryptophan is increased, and the yield of 5-hydroxytryptophan is increased. The ATP synthesis efficiency is improved, and more energy is provided for cell growth; the alpha-ketoglutaric acid can balance amino acids required in the growth process of escherichia coli, promote the generation of proteins and nucleic acids and accelerate the growth of thalli; the alpha-ketoglutaric acid metal salt can improve the utilization efficiency of microelements by thalli; ferrous ions are cofactors of 5-hydroxytryptophan hydroxylase and can accelerate the hydroxylation process of tryptophan. Through the synergistic effect of the added components, the yield of the 5-hydroxytryptophan and the sugar-acid conversion rate are improved.

The invention discloses a preparation method of ferromanganese carbonate for a lithium battery, and relates to the technical field of battery materials. The method comprises the following steps: under the protection of an antioxidant and an inert atmosphere, preparing a mixed metal salt solution from manganese salt and ferrous salt, mixing the mixed metal salt solution with a solution containing carbonate ions, carrying out a co-precipitation reaction, and controlling the reaction temperature, the pH value, the dropwise adding rate, the reaction time and the molar ratio of the manganese salt to the ferrous salt; and filtering, washing and drying the obtained product ferromanganese carbonate in sequence to finally obtain the required battery material ferromanganese carbonate. The method for preparing the ferromanganese carbonate is stable, high in yield and convenient for industrial production, and a product which is uniform in morphology, stable in iron-manganese ratio at 4: 6 and uniform in metal ion distribution can be obtained.

This application relates to the field of chemical production and discloses a metal salt catalyst for desulfurization and denitrification, its preparation method, and its application. The catalyst comprises an active metal component of 30%-35%, a support of 60%-65%, and an additive of 5%-10%. The active metal component is specifically ferrous sulfate. The activity of the ferrous salt at medium and low temperatures, combined with the adjustment of the catalyst surface acidity by alkali metal sodium and rare earth element cerium, broadens the active temperature range. The support is specifically alumina. The additives consist of 3%-6% alkali metal sodium and 2%-4% rare earth element cerium by mass. Simultaneously, alkali metal sodium and rare earth element cerium can reduce impurity adsorption and enhance resistance to poisoning. This invention, through the rational selection of the active metal component, support, and additives, broadens the active temperature range of the catalyst, enabling it to adapt to flue gas temperature changes under different operating conditions, thus providing a wider range of applications for desulfurization and denitrification in industrial production.

This invention discloses an in-situ removal process for total inorganic iodide in water based on oxidation-adsorption, belonging to the field of water treatment technology. The process includes: first, taking raw water containing inorganic iodide, adding bicarbonate and adjusting the pH of the solution to 7-7.5; then, adding ferrous salt to the raw water; finally, adding KMnO4 to the raw water with added ferrous salt under stirring conditions, reacting to prepare a MnO2-nascent iron particle complex; on the one hand, promoting the removal of total inorganic iodide from water through mild oxidation-adsorption. ‑ Oxidation transformation occurs to generate HOI / I2; on the other hand, the in-situ products HOI / I2 are adsorbed and fixed through adsorption / co-precipitation methods, and nascent iron is captured through surface coordination or electrostatic adsorption. This invention achieves the capture of I2 under neutral / weakly alkaline drinking water conditions through a mild and controllable oxidation-adsorption synergistic mechanism. ‑ Simultaneous adsorption and removal of its conversion products are achieved to ensure that total iodine is removed to the required standard.

The application discloses a method for synthesizing tervalent tetraaryl iron porphyrin from pyrrole, aromatic aldehyde and ferrous salt, which comprises the following steps: adding anhydrous aluminum chloride, aromatic aldehyde, pyrrole and ferrous salt into DMF under stirring, and then heating and refluxing the reaction mixture for 0.5 hours under nitrogen; removing the nitrogen and continuing to heat the reaction mixture for a certain time; stopping the reaction; cooling the reaction mixture; and placing the reaction mixture at 273K overnight; and finally filtering the reaction mixture to obtain the iron porphyrin.

The invention relates to the technical field of environmental functional material preparation, in particular to magnetic ferro-aluminum loaded modified sludge hydrothermal carbon as well as a preparation method and application thereof, and the sludge hydrothermal carbon prepared by a hydrothermal carbonization technology is a porous carbonaceous carrier with high specific surface area and rich oxygen-containing functional groups. A product obtained from the sludge hydrothermal carbon, an aluminum precursor, ferrous salt and ferric salt through an impregnation precipitation method is porous sludge carbon loaded aluminum iron oxide (mainly Fe3O4), and efficient chemical adsorption of fluorine ions is achieved through rich acidic functional groups and metal oxide active sites on the surface of the product. Adsorption mainly depends on complexation, exchange and surface combination of phases such as Al (OH) 3 and fluorine ions, and the magnetic ferro-aluminum loaded modified sludge hydrothermal carbon can be rapidly recycled through an external magnetic field after adsorption, so that secondary pollution is avoided, and therefore, the magnetic ferro-aluminum loaded modified sludge hydrothermal carbon has the dual advantages of efficient fluorine removal and magnetic recovery.

The invention provides a preparation method of manganese-doped iron phosphate, and relates to the technical field of lithium ion battery positive electrode materials, the preparation method comprises the following steps: S1, preparing a phosphoric acid solution, a ferrite solution, a phosphorus-oxygen mixed solution containing a phosphorus source and an oxidizing agent, a divalent manganese salt solution and an oxidizing agent solution; s2, adding a base solution, and pumping the ferrite solution and the phosphorus-oxygen mixed solution while stirring to obtain slurry A; s3, filtering and washing the slurry A to obtain a filter cake; s4, mixing and pulping the filter cake and water, sequentially adding a divalent manganese salt solution, an oxidant solution and phosphoric acid, heating to 80-100 DEG C, and carrying out conversion reaction for 1-3 hours to obtain slurry B; s5, filtering, washing and drying the slurry B to obtain manganese-doped iron phosphate dihydrate, and calcining the iron phosphate dihydrate to obtain manganese-doped anhydrous iron phosphate; the manganese salt solution is added in the precursor preparation stage, so that the manganese element is doped into iron phosphate crystal lattices in the form of ions, and the bulk phase doping effect can be better improved.

This invention provides a lithium iron phosphate cathode material, its preparation method, and its application. The preparation method includes the following steps: (1) mixing ferrous salt and phosphorus source with an alcohol solvent, heating and stirring, and adding a first lithium source solution to obtain a mixed solution; adjusting the pH of the mixed solution to obtain a mixed precursor; (2) mixing a complexing agent, ferric salt, a second lithium source, phosphorus source, and surfactant with water, stirring to form a sol solution; mixing the mixed precursor obtained in step (1) with the sol solution, heating and stirring to obtain a gel precursor; (3) sintering the gel precursor to obtain the lithium iron phosphate cathode material; wherein the mixed precursor includes lithium phosphate and ferrous phosphate. This invention can achieve lithium iron phosphate gradation of different particle sizes through a single production line, improving the uniformity and compaction density of the material, and avoiding performance differences and poor stability between different batches.

The application discloses a high specific surface area desulfurizer hydrated iron oxide component and a preparation method thereof. First, an iron source ferrous salt and a precipitant are respectively dissolved completely by being heated to 40 DEG C, then the precipitant is put into the ferrous salt solution to carry out stirring and mixing reaction, pH is kept at 6.5-9.5, then small molecule organic alcohol, acid or amine substance is added, air is introduced to carry out oxidation reaction, finally, the material liquid is filtered, rinsed and dried, and the high specific surface area hydrated iron oxide desulfurizer active component is obtained. The preparation method of the high specific surface area hydrated iron oxide desulfurizer active component has the advantages of mild reaction condition, simple technological process, low production cost, non-toxic and non-pollution, and the specific surface area of the prepared hydrated iron oxide is greatly improved, the sulfur capacity is as high as 60.85%, and the method has good application prospect and potential practical value.

The invention discloses antioxidant neodymium iron boron permanent magnet powder and a preparation method thereof, and the preparation method comprises the following steps: mixing neodymium iron boron permanent magnet powder, a polyvinylpyrrolidone solution, a sodium borohydride solution and a ferrite solution under an anoxic condition, and carrying out a hydrothermal reaction to obtain the antioxidant neodymium iron boron permanent magnet powder. According to the oxidation-resistant neodymium-iron-boron permanent magnet powder prepared by the preparation method disclosed by the invention, a compact oxidation-resistant shell protection layer is formed on the surface of the neodymium-iron-boron permanent magnet powder, so that oxygen and moisture are effectively blocked, the magnetic powder is prevented from being oxidized, the service life of the magnetic powder is prolonged, and the magnetism of the permanent magnet powder can be ensured not to be influenced; the optimal balance between the anti-oxidation protection and the magnetic performance maintenance of the neodymium-iron-boron permanent magnet powder is realized; meanwhile, the permanent magnet powder does not need to be isolated from air, subsequent neodymium-iron-boron magnet manufacturing can be carried out in the air, the storage cost is reduced, safe use of the permanent magnet powder is guaranteed, and the permanent magnet powder is suitable for large-scale batch continuous production.

The invention belongs to the technical field of semiconductor material polishing, and particularly relates to an alkaline polishing solution for a silicon carbide substrate as well as a preparation method and application. According to the alkaline polishing solution for the silicon carbide substrate, the colloidal SiO2 nano abrasive and the alpha-Al2O3 nano abrasive are used as compound abrasive, the particle size of the alpha-Al2O3 nano abrasive is controlled to be smaller than that of SiO2 nano abrasive in the colloidal SiO2 nano abrasive, the pH is adjusted to be 9.5-13.0, and components such as ferrite, oxidizing agent hydrogen peroxide and sodium pyrophosphate are added; bulges and defect layers on the surface of the silicon carbide substrate can be quickly removed in the polishing process, and Rad can be efficiently obtained; the alkaline polishing solution is a high-performance alkaline polishing solution for the silicon carbide substrate, and the technical problem that in the prior art, the polishing solution is low in performance can be solved.

The application discloses a low-temperature lithium iron phosphate material and a preparation method and lithium ion battery thereof, and belongs to the technical field of lithium ion batteries. The preparation method is as follows: a ferrous salt and a polycarboxylic acid complexing agent containing alpha-hydroxyl are mixed and dissolved in water, then a phosphoric acid solution and a lithium source solution are introduced, and the pH in the system is controlled to be less than or equal to 3; the solid product is washed and dried after being reacted at 20-55 DEG C for 4-8 hours to obtain a precursor; the precursor, a carbon source, phosphoric acid and a dopant are sand-milled to obtain a slurry; the slurry is subjected to spray drying, sintering and crushing to obtain the low-temperature lithium iron phosphate material. The application can realize directional growth of lithium iron phosphate crystal grains, obtain micron-level flat-structure lithium iron phosphate, and make the material maintain high tap density (greater than or equal to 2.5 g / cm 3 ) while keeping good low-temperature performance.

The invention discloses a preparation method of a glucose-iron-zinc double complex, which comprises the following steps: dissolving glucose in water, adding ferrite under a stirring condition, uniformly stirring, adjusting the pH value to 7.5-8.5 by using a sodium hydroxide aqueous solution, and stirring and reacting at 70-90 DEG C for 1-2 hours to obtain a reaction solution A; adding zinc salt into the reaction liquid A, uniformly stirring, adjusting the pH value to 8.0-9.0 by using a sodium hydroxide aqueous solution, and stirring and reacting at 70-90 DEG C for 1-2 hours to obtain a reaction liquid B; and carrying out microwave treatment on the reaction liquid B, adding an ethanol water solution under a stirring condition, standing at normal temperature, separating out precipitate, and carrying out vacuum drying on the precipitate to obtain the glucose-iron-zinc double complex. Glucose sequentially reacts with ferrous salt and zinc salt, metal ions are complexed, the glucose-iron-zinc double complex is prepared, and the glucose-iron-zinc double complex is good in stability, good in solubility and easy to absorb, is added into animal feed, is high in bioavailability and can promote growth and development of animals, reduce the diarrhea rate and improve the health level of the animals.

The present invention discloses a flame retardant and smoke suppressing coating, and a preparation method and application thereof. The raw materials of the coating include the following components in terms of weight percentage: 2-30% gelatin, 1-5% metal oxide functionalized black phosphorus, 5-25% kosmotropic salt, 0.1-2% antibacterial agent, and the balance water; the metal oxide functionalized black phosphorus is prepared by solvent thermal reaction using black phosphorus nanosheets, cobalt salts, ferrous salts and sodium acetate as raw materials and an organic solvent as solvent, and the mass ratio of black phosphorus nanosheets, cobalt salts and ferrous salts is 2:2.5-5:2.5-3.75. The present invention enables the coating to have excellent flame retardant properties through the interaction of the components in the above contents. The limiting oxygen index of the polyurethane foam after coating modification increases from 17.5% to 32.0%; the peak heat release rate increases from 485kW / m 2 Down to 200kW / m 2 ; Peak smoke release rate from 0.30m 2 / s dropped to 0.15m 2 / s; tensile strength increased from 0.8MPa to 1.8MPa.

This application provides a method for preparing nano-sized orthogonal iron phosphate and a method for preparing lithium iron phosphate cathode materials, relating to the field of electrode materials. The method for preparing nano-sized orthogonal iron phosphate includes: mixing a first ferrous salt solution with a first phosphorus source solution and an oxidant to perform a co-precipitation reaction to obtain amorphous iron phosphate; mixing the amorphous iron phosphate with water to form a slurry, controlling the slurry particle size, and then adding a crystal transformation aid to the slurry, followed by aging under stirring conditions at a pH of 0.8–1.5 to obtain nano-sized orthogonal iron phosphate; wherein the crystal transformation aid includes a second ferrous salt and a second phosphorus source. The iron phosphate prepared in this application is single-crystal nano-sized orthogonal iron phosphate, reducing the grinding pressure at the lithium iron phosphate end. Simultaneously, its unique octahedral structure is more stable than monoclinic iron phosphate produced by conventional processes, with fewer crystal defects and higher lattice integrity, effectively avoiding the generation of magnetic foreign matter during sintering and contributing to the performance of lithium iron phosphate materials.