256 results about "Hydrogen phosphate" patented technology

The invention discloses a manganese hydrogen phosphate precursor, lithium iron manganese phosphate, a preparation method of the manganese hydrogen phosphate precursor, a positive pole piece containing the lithium iron manganese phosphate, a battery containing the lithium iron manganese phosphate, and an electric device containing the lithium iron manganese phosphate. The preparation method comprises the following steps: firstly, carrying out primary precipitation reaction on soluble manganese salt and a precipitator to prepare manganese hydroxide, and then carrying out secondary precipitation reaction on the manganese hydroxide and phosphoric acid to prepare the manganese hydrogen phosphate precursor. The manganese hydrogen phosphate precursor with low impurity ion content and high yield is prepared through secondary precipitation reaction.

The invention discloses a preparation method of a sodium ferromanganese vanadium phosphate material of a sodium battery positive electrode. The preparation method comprises the following steps: S1, preparing a hydrophosphate solution and a manganous salt solution; and S2, adding the hydrophosphate solution into the manganous salt solution, and reacting to obtain the manganous hydrogen phosphate crystal nucleus slurry. And S3, filtering and washing the manganese hydrogen phosphate crystal nucleus slurry, adding water into the manganese hydrogen phosphate material to prepare slurry, heating to 85-95 DEG C, respectively adding a ferrous source and a phosphorus salt solution, and reacting to obtain the manganese iron hydrogen phosphate slurry. And S4, filtering, washing and drying the iron manganese hydrogen phosphate slurry, adding water into the dried slurry to prepare slurry, adding phosphoric acid, heating to 90-100 DEG C, reacting to obtain an iron manganese phosphate compound precipitate, and filtering, washing and drying the precipitate to obtain an iron manganese phosphate material. The sodium manganese iron vanadium phosphate product is prepared by adopting a coprecipitation method and high-temperature sintering, and the method has the advantages of short process flow, simple process, only one-time sintering, low energy consumption and the like.

The invention relates to the technical field of mine water treatment, and discloses a method for treating high-calcium-hardness mine water through induced crystallization. The method comprises the following steps: adding coal gangue and sodium phosphate or sodium hydrogen phosphate into the mine water to carry out first induced crystallization so as to remove calcium ions in the mine water; according to the method provided by the invention, the concentration of calcium ions in the mine water after calcium removal can be stabilized for a long time, and the removal rate of the mine water is improved to a certain extent. The method provided by the invention can effectively ensure that the Ca < 2 + > content of the effluent quality of the mine water reaches the standard, and can also reduce secondary environmental pollution.

The invention relates to a lithium manganese iron phosphate composite material, a preparation method and a related device. The preparation method comprises the steps that phosphoric acid, an inorganic manganese source and a reducing agent are added into a solvent, manganese ions in the inorganic manganese source are reduced into divalent manganese ions in the reducing atmosphere, so that the divalent manganese ions and phosphoric acid react to generate a manganese hydrogen phosphate precursor, and the valence state of the manganese ions in the inorganic manganese source is higher than that of the divalent manganese ions; mixing an M source, the manganese hydrogen phosphate precursor and a carbon source, grinding, and performing spray granulation to form a lithium iron manganese phosphate precursor, the M source including an iron source and a lithium source; and calcining the lithium manganese iron phosphate precursor in an inert atmosphere to generate the lithium manganese iron phosphate composite material, the lithium manganese iron phosphate composite material comprises lithium manganese iron phosphate particles and a carbon coating layer, and the carbon coating layer coats at least part of the outer surface of the lithium manganese iron phosphate particles.

The invention provides a novel D-A-D type fluorescent probe material as well as a preparation method and application thereof. The fluorescent probe material has good stability, the preparation process is simple, and the synthesis condition is mild. Moreover, the D-A-D type fluorescent probe material has good solubility and stability, and a complex of the D-A-D type fluorescent probe material and zinc ions can identify pyrophosphate ions with high selectivity and high sensitivity. The interference of phosphate ions, hydrogen phosphate ions, dihydrogen phosphate ions, fluorine ions, chloride ions, nitrate ions, acetate ions, sulfate ions and carbonate ions is avoided; after the zinc ion complex of the D-A-D type fluorescent probe material is combined with PPi, the fluorescence intensity is remarkably enhanced, the D-A-D type fluorescent probe material has a higher signal-to-noise ratio, in-situ imaging detection of a target object in living cells or tissues is realized, the defects of a traditional molecule and ion detection method are overcome, and the D-A-D type fluorescent probe material is suitable for being widely applied to the field of biological imaging. # imgabs0 #

A fire extinguishing liquid is described comprising (a) one or more of a phosphate, hydrogen phosphate, dihydrogen phosphate or polyphosphate salt; (b) a carbonate or hydrogen carbonate salt; (c) a sulphate salt; and (d) an intumescent component. Methods of manufacturing the fire extinguishing liquid and fire extinguishers containing the liquid are also described. The liquid is useful for extinguishing fires, in particular lithium-ion battery fires.

The present application discloses a spraying device for the production of anhydrous calcium hydrogen phosphate, belonging to the technical field of spray drying, which includes a power structure, a high-pressure spraying structure, and an outer spinning disk; the high-pressure spraying structure includes an annular housing member connected to the power structure; pressure spray nozzles are provided on the side wall of the annular housing member; and an elastic packing component is provided in the inner cavity of the annular housing member. When the pumping of the calcium hydrogen phosphate dihydrate slurry into the annular housing member is stopped or interrupted, the hydraulic pressure applied to the piston assembly gradually decreases, so that the piston assembly gradually moves upward under its own elastic force. During this process, the plug column part in the elastic packing component is continuously driven to insert into the pressure spray nozzle again and push out the residual liquid remaining in the pressure spray nozzle. When the slurry is pumped into the annular housing member again, during the downward movement of the piston assembly under the action of hydraulic pressure, the plug column part disengages from the pressure spray nozzle again under the action of elastic force, so that the pressure spray nozzle is exposed again.

The invention relates to a pH-responsive copper hydrogen phosphate-loaded hydrogel with multiple enzyme-like activities and a preparation method and application thereof. The material mainly shows catalase-like activity in a neutral microenvironment, and can remove H2O2 and relieve oxidative stress; in a weakly acidic microenvironment, the compound mainly shows peroxidase-like activity and catalyzes H2O2 to generate. OH bacteria with higher toxicity; meanwhile, the inherent osteogenesis promoting performance of copper synergistically enhances bone regeneration, the biocompatibility, the oxidation resistance, the osteogenesis promoting capacity under the oxidative stress condition and the antibacterial efficiency under the weak acid condition of the SA / CuHP hydrogel are evaluated through in-vitro experiments, and a type II diabetes rat periodontitis model is established; the in-vivo antibacterial and osteogenesis promoting effects and the biological safety performance of the compound are verified, and a new strategy is provided for treatment of periodontitis with diabetes mellitus.

The invention provides an electrolyte additive for synergistically regulating and controlling activity and stability of an all-vanadium redox flow battery and application of the electrolyte additive, the electrolyte additive is a composite additive of an organic amino acid compound and inorganic phosphate, the organic amino acid compound is one of aspartic acid, glycine and cysteine, and the inorganic phosphate is one of amino acid, glycine and cysteine. The inorganic phosphate is one or two or more of phosphate, dihydric phosphate, dihydric phosphate, polyphosphate and pyrophosphate, and cations of the inorganic phosphate are one or two or more of potassium, sodium and ammonium salt. The composite additive is used as an electrolyte additive to be added into an all-vanadium redox flow battery electrolyte, so that the vanadium electrolyte can be effectively prevented from generating precipitates at high temperature, the capacity fading in the battery operation process is avoided, and the stable operation of the battery is realized. The preparation process is simple to operate, energy-saving, environment-friendly and low in cost, and stable operation of the electrolyte in the battery can be realized.

The invention provides a method for preparing 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 a lithium source with a phosphoric acid solution to obtain a first mixture; mixing the first mixture with manganese hydrogen phosphate, an iron source and an optional M element source to obtain a second mixture; and drying and sintering the second mixture to obtain the lithium iron manganese phosphate positive electrode material, wherein the M element comprises one or more of transition metal elements except manganese and iron elements, IIA group metal elements, IIIA group metal elements, IVA group metal elements and VIIA group elements. According to the method, side reaction gas and by-products are reduced, the compaction density of the positive electrode material is improved, the resistivity of the positive electrode material is reduced, and the specific capacity and rate capability of the battery are improved.

The invention discloses heat-resistant ammonium polyphosphate with ultrahigh polymerization degree and a synthesis method thereof. The method comprises the following steps: (1) preparing ammonium polyphosphate: S1, mixing phosphorus pentoxide and diammonium hydrogen phosphate, stirring to react, and introducing ammonia gas to react; s2, mixing phosphoric acid with melamine for reaction, supplementing phosphoric acid, and stirring for reaction; s3, when the temperature in the first-step reaction is 280-300 DEG C, stopping introducing the ammonia gas, adding a product obtained in the step S2, supplementing diammonium hydrogen phosphate, and introducing the ammonia gas to continue the reaction; (2) end sealing; (3) pre-curing; and (4) mixing and dissolving epoxy resin and a curing agent, and then coating the surface of the pre-cured ammonium polyphosphate with the mixture. The initial polymerization degree of the ammonium polyphosphate can be improved, the initial molecular weight of the ammonium polyphosphate is higher, the application capacity of the ammonium polyphosphate in a humid and hot environment can be improved after modification treatment, especially when the ammonium polyphosphate is soaked in hot water at the temperature of 80 DEG C for 4 h, the product does not separate out or migrate, and the stability of the flame-retardant effect of the product is guaranteed.

The invention provides a lithium iron phosphate material and a preparation method and application thereof, the preparation method comprises the following steps: adding iron powder and a reducing agent into phosphoric acid, and carrying out first reaction to obtain a mixed solution; adding an iron oxide and a lithium source into the mixed solution, and carrying out a second reaction to obtain a lithium iron phosphate precursor; and sintering the lithium iron phosphate precursor to obtain the lithium iron phosphate material. Wherein the mixed solution comprises iron dihydrogen phosphate and phosphoric acid, and the lithium iron phosphate precursor comprises lithium dihydrogen phosphate, iron hydrogen phosphate and iron oxide. And the iron hydrogen phosphate and the iron oxide have different morphologies, so that the mixing of large and small particles is realized, and a more compact stacking structure is formed, so that the lithium iron phosphate material has high compaction density and high rate performance.

Modified iron phosphate, and a preparation method therefor and the use thereof. The preparation method comprises the following steps: (1) mixing a zirconium salt, a hydrogen phosphate and a tungstate with a solvent to obtain a mixed salt solution, and performing a heating reaction, so as to obtain zirconium phosphotungstate; (2) mixing the zirconium phosphotungstate serving as a seed crystal with an iron salt, a phosphate, phosphoric acid and an oxidizing agent, and performing a synthesis reaction, so as to obtain a modified material; and (3) sintering the modified material, and then grinding same, so as to obtain modified iron phosphate. In the present disclosure, zirconium phosphotungstate is used as a seed crystal to prepare iron phosphate, which can promote the generation of cracks in secondary particles, making iron phosphate easy to break and an iron phosphate precursor having a smaller particle size be obtained; therefore, a high-energy and high-power-density lithium iron phosphate positive electrode material is prepared.

The invention relates to the field of wastewater treatment, and discloses a hydroxyapatite modified biochar material as well as a preparation method and application thereof in treatment of fluorine-containing wastewater. The preparation method comprises the following steps: preparing a hydroxyapatite-biochar composite material by using an in-situ precipitation method, and modifying by using metal aluminum ions, specifically, uniformly mixing peanut shell powder and anhydrous calcium chloride, dispersing, dropwise adding diammonium hydrogen phosphate for reacting, adjusting pH by using NaOH, stirring at constant temperature for reacting, washing with water and absolute ethyl alcohol to be neutral, and drying to obtain an HAP / C composite material; the HAP / C composite material is placed in a tubular furnace for pyrolysis, and an HAP / BC composite material is obtained; and adding an A1Cl3. 6H2O solution into the HAP / BC composite material, uniformly stirring, standing, carrying out suction filtration and washing until the HAP / BC composite material is neutral, and finally drying the HAP / BC composite material in a constant-temperature drying box to obtain the Al-HAP / BC composite material with low cost, large adsorption capacity and strong stable regeneration performance, and the obtained Al-HAP / BC composite material is applied to fluorine ion-containing wastewater, has a remarkable fluorine removal effect and has a good application prospect.

The invention discloses a spraying device based on anhydrous calcium hydrogen phosphate production, and belongs to the technical field of spray drying. The spraying device comprises a power structure, a high-pressure eruption structure and an outer throwing disc; the high-pressure eruption structure comprises an annular housing piece connected to the power structure; a pressure nozzle is formed in the side wall of the annular housing piece; an elastic port filling assembly is arranged in an inner cavity of the annular cover shell piece. When the pumping of the calcium hydrogen phosphate dihydrate slurry into the annular housing piece is stopped or interrupted, the hydraulic pressure applied to the piston assembly is gradually reduced, so that the piston assembly gradually moves upwards under the action of self elasticity; the piston assembly continuously drives a plunger part in the elastic filling opening assembly to be inserted into the pressure nozzle again and ejects residual liquid remaining in the pressure nozzle out, after the slurry is pumped into the annular housing piece again, in the process that the piston assembly moves downwards under the action of hydraulic pressure, the plunger part is separated out of the pressure nozzle again under the action of elastic force, and the residual liquid in the pressure nozzle is ejected out. And the pressure nozzle is exposed again.

The invention relates to a flow battery electrolyte and an application thereof. The flow battery electrolyte comprises vanadium ions, a supporting electrolyte and an additive, the additive is selected from one, two or more of ammonium sulfate, ammonium phosphate, potassium phosphate, sodium metaphosphate, diammonium hydrogen phosphate and hydrogen peroxide. According to the vanadium battery electrolyte provided by one embodiment of the invention, the specific additive is added, so that vanadium ions can be in a liquid state or a microemulsion state, separation or precipitation of the vanadium ions is prevented, and the efficiency of the battery is remarkably improved.

The invention discloses novel modified biochar and a preparation method and application thereof.The preparation method comprises the following steps that calcium-rich solid waste raw materials are placed in a crusher to be crushed and fully mixed with biochar with dissolved organic matter removed according to the mass ratio of 1: (1-4); adding pure water with the mass volume ratio of 1g: (60-100) mL, diammonium hydrogen phosphate with the calcium-phosphorus ratio of 1: (2.5-3.34) and ammonium dihydrogen phosphate with the calcium-phosphorus ratio of 1: (2.5-3.34); all the raw materials are placed in a ball milling tank, the mass ratio of the raw materials to zirconium oxide balls before ball milling is 1: (10-15), and ball milling is conducted for 6-12 h at the rotating speed of 250-600 r / min; transferring the biochar slurry subjected to ball milling into a centrifugal tube, and centrifuging for 10 minutes at the rotating speed of 5000 r / min; the solid precipitate is washed with pure water three times to remove excessive phosphate, the solid precipitate is placed in a drying oven to be dried, and the novel ball-milled modified biochar is obtained, the novel modified biochar is simple in synthesis method and low in energy consumption, can be easily separated through a centrifugal machine and has high adsorption performance on heavy metal.

Provided are a method for preparing a positive electrode material, a positive electrode material, a positive electrode sheet, a battery, and an electric device. The method comprises: mixing a lithium source with a phosphoric acid solution, so as to obtain a first mixture; mixing the first mixture with manganese hydrogen phosphate, an iron source and a source of an optional M element, so as to obtain a second mixture; and drying and sintering the second mixture, so as to obtain a lithium manganese iron phosphate positive electrode material, wherein the M element comprises one or more of transition metal elements other than manganese and iron, metal elements of group IIA, metal elements of group IIIA, metal elements of group IVA, and metal elements of group VIIA. The method reduces side reaction gases and byproducts, improves the compaction density of a positive electrode material, decreases the resistivity of the positive electrode material, and improves the specific capacity and rate performance of a battery.

The invention provides sodium ferric pyrophosphate and a preparation method thereof, and the preparation method comprises the following steps: mixing waste sodium ferric pyrophosphate with carbonate and an iron source to obtain a mixture, and calcining the mixture to obtain a calcined material; washing and filtering the calcined material to obtain a first filter residue and a first filtrate; performing impurity removal, concentration and crystallization on the first filtrate to obtain sodium carbonate; the first filter residues are subjected to acid pickling and filtering treatment, and second filtrate is obtained; adding phosphate and a pH regulator into the second filtrate, and heating for reaction to obtain mixed slurry; filtering the mixed slurry to obtain second filter residues, and sequentially drying, screening and deironing the second filter residues to obtain iron hydrogen phosphate; the preparation method comprises the following steps: mixing sodium carbonate with ferric hydrogen phosphate, then adding a doping agent, an auxiliary agent and a carbon source, and grinding and calcining to obtain the ferric sodium pyrophosphate. According to the method, high-purity sodium carbonate and iron hydrogen phosphate can be recycled, then pyrophosphate ferric sodium phosphate is prepared, and the pyrophosphate ferric sodium phosphate is good in particle dispersity, high in sphericity degree and high in capacity.

The present disclosure provides an aluminum phosphite-based complex with dual-peak thermal gravity decomposition characteristics and a preparation method and use thereof. A structural formula of the complex is as follows: ((HPO3)3Al2)·((H2PO3)3Al)x, wherein x is 0.01-0.5 and represents a molar ratio of (H2PO3)3Al to (HPO3)3Al2. The dual-peak thermal gravity decomposition characteristics are as follows: a first gravity peak temperature is 460-490° C., and a second gravity peak temperature is 550-580° C. The preparation method includes: uniformly mixing aluminum phosphite and aluminum hydrogen phosphite according to the ratio in the structural formula, and then performing stepwise heating at a rate of 5° C. / min to raise the temperature of a mixture from the normal temperature to no more than 350° C. within 1-10 hours, so as to obtain the aluminum phosphite-based complex with the dual-peak thermal gravity decomposition characteristics. The complex may serve as or is configured to prepare a flame retardant or a flame-retardant synergist.

The invention provides a stable acidic bird droppings simulant and a preparation process thereof, and relates to the technical field of power grid anti-pollution flashover protection. According to the stable acidic bird droppings simulant, every 100 g of the bird droppings simulant is prepared from, by weight, 4-6 g of sodium chloride, 8-9 g of uric acid, 11-13 g of flour, 0.8-2 g of xanthan gum, 1-3 g of a compound and the balance water, the compound is a phosphate compound or a citric acid compound, the phosphate compound is composed of sodium hydrogen phosphate and sodium dihydrogen phosphate in the mass ratio of (1.5-2.5): (0.5-1.5), and the citric acid compound is composed of sodium hydrogen phosphate and sodium dihydrogen phosphate in the mass ratio of (1.5-2.5): (0.5-1.5). The citric acid compound is prepared from citric acid and sodium citrate in a mass ratio of (1.5-2.5): (1.0-1.5). The bird droppings simulant formula can be applied to long-period power transmission line pollution experiments, it is ensured that the pH value of the bird droppings simulant is stable, the comparability and credibility of experimental data are improved, and experimental results can provide important support for long-term protection strategies of power transmission lines under bird droppings pollution.

The present invention relates to the technical field of corn soaking water recycling and treatment, and in particular to a process method for preparing potassium dihydrogen phosphate and magnesium hydrogen phosphate using corn soaking water, comprising the following steps: (1) the supernatant after the corn soaking water is settled is fed into a cationic resin column, and the collected effluent is used for standby; (2) the cationic resin column is rinsed in reverse flow with purified water, and then the cationic resin column is rinsed in forward flow with phosphoric acid, and the collected effluent is used for standby; (3) the standby effluent in step (2) is taken, concentrated, pH adjusted, heated, and after white solid suspension is precipitated, the mixture is kept warm and stirred for a period of time, then cooled, filtered, and the filtrate and precipitate are collected respectively; (4) the filtrate in step (3) is taken, phosphoric acid is added to adjust the pH, vacuum concentrated and crystallized, cooled, centrifuged, and the collected filter cake is rinsed and dried to obtain a potassium dihydrogen phosphate product. Potassium dihydrogen phosphate and magnesium hydrogen phosphate products can be obtained by the above process method.

The present invention provides a preparation method and application of a sulfur-containing molybdenum phosphide catalyst for the hydrogenation of medium- and low-temperature coal tar. The method uses ammonium heptamolybdate as a molybdenum source, diammonium hydrogen phosphate as a phosphorus source, and silicon-surface-modified alumina as a carrier. After equal volume impregnation and drying and calcination, the catalyst is first sulfurized and then hydrogenated in a fixed-bed reactor to reduce the severity of the activation process of the molybdenum phosphide and simultaneously form a sulfur-doped molybdenum phosphide active structure to obtain a sulfur-containing molybdenum phosphide catalyst. Medium- and low-temperature coal tar is then directly introduced into the original fixed-bed reactor to carry out a medium- and low-temperature coal tar full-fraction hydrogenation refining reaction. The preparation of the sulfur-containing molybdenum phosphide catalyst and the in-situ activation in the reactor of the present invention can be completed completely within the preparation and reaction system of the existing transition metal sulfide catalyst, greatly reducing the difficulty of preparing and using the phosphating catalyst. Moreover, the sulfur-containing molybdenum phosphide catalyst prepared by the present invention can be used completely based on the existing hydrogenation system and exhibits good hydrogenation activity.

The invention discloses a treatment process for metal ions in phosphating wastewater, and belongs to the technical field of industrial phosphating wastewater treatment. The method comprises the following steps: homogenizing phosphating wastewater to adjust the pH value to 4-5, adding Fe3O4 (at) SiO2 (at) DTPA shell-core microspheres and an induction coprecipitation agent into the wastewater, stirring, mixing and reacting, transferring the mixture into a magnetic separator for solid-liquid separation, filtering the filtrate through non-magnetic sand, and discharging the effluent; the dosage of the Fe3O4 (at) SiO2 (at) DTPA shell-core microspheres is 0.9 to 1.5 g / L; the induced coprecipitation agent is composed of magnesium hydrogen phosphate and aluminum chloride, the dosage of the magnesium hydrogen phosphate is 0.5-0.6 g / L, and the dosage of the aluminum chloride is 0.03-0.05 g / L. In the phosphating wastewater treatment process, only one-time acid adjustment is needed, chelation-coprecipitation is coupled in one reactor, only magnetic separation is needed, two-time acid adjustment is not needed, the process structure is simple, the whole-process retention time is short, and the process is effectively simplified.

The invention provides a method for preparing aza-2, 5-cyclohexadienone, and relates to the technical field of organic synthesis. Substituted phenol, an azo compound, inorganic salt and water are mixed, an intermolecular coupling reaction is carried out, aza-2, 5-cyclohexadienone is obtained, and the inorganic salt comprises one or more of carbonate, bicarbonate, phosphate, dihydric phosphate, dihydric phosphate, chlorine salt, sulfate, sulfite and silicate of alkali metal elements. According to the present invention, the cheap and easily available inorganic salt is adopted as the catalyst to catalyze the substituted phenol and azo compound molecule coupling reaction to prepare the aza-2, 5-cyclohexadienone, and the water is adopted as the reaction solvent, such that the preparation conditions are mild, the production cost is low, the produced by-products are less, the product yield is high, the atom economy is high, and the separation and the purification are simple. The method provided by the invention is simple and convenient to operate, has no pollution, meets the requirements of green chemical development and is suitable for industrial production.

The invention relates to the technical field of water treatment, in particular to a method for reducing solid waste by treating phosphatized sewage through ternary composite alkali, which comprises the following steps: collecting phosphatized sewage data in real time through an online water quality sensor, inputting a support vector regression model optimized by an improved particle swarm optimization algorithm, calculating the dosage of the ternary composite alkali, and calculating the dosage of the ternary composite alkali. The pH value is adjusted in a segmented adding mode, so that heavy metal ions and phosphate are precipitated in sequence; adding a magnetic micro-nano seed crystal and cationic polyacrylamide in a neutralization reaction to promote the growth of precipitated particles, separating a mixed solution by using a superconducting high-gradient magnetic separator, and carrying out electroosmotic dehydration on the magnetic sludge; finally, mixing the dewatered sludge with sulfuric acid for acid leaching, filtering, adding ammonium bicarbonate to crystallize and separate out calcium hydrophosphate, removing heavy metal ions from mother liquor, and recovering calcium sulfate; the invention aims to solve the problems that the dosage of a medicament is difficult to accurately control and the treatment cost is high and resources are wasted due to water quality fluctuation when phosphating sewage is treated by using the traditional ternary composite alkali.

Quality-optimized process for preparing a vanadium / phosphorous mixed oxide catalyst A quality-optimized process for preparing a vanadium / phosphorus mixed oxide catalyst (VPO-catalyst) containing crystalline vanadyl pyrophosphate, comprising the steps: • (a) preparing a VPO catalyst precursor containing vanadyl hydrogen phosphate by reacting a mixture containing a vanadium-containing compound, preferably vanadium pentoxide, and a phosphorous- containing compound, preferably phosphoric acid or polyphosphoric acid, and optionally a promotor metal containing compound, in an alcoholic medium, • (b) pre-calcining the VPO catalyst precursor, • (c) optionally shaping the VPO catalyst precursor, • (d) calcining the VPO precursor in an oxygen containing calcination atmosphere, • (e) taking at least one sample of the calcined VPO precursor during or after step (d), • (f) thermally treating, in at least one temperature treatment step, the calcined VPO catalyst precursor in an inert gas atmosphere containing steam at a higher temperature than in the calcination step (d), wherein the final VPO catalyst is obtained, • (g) determining, via XRD, the content of crystalline vanadyl pyrophosphate of at least one sample taken in step (e), • (h) based on the result of step (g), modifying the process conditions of step (d) with regard to one or more of the process parameters selected from calcination time, calcination temperature and composition of the calcination atmosphere in order to ensure that the content of crystalline vanadyl pyrophosphate in the calcined VPO precursor is at least 45% by weight before step (f) is carried out. The VPO catalyst thus obtained is used for producing maleic anhydride from n-butane or benzene.

The invention discloses a method for preparing feed-grade calcium hydrophosphate from raffinate acid, which comprises the following steps of: mixing alkali liquor D and raffinate acid, reacting, filtering after the reaction to obtain filtrate A and a filter cake E, and using the filter cake E for producing compound fertilizer, ammonium phosphate, superphosphate or rich calcium, and reacting the filtrate A with the calcium slurry, filtering after the reaction is finished to obtain a filtrate B and a filter cake C, returning the filtrate B to prepare an alkali liquor D, and finally drying and packaging the filter cake C to obtain the feed-grade calcium hydrogen phosphate. The method is simple in process, the value of the raffinate acid is increased, and the method is very convenient for actual production.

The application discloses a manganese iron hydrogen phosphate material and a preparation method and application thereof, relates to the technical field of battery materials. The chemical formula of the manganese iron hydrogen phosphate material is as follows: Fe x Mn (1‑x) HPO4, wherein x is 0.1-0.7.The manganese iron hydrogen phosphate material is used in a lithium battery, and the platform voltage of the manganese iron hydrogen phosphate material reaches 4.1v, the cycle life is greatly improved in comparison with a lithium iron phosphate battery, in addition, the manganese material is rich in domestic reserves, is easy to obtain, is low in price, and is small in environmental hazards, and the manganese iron hydrogen phosphate material can make up for the shortcomings of ternary and lithium iron phosphate.

The invention relates to the technical field of composite material preparation, in particular to a liquid silica gel composite material filled with hydroxyapatite nanowires and a preparation method of the liquid silica gel composite material. Calcium ions and hydrogen phosphate ions are added into a mixed solution of ethanol and oleic acid, and the one-dimensional hydroxyapatite nanowire with a hydrophobic surface is hydrothermally synthesized in an alkaline environment through a one-step method. Wherein oleic acid is used as a surface modifier to endow the material with a hydrophobic property, and nucleation and growth of hydroxyapatite nanowire crystals are adjusted by simply regulating and controlling the volume ratio of ethanol to water, so that the size of the hydroxyapatite nanowire is highly controllable from 8 microns to 50 microns. According to the invention, the biocompatibility and implantation stability of the liquid silica gel are improved. Besides, based on the enhancement effect of nanowires with different sizes on the mechanical property of the composite material, the adaptation range and the application field of the composite material are expected to be expanded, so that the requirement of the current medical material for precise and personalized development is met.