61 results about "Sodium oxalate" patented technology

The invention relates to the technical field of wave-absorbing materials, in particular to a preparation method of an MXene-NiO-PPy ternary composite wave-absorbing material. The invention provides a preparation method of an MXene-NiO-PPy ternary composite wave-absorbing material, which comprises the following steps of: etching titanium aluminum carbide powder through a LiF / HCl mixture, and performing ultrasonic stripping to prepare a uniform dispersion of MXene nanosheets; the preparation method comprises the following steps: dispersing MXene nanosheets in a solution of water and absolute ethyl alcohol, and adding a pyrrole monomer and a FeCl3. 6H2O aqueous solution for reaction; after the reaction, washing is performed to obtain a PPy-MXene composite material; the preparation method comprises the following steps: by taking NiCl2. 6H2O as a nickel source and sodium oxalate as a precipitator, preparing NiO nanowires by adopting a hydrothermal method combined with a calcining process; the invention discloses a preparation method of an MXene-NiO-PPy ternary composite wave-absorbing material.According to the method, the MXene-NiO-PPy ternary composite wave-absorbing material with rich heterogeneous interfaces and a porous micro-nano structure is constructed, cooperation of dielectric loss, magnetic loss and interface polarization loss is achieved, and finally the light, efficient and broadband wave-absorbing performance is obtained.

The invention discloses a water-based compensation sodium source sodium ion battery positive pole piece and a preparation method thereof. Mixing a positive active material, a conductive agent, a water-based binder, a water-soluble sodium supplement agent and a solvent to obtain positive slurry; wherein the water-soluble sodium supplement comprises sodium nitrite, sodium oxalate and sodium citrate; the solvent is water; and coating the surface of a current collector with the positive electrode slurry to prepare the positive electrode plate. Deionized water is used for replacing a traditional organic solvent to serve as a pulping solvent, and dual-function optimization is achieved by adding a specific water-soluble sodium supplementing agent. The sodium supplementing agent is uniformly distributed in the pole piece through a dissolution-recrystallization mechanism, and an efficient sodium ion pre-compensation system is formed. According to the method, the production cost and the energy consumption are remarkably reduced, the structural degradation of the positive active material in a water system environment can be effectively inhibited, irreversible sodium loss caused by formation of a first-week solid electrolyte interface (SEI) of a negative electrode is counteracted through a sodium source compensation mechanism, and the method has remarkable environmental friendliness and industrial application value.

The invention belongs to the technical field of catalyst preparation, and particularly relates to an ozone catalyst for water treatment and a preparation method thereof, and the preparation method comprises the following steps: uniformly mixing iron-manganese modified zeolite subjected to hot water treatment, TEOS hydrolysate, VTMS hydrolysate, a VSNa solution, divinyl benzene, an initiator, sodium chloride and CMC to obtain slurry, treating the slurry into wet particles, and drying the wet particles to obtain the ozone catalyst for water treatment. Carrying out heating curing treatment on the wet particles to obtain a catalyst precursor, washing the catalyst precursor with deionized water, and then carrying out heat treatment and cooling to obtain the catalyst. The method can effectively reduce the effluent COD of the petrochemical wastewater containing sodium oxalate, and is high in long-term use stability.

The invention relates to a sodium-ion battery and application thereof.The sodium-ion battery comprises a positive plate, a diaphragm, a negative plate, electrolyte and a current interruption device, and the sodium-ion battery meets the following two conditions that (1) a positive active material layer of the positive plate contains gas production particles and auxiliaries, the gas production particles are selected from sodium carbonate and / or sodium oxalate, the auxiliary agent is selected from ferric chloride and / or aluminum chloride, and the mass fraction of the gas production particles in the positive electrode active material is greater than that of the auxiliary agent in the positive electrode active material layer; the sum of the mass fractions of the gas generation particles and the auxiliary agent in the positive electrode active material layer is within 4%; and (2) the trigger threshold value of the current interruption device is 0.55 MPa to 0.85 MPa. According to the sodium ion battery disclosed by the invention, the potential safety hazard of the traditional sodium ion battery under the working conditions of overcharge and thermal abuse can be solved by optimizing the synergistic effect of the internal gas production mechanism of the battery cell and the CID trigger threshold value.

The invention provides a method for synergistically removing organic matters in an aluminum oxide production process, and belongs to the field of aluminum oxide production. The method comprises the following steps: adding a macromolecular organic matter oxidant into a sodium aluminate solution, and carrying out a stirring reaction to degrade macromolecular organic matters in the sodium aluminate solution into medium and small molecular organic matters, so as to obtain a first mixed solution; carrying out solid-liquid separation on the first mixed solution to obtain a first filtrate; adding a sodium oxalate adsorbent into the first filtrate, and carrying out stirring reaction, so that sodium oxalate in the first filtrate is subjected to controlled crystallization on the surface of the sodium oxalate adsorbent to obtain a second mixed solution; carrying out solid-liquid separation on the second mixed solution to obtain a second filtrate; and returning the second filtrate to the aluminum oxide production process. Through a step-by-step targeted treatment design, the limitation of single type of removed organic matters in the existing organic matter removal technology is effectively overcome, and meanwhile, by virtue of an adsorbent mediated crystallization mechanism, the problem that the sodium oxalate crystal morphology is difficult to effectively control is solved.

An integrated energy system comprising a power plant configured to generate steam. The power plant may comprise a nuclear reactor and / or an electricity generation system. A chemical product generation system may comprise a first reaction chamber that receives sodium formate (HCOONa), which decomposes into sodium oxalate ((COO)2Na2) and hydrogen (H2), via the insertion of a first portion of steam at a first temperature, wherein the steam may comprise a first reaction chamber containing superheated steam. A chemical product generation system may comprise a second reaction chamber that receives sodium oxalate ((COO)2Na2), which decomposes into sodium oxide (Na2O), carbon monoxide (CO), and carbon dioxide (CO2), via the insertion of a second portion of steam at a second temperature. A syngas generation system may be operably connected to the chemical product generation system and configured to generate a combination of hydrogen (H2), carbon monoxide (CO), and / or carbon dioxide (CO2), and / or syngas.

A method for efficiently recovering cobalt and nickel from waste lithium battery extract belongs to the field of hydrometallurgical technology. The technical problem solved by this invention is to provide a low-cost, low-pollution, and high-efficiency method for recovering cobalt and nickel from waste lithium battery extract. Specifically, it discloses a method using sodium oxalate solution to back-extract from a nickel-cobalt containing extract, obtaining a back-extract, then precipitating by adjusting the pH, and finally obtaining cobalt oxalate and nickel oxalate products after drying. The method includes the following steps: (1) preparing a sodium oxalate solution; (2) back-extraction; (3) cobalt precipitation; (4) nickel precipitation; (5) washing and drying the precipitate. This method is not only simple to operate, highly efficient, low-cost, and environmentally friendly, but also regenerates the extract, making it suitable for industrial production.

The present application provides a kind of high-efficiency polymerization inhibitor for styrene rectification, by weight parts, including following each component: 20-40 parts of radical scavenger, 15-25 parts of modified alkylamine and 50-100 parts of composite alcohol solution, 2-4 parts of sodium citrate and 1-3 parts of sodium oxalate;The radical scavenger is porous calcium carbonate microspheres loaded with nitroxyl radical and plant extract;The modified alkylamine is layered double hydroxide LDH loaded with alkylamine;The composite alcohol solution is ethylene glycol, glycerol and polyvinyl alcohol;It is applied to styrene rectification, and the polymerization inhibition capacity is obviously improved by efficient capture of free radical.

The invention discloses a degreasing agent for a base plate of a cold-rolled hot-dip aluminum-zinc steel plate and a degreasing method, and mainly solves the technical problems that an existing degreasing agent for the base plate of the cold-rolled hot-dip aluminum-zinc steel plate is low in degreasing efficiency, and oxides on the surface of the steel plate cannot be completely removed. According to the technical scheme, the degreasing agent for the base plate of the cold-rolled hot-dipped aluminum-zinc steel plate comprises the following components in percentage by weight: 10%-25% of sodium hydroxide, 5%-15% of potassium hydroxide, 3%-6% of a surfactant OP-10, 4%-8% of sodium dodecyl benzene sulfonate, 1%-2% of fatty alcohol polyoxyethylene ether sodium sulfate, 2%-10% of sodium oxalate and the balance of water. 2%-5% of sodium gluconate, 1%-5% of potassium chloride, 2%-4% of organic silicon defoaming agent and the balance of deionized water. The degreasing agent is suitable for removing residual oil and iron oxide on the surface of a base plate of a cold-rolled hot-dipped aluminum-zinc steel plate, the degreasing capacity and the iron removal capacity are high, and the using effect is good.

The present application relates to the technical field of lithium carbonate preparation, in particular to a method for preparing battery-grade lithium carbonate by using salt lake lithium carbonate, comprising the following steps: adding purified water and ethanolamine to crude lithium carbonate from salt lake brine, wet ball milling, then adding sodium hydroxide solution for alkali washing, adopting purified water to make slurry of the obtained filter residue A, carbonizing to obtain filter liquor B, adding magnesium chloride and sodium oxalate in sequence for impurity removal, pyrolyzing and crystallizing, drying the obtained lithium carbonate wet product to obtain battery-grade lithium carbonate. The method has the advantages of high purification process treatment efficiency and high lithium recovery rate, and the prepared lithium carbonate product can meet the requirements of battery-grade lithium carbonate.

The application provides a method for preparing lead oxide from copper smelting electric dust ash, and comprises the following process steps: (1) sulfuric acid leaching: adding sulfuric acid; (2) acetic acid leaching: adding acetic acid; (3) ammonia water-sodium acetate leaching: adding ammonia water and sodium acetate; (4) lead precipitation: adding sodium oxalate; (5) lead oxide. The application adopts twice acid leaching, on the one hand, valuable metals in the copper smelting electric dust ash except lead are effectively leached; on the other hand, impurity elements in the acid leaching residue are reduced, and high-purity lead oxide products are prepared subsequently. The lead element in the acid leaching residue is leached by ammonia water-sodium acetate, and under the weak alkaline condition, the leaching of lead is beneficial, and the leaching of other elements such as copper, arsenic and zinc is inhibited.

The invention relates to the technical field of battery materials, in particular to a sodium ion battery positive electrode material and a preparation method and application thereof. The sodium ion battery positive electrode material is prepared by the method. The method comprises the following steps: carrying out ultrasonic treatment on a reaction system, and then carrying out heating and stirring treatment to obtain a precipitate mixed solution; carrying out centrifugal treatment on the precipitate mixed solution to obtain a coarse precipitate; washing and centrifuging the coarse precipitate to obtain a precipitate; performing freeze drying treatment on the precipitate to obtain precursor powder; and uniformly mixing the precursor powder, the nano TiO2 powder, anhydrous sodium carbonate and sodium oxalate, and sequentially carrying out ball milling treatment, screening treatment, tabletting treatment and calcination treatment to obtain the sodium ion battery positive electrode material. The application is the application of the sodium ion battery positive electrode material in a sodium ion secondary battery. According to the invention, the problems of irreversible structure phase change and high sodium ion diffusion barrier in charge-discharge cycles due to the adoption of O3-phase layered transition metal oxide in the existing commercial sodium ion positive electrode material are solved.

The invention provides an alkaline chemical polishing solution suitable for a high-Si-content aluminum alloy inner runner and a polishing method, and belongs to the technical field of metal material surface treatment. According to the method, an alkaline polishing solution composed of sodium hydroxide, sodium nitrate, thiourea, sodium silicate, sodium phosphate, sodium fluoride, ceric sulfate and an additive is adopted for conducting long-time chemical polishing on the high-silicon aluminum alloy at the room temperature, and dilute acid neutralization, acetic acid activation and sodium oxalate and sodium dodecyl benzene sulfonate composite cleaning solution are matched for ultrasonic dust removal. According to the technology, nitric oxide pollution generated by acid polishing is avoided, the corrosion rate is reduced, effective polishing of a complex inner runner is achieved, the surface roughness is remarkably reduced, material loss is small, hanging dust is completely removed, and the technology has environment friendliness and high-precision machining capacity.

This application provides a method for deep removal of calcium impurities from scandium oxide, belonging to the field of rare earth metal oxide purification. The method includes: dissolving scandium oxide raw material containing calcium impurities to obtain a calcium-containing scandium solution; adding a pH adjuster to the calcium-containing scandium solution to obtain a first scandium solution; reacting the first scandium solution with phosphoric acid and / or phosphate to obtain a second scandium solution and solid calcium phosphate; reacting the second scandium solution with a complexing agent to obtain a third scandium solution; reacting the third scandium solution with oxalic acid and / or sodium oxalate to obtain scandium oxalate crystals and a calcium complex solution; adding a strong acid solution to the calcium complex solution; and calcining the scandium oxalate crystals to obtain scandium oxide. Through calcium phosphate precipitation-complexation-crystallization, not only can calcium impurities be deeply removed from scandium oxide products, but impurities such as iron, titanium, and zirconium can also be removed, resulting in scandium oxide products with a purity of over 99.99%.

The present application relates to white cement admixture technical field, specifically to a kind of composite liquid early strength agent of white Portland cement, including the following weight parts of raw material, reinforcing component 30~40 parts, auxiliary solubilization stabilizing component 5~10 parts and carrier 50~65 parts, the total part of the composite liquid early strength agent is 100 parts, the reinforcing component is organic salt, inorganic salt reinforcing agent, the organic salt, inorganic salt reinforcing agent includes sodium oxalate, sodium carbonate and magnesium fluorosilicate, the auxiliary solubilization stabilizing component is the mixture of lignosulfonate and polyglycerol, the lignosulfonate is sodium lignosulfonate, and the polyglycerol is triglycerol, the composite liquid admixture of the present application, environmental friendly, preparation process is simple, improve white cement early (3d) strength 10%~15%, save white cement product curing time and improve formwork turnover rate.

The invention relates to the technical field of batteries, in particular to a battery monomer, a preparation method of a secondary battery, an electrolyte and an electric device. Each single battery comprises a positive pole piece, a negative pole piece and an electrolyte, at least partial structures of the positive pole piece and the negative pole piece are located in the electrolyte, the electrolyte comprises a metal ion complexing agent, and the metal ion complexing agent comprises an organic complexing agent and / or an inorganic complexing agent; the organic complexing agent comprises at least one of phenanthroline, a crown ether compound, oxalic acid, citric acid, tartaric acid, ethylenediamine tetraacetic acid and deferoxamine; and / or the inorganic complexing agent comprises at least one of sodium oxalate, sodium citrate, sodium tartrate and sodium ethylene diamine tetracetate. The metal ion complexing agent in the electrolyte can be combined with impurity metal ions in the electrolyte to form a stable complex, so that the risk that the impurity metal ions are separated out into dendritic metal foreign matters at an anode to pierce a diaphragm to cause self-discharge of the battery is reduced.

This application provides a method for preparing high-whiteness aluminum hydroxide based on oxalate filter cake, belonging to the field of aluminum hydroxide preparation. The method includes: adding sodium oxalate circulating seed to the Bayer process seeding mother liquor to obtain an oxalate filter cake containing aluminum hydroxide; adding sodium carbonate to the oxalate filter cake to adjust the alkali ratio to 0.85–1.15, and adding lime to the oxalate filter cake to obtain a mixture; sintering the mixture to obtain sintered clinker; dissolving the sintered clinker to obtain a sodium aluminate solution; and seeding the sodium aluminate solution to obtain high-whiteness aluminum hydroxide. This application, through precise coupling of process parameters and a full-process design of the impurity control chain, simultaneously achieves deep removal of key impurities such as Fe and Si during the oxalate removal process, transforming the oxalate filter cake from waste into a high-quality raw material for high-whiteness aluminum hydroxide, thus combining the removal of organic matter from oxalate and the preparation of high-whiteness aluminum hydroxide in the Bayer process alumina production.

This invention discloses a method for determining the permanganate index based on modified biochar adsorbents, comprising the following steps: Step 1, modifying the biochar with a modifying solution. When the concentration of the modifying solution is 0.1 mol / L, an acidic modifier is used to modify the biochar adsorbent; when the concentration of the modifier solution is 0.2~0.4 mol / L, a salt modifier is used. Step 2, thoroughly shaking and mixing the modified biochar adsorbent with a water sample, adding sulfuric acid solution to acidify the water sample, adding potassium permanganate solution to the acidified water sample and heating the reaction, adding sodium oxalate solution after heating, shaking until the solution becomes colorless and without precipitate, titrating with potassium permanganate solution while hot until a light pink color appears and does not fade within a fixed time, recording the volume of potassium permanganate solution consumed, and calculating the potassium permanganate index. The type and concentration of the modifier used in this invention have a significant impact on the adsorption performance of biochar.

An integrated energy system including a power plant is discussed herein. In some examples, the integrated energy system may include at least one nuclear reactor and electrical power generation system configured to generate steam and electricity, a water treatment plant configured to produce Sodium Hydroxide (NaOH) from salt water, a Sodium Formate (HCOONa) production plant configured to receive the Sodium Hydroxide (NaOH) to produce Sodium Formate (HCOONa), a Thermal Decomposition reactor configured to receive the Sodium Formate (HCOONa) and configured to receive at least a first portion of the steam or at least a second portion of the electricity from the power plant to indirectly heat the Thermal Decomposition reactor to produce Hydrogen (H2), Carbon Dioxide (CO2), and Carbon Monoxide (CO) from the Sodium Formate (HCOONa), and a Methanol (CH3OH) reaction chamber configured to receive the Hydrogen (H2), the Carbon Dioxide (CO2), and the Carbon Monoxide (CO) to produce Methanol (CH3OH).

The invention relates to the technical field of sodium battery materials, in particular to a sodium supplementing coating based on a spiral iron-carbon-based composite material and a preparation method thereof.A spiral polypyrrole template is synthesized through a chiral template method, and a Fe3C-CNS spiral carbon composite material rich in Fe3C nanocrystals and iron monatomic sites is prepared through iron loading, vulcanization and high-temperature pyrolysis. The preparation method comprises the following steps: preparing a Na2C2O4-coated Fe3C-coated CNS composite material, loading sodium oxalate on the surface and in pore channels of the Na2C2O4-coated Fe3C-coated CNS composite material in a high-dispersion manner through a recrystallization method to prepare the Na2C2O4-coated Fe3C-coated CNS composite material, finally mixing the Na2C2O4-coated Fe3C-coated CNS composite material with a conductive agent and a By adopting the sodium supplementing coating based on the spiral iron-carbon-based composite material and the preparation method of the sodium supplementing coating, the problems of irreversible sodium loss in the first week and poor interface stability of an existing sodium ion battery are solved, efficient pre-sodium treatment and interface cooperative regulation and control are realized, and the comprehensive performance of the battery is improved.

The present application belongs to the technical field of water quality permanganate index detection, and particularly relates to a detection system for online monitoring of permanganate index. The present application provides a detection system for online monitoring of permanganate index, aiming at solving the problem of low detection precision of permanganate index in the prior art. The present method adopts a spectrophotometric colorimetric method, eliminates the reducing agent in the traditional online analysis method, reduces the reagent use cost, and also avoids the instability of sodium oxalate in a high-temperature and acidic environment, thereby generating systematic errors. The present method eliminates the use of reducing agent, and compared with the laboratory and the traditional online analysis process, the analysis process of the present method is reduced, the single test cycle is about 25 minutes, which is about 56-63% of the traditional online time length, and is far less than the analysis time length of the laboratory.

The invention belongs to the technical field of electronic materials, and particularly relates to a composite insulation coated FeSi soft magnetic composite material and a preparation method thereof. The preparation method comprises the following steps: (1) reacting FeSi powder, aluminum nitrate and sodium oxalate to obtain FeSi coated Fe3O4 / Al (OH) 3 core-shell powder; (2) treating the obtained sample to obtain FeSi coated SiO2 / Al2O3 insulating coating powder; (3) adding a silane coupling agent and organic resin into the obtained sample to obtain organic resin coated FeSi coated SiO2 / Al2O3 insulating coating powder; and (4) mixing the obtained sample with a lubricant, and treating to obtain the FeSi soft magnetic composite material. Through coating of the composite insulating layer, the thickness of the insulating layer in the soft magnetic composite material is uniform and easy to control, the insulating layer and the matrix metal form metallurgical and chemical combination, the binding force is high, the resistivity of the insulating layer is high, and the FeSi soft magnetic composite material prepared through the method has high magnetic conductivity and lower magnetic loss.

The invention provides a sodium ion battery, and relates to the technical field of sodium ion batteries. The sodium ion battery comprises a positive electrode, a negative electrode and electrolyte, the positive electrode comprises a positive electrode material layer, and the positive electrode material layer comprises a positive electrode active material and electrolyte; the electrolyte comprises a functional additive; the functional additive comprises a fluorine-containing crown ether compound and a sodium bisoxalate-containing compound. The sodium ion battery provided by the invention has excellent high and low temperature performance.

The invention discloses a method for determining an organic additive in an ammonia chloride method electrolytic zinc solution, and relates to the technical field of ammonia chloride method electrolytic zinc solution determination, and the method comprises the following steps: preparing an organic additive standard solution A with a concentration of a; the method comprises the following steps: diluting a to-be-detected sample of an ammonia chloride process electrolytic zinc solution with water to n times of volume to obtain a diluted sample; respectively measuring the permanganate indexes of the standard solution A and the diluted sample by adopting a potassium permanganate oxidation-sodium oxalate reduction titration method; calculating a conversion coefficient; and calculating the concentration of the organic additive in the to-be-detected sample according to a formula. According to the method, the unknown additive can be measured, and the measurement precision and reliability are improved, so that accurate data support is provided for the production process.

The application relates to a method for producing vanadium concentrate and sodium oxalate from a Bayer process, comprising the following steps: providing a seed mother liquor in a Bayer production process, evaporating and concentrating the seed mother liquor to obtain a concentrated mother liquor; after cooling the concentrated mother liquor, adding vanadium salt seeds to the concentrated mother liquor for vanadium salt crystallization; performing solid-liquid separation on the concentrated mother liquor to obtain vanadium concentrate and a separated liquor; after heating the separated liquor to a predetermined temperature, increasing the caustic alkali concentration of the separated liquor; cooling the separated liquor with the increased caustic alkali concentration to perform sodium oxalate crystallization, and obtaining rich sodium oxalate crystals, wherein the caustic alkali concentration of the separated liquor is increased by at least one of the following two ways: evaporation and concentration or caustic alkali addition. The application can obtain high-grade vanadium concentrate and rich sodium oxalate crystals.

The invention provides a composite phase change energy storage material and a preparation method and application thereof, and belongs to the field of heat exchange materials. The composite phase change energy storage material provided by the invention comprises the following components: erythritol, oxalic acid and sodium oxalate, the mass of the sodium oxalate is 8% of the mass of the composite phase change energy storage material; the mass of the oxalic acid is 1-3% of the mass of the composite phase change energy storage material. The raw material components of the composite phase change material provided by the invention are simply and physically mixed, and no chemical change occurs; due to the addition of sodium oxalate, the supercooling phenomenon of erythritol is inhibited to a certain extent, and the composite phase change energy storage material has good cycle stability within 145 DEG C; and when the mass fraction of sodium oxalate is 8 wt%, the permeability of the obtained composite phase change energy storage material is the lowest and is only about 5%.

The invention belongs to the technical field of fire fighting, and particularly relates to a novel oxygen-control fire-extinguishing composition for an electrical fire environment and application of the novel oxygen-control fire-extinguishing composition. The invention firstly provides a composition with oxygen control and fire extinguishing effects. The composition comprises a first powder material, a second powder material and an adhesive, the first powder material is carbon powder; the second powder material comprises potassium nitrate, ammonium chloride and sodium oxalate; and the adhesive is guar gum. The fire extinguishing material provided by the invention has the performance of generating a chain reaction, and can generate inert gas during ignition to remove air in a closed space in a short time, so that the purpose of extinguishing fire is achieved, and the fire extinguishing material is particularly suitable for a fire scene caused by electricity in the closed space.

The invention discloses a modified Na-PHI carbon nitride catalyst with high photocatalytic performance, a synthesis method and application of the modified Na-PHI carbon nitride catalyst in photocatalytic hydrogen production. Firstly, a urea raw material and multiple carbon dopants are subjected to high-temperature calcination to synthesize an intermediate product, then sodium chloride, sodium oxalate and the intermediate product in a certain proportion are mixed, calcined and treated, and finally a series of modified Na-PHI carbon nitride is obtained. The preparation method has the advantages of cheap raw materials, simple operation process and green and stable sample, and can be recycled for many times. The modified Na-PHI shows excellent photocatalytic hydrogen production efficiency in a photocatalytic water electrolysis hydrogen production reaction, wherein the hydrogen production efficiency of a modified Na-PHI sample with the most excellent activity is 20.6 times that of common carbon nitride PCN and 4.2 times that of common Na-PHI at the wavelength lambda larger than or equal to 420 nm; the hydrogen production efficiency at the wavelength lambda larger than or equal to 500 nm is 35.4 times that of common Na-PHI (common carbon nitride PCN is inactive).

The present application relates to the inorganic nonmetal field, specifically to a kind of silver-coated hollow glass microsphere and its preparation method and application in electromagnetic shielding.The preparation method provided by the present application utilizes alkali activation silane coupling agent and silver nitrate to activate hollow glass microsphere, lays foundation for subsequent silane coupling agent and silver oxalate connection, improves silver-coated coating amount and degree of combination;Adopt sodium oxalate as the precipitant of silver, and the property is stable, transportation is convenient, reduction reaction is also stable, and sodium oxalate is low in cost, easy to obtain.The whole process does not produce waste gas, no resource waste, and the reagent consumed can be recycled;Two kinds of silver ion solution are configured in the preparation process, to avoid the excessive use of silver ion solution, further reduce cost.In addition, the silver-coated hollow glass microsphere obtained by the preparation method provided by the present application is uniformly coated with silver, not only good electromagnetic shielding performance, but also high thermal conductivity.

The present application relates to a kind of lithium iron phosphate black powder full element recovery preparation battery grade lithium dihydrogen phosphate and ferrous oxalate method, belong to waste battery recycling technical field.The method includes: lithium iron phosphate black powder is mixed with sodium salt and is calcined, lithium, iron, phosphorus is converted into soluble sodium phosphate and iron-containing lithium residue;By water immersion and dilute sulfuric acid assisted leaching, sodium phosphate leaching liquid and iron-containing lithium solid residue are obtained by separation;Iron-containing lithium solid residue is acid leaching, iron powder reduction, calcium and magnesium are removed by chelating resin, and then reacted with sodium oxalate to prepare battery grade ferrous oxalate;After sodium phosphate leaching liquid is removed by chelating resin aluminum, it is mixed with lithium-rich liquid of ferrous oxalate preparation section, and lithium phosphate is prepared by double decomposition reaction;Lithium phosphate is reacted with phosphoric acid to obtain battery grade lithium dihydrogen phosphate finally.The present application realizes the full element recovery of lithium, iron, phosphorus and carbon, and the product has high purity, which can be directly used to prepare high-pressure lithium iron phosphate positive material, and has the advantages of simple process, low cost and green environmental protection.