324 results about "FERRIC IRON" patented technology

This invention discloses a method for leaching lithium iron phosphate mixed powder with iron salts and recovering all components, belonging to the field of battery recycling. The invention uses an iron salt solution to leach the mixed powder, obtaining a lithium-containing leachate and leaching residue. Ferrous ions in the leachate are regenerated into ferric iron through acidification and oxidation, and recycled for leaching the next batch of mixed powder. After reaching a preset number of cycles, the leachate is used for re-leaching multiple batches of leaching residue to improve the lithium leaching rate. Ultimately, a enriched solution containing Li, Fe, Cu, and Al and graphite-containing iron phosphate residue are obtained. Copper is recovered from the enriched solution through iron powder replacement, and a high-purity lithium chloride solution is obtained through extraction and separation, while ferric chloride (recycled) and aluminum chloride crystals are also recovered. The leaching residue is treated with hydrochloric acid to obtain regenerated graphite, and the pH is adjusted with alkali to obtain high-purity iron phosphate. This method achieves full component recovery under mild conditions, reducing separation steps and chemical consumption through a "leaching-regeneration-leaching" cycle mechanism, thus achieving both environmental and economic benefits.

The invention provides an improved treatment method for laterite-nickel ore. The improved treatment method comprises the following steps: S1, carrying out acid leaching on the laterite-nickel ore, and then filtering and washing to obtain a leached solution and first leached residues; step S2, the step S2 is selected from any one of a step S2-1, a step S2-2 and a step S2-3; s3, performing first-stage nickel and cobalt precipitation and dense filtration on the aluminum and scandium removed liquid or the iron and aluminum removed liquid by adopting a precipitator to obtain first-stage nickel and cobalt precipitation liquid and a nickel cobalt hydroxide product; and S4, carrying out second-stage nickel-cobalt precipitation on the first-stage nickel-cobalt precipitation solution by adopting a nickel-cobalt precipitation neutralizer and an oxidizing agent to obtain a magnesium sulfate manganese solution and nickel-cobalt-manganese slurry. In the traditional process, ferrous iron is oxidized by using compressed air, so that energy is wasted. According to the method, the manganese-containing substance is adopted as the oxidizing agent, ferrous iron is oxidized into ferric iron, the problems that the ferrous iron is low in oxidation rate under the low pH and compressed air is wasted are solved, and the scandium recovery rate is increased.

The invention discloses a resource utilization method of Fenton iron mud. According to the method, a citric acid-ascorbic acid composite solution is used for soaking Fenton iron mud, hydrothermal liquefaction is carried out in an inert reduction system, ferric iron is reduced into ferrous iron, and a ferrous iron solution generated after reaction can directly form a Fenton reagent with hydrogen peroxide to be reused for Fenton reaction. By the adoption of the method, iron can be completely recycled, resource utilization of the Fenton iron mud is facilitated, the mass of the treated filter residues is only 1 / 10 of that of the iron mud, and the disposal amount of hazardous waste is effectively reduced.

The present invention discloses a rapid preparation method and application of a NiFe-LDH nickel-based electrode, belonging to the technical fields of electrolytic water hydrogen production and anion exchange membrane electrolytic water. The preparation method includes the following steps: S1. Under normal temperature and pressure, immerse the cleaned nickel-based substrate material into a ferric iron (Fe<supgt;3+< / supgt;) etching solution for chemical etching, let it stand for an appropriate time to fully react, and then take it out and dry; S2. Immerse the material obtained in step S1 into a strong alkaline solution for soaking treatment, let it stand for an appropriate time to fully react, and then take it out and dry; S3. Assemble the electrode material prepared in step S2 into a membrane electrode, and install it into a single cell of an anion exchange membrane electrolytic water tank for testing, so that it can stably convert electrical energy into hydrogen energy during operation. This technical solution can rapidly, low-cost, greenly and in large quantities prepare an electrolytic water anode electrode, overcomes the drawbacks of the cumbersome electrode preparation methods in the current same field, and is expected to promote the commercial development of alkaline membrane electrolytic water hydrogen production technology.

The invention discloses a method for separating and recycling phosphorus, iron and lithium in battery black powder, and relates to the technical field of battery recycling. The method comprises the following steps: carrying out acid leaching on battery black powder to obtain a battery black powder leaching solution and filter residues; an oxidizing agent is added into the battery black powder leaching solution, the pH of the solution is adjusted to 1.8-2.5, solid-liquid separation is conducted after the reaction is completed, and iron phosphate sediment and a lithium-containing solution are obtained; adjusting the pH value of the lithium-containing solution to 10-12, and carrying out solid-liquid separation after the reaction is completed to obtain a metal precipitate and a lithium sulfate solution; dissolving the iron phosphate precipitate in a sulfuric acid solution, adding a reducing agent to reduce ferric iron into ferrous iron, separating out ferrous sulfate by adopting an alcohol precipitation method or an ammonium sulfate crystallization method, and performing solid-liquid separation after the reaction is completed to obtain ferrous sulfate precipitate or ammonium ferrous sulfate crystals and mother liquor; and evaporating and concentrating the mother liquor, and extracting to obtain a phosphoric acid solution. According to the method, the three elements of phosphorus, iron and lithium in the battery black powder can be recycled, and the environmental problem caused by stacking of the lithium extraction slag can be avoided.

The invention discloses an organic wastewater advanced treatment method and device with low agent input. The method comprises the following steps: an anaerobic biological iron-sulfur reduction reaction process: fully mixing elemental sulfur, ferric iron, iron-sulfur reduction sludge and wastewater containing organic carbon and organic pollutants with electronegative groups, carrying out anaerobic biological elemental sulfur reduction and iron reduction reactions, and directionally generating polysulfide and ferrous sulfide in situ; a nucleophilic substitution reaction process: carrying out nucleophilic substitution reaction on the organic pollutants with the electronegative groups and the polysulfide, and removing the electronegative groups to generate a reduced organic product; in the oxidation reaction process, ferrous sulfide reacts with dissolved oxygen to generate hydroxyl free radicals, the reduction state organic product is oxidized and degraded, and elemental sulfur and ferric iron are generated; and a sludge precipitation process: refluxing the precipitate to the anaerobic biological iron-sulfur reduction reaction zone, and discharging clarified water. The method provided by the invention realizes deep degradation and detoxification of refractory organic pollutants, and has the advantages of low agent investment, low cost and no secondary pollution.

The invention relates to the technical field of preparation of battery materials, and discloses a method for synthesizing iron phosphate through continuous oxidation, which comprises the following steps: oxidation: oxidizing a ferrous solution by adopting oxygen-containing gas to obtain a ferric iron solution; synthesizing iron phosphate: reacting the ferric iron solution with a phosphorus source to obtain amorphous iron phosphate; and crystal transformation and roasting: carrying out crystal transformation and roasting on the amorphous iron phosphate to obtain the iron phosphate. The iron phosphate material prepared by the invention is oxidized by adopting the oxygen-containing gas, so that compared with hydrogen peroxide adopted in the prior art, the cost is lower, and the specific surface area and the tap density of the prepared iron phosphate material are higher.

The invention discloses a method for circularly leaching lithium iron phosphate mixed powder from ferric salt and recovering all components, and belongs to the field of battery recovery. The method comprises the following steps: leaching mixed powder by adopting an iron salt solution to obtain a lithium-containing leaching solution and leaching residues; ferrous ions in the leachate are regenerated into ferric iron through acidification and oxidation, the ferric iron is cyclically used for leaching the next batch of mixed powder, after the preset cycle number is reached, the leachate is used for re-leaching treatment of multiple batches of leaching residues, and the lithium leaching rate is increased. And finally obtaining enriched liquid containing Li, Fe, Cu and Al and iron phosphate slag containing graphite. And replacing the enriched liquid with iron powder to recover copper, extracting and separating to obtain a high-purity lithium chloride solution, and simultaneously recovering ferric chloride (recycling) and aluminum chloride crystals. And treating the leaching residues with hydrochloric acid to obtain regenerated graphite, and adjusting the pH value with alkali to obtain high-purity iron phosphate. According to the method, all-component recovery is achieved under the mild condition, separation steps are reduced through a leaching-regeneration-leaching circulation mechanism, chemical consumption is reduced, and the method has both environmental and economic benefits.

The present invention provides a Fenton iron sludge treatment method and device, comprising the following steps: allowing the Fenton iron sludge to enter an iron reduction unit, undergoing reduction treatment under the action of dissimilatory iron-reducing bacteria, reducing the trivalent iron in the Fenton iron sludge to divalent iron through the reduction treatment to obtain reduced iron sludge; allowing at least a portion of the reduced iron sludge to enter a bioleaching unit, undergoing bioleaching treatment under the action of specific microorganisms to obtain a first mixed liquid; dehydrating the first mixed liquid to obtain an aqueous phase and dehydrated sludge, respectively; and returning the aqueous phase to the bioleaching system to participate in the bioleaching treatment. The present invention can solve technical problems existing in the prior art, such as the need for additional acid, the generation of a large amount of strongly acidic water, the susceptibility to environmental pollution, the inability to recycle iron, and high costs.

The invention discloses a method for measuring the content of ferric ions in an iron-chromium flow battery electrolyte, which comprises the following steps: before the content of the ferric ions is measured, pretreating the electrolyte to be measured to remove the influence of Cr ions and other impurity ions in the electrolyte on an experimental result, and then titrating with a sodium thiosulfate standard solution; the method has the advantages that the method is suitable for directly measuring the content of the ferric ions under the coexistence condition of a large amount of ferrous ions, the problems that in the prior art, when a large amount of ferrous ions and a trace amount of ferric ions coexist, the error is large, and the accuracy is low are solved, and a technical guarantee is provided for capacity recovery and efficiency improvement of the electrolyte of the flow battery.

The invention discloses a preparation method and application of an aqueous iron ion battery positive electrode material. The preparation method comprises the following steps: (1) respectively mixing a single type of ferric salt and potassium ferricyanide with water to obtain a solution A and a solution B; (2) mixing the solution A and the solution B, stirring in a water bath kettle, and carrying out a co-precipitation reaction to obtain a solid precipitate; and (3) centrifuging, washing and drying the solid precipitate to obtain the nano-particles with the particle size of 150-200nm. The obtained nanoparticles can be used as an aqueous iron ion battery positive electrode material, the positive electrode can realize Fe < 2 + > and NH4 < + > ion co-de-intercalation electrochemical reaction in the charging and discharging process, and the reversible specific capacity of the battery is remarkably improved; the embedded NH < 4 + > and N in the positive electrode material can form a stable hydrogen bond structure, so that the cycling stability of the battery is effectively improved. The preparation process is easy to operate, the product yield is high, the consistency is excellent, and the method is suitable for large-scale preparation and application.

Described are methods for producing industrial gases (e.g., hydrogen, ammonia, and / or methane) using ferrous iron-containing materials (e.g., olivine) while concurrently sequestering carbon dioxide. The process may involve mixing a ferrous iron-containing material with water and, in some examples, a reaction accelerant. The mixture may be heated to 100-300°C to initiate the oxidation of ferrous cations (Fe2+) to ferric cations (Fe3+) while reducing hydrogen (from water) and / or methane (from water and carbon dioxide, when carbon dioxide is introduced into the ferrous iron-containing mixture). In some examples, carbon dioxide may be added later (after recovering hydrogen) to form carbonates. Specifically, carbon dioxide may be injected at a high pressure (e.g., about 200 bar) post-oxidation to facilitate mineralization, using the exothermic reaction to maintain a favorable temperature. In some examples, metal complexing / chelating reagents are added to bind trace metals such as nickel, copper, cobalt, and platinum group metals for recovery.

The invention discloses an iron-carbon modified basalt fiber particle electrode biological carrier as well as a preparation method and application thereof, the preparation method comprises the following steps: Sa1, grinding and sieving basalt fibers subjected to pretreatment and etching treatment, and soaking the basalt fibers in an iron salt solution for 6-12 hours at the soaking temperature of 50-90 DEG C; sa2, the basalt fibers obtained in the step Sa1 are soaked in a sodium p-toluenesulfonate solution, a pyrrole monomer is added, then a ferric salt solution is added, a reaction is conducted for 12-24 h at the room temperature, and the mass ratio of the basalt fibers to the sodium p-toluenesulfonate to the pyrrole monomer to ferric iron is 5.0: (9.7-10.8): (3.4-4.2): (5.5-6.6); and Sa3, calcining the basalt fiber obtained in the step S2 in stages. The porosity of the iron-carbon modified basalt fiber particle electrode biological carrier is 90-93%, the density of the iron-carbon modified basalt fiber particle electrode biological carrier is 1.03-1.15 g / cm < 3 >, the iron-carbon modified basalt fiber particle electrode biological carrier is easy to suspend due to the high porosity and the low density, microorganisms can be enriched on the surface to grow, enrichment culture of marine anaerobic ammonium oxidation bacteria can be achieved, and therefore the iron-carbon modified basalt fiber particle electrode biological carrier shows excellent denitrification performance on high-salinity nitrogen-containing wastewater.

The invention discloses a method for recycling retired lithium iron phosphate batteries and producing iron phosphate. The method comprises the following steps: adding alkali into a mixed solution containing Fe < 3 + >, Li < + > and PO4 < 3-> obtained after acid leaching to adjust the pH value, separating out an iron phosphate solid, reacting iron phosphate with acid and a reducing agent, and then reacting with oxalate, so that the iron element is mainly recovered in the form of ferrous iron; reacting the lithium salt solution by a method of adding an alkaline carbonate solution or introducing carbon dioxide gas to generate lithium carbonate precipitate, and recovering lithium carbonate; the recycled ferrous chloride can be used for preparing a ferric iron solution, and the ferric iron solution is directly used for producing iron phosphate, so that the iron element is regenerated and reused in the lithium iron phosphate.

This invention discloses a ternary composite adsorbent based on iron-catechol-boric acid, its preparation method, and its application, belonging to the field of dyeing and printing wastewater treatment. The adsorbent of this invention uses tannic acid with a surface rich in catechol groups as a substrate. A stable metal-phenolic network is formed through the coordination of trivalent iron with catechol groups, efficiently capturing anions using metal bridging and electrostatic attraction to form the adsorption core. Boric acid groups are further introduced as specific recognition units, forming specific dynamic covalent bonds with the catechol groups of anionic dyes. Compared with traditional adsorbents, the adsorbent of this invention provides ultra-high adsorption capacity and selectivity through the synergistic effect of multiple mechanisms, including electrostatic adsorption, coordination complexation, hydrogen bonding, and reversible covalent bonding of borate ester bonds. It can achieve efficient desorption of dyes and recycling of materials, and efficiently and rapidly remove anionic dyes from water.

The invention discloses a resourceful treatment method for stainless steel pickling waste liquid and waste water. The waste liquid is divided into high-concentration waste liquid and low-concentration waste liquid according to the acid concentration and the salt concentration to be treated respectively. Sequentially recovering gypsum, chromic hydroxide, nickel sulfide, ferrous hydroxide and manganese-rich slag from the low-concentration waste liquid through gradient precipitation; and neutralizing free acid from the high-concentration waste liquid by using ferrous hydroxide generated in a low-concentration section, cooling and crystallizing to recover ferrous sulfate, deeply removing nickel by using nickel sulfide generated in the low-concentration section, and precipitating to recover chromium hydroxide. In the whole process, generation of ferric iron is strictly controlled, and high-value productization recovery of free acid and all metals is achieved. The method has the advantages of low medicament consumption, high metal recovery rate, high product value, no secondary pollution and the like.

The invention relates to the field of glass detection, and particularly discloses a method for testing the content ratio of ferrous iron to ferric iron in glass. The method specifically comprises the following steps: washing a to-be-detected glass sample, grinding into micro powder, drying, respectively taking the same amount of glass micro powder, and marking as a sample 1 and a sample 2; divalent iron can be converted into ferric iron by adding perchloric acid into the sample 1, and the test result is the content of total iron in the glass. And dimethyl silicone oil is added into the sample 2 so as to isolate air and prevent ferrous iron from being oxidized into ferric iron in the testing process to influence the experiment result. According to the method, the proportion of Fe < 2 + > to Fe < 3 + > in an unknown glass sample can be simply and quickly obtained, the result is accurate and reliable, the test period is short, and the working efficiency is greatly improved.

The application discloses a method for removing organic pollutants by using molybdenum dioxide to promote activated periodate, and comprises the following steps: adding molybdenum dioxide, ferric salt and periodate into wastewater containing organic pollutants, and then performing catalytic degradation reaction to remove the organic pollutants in the wastewater. In the method, molybdenum dioxide is introduced into the homogeneous ferric / periodate system, and serves as an electron donor and mediator of a Fenton-like reaction. The molybdenum dioxide can not only accelerate the Fe 3+ / Fe 2+ cycle rate and promote the activation of the periodate, but also promote the generation of high-valence iron (Fe(IV)) in the system, form a non-radical pathway dominated oxidation mechanism, promote the degradation reaction to be more rapid and intense, and finally realize the efficient degradation of the organic pollutants. The method has the advantages of rapid degradation rate, good reusability, simple process, convenient operation and environmental friendliness, and can be widely used in the treatment of organic pollutant wastewater.

The application discloses a kind of with waste to treat iron-containing waste slag and battery-grade iron phosphate.The method comprises the following steps: S1, iron-containing waste slag is treated by acid leaching, and solid-liquid separation is carried out after acid leaching to obtain a first filtrate;S2, reducing waste slag is added to the first filtrate, and the ferric iron in the first filtrate is reduced to ferrous iron;S3, the pH of the first filtrate is adjusted and controlled to 1.5-3, and then solid-liquid separation is carried out to obtain a second filtrate, phosphoric acid is added to the second filtrate to obtain a mixed solution;S4, an oxidizing agent is added to the mixed solution, and solid-liquid separation is carried out after reaction to obtain a solid, which is washed and dried to obtain iron phosphate.The method for treating iron-containing waste slag in the application can treat at least two types of waste slag simultaneously using the waste-to-waste technology, which not only reduces the treatment cost of waste slag, but also converts waste slag into high-value battery-grade iron phosphate product, greatly reducing the preparation cost of battery-grade iron phosphate.

The invention discloses a copper oxide tailing treatment method based on a ferric iron-sulfuric acid leaching system, which comprises the following steps: S1, pretreatment: copper oxide tailing ore pulp is fed into a two-section closed circuit ore grinding system, and the ore pulp after ore grinding is preheated to complete low-temperature activation before entering a leaching reactor; s2, low-temperature-gradient-dynamic leaching is conducted, specifically, the preheated ore pulp is pumped into a leaching reactor, and temperature control, Fe and acidity dynamic control and parameter regulation and control in the leaching process are conducted in the leaching process; and S3, solid-liquid separation is conducted, slurry obtained after leaching is completed is pumped into an automatic plate-and-frame filter press, obtained filter cakes are conveyed to a tailing pond, leachate is conveyed to an SX-EW workshop to be treated, and cathode copper is prepared. According to the method, copper oxide is fully leached, gangue acid consumption is reduced by 60-70%, and meanwhile waste heat in the reaction process, acid barren liquor obtained after leaching and waste water are effectively utilized.

The application belongs to the technical field of food quality monitoring, and particularly relates to a ferric magnetic solid-phase masking agent and a quantitative detection method for lead in vegetable products. The ferric magnetic solid-phase masking agent is prepared by the following method: S1, performing carboxylation on the terminal amino group of DFO to obtain DFO-COOH; S2, coating a SiO2 layer on the surface of Fe3O4 magnetic core to obtain Fe3O4@SiO2; S3, modifying the Fe3O4@SiO2 by amination to obtain Fe3O4@SiO2-NH2; and S4, coupling Ac-DFO with Fe3O4@SiO2-NH2 to obtain Fe3O4@SiO2-DFO. The three hydroxamic acid groups of DFO are combined with Fe 3+ to form a stable chelate, and Fe 3+ can be removed through magnetic separation, the removal rate is increased to more than 99%, and the quantitative detection of lead ions is further faster and more accurate in combination with mature immunochromatography technology.

The invention provides a method for removing ferrous iron in a nickel chloride solution through efficient oxidation promotion, belongs to the technical field of purification treatment of chlorination system solutions, and solves the problem that free ferrous iron in the nickel chloride solution cannot be effectively oxidized and converted into ferric iron in the prior art. Controlling the concentration of main metal nickel ions, and adding a corresponding amount of hydrogen peroxide into the nickel chloride solution for stirring according to the content of impurity Fe in the nickel chloride solution; injecting the stirred nickel chloride solution into an electrolytic bath, heating, and raising the temperature of the nickel chloride solution in the bath; and the cathode and the anode in the electrolytic bath are conducted, and the introduced nickel chloride solution is subjected to electrolytic treatment, so that divalent iron in the nickel chloride solution can be converted into trivalent iron. The process flow is simple, the production process is easy to control, the facility equipment investment is low, and the final benefit is remarkable.

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 invention relates to the technical field of battery electrodes, and discloses a negative electrode coating preparation method, a negative electrode plate and a battery. According to the negative electrode coating preparation method, a zinc-based composite negative electrode plate is coated with colloid formed by taking ferric iron complex salt as an effective component; a protective film can be formed on the surface of the zinc-based composite negative pole piece in the charging and discharging process of the battery, and the protective film prevents a negative active substance from being dissolved in an electrolyte, slows down the rapid attenuation of the discharge capacity of the battery, prevents the negative pole piece from being in direct contact with the electrolyte, reduces gas production of the battery, enables zinc to be uniformly deposited and prevents zinc dendrites from being formed, so that the service life of the battery is prolonged. And the charge-discharge efficiency of the battery is improved under the condition of prolonging the cycle life.

The invention particularly relates to a method for determining a reaction rate constant of tetravalent iron and organic pollutants by using a chemiluminescence method, and belongs to the technical field of water quality detection. According to the method, on the basis of a chemiluminescence reaction between Fe (IV) and naproxen (NAP), a target organic pollutant (TrOC) is introduced, the quenching effect of the target organic pollutant on a chemiluminescence signal is measured, and a competitive kinetic model between the chemiluminescence quenching capacity (CLQC) and a secondary reaction rate constant (kFe (IV), TrOC) of Fe (IV) on the target pollutant is constructed. According to the method, the concentration of Fe (IV) does not need to be monitored in real time, and the reaction activity between Fe (IV) and various pollutants can be directly and rapidly measured only by comparing the intensity change of the chemiluminescence signals when the target pollutants exist and do not exist.

The invention discloses a device and a method for strengthening the denitrification efficiency of Fammox based on an extracellular electron transfer regulation and control strategy. The device comprises a CSTR (continuous stirred tank reactor) main body, a water inlet and outlet system, a stirring and constant temperature device, an aeration and anaerobic maintenance device and an EET (ethylene terephthalate) enhanced feeding device, the temperature, the stirring speed and the inlet water iron ion concentration in the Fammox reactor are accurately regulated and controlled, and the L-cysteine and the corn straw biochar are added, so that the electron transfer efficiency and the iron matrix utilization rate in the reaction are effectively improved, and the nitrogen removal efficiency and the Fe (III) utilization and reduction rate are remarkably improved. The L-cysteine and the corn straw biochar adopted by the invention have relatively good economical efficiency and environmental protection property, the denitrification efficiency of Fammox can be remarkably improved, and the utilization and reduction capability of ferric iron (Fe (III)) is effectively enhanced.

The application discloses a Ce2S3@Fe composite material and a preparation method and application thereof, and belongs to the technical field of radioactive wastewater treatment, and the preparation of the Ce2S3@Fe composite material comprises the following steps: under the protection of inert gas, cerium sulfide is added into a ferric iron solution, and then a sodium borohydride solution is slowly added dropwise, so that the ferric iron is reduced to zero-valent iron by using the reducing property of the sodium borohydride solution and is uniformly loaded on the surface of the cerium sulfide, thereby forming the Ce2S3@Fe composite material; and the prepared Ce2S3@Fe composite material is applied to purification of uranium-containing wastewater. 2+ The application adopts the above Ce2S3@Fe composite material, the preparation method and the application thereof, and has the advantages of convenient operation, low cost, environmental friendliness, fast reduction rate, long UO2 stabilization time, all-weather operation, simultaneous consideration of radioactive wastewater treatment and uranium resource recovery.

This invention discloses a method for preparing battery-grade nickel sulfate and iron phosphate using nickel pig iron and ferric phosphate slag as raw materials. The preparation process involves first mixing the ferric phosphate slag with cationic alkyl polyacrylamide to form a uniform mixture. This mixture is then added to dilute acid and stirred to disperse it. Nickel pig iron powder is added, and the mixture is filtered to obtain a leaching solution. The leaching solution is then subjected to nickel-iron separation using resin to obtain an iron-containing solution and a nickel-containing resin. The nickel-containing resin is desorbed to obtain a desorbed solution. A nickel-based pH adjuster is added to this desorbed solution, and the solution is filtered to obtain a nickel sulfate solution. After evaporation and concentration to precipitate crystals, the solution is dried and crushed to obtain battery-grade nickel sulfate. Hydrogen peroxide is added to the iron-containing solution to oxidize ferrous iron to ferric iron. A phosphorus source is added, the pH is adjusted, and the solution is reacted, filtered, and dried to obtain iron phosphate dihydrate. This is then calcined to obtain battery-grade iron phosphate. This invention uses nickel pig iron and ferrophosphate slag as raw materials, and utilizes the ferrophosphate slag to promote the full leaching of iron from nickel pig iron, and nickel pig iron to promote the leaching of phosphate and iron from ferrophosphate. With the addition of cationic alkyl polyacrylamide, it achieves high leaching rates of iron and nickel in a short time, and simultaneously achieves the separation of non-ferrous and nickel metal ions during the acid leaching process, so as to finally obtain high-purity, qualified battery-grade nickel sulfate and ferrophosphate.

The invention discloses a ferric phosphate acid wastewater reverse osmosis membrane filtration method based on reducing agent treatment, which comprises the following steps: S1, pretreatment: respectively adding a reducing agent into ferric phosphate washing water and ferric phosphate filtrate to reduce ferric iron in the system into ferrous iron; s2, washing water membrane treatment: carrying out normal-pressure reverse osmosis treatment on the reduced iron phosphate washing water to obtain a first reverse osmosis concentrated solution and first reverse osmosis produced water; s3, filtrate membrane treatment: mixing the first reverse osmosis concentrated liquor and the reduced iron phosphate filtrate, and performing high-pressure reverse osmosis treatment to obtain second reverse osmosis concentrated liquor and second reverse osmosis produced water; and S4, phosphorus recovery: adding an oxidizing agent into the second reverse osmosis concentrated liquid, and adjusting the pH value to settle the iron phosphate. According to the method, ferric iron in the wastewater is reduced into ferrous iron with high solubility by adopting the reducing agent, so that the risk of membrane pollution is reduced, and then the wastewater is purified and recycled by combining a reverse osmosis technology.

The invention relates to the field of radar wave-absorbing materials, in particular to a magnetic carbon nanobelt wave-absorbing agent and a preparation method thereof. The magnetic carbon nanobelt wave-absorbing agent comprises nitrogen-doped carbon converted by polyimidazolium salt and magnetic nanoparticles carbonized and converted by ferric iron salt; the average particle size of the magnetic nanoparticles is 5nm-20nm, and the mass loading capacity of the magnetic nanoparticles is 20%-50%. The magnetic carbon nanobelt wave-absorbing agent provided by the embodiment of the invention can give consideration to dielectric loss and magnetic loss, and the wave-absorbing performance of the material is improved.