394 results about "FERRIC IRON" patented technology

The invention discloses an oxidation leaching system and method for argillaceous sandstone uranium ore. The system comprises a uranium leaching pool, a recovery pool, a liquid preparation-dosing unit pool and an intermediate pool. Wherein the uranium leaching tank is provided with a water dispersing layer, a uranium ore layer and a liquid collecting layer from top to bottom, and efficient oxidation of uranium ore is achieved through coupling of oxygen and ferric iron; the recovery pool is sequentially provided with a resin adsorption layer and a water inlet layer from top to bottom, and efficient recovery of uranium in the leachate is achieved; the liquid preparation-dosing unit pool is provided with an acid-resistant submersible sewage pump used for circularly conveying the ore leaching liquid to the uranium leaching pool and adjusting the pH value of the ore leaching liquid and the initial concentration of Fe < 3 + >. And the middle tank drives the ore leaching liquid to form periodic tidal flow circulation in the uranium leaching tank through an acid-resistant submersible sewage pump. According to the system and the method, tidal flow regulation and control, aeration oxygen supply enhancement and iron ion circulation oxidation technologies are coupled, and the uranium leaching rate gt of the argillaceous sandstone uranium ore is achieved by establishing a multi-stage oxidation field domain, optimizing a fluid migration path and establishing an iron element regeneration mechanism; 92%.

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 present invention relates to the technical field of inorganic materials, and particularly to a method for clean smelting of beryllium oxide and beryllium oxide. The smelting method includes using iron powder to remove trivalent iron in the acid leaching solution of beryllium ore; using a non-saponified extraction system without sodium ions and ammonium cations, and the non-saponified extraction system exchanges hydrogen ions with itself when extracting beryllium ions. The present invention solves the problems existing in beryllium smelting preparation in the prior art, such as low beryllium recovery rate, easy interference by associated elements, large pollution, and difficult waste liquid treatment. An alkaline earth metal compound is used as a raffinate impurity removal reagent and a non-saponified extraction system, and the raffinate after impurity removal is recycled for beryllium ore leaching, improving the beryllium recovery rate and reducing the environmental pollution caused by waste liquid discharge.

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 relates to an electrochemical cleaning method for removing organic matters on the surface of a silicon carbide wafer, which comprises the following steps of: immersing the silicon carbide wafer with the polluted surface into electrolyte containing bivalent and / or trivalent ferric salt, applying voltage or current between a cathode material and an anode material, and carrying out electrochemical reaction to remove the organic matters on the surface of the silicon carbide wafer. The surface of the silicon carbide wafer is subjected to organic matter removal. According to the method, an electrochemical oxidation method technology is adopted, the strong oxidation effect of hydroxyl free radicals is utilized, organic residues on the surface of the silicon carbide wafer are oxidized and decomposed into short-chain organic matter, water, carbon dioxide and other products, and the purpose of removing the organic residues is achieved. The method provided by the invention is simple and efficient, can quickly remove organic pollutant residues on the surface of the silicon carbide wafer, does not use high-concentration chemicals and organic component cleaning agents which are difficult to degrade in the cleaning process, is safe and reliable to operate, reduces the consumption of the chemicals, avoids secondary pollution, and is more environment-friendly.

The invention discloses a method for directly and selectively extracting indium from a high-iron indium-containing solution without reduction, which comprises the following steps: mixing the high-iron zinc indium-containing solution obtained by acid leaching of zinc oxide with a composite extractant, extracting, separating to obtain an indium-iron-containing organic phase, adding a detergent into the indium-iron-containing organic phase for washing, and separating to obtain a zinc-removed indium-iron-containing organic phase, the method comprises the following steps: adding a composite extractant into a high-iron-zinc indium-containing solution, then adding a stripping agent to carry out indium stripping to obtain an indium-containing stripping solution so as to realize the separation of indium in the high-iron-zinc indium-containing solution, and the composite extractant consists of 10-40% by volume of a phosphate extractant A, 5-20% by volume of a phosphoric acid synergistic extractant B and 40-85% by volume of sulfonated kerosene. According to the method, ferric iron does not need to be reduced, the indium-iron separation coefficient is high, extraction is not prone to emulsification, and the indium recovery rate is high.

The utility model discloses a treatment device capable of accelerating starting of autotrophic denitrification of pyrite, and belongs to the technical field of sewage treatment. The Fe < 3 + > dosing unit comprises a Fe < 3 + > dosing tank (4) and a dosing pump (6); according to the water inlet unit, an aeration head (2) is arranged in a raw water tank (3), the aeration head (2) is connected with a nitrogen cylinder (1) through a valve, filler filled in the reactor is modified pyrite filler particles and modified ceramsite, the bottom of the reactor is connected with an aeration pump, and a Fe < 3 + > dosing tank (4) is connected with a water inlet (7) in the bottom of the reactor (13) through a dosing pump (6). The method comprises the following steps: aerating sludge, standing, discharging water, and adding ferric iron into the water subjected to nitrogen aeration treatment to carry out accelerated reaction. By adopting the technology of the utility model, the starting can be quickly carried out for more than 10 days.

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 invention relates to the technical field of wastewater treatment, and discloses a method for synergistically strengthening denitrification of an anaerobic ammonia oxidation system based on tea polyphenol and ferric iron, and the method comprises the following steps: in an anaerobic ammonia oxidation reactor, inoculating anaerobic ammonia oxidation sludge, adding wastewater, adding tea polyphenol-Fe < 3 + >, and treating the wastewater. According to the invention, the tea polyphenol can promote the anaerobic ammonium oxidation bacteria to absorb ferric iron and enhance the biological utilization of iron element in the anaerobic ammonium oxidation system. Iron elements absorbed by the anaerobic ammonium oxidation bacteria can be used for synthesizing key functional enzymes, the metabolic activity of anaerobic ammonium oxidation and dissimilatory nitrate reduction into ammonium of the anaerobic ammonium oxidation bacteria is enhanced, meanwhile, coupling of two nitrogen conversion ways is promoted, the total nitrogen removal rate is synergistically increased, and the denitrification efficiency of an anaerobic ammonium oxidation system is enhanced.

The invention discloses a method for accelerating straw composting by utilizing magnetite and compound microorganisms to drive biological advanced oxidation, and belongs to the technical field of efficient composting of agricultural organic solid wastes. The method comprises the following steps: (1) uniformly mixing straws and excrement as a compost body, adjusting the C / N ratio and the water content, adding magnetite, a bacillus subtilis liquid and a crushed white rot fungus liquid, and putting the mixture into a composting device; (2) intermittent aeration is carried out, the temperature is 28-32 DEG C, and the composting period is 40-50 days. According to the composting method, through intermittent aeration, controllable aerobic conditions and anoxic conditions are formed in a compost body, under the anoxic conditions, ferric iron is subjected to dissimilatory iron reduction to generate ferrous iron, and under the aerobic conditions, compound microorganisms reduce oxygen through extracellular electron transfer to form hydrogen peroxide, so that the composting effect is improved. Divalent iron and hydrogen peroxide are subjected to a Fenton-like reaction to generate hydroxyl free radicals with high oxidizing property, so that decomposition of straw lignocellulose is accelerated, and the composting efficiency of compost is improved.

The invention belongs to the technical field of wastewater treatment, and discloses a magnetic nano composite adsorbent as well as a preparation method and application thereof. The preparation method comprises the following steps: dissolving a divalent iron salt and a trivalent iron salt in water, adding ammonia water under a protective gas, and carrying out a stirring reaction at a rotating speed of 350-600 rpm to prepare Fe3O4 nanoparticles; the preparation method comprises the following steps: dispersing Fe3O4 nanoparticles in a mixed solution of acrylic acid and ethidene diamine, then adding an initiator, and carrying out a stirring reaction at a rotating speed of 150-300 rpm to prepare the magnetic nano composite adsorbent. The magnetic nano-composite adsorbent provided by the invention can efficiently remove lead ions in wastewater, is not influenced by mercury ions and copper ions, also has relatively good adsorption capacity on the mercury ions and the copper ions, and can treat various heavy metal ions in the wastewater at the same time. The magnetic nano composite adsorbent is easy to separate and good in reusability.

The invention provides a multi-characteristic iron-carbon derivative material for adsorbing and repairing PFAS pollution of a water body as well as a preparation method and application of the multi-characteristic iron-carbon derivative material. The preparation method comprises the following steps: 1, dissolving a ferric salt in N, N-dimethylformamide, adding a ligand terephthalic acid under a stirring condition, and synthesizing a precursor through a solvothermal method; and 2, carrying out heat treatment on the precursor in an inert atmosphere to obtain the multi-characteristic iron-carbon derivative material. The application of the multi-characteristic iron-carbon derivative material in the aspect of environmental restoration comprises the following steps: by taking the multi-characteristic iron-carbon derivative material as an adsorbent, carrying out adsorption purification treatment on a PFAS polluted water body under the assistance of a cationic complexing agent. The multi-characteristic iron-carbon derivative material is synthesized through a solvothermal-thermal treatment two-step method, so that the multi-characteristic iron-carbon derivative material has high hydrophobicity, a two-dimensional-three-dimensional tight interface and magnetism, can quickly remove PFAS with various different structures and carbon chain lengths, can realize material separation within 30 seconds after the PFAS is removed through adsorption, and does not generate secondary pollution.

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 a biochar-plant combined remediation method for mine heavy metal contaminated soil, and relates to modified biochar and a remediation accelerator.The preparation method of the modified biochar comprises the steps that peanut shells are subjected to high-temperature carbonization and then added into a ferric iron solution to neutralize a NaOH solution, ultrasonic treatment is conducted, and the biochar is obtained; a biomass raw material is crushed and composted to obtain pretreated biomass, then the pretreated biomass and a ferric iron solution are subjected to a heating reaction, a reaction product is mixed with the biochar, carbonization is continued, and the biochar is obtained. The repairing accelerant comprises turf, phospholime powder, mannitol, a plant growth regulator, a microbial agent and a chelating agent. According to the remediation method, planting of the modified biochar, the remediation accelerant and the enrichment plants is combined, a synergistic remediation mechanism is formed, the three components have a synergistic effect, the removal efficiency of heavy metal is remarkably improved, the biomass and the survival rate of the enrichment plants are improved, and efficient and accurate remediation of the mine heavy metal contaminated soil is achieved.

The invention relates to the technical field of sewage treatment and resource utilization, in particular to a method for recovering phosphorus from sludge, which comprises the following steps: carrying out anaerobic digestion on the sludge to be treated under anaerobic conditions to release phosphorus in the sludge into supernate to obtain sludge anaerobic digestion liquid, adding an iron salt coagulant into the sludge anaerobic digestion liquid, precipitating, filtering, washing and drying to obtain the phosphorus-containing sludge. Removing phosphorus from the supernate, enabling the phosphorus to enter a precipitate, and removing the supernate to obtain a solid-liquid mixture; and adding the solid-liquid mixture into a reactor, adding a mixed bacterial agent of iron reducing bacteria and metal-resistant bacteria into the reactor, reducing ferric iron into ferrous iron under the action of the iron reducing bacteria, dissolving the precipitate, and recrystallizing to obtain the blue iron ore, thereby realizing the recovery of phosphorus in the sludge. According to the invention, ferric salt precipitates are re-induced to precipitate and recrystallize, so that the problems of low phosphorus load, large volume, low economic benefit of direct recovery, low crystallinity of chemical precipitates, more impurities, difficulty in controlling dissolved oxygen and easiness in oxidation at present are solved.

A molecular sieve catalytic slag melting agent for high-iron coal liquid slag removal comprises 10-20 parts of a loosening and expanding agent, 10-20 parts of a molecular sieve catalyst and 30-60 parts of a fluxing reducing agent, and has the beneficial effects that the loosening and expanding agent can crack and expand ash; vanadium anhydride added in the fluxing reducing agent can promote generation of low-temperature eutectic substances in the ash residues when the mass fraction is lower than 5%. And further, under the action of the molecular sieve catalyst enhanced reaction, the fluxing reducing agent can enhance the reducing atmosphere, promote the conversion of ferric iron in the slag body to ferrous iron, reduce the melting point of an iron-containing compound, promote the conversion of the solid slag body at the slag discharge port to low-melting-point liquid-phase flow slag, and ensure that ash in the furnace is smoothly discharged out of the furnace body. Through reasonable preparation, the slag melting agent developed by the invention can realize fluidization of slag at a slag discharge port within a temperature range of 900 DEG C, avoids unplanned furnace shutdown or safety problems caused by slag blockage, and also can realize the effect of replacing the existing natural gas heating fluxing anti-slag-blocking technology.

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 preparation method of a size-controllable alpha-iron oxide nanosheet catalyst, the prepared catalyst and application of the catalyst. Comprising the following steps: mixing ferric iron salt, ethanol, water and sodium acetate at room temperature, reacting in a closed container, centrifuging, washing, drying and roasting to obtain the size-controllable alpha-iron oxide nanosheet catalyst. The catalyst provided by the invention is controllable and uniform in size and is used for ortho-parahydrogen reaction, and an effective method is provided for structural design and development of the high-activity ortho-parahydrogen catalyst.

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 invention provides a method for recycling iron phosphate from waste lithium iron phosphate positive and negative electrode mixed lithium extraction slag and application of the method. The method comprises the steps that 1, the waste lithium iron phosphate positive and negative electrode mixed lithium extraction slag and hydrochloric acid are placed in a reaction kettle to leach out metal elements in the slag, and filtering is conducted to obtain filtrate and graphite slag; step 2, detecting the contents of copper ions and aluminum ions in the filtrate, calculating the amount of required iron powder, adding the iron powder into the filtrate to remove the copper ions in the filtrate, adjusting the pH value to remove the aluminum ions, and oxidizing ferrous iron in the filtrate into ferric iron by using an oxidizing agent; 3, ammonia water and ammonium dihydrogen phosphate are added into the filtrate, the ammonia water is used for adjusting the PH, the ammonium dihydrogen phosphate is used for adjusting the iron-phosphorus ratio to be 0.96-1.02, an iron phosphate dihydrate precipitate is synthesized through a synthesis reaction, and iron phosphate dihydrate and lithium-containing filtrate are obtained through solid-liquid separation; and 4, washing and drying the iron phosphate dihydrate precipitate to obtain regenerated iron phosphate. The economic benefit of recycling the waste lithium iron phosphate battery is increased, and the generation of solid wastes is reduced.

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 halloysite-based ferric oxide nano composite material as well as a preparation method and application thereof, and belongs to the technical field of environmental chemistry. The preparation method of the halloysite-based ferric oxide nano composite material provided by the invention comprises the following steps: (1) mixing a halloysite suspension and a ferric iron salt aqueous solution, and stirring to obtain a mixed suspension; and (2) adding an alkali solution into the mixed turbid liquid obtained in the step (1), then separating out a solid-phase substance, and drying to obtain the halloysite-based iron oxide nano composite material. The preparation process of the halloysite-based ferric oxide nano composite material is simple, convenient and reliable, the production period is short, and batch production is facilitated; the nano composite material is environment-friendly, and the material is free of toxic and harmful effects; the adsorbent has good adsorption capacity on arsenic and antimony, and can be used for repairing arsenic and / or antimony polluted water or soil.

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.

The present disclosure belongs to the technical field of water body environmental pollution control, and relates to an α-Fe2O3 material and its preparation method and application for reducing and repairing PFASs pollution in water bodies. The preparation method includes: a precursor preparation step: dissolving a trivalent iron source to obtain an iron salt solution, adding a dispersant under stirring conditions to coat and separate the iron ions, generating a flocculent brown precipitate, and obtaining a precursor suspension, from which the precipitate is separated and washed, purified, dried, crushed and sieved in sequence to obtain a precursor; a calcination step: heat-treating the precursor in an inert atmosphere, and then crushing and sieving to obtain an α-Fe2O3 material. The Fe2O3 particles in the material have a hydrophobic surface, and there is a confined space between two adjacent Fe2O3 particles, which can limit the movement of reactant molecules, broaden the degradation pathway, and make PFASs quickly gather on the surface of the hydrophobic Fe2O3 particles under ultraviolet light excitation and degrade better in the confined space.