75 results about "Dissolved iron" patented technology

The present invention relates to the technical field of test and detection, and particularly to an on-line measurement method and device for total iron in power station water vapor. A catalytic reagent is added to the water sample to be measured and acts through an ultraviolet light oxidizer, so as to completely convert the colloidal iron in the water sample into ferric ions. The dissolution and conversion of the colloidal iron are completed without adding acid throughout the process. Since no acid is added during the process of converting the whole colloidal iron into dissolved iron, only a chromogenic reagent needs to be added to accurately measure the total iron content in the water sample, and it is also easier to realize the on-line measurement of total iron in the water sample. When the total iron content in the water sample is less than 10 μg / L, the water sample enters the concentration system for concentration and then optical measurement, so that the low-concentration total iron in the water sample can also be accurately measured. This measurement method can automatically measure the total content in the water sample on-line, avoid manual sampling and detection, can monitor the total iron in the water sample in real time, and has a lower detection limit and more accurate detection results, which is beneficial to the adjustment of the water condition during the start-up and shutdown stages of the power station.

The invention discloses a method for preparing a scale layer on a secondary side of a steam generator and a test sample piece on the secondary side of the steam generator. The method comprises the following steps: dissolving ferric salt, oxysalt, an acid compound and an organic solvent in deionized water to form a mixed aqueous solution; taking the mixed aqueous solution as a raw material, and depositing a scale layer precursor on a test sample on the secondary side of a steam generator by adopting a hydrothermal method; and heating the scale layer precursor in an inert gas atmosphere so as to form a simulated scale layer on the test sample. According to the method, preparation of the simulated scale layer is completed based on hydrothermal synthesis-high-temperature firing, the ultra-long period of preparing the simulated scale layer through high-temperature and high-pressure corrosion is avoided, rapid preparation of the steam generator secondary side sample sediment simulated scale layer is achieved, and the deposited scale layer growing closer to the actual operation environment can be simulated.

The invention relates to a surface treatment method of an iron material inner container, which comprises the following steps of: 1, putting the iron material inner container into a cleaning pool, primarily cleaning the iron material inner container by using a cleaning agent, and dissolving various types of grease in the iron material inner container; secondly, a cleaning agent is added into a soaking pool, then the iron material inner container in the first step is put into the soaking pool, the soaking time is adjusted to be 5-8 minutes, the soaking temperature is adjusted to be 30-50 DEG C, and therefore a layer of stable protective film is formed on the surface of the iron material inner container; thirdly, the iron material inner container in the second step is taken out and cleaned with clear water, and the cleaning agent remaining on the surface of the iron material inner container is removed; fifthly, the surface of the iron material inner container in the fourth step is evenly coated with enamel paint, and curing treatment is conducted; a special cleaning agent and low-frequency ultrasonic wave are adopted to assist cleaning, so that various greases and dirt on the surface of the inner container can be quickly and thoroughly dissolved and removed, and the basic cleanness of subsequent treatment is ensured.

The invention discloses a method for treating red mud by using waste sulfuric acid, which comprises the following steps: mixing waste sulfuric acid and red mud, placing the mixture in a double-chamber electrochemical reaction system, breaking the silicate structure of the red mud in an anode chamber through 0.8-1.0 V voltage, and introducing acidithiobacillus acidophilus for metabolism to generate oxalic acid and citric acid to dissolve iron and aluminum oxides; the extracellular polymer fixes heavy metal ions to reduce the leaching toxicity by 90%, a cathode chamber is blocked by an ion exchange membrane to recycle more than 85% of waste acid, step-by-step precipitation of Fe < 3 + >, Al < 3 + > and Ca < 2 + > is realized by regulating and controlling the pH gradient in stages, goethite with the magnetic separation purity being greater than or equal to 95% and aluminum gel are used as functional materials, and 99% high-purity gypsum is generated through induction of nanocrystalline seeds. According to the method, 95% of iron recovery rate and heavy metal stabilization in the red mud are achieved, the waste acid recycling rate reaches 85%, the method has the advantages of low energy consumption and recycling, the treatment cost is reduced by 50% or above compared with a traditional method, and an efficient solution is provided for cooperative treatment of the red mud and the waste acid.

The invention belongs to the technical field of hydrogen production by water electrolysis, and discloses a device and a method for hydrogen production by alkaline water electrolysis enhanced by active ions regulated and controlled by a magnetic field. An anode magnetic flow channel and an anode non-magnetic substrate in the electrolytic cell are integrally designed and are combined to form an anode magnetic field functional bipolar plate, and the anode magnetic flow channel is formed. In the electrolysis operation process, the migration behavior and spatial distribution of iron ions dissolved in the electrolyte are actively regulated and controlled by applying an external magnetic field to the anode region, so that the iron ion concentration of the electrolyte phase is not increased, and the main body structure and material system of the existing industrial electrolytic cell are not changed; and the dissolved iron ions are directionally enriched on an anode interface. Through the regulation and control, relatively high dynamic iron active site coverage can be maintained on the surface of the anode, the polarization loss of oxygen evolution reaction is reduced, and the efficiency and stability of the process of hydrogen production by alkaline water electrolysis under the conditions of high current density and wide load operation are improved.

The invention discloses a preparation method and application of a FeCo-MOF derived CoFe2O4 / biochar composite material, and belongs to the technical field of antibiotic wastewater treatment. The method comprises the following steps: (1) dissolving terephthalic acid in DMF (Dimethyl Formamide) to form a solution A, dissolving ferric salt and cobalt salt in DMF to form a solution B, mixing the two solutions, reacting, centrifuging, washing, drying and grinding to obtain a FeCo-MOF material; and (2) mixing the FeCo-MOF material with peanut shells, grinding, calcining the obtained mixed powder in an N2 atmosphere, and then grinding to obtain the FeCo-MOF derived CoFe2O4 / biochar composite material. When the prepared composite material is used as a catalyst to degrade OFL in a PMS system, the degradation efficiency reaches 79.78%-89.89%, and the degradation rate constant reaches 0.094 min <-1 >-0.139 min <-1 >.

The application discloses a method for rapidly and harmlessly treating phosphogypsum, and particularly relates to the harmless treatment technical field of industrial solid waste. The method comprises the following steps: mixing raw materials with an alkaline neutralizing agent, a trapping agent and an activating agent, adding a phosphorus solidifying agent and a fluorine solidifying agent, mixing, carbonizing and aging, and obtaining harmless phosphogypsum. The method adopts the alkaline neutralizing agent to rapidly neutralize free acid and improve the pH of the system; the trapping agent adsorbs heavy metals; the activating agent promotes As, Cd and the like to form a difficult-to-dissolve iron oxide gel or a precipitate; the phosphorus solidifying agent and the fluorine solidifying agent perform deep chemical precipitation to form a stable iron-calcium-phosphate / ferric fluoride composite solidified body. The functions of the agents are clear, and the agents have synergistic effects; the solidification effect of the agents on high water-solubility phosphorus, fluorine and various heavy metals is far better than that of a single or simply compounded agent system; and the leaching concentration can be reduced to a level far lower than the national standard.

The invention provides a method for rapidly dissolving a zinc ferrite material and a resourceful treatment method. The method for rapidly dissolving the zinc ferrite material comprises the steps that S1, copper powder and an acidic copper sulfate solution are provided, the concentration of bivalent copper ions in the acidic copper sulfate solution is not smaller than 10 g / L, and the concentration of sulfuric acid in the acidic copper sulfate solution is not smaller than 80 g / L; s2, mixing the zinc ferrite material, the copper powder and the acidic copper sulfate solution together to obtain a zinc ferrite leaching solution; the mass ratio of zinc ferrite in the zinc ferrite material to the copper powder is less than 1: 0.27. According to the method, the dissolving time of zinc ferrite can be remarkably shortened, and zinc ferrite can be completely dissolved within 2-5 min.

The invention provides a method for selectively leaching titanium from red mud, and belongs to the field of red mud resourceful treatment. The method comprises the following steps: slurrying red mud to obtain red mud slurry; mixing the red mud with a deconstruction agent, and performing microwave activation to obtain active red mud; the method comprises the following steps: mixing active red mud with an acidic inhibitor, and carrying out wet impurity removal pretreatment to obtain a titanium-rich filter cake; and mixing the titanium-rich filter cake with a targeted leaching synergist for selective enhanced dissolution to obtain a titanium-rich solution. Firstly, a deconstruction agent is used for carrying out microwave activation on red mud, and the subsequent leaching reaction activity of the red mud is improved; then an acidic inhibitor is used for conducting wet impurity removal pretreatment on the active red mud, effective components in the acidic inhibitor can preferentially dissolve iron and aluminum elements in the red mud, meanwhile, dissolution of the titanium element is inhibited, and titanium is enriched in slag to obtain a titanium-rich filter cake; and finally, carrying out selective enhanced dissolution on the titanium-rich filter cake by using a targeted leaching synergist to realize selective efficient leaching of the titanium element.

The application is suitable for the field of nuclear power detection, and discloses a method and device for measuring the dissolved iron content in liquid lead bismuth, which comprises the following steps: S1, taking out the liquid lead bismuth and adding it into a test container, and heating the assembly to a set temperature; S2, injecting argon into the test container to remove other gases, and then inputting oxygen, and measuring the change of the dissolved oxygen concentration in the liquid lead bismuth through an oxygen detection sensor; S3, substituting the measured oxygen concentration change rate and the net oxygen addition rate into a differential equation to calculate the solubility product; and S4, deriving the dissolved iron content through the measured equilibrium oxygen concentration in the saturated iron and the solubility product obtained in step S3. The method for measuring the dissolved lead bismuth eutectic oxygen activity through the oxygen detection sensor is simple in operation, can quickly and accurately measure the dissolved iron content, and can keep the liquid metal system in a balanced state by adjusting the oxygen addition rate in the system, so that the experimental efficiency is higher.

This invention discloses a sulfur-nitrogen co-doped porous carbon-supported diatomic iron catalyst and its preparation and application. The preparation process involves: 1) dissolving iron dimer and zinc nitrate fully in methanol solvent, followed by ultrasonic dispersion to obtain a mixed solution; 2) dissolving an organic nitrogen source in methanol solvent, followed by ultrasonic dispersion to obtain a mixed solution, then adding this to the mixed solution from step 1), mixing thoroughly, centrifuging, washing, drying, and pyrolysis to obtain a dry powder; 3) mixing the dry powder with an organic sulfur source, grinding, and calcining at high temperature to obtain the sulfur-nitrogen co-doped porous carbon-supported diatomic iron catalyst. The synthesis method of this invention is simple, the raw materials are readily available, and the obtained sulfur-nitrogen co-doped porous carbon-supported diatomic iron catalyst can effectively form a structure with diatomic iron sites. Furthermore, an appropriate concentration of sulfur atom doping can effectively anchor the diatomic iron active sites, thereby regulating the coordination environment of the active center, exhibiting oxygen reduction reaction performance comparable to commercial Pt-based catalysts.

The invention discloses a Fe-doped Bi2SeO5 nano material as well as a preparation method and application of the Fe-doped Bi2SeO5 nano material. The preparation method comprises the following steps: dissolving ferric chloride hexahydrate, bismuth nitrate pentahydrate and sodium selenite according to a specific ratio by using a hydrothermal synthesis technology and taking pure water as a solvent, and stirring at the room temperature of 25 DEG C until a system is uniform, so as to obtain a precursor mixed solution of the Fe-doped Bi2SeO5 nano material; the mixed solution is subjected to a hydrothermal reaction and then is subjected to heat treatment in an air atmosphere, and the target Fe-doped Bi2SeO5 nano material is finally obtained by regulating and controlling parameters such as a precursor ratio, a hydrothermal reaction temperature, heat preservation time and heat treatment conditions through a system. The nano material is used for catalytic degradation of antibiotics in a PMS system, and has the characteristics of strong anti-interference capability, good tolerance to acid and alkali environments, remarkable catalytic effect, high stability and the like.

The application discloses a kind of magnetic foam structure composite material and its preparation method and application, belong to heat-conducting-wave-absorbing multifunctional material preparation technical field.The in-situ bubble assisted annealing process disclosed in the application is to dissolve iron nitrate, nickel acetate and polyvinylpyrrolidone in deionized water to obtain a mixed solution, then dry the solution to a viscous state, then place the viscous liquid in a tube furnace, pass inert gas and perform high-temperature annealing treatment to obtain the product.The application is simple to operate, has strong repeatability, low production cost, short cycle, is green and environmentally friendly, and can be prepared on a large scale.It can also prepare a series of magnetic foam structure composites by changing the feeding ratio and annealing temperature.The obtained magnetic foam has adjustable composition, texture, high thermal conductivity and wideband microwave absorption characteristics, and has good industrial application potential in heat management, microwave absorption and other fields.

A natural gas (NG) processing plant and method of operating the NG processing plant including: receiving feed NG, removing acid gas from the feed NG gas via a gas sweetening unit having an amine absorber column that absorbs the acid gas, collecting an amine sample in the gas sweetening unit, removing water from the feed NG via a NG dehydration system having a column vessel that contacts the feed NG with liquid desiccant including glycol to remove the water, collecting a glycol sample in the NG dehydration system, adding reagent water and ferrozine to each of the amine sample and the glycol sample, and measuring total dissolved iron via ultraviolet-visible (UV-Vis) spectrophotometry in each of the amine sample and the glycol sample.

The application discloses a preparation method of superfine gold powder for conductive paste, and the method comprises the following steps: firstly, adding chloroauric acid and ferric chloride into deionized water, then adding gelatin and heating and stirring to dissolve, and preparing a mixed solution; secondly, performing ultrasonic atomization on the mixed solution to obtain nanoscale gold-iron mist droplets, then performing calcination and decomposition, collecting gold-iron alloy nanopowder by using a hydrochloric acid solution, and soaking, filtering and drying to obtain superfine gold powder. By adding gelatin as a dispersant, more and more nanoscale gold-iron mist droplets with a more stable structure are formed, the size of the superfine gold powder is ensured, and the gelatin is utilized to prevent particle adhesion during the calcination and decomposition process, so that the gold-iron alloy nanopowder is spherical and cannot be aggregated, the gelatin decomposition is residue-free, the iron is collected and dissolved by using the hydrochloric acid, the dispersibility of the nanoscale gold particles is ensured, the superfine gold powder with a large specific surface area is obtained, the superfine gold powder is suitable for thick film conductive paste, and the method is simple in process, high in product yield, large in output, and easy for industrial production.

The invention discloses a catalyst for preparing sulfur through low-temperature oxygen-resistant reduction of SO2 as well as a preparation method and application of the catalyst, and belongs to the technical field of catalysts. The method comprises the following steps that under the condition of a low-frequency ultrasonic field, ferric salt and optional auxiliary metal salt are dissolved in water to be mixed to form a metal solution, and then the metal solution is added into nanoscale titanium dioxide to obtain a mixed material; performing ultrasonic oscillation stirring on the mixed material to obtain a precursor solution; carrying out microwave treatment on the precursor solution under a low-frequency microwave condition, then carrying out ultrasonic treatment, standing and aging at room temperature, and drying after aging to obtain a dried block; and grinding the dried block, and roasting to obtain the catalyst for low-temperature oxygen-resistant reduction of SO2 to prepare sulfur. The catalyst is prepared under the synergistic effect of microwaves and ultrasonic waves, the structure of the catalyst is optimized, and the catalyst has more uniform and smaller particle size, shows larger specific surface area, exposes more active sites and can be used under complex atmosphere conditions such as oxygen-containing, water-containing, hydrogen-containing and the like.

The invention relates to the technical field of electro-catalytic materials, in particular to a CeFe-coated C / NF self-supporting electro-catalytic material and a preparation method and application thereof.The preparation method comprises the steps that ferric salt, terephthalic acid and benzoic acid are dissolved in a mixed solution of N, N-dimethylformamide, ethyl alcohol and water, then a first hydrothermal reaction and calcination are conducted, and derivative powder of an Fe-based MOF precursor MIL-53 (Fe) is obtained; the preparation method comprises the following steps: adding derivative powder of a Fe-based MOF precursor MIL-53 (Fe), cerous nitrate hexahydrate and polyvinylpyrrolidone into a mixed solution of ethanol, ethylene glycol and water, and uniformly mixing to obtain a mixed solution; the foamed nickel is put into the mixed solution for a second hydrothermal reaction, and the CeFe-coated C / NF self-supporting electro-catalytic material is obtained. According to the method, monocarboxylic acid benzoic acid is adopted as a structure regulating agent to obtain an ultrathin nanosheet-shaped Fe-based MOF precursor MIL-53 (Fe) nanosheet with a controllable microstructure and a controllable crystal structure, the nanosheet is calcined and then loaded with CeO2 in situ, and the problems that in the prior art, an electrocatalyst is high in manufacturing cost, high in overpotential and low in catalytic activity are solved.

The invention discloses a platinum-iron-molybdenum catalyst with high activity and stability as well as a preparation method and application thereof, and belongs to the technical field of heterogeneous catalysis. The preparation method comprises the following steps: dissolving ferric nitrate, ammonium molybdate and citric acid in water, mixing, and adjusting the pH value to be less than 1.0; carrying out water bath gelation on the solution, drying, and calcining in a tubular furnace to obtain an iron molybdate carrier; mixing a platinum source with the iron molybdate carrier, drying by distillation in an oil bath, and calcining in a muffle furnace after drying to obtain the platinum-iron-molybdenum catalyst. The platinum-iron-molybdenum catalyst prepared by the preparation method disclosed by the invention can show efficient catalytic activity and excellent stability in propane oxidation reaction no matter whether the platinum cluster prepared in advance or the precursor salt of direct wet impregnation platinum is loaded.

The invention discloses a method for improving the carbon sequestration efficiency of diatom in a water body and the pH value of the water body, and relates to the technical field of carbon dioxide sequestration. The method comprises the following steps: adding a mixed mineral consisting of an aluminosilicate mineral and an iron magnesium silicate mineral into the diatom-containing water body, and culturing. The aluminosilicate mineral disclosed by the invention can be dissolved in a water body and release a Si nutrient element required by diatom growth, and meanwhile, the released Al element can enter diatom shells so as to inhibit dissolution of the diatom shells. The iron-magnesium silicate minerals can be dissolved in water and release nutrient elements such as Si, Mg and Fe, so that diatom breeding is promoted. Moreover, both the aluminosilicate minerals and the iron magnesium silicate minerals have certain surface adsorption specificity, so that the aluminosilicate minerals and the iron magnesium silicate minerals are flocculated with the diatom and the sedimentation of flocculates is accelerated, thereby increasing the amount of the flocculates deposited to the water bottom, improving the carbon sequestration efficiency and synchronously increasing the pH value of seawater. Therefore, acidification of water bodies such as seawater is inhibited while the carbon sequestration amount of the water bodies is increased.

The invention provides a method for producing aluminum oxide by directly dissolving out high-sulfur bauxite by regulating and controlling oxidation-reduction potential, and relates to the technical field of aluminum oxide production. According to the method, on the basis of the potentials of S < 2->, S < 2->, Fe < 2 + > and Fe < 3 + > in the bauxite, an oxidizing agent is used as a potential regulation and control means, a weak reduction environment is constructed, the existence forms of sulfur and iron are regulated and controlled through the potentials in pre-desiliconization and high-temperature dissolution, the reaction of pyrite is inhibited, dissolved iron and sulfur are directionally converted into magnetite and S2O3 < 2->, sodium silicon slag is embedded into the S2O3 < 2-> in desiliconization, efficient desulfurization is achieved, and high-efficiency desulfurization is achieved. Iron ore concentrate is recycled in magnetic separation, so that red mud is reduced, and high-sulfur bauxite is efficiently and economically utilized. The method synchronously achieves the goals of pyrite reaction inhibition, efficient desulfurization and reinforced iron ore concentrate recovery, is suitable for high-sulfur high-iron ore, has the characteristics of small oxidizing agent amount, short process, easiness in industrialization, red mud process reduction, low cost and the like, is beneficial to economically and green processing of high-sulfur bauxite, and promotes sustainable development of the aluminum oxide industry.

The invention discloses iron phosphate and a preparation method thereof.The preparation method of the iron phosphate comprises the steps that iron phosphate slag is dissolved with acid, and iron phosphate metal liquid is obtained; carrying out recrystallization and solid-liquid separation on the iron phosphate metal liquid, and washing the separated solid phase to obtain a washing material; mixing the sizing material with a cloth bag dust collection material, and carrying out solid-liquid separation to obtain an iron phosphate dihydrate filter cake; and sequentially drying and roasting the iron phosphate dihydrate filter cake to obtain the anhydrous iron phosphate. According to the invention, the cloth bag dust collecting material can be recycled by adopting lower energy consumption and a simpler process, so that the production cost is greatly reduced. Meanwhile, the cloth bag dust collection material is dehydrated, does not need to be dehydrated in the sintering process, and is doped among the iron phosphate dihydrate particles, so that the probability of forming hard agglomeration among the particles is reduced, and the particle consistency of the anhydrous iron phosphate product is improved.

Acrolein is a useful additive for treating hydrocarbon fluids, such as crude oil, for multiple purposes including, but not necessarily limited to, reducing or preventing microbial activity, scavenging hydrogen sulfide (H2S), and / or at least partially dissolving iron sulfide (FexSy). Acrolein can be stabilized against decomposition by mixing or combining it with at least one alkyl carbonate, which can also raise the flash point of the stabilized acrolein composition.

The invention belongs to the technical field of water treatment adsorption, and discloses amine-modified ferroferric oxide for wastewater phosphorus removal and a preparation method and application thereof.The preparation method comprises the following steps that ferric acetylacetonate and long-chain organic amine are dissolved in absolute ethyl alcohol, and a dark red clear solution is obtained; performing constant-temperature water bath on 1-octadecene for later use; under the condition of stirring, slowly dropwise adding the dark red clear solution into the 1-octadecene, and continuously performing constant-temperature water bath to obtain a mixed solution; transferring the mixed solution into a reaction kettle, and carrying out high-temperature reaction in an inert atmosphere to obtain a black mixture; and sequentially carrying out magnetic separation, washing and freeze drying on the black mixture to obtain the amine modified ferroferric oxide. The prepared amine-modified ferroferric oxide has the advantages of strong saturation magnetization, rapid and deep phosphorus removal capability, high phosphate selectivity, environment friendliness and the like, and the adsorption capacity of the amine-modified ferroferric oxide is more than two times that of an unmodified material.

The invention discloses a method and a system for co-producing high-purity iron through a Bayer process and high-purity iron powder, and belongs to the field of metallurgical recycling and green chemical engineering. According to the method, residual alkali liquor and process waste heat in the Bayer process red mud are utilized, the ultrasonic cavitation effect is cooperated with sodium thiosulfate to serve as a Fe < 3 + > stabilizer, iron oxide in the red mud is selectively dissolved at the temperature of 80-100 DEG C, and meanwhile dissolution of Al2O3 is inhibited. And filtering the dissolved iron alkali liquor through a ceramic membrane, complexing and purifying the iron alkali liquor through EDTA (Ethylene Diamine Tetraacetic Acid), introducing the iron alkali liquor into a diaphragm electrolytic cell, directly electrolyzing to generate Fe (OH) 2 under the conditions that the pH is 10-11 and the current density is 3000-5000 A / m, and dehydrating and reducing to obtain iron powder with the purity of more than or equal to 99.5%. And the electrolytic residual liquid is returned to a reaction process after alkali is supplemented, and filter residues are recycled to a Bayer process dissolution section, so that full circulation of resources is realized. According to the method, the technical bottlenecks of high acid consumption and alkaline electrolytic iron of a traditional acid leaching method are broken through, and the energy consumption per ton of iron is only 2100 kWh and is reduced by 38% compared with that of a traditional process.

The invention discloses a method for repairing a bolt with a rusted surface. The method comprises the following steps that the bolt with the rusted surface to be repaired is placed in a cleaning tank containing acid cleaning liquid; the sound velocity and the conductivity of tank liquid are monitored in real time through a cooperative sensing system arranged in a circulation loop of the cleaning tank; calculating the concentration of acid in the acidic cleaning solution and the concentration of dissolved iron generated by dissolution of the rust in real time; calculating the instantaneous dissolution reaction rate of the rust in the acidic cleaning solution; an end point of the cleaning process is determined based on a variation trend of the instantaneous dissolution reaction rate, and the cleaning step is terminated when the end point is reached. According to the method, the reaction rate is monitored in real time, the optimal end point of rust removal is automatically judged, it is guaranteed that rust is thoroughly removed, meanwhile, the situation that bolt base metal is damaged due to excessive cleaning is avoided, and therefore the high consistency of repairing quality is guaranteed.

A method for preparation of an iron salt battery electrolyte comprises: supplying FeCl3 into an agitated reactor containing a dilute solution of HCl having a pH less than 1; supplying elemental iron into the reactor such that the elemental iron reacts with iron(III) to form iron(II); monitoring the pH of reactor solution; using the monitored pH to control supplying additional HCl into the reactor in order to maintain a pH of the reactor solution less than 1; and converting excess Fe3+ to Fe2+ in an electrochemical cell having a membrane or separator between an anode and cathode by directing the reactor solution from the reactor through the anode. A flow rate of the reactor solution through the anode is controlled to obtain a final Fe3+ concentration in the anode outlet FeCl2 stream of 15% or less than 15% of a total dissolved iron concentration as the iron salt battery electrolyte.

The invention discloses an attapulgite / bimetal oxide composite material and a preparation method and application thereof, and relates to the technical field of heavy metal Cd (II) treatment.The preparation method comprises the following steps that 1, ferric salt and magnesium salt are dissolved in a water-based solvent to form a homogeneous solution, 2, attapulgite powder is added into the solution obtained in the step 1, stirring reaction is conducted under the alkaline condition, and the attapulgite / bimetal oxide composite material is obtained; carrying out solid-liquid separation, drying and grinding to obtain an attapulgite / double-metal hydroxide composite material; and (3) calcining the A-LDH obtained in the step (2) in an inert atmosphere, and cooling to obtain the attapulgite / bimetallic oxide composite material. According to the invention, A-LDH is synthesized by adopting a simple coprecipitation method, and ATP is uniformly distributed on the surface of FeMg-LDH. Therefore, along with the improvement of the dispersing performance of the A-H composite material in an aqueous solution, the aggregation behavior of LDH is obviously reduced, and after the A-LDO is further formed through high-temperature pyrolysis, the distribution area of each component is uniform, the pore structure is richer, and the adsorption effect is better.

The invention discloses a preparation method of a Fe-based catalyst for preparing ethanol through CO2 hydrogenation in the technical field of catalysts, which comprises the following steps: step 1) solution mixing: dissolving iron salt and a complexing agent in water and fully stirring to form a uniform solution, and aging and washing to obtain a material; (2) drying the solution: putting the material obtained in the step (1) into a drying oven, and carrying out drying operation to obtain a dried material; (3) calcining a precursor: calcining the material obtained in the step (2) in a muffle furnace in calcining equipment to obtain a catalyst; 4) atmosphere treatment: carrying out atmosphere treatment on the material obtained in the step 3) to obtain an active component iron species; and step 5) carrier loading: loading an active component iron species on the carrier to obtain the combined catalyst, the Fe-based catalyst which is mild in reaction condition, simple in preparation method, environment-friendly, energy-saving and high in economic benefit is obtained, and the Fe-based catalyst can be used in preparation of ethanol by hydrogenation of carbon dioxide.

The application provides a preparation method of an iron-zinc co-doped graphite-like wastewater self-purification catalyst and application thereof, and the method comprises the following steps: dissolving iron metal salt and zinc metal salt in deionized water, adjusting pH to form a solution A by using ammonia water, adding melamine to form a dispersion B after stirring, then adding an organic complexing agent, stirring, and then stirring to dryness in a water bath, and then drying in a blast drying oven, and finally uniformly grinding the obtained product and sodium bicarbonate, and then calcining, and grinding the obtained black solid to obtain the Fe 0 -Fe x C y @C catalyst. The preparation method is simple, requires low equipment, and the prepared Fe 0 -Fe x C y @C catalyst can effectively and rapidly remove organic pollutants such as bisphenols, ciprofloxacin and sulfamethoxazole in water without adding an oxidant; has excellent removal effect on difficult biodegradable organic pollutants at neutral room temperature, has high stability, and has very low metal ion dissolution rate.