408 results about "Ferrous salts" patented technology

The invention provides a low-cost preparation method of high-performance titanium-doped iron phosphate, and relates to the technical field of batteries. The low-cost preparation method comprises the following steps: S1, respectively preparing a phosphoric acid solution, a hydrogen peroxide solution, a phosphorus salt solution and a ferrite solution; s2, adding titanium sulfate into the ferrite solution to obtain an iron-titanium mixed solution; s3, directly adding ammonia water and a hydrogen peroxide solution into the phosphorus salt solution to obtain a phosphorus-oxygen mixed solution; s4, the iron-titanium mixed solution is heated, the phosphorus-oxygen mixed solution is put into the iron-titanium mixed solution, and slurry A is obtained; s5, obtaining a filter cake A; s6, adding pure water and a phosphoric acid solution, and heating to obtain slurry B; s7, obtaining anhydrous iron phosphate; the synthesized iron phosphate is compact and compact in morphology, internal pore channels of primary particles are still rich, the compaction density of the lithium iron phosphate material obtained through grinding and sintering reaches 2.613 g / cc, the 0.1 C discharge capacity can still reach 156.35 mAh / g, and the 1C discharge capacity reaches 131.47 mAh / g.

The invention discloses a method for recovering lithium, nickel cobalt manganese composite hydroxide and aluminum copper powder from a waste ternary lithium ion battery pole piece. The method comprises the following steps: treating waste pole pieces of a ternary plant or a mixture of positive and negative pole pieces by using a Fenton technology, leaching by using a mixed ferric salt solution, and filtering to obtain lithium-containing leachate and slag; adjusting the pH value of the leachate, oxidizing and filtering to obtain a purified solution and ferric hydroxide precipitate, and adding the purified solution and a lithium hydroxide solution into a reactor for coprecipitation to obtain a deeply purified solution and the nickel-cobalt-manganese composite hydroxide. And dissolving the ferric hydroxide precipitate with dilute acid, adding a reducing agent to generate a ferrous salt solution, and returning the ferrous salt solution for Fenton reaction and leaching reaction. And adding the sodium carbonate saturated solution into the deep purification solution, and crystallizing and precipitating to obtain the battery-grade lithium carbonate. And performing hydrodynamic screening on the leaching residues to obtain an aluminum-copper mixture and graphite residues, and performing grinding and specific gravity separation on the aluminum-copper mixture to obtain high-purity aluminum powder and copper powder. According to the method, the iron salt is directly leached from the pole piece, the used iron salt can be recycled, and the method is suitable for large-scale recovery of the waste ternary lithium ion battery.

The preparation method comprises the following steps: S1, preparing a phosphoric acid solution, a hydrogen peroxide solution, a Ti salt, a phosphor salt solution and a ferrite solution; s2, Ti salt and the ferrite solution are mixed, and a titanium iron salt solution is obtained; mixing the phosphoric acid solution and the phosphorus salt solution to obtain a phosphorus source solution; s3, adding the titanium iron salt solution into a reaction kettle, and adding the hydrogen peroxide solution; s4, adding the phosphorus salt solution into the reaction kettle to obtain yellow slurry; s5, after the color of the slurry is heated to be white, white slurry is obtained; s6, carrying out solid-liquid separation on the white slurry to obtain an iron phosphate dihydrate filter cake; and S7, drying and calcining the iron phosphate dihydrate filter cake to obtain the Ti-doped battery-grade anhydrous iron phosphate. The titanium-doped iron phosphate is firstly prepared by a one-step method, the pH value of the reaction system is controlled by controlling the molar ratio of the iron element to all phosphorus elements in total phosphorus, ammonium phosphate and phosphoric acid in the reaction system, and the retention of the Ti element in the finished product and the regulation and control of the iron-phosphorus ratio in a specified range are ensured.

The invention relates to a method for recycling iron phosphate from lithium iron phosphate waste and application of the method, and belongs to the technical field of iron phosphate recycling. Comprising the following steps that firstly, the lithium iron phosphate waste, a reducing agent and sodium carbonate are mixed and roasted at the temperature of 820-890 DEG C, the reducing agent reacts with oxygen in the lithium iron phosphate waste, and Fe (II) easier to leach by acid is generated; subsequently, the roasted product is immersed in a mixed acid and ferrite solution, Fe < 2 + > is dissolved in a solution system through the mixed acid, insoluble iron phosphate precipitates are promoted to be formed, and therefore the Li < + > leaching rate of insoluble phosphate minerals in the roasted product can be increased. According to the method, a mixed acid solution is added, the pH value in an acid leaching system is limited to be 1.0-5.0, so that impurity components containing copper, manganese, aluminum, nickel and the like in a roasted product can be dissolved in the mixed acid solution, finally, an iron phosphate-containing solid obtained after solid-liquid separation is calcined, and comprehensive utilization of recovering lithium and iron phosphate from the lithium iron phosphate waste at the same time is achieved.

The invention relates to the technical field of ORR catalyst preparation, in particular to an iron-nitrogen-carbon catalyst and a preparation method and application thereof. The invention provides a preparation method of an iron-nitrogen-carbon catalyst, which is characterized by comprising the following steps: dispersing zinc salt and ferrite in methanol to obtain a mixed solution A; the preparation method comprises the following steps: dispersing 2-methylimidazole and 1, 4-terephthalonitrile in methanol under a heating condition to obtain a mixed solution B; stirring and mixing the mixed solution A and the mixed solution B to obtain precursor powder, and calcining the precursor powder in an inert atmosphere to obtain the iron-nitrogen-carbon catalyst with the hierarchical porous structure. The invention provides a novel preparation method for preparing the iron-nitrogen-carbon catalyst with the hierarchical pore structure, and the iron-nitrogen-carbon catalyst with the hierarchical pore structure is prepared by introducing a 1, 4-terephthalonitrile molecular template.

The present invention provides a carbon-based iron-nitrogen composite material, a preparation method and application thereof, and a lithium-ion battery. The preparation method uses nitrogen-containing ligands and ferrous salts as raw materials, generates an iron-containing complex through a self-assembly reaction between the two, and then dries and calcines the iron-containing complex to obtain a carbon-based iron-nitrogen composite material. The carbon-based iron-nitrogen composite material obtained by calcining the iron-containing complex prepared by the preparation method includes carbon, Fe 3 C.Fe 3 A material with multiple components such as N and Fe, and having a layered structure and a hollow tubular particle structure attached to the surface of the layered structure. The carbon-based iron-nitrogen composite material having the above components and the layered structure and the hollow tubular structure is used in lithium-ion batteries, which can make lithium ions migrate more easily therein, thereby effectively improving the gram capacity and stability of lithium-ion batteries, and enabling lithium-ion batteries to be used for a long period of time. The nitrogen-containing ligand has a structure shown in formula (I). #imgabs0#

The present invention relates to the technical field of ORR catalyst preparation, and in particular to an iron-nitrogen-carbon catalyst and its preparation method and application. The present invention provides a method for preparing an iron-nitrogen-carbon catalyst, characterized in that it comprises: dispersing a zinc salt and a ferrous salt in methanol to obtain a mixed solution A; under heating conditions, dispersing 2-methylimidazole and 1,4-terephthalonitrile in methanol to obtain a mixed solution B; stirring and mixing the mixed solution A and the mixed solution B to obtain a precursor powder, and calcining the precursor powder under an inert atmosphere to obtain an iron-nitrogen-carbon catalyst with a hierarchical porous structure. The present invention provides a new preparation method for preparing an iron-nitrogen-carbon catalyst with a hierarchical pore structure, which prepares the iron-nitrogen-carbon catalyst with a hierarchical pore structure by introducing a 1,4-terephthalonitrile molecular template.

The invention provides a preparation method of a three-dimensional structure ferrous phosphate pigment with corrosion early warning capability, which comprises the following steps: preparing a ferrous ion-containing solution for providing ferrous ions, the ferrous ion-containing solution contains soluble ferrite and a surfactant and does not contain oxidizing ions, the ferrous ion-containing solution is in an acidic environment; preparing an initial mixed solution for providing phosphate ions and ammonium ions; atomizing and spraying the initial mixed solution into a ferrous ion-containing solution to obtain an intermediate mixed solution, carrying out ultrasonic refining on the intermediate mixed solution by utilizing an ultrasonic oscillation and microwave heating auxiliary device, heating and carrying out heat preservation to obtain a final mixed solution; and filtering the precipitate in the final mixed solution, transferring the precipitate to a vacuum environment, and carrying out high-temperature heating treatment to obtain the three-dimensional structure ferrous phosphate pigment with the corrosion early-warning capability, which can have the corrosion early-warning capability.

The invention relates to the technical field of surface treatment of anodes, in particular to a method for electrochemically removing a lead dioxide failure coating on the surface of an anode, which comprises the following steps: S1, pretreating the surface of the anode; s2, preparing an electrolyte; s3, the anode pretreated in the step S1 serves as a cathode, the insoluble anode serves as an anode, the cathode and the anode are arranged in an electrolytic bath containing the electrolyte in the step S2 in a cathode-anode-cathode mode to be powered on, and the lead dioxide failure coating on the surface of the anode is removed; and S4, cleaning the surface of the electrode treated in the S3. According to the method, when the lead dioxide invalid coating on the surface of the anode is removed, the ferrous salt is introduced into the prepared electrolyte, and Fe2 + ions in the ferrous salt can reduce PbO2, so that the removal efficiency of the lead dioxide invalid coating on the surface of the anode is greatly improved, and the treated surface of the anode is clean and free of invalid active layer residues; and the concentration of nitric acid in the prepared electrolyte is reduced, and the anode base material is not damaged on the basis of improving the environment.

The invention provides a doped ferric sodium pyrophosphate material as well as a preparation method and application thereof. The preparation method comprises the following steps: S1, blending ferrite, phosphate, strong acid and an antioxidant to form a solution A; s2, adding doped metal salt, sodium salt and a chelating agent into the solution A to form a solution B; s3, co-dropwise adding the solution B and the coprecipitation solution into grinding equipment, and maintaining the pH value to be 4.5-5.5 in the grinding process; s4, mixing and stirring the reaction product and water to form a suspension, and freeze-drying to obtain a precursor material; and S5, mixing the precursor material with a carbon source, and performing high-temperature heat treatment to obtain the doped ferric sodium pyrophosphate material. The material has excellent electrochemical performance, high compaction density and regular product morphology.

The invention provides an oxytetracycline-containing organic pyrite micron column and a synthesis method thereof, the oxytetracycline-containing organic pyrite micron column is prepared by preparing a solution containing potassium salt and oxytetracycline, adding ferrous salt and KFeS2 and reacting under stirring, an organic pyrite material is synthesized under a mild condition, the morphology is uniform, and the preparation method is simple. The organic sulfur iron micron column shows the reduction coordination characteristic of an oxytetracycline-Fe / S ligand, the performance stability of a Fe / S structural material is enhanced, the applicable pH range is wide, and the complexing breaking and chromium removal efficiency on organic chromium under the action of an electric field is remarkably enhanced.

The present solution provides a preparation method for a three-dimensional structured ferrous phosphate pigment with corrosion early warning capability, including following steps: preparing a ferrous ion-containing solution for providing ferrous ions, where the ferrous ion-containing solution includes a soluble ferrous salt and a surfactant but no oxidizing ions, and the ferrous ion-containing solution is maintained in an acidic environment; preparing an initial mixed solution for providing phosphate ions and ammonium ions; and performing ultrasonic refinement, heating, and holding on the intermediate mixed solution using an auxiliary device with ultrasonic oscillation and microwave heating functions to obtain a final mixed solution; and filtering out precipitates from the final mixed solution, and then transferring the precipitates to a vacuum environment for high-temperature heating treatment to obtain a three-dimensional structured ferrous phosphate pigment with corrosion early warning capability.

The invention relates to a nickel-iron layered double hydroxide with flaky nanoflower morphology and a preparation method and application thereof. The preparation method of the nickel-iron layered double hydroxide comprises the following steps: S1, dissolving nickel acetate in an organic solvent or a mixed solvent of the organic solvent and water to prepare a first solution; dissolving ferrite in water to prepare a second solution; and S2, uniformly mixing the first solution and the second solution to obtain a mixed solution, and standing and aging to obtain the ferronickel layered double hydroxide. The method is simple to operate, mild in reaction condition, low in equipment cost and green and environment-friendly in synthesis process; the NiFe-LDH prepared by the method is of a three-dimensional nanoflower structure, is uniform in morphology, has a high specific surface area, can provide more active sites, shows excellent electro-catalytic performance when being used as a catalyst for oxygen evolution by electrolysis of water, and has a wide application prospect in the fields of electrochemical energy storage, electro-catalysis, catalytic oxidation and the like.

The present disclosure provides a method for preparing lithium iron phosphate and use thereof. The method comprises: adding a mixed solution of ferrous salt and ammonium dihydrogen phosphate, a citric acid solution and a pH adjusting agent in parallel into a first reactor for reaction, and simultaneously extracting the materials in the first reactor to a second reactor, and adding a copper salt solution and a sodium hydroxide solution to the second reactor for reaction, and refluxing the materials in the second reactor into the first reactor, mixing the solid material obtained in the reaction with a lithium source, and calcining the mixture in an ammonia gas stream to obtain lithium iron phosphate. This method can prepare a lithium iron phosphate precursor with a spherical structure, thereby improving the electrochemical performance of the subsequently prepared lithium iron phosphate material, which has a relatively high conductivity.

The present application provides a low-impurity high-specific-surface-area iron phosphate and its preparation method and application, which belongs to the field of lithium battery materials. The preparation method of the low-impurity high-specific-surface-area iron phosphate provided by the present application includes: providing a ferrous salt solution and a mixed solution containing an oxidant and a phosphorus source; mixing the ferrous salt solution with the mixed solution, and performing a precipitation reaction to obtain a reaction slurry; introducing an oxidizing gas into the reaction slurry, and then heating and aging to obtain a hydrated iron phosphate slurry; after solid-liquid separation, washing, drying and sintering of the hydrated iron phosphate slurry, a low-impurity high-specific-surface-area iron phosphate is obtained. In the above process of iron phosphate crystal transformation, under the oxidation action of the oxidizing gas, a trace amount of trivalent iron ions is always present in the system to inhibit the formation of other impurity phosphate precipitations, and at the same time, through the pore-forming action of the oxidizing gas, the microscopic morphology of the prepared iron phosphate is a porous structure, thereby preparing a low-impurity high-specific-surface-area iron phosphate.

The invention discloses a vanadium iron-site doped iron phosphate material and a preparation method, and relates to the technical field of lithium ion battery positive electrode material preparation, pure water is used as a base solution, and a vanadium salt solution with the pH value of 2.0-3.0, a ferrite solution with the pH value of 1.0-2.5 and a phosphorus-oxygen mixed solution with the pH value of 5.0-7.0 are simultaneously added into a reaction kettle in a three-strand parallel flow mode for a co-precipitation reaction. By controlling the acid environment of a key solution system, reduction of metavanadate radicals or generation of ferric vanadate precipitates is effectively inhibited, and vanadium elements are successfully and uniformly doped to iron sites of iron phosphate crystal lattices; the mass ratio of iron to phosphorus in the obtained iron phosphate material is stabilized at 95-98%, the doping amount of vanadium is 100-10000 ppm, and the vanadium is uniformly distributed. Lithium iron phosphate prepared by taking the material as a precursor has higher discharge capacity and compaction density, and the electrochemical performance of a lithium ion battery is remarkably improved.

The invention provides continuous wastewater treatment equipment, which belongs to the technical field of wastewater treatment, and comprises a treatment tank and an observation window arranged in the middle of the treatment tank, and further comprises a multi-stage treatment assembly, a pollution discharge purification assembly and a stripping assembly, deep purification of the wastewater is realized through multi-stage treatment; the vertical spraying is combined with the stirring of the fan blades and the scrapers, strong water flow scouring force is formed above the elastic filter plate, meanwhile, the convex plates periodically extrude the elastic filter plate during rotation to enable the elastic filter plate to vibrate, suspended particles and impurities can be effectively prevented from being accumulated on the surface of the elastic filter plate, the risk of filter plate blockage is reduced, and meanwhile, the service life of the filter plate is prolonged. Ferric hydroxide colloid generated by ferrite reaction can more uniformly adsorb suspended particles under the driving of upper and lower water flows, and the precipitation separation of the suspended particles is accelerated; the connecting shaft rotates to drive the mounting cylinder, the arc-shaped groove of the trigger cavity is matched with the ball, the oxidation disc vibrates, the vibration strength is adjusted according to the descending amplitude of the oxidation disc, and the overall wastewater treatment efficiency is improved.

The present invention relates to a nickel-iron layered double hydroxide having a flaky nanoflower morphology and its preparation method and application. The preparation method of the nickel-iron layered double hydroxide comprises the following steps: S1, dissolving nickel acetate in an organic solvent or a mixed solvent of an organic solvent and water to prepare a first solution; dissolving a ferrous salt in water to prepare a second solution; S2, mixing the first solution and the second solution to obtain a mixed solution, and obtaining the nickel-iron layered double hydroxide through standing and aging. The method is simple to operate, has mild reaction conditions, low equipment cost, and a green synthesis process; and the NiFe-LDH prepared by the above method presents a three-dimensional nanoflower structure with uniform morphology and high specific surface area, which can provide more active sites. It exhibits excellent electrocatalytic performance as a catalyst for electrolysis of water and oxygen evolution, and has broad application prospects in the fields of electrochemical energy storage, electrocatalysis, and catalytic oxidation.

The invention provides a sodium-rich ferric sodium pyrophosphate positive electrode precursor and a preparation method and application thereof.The preparation method comprises the following steps that a ferrite solution, a phosphoric acid source solution, a pyrophosphoric acid source solution, an alkaline solution and a sodium persulfate solution are injected into a base solution in a parallel flow mode for a co-precipitation reaction, the sodium-rich ferric sodium pyrophosphate positive electrode precursor is obtained; wherein the base solution is pure water. The method disclosed by the invention is simple to operate, the sodium-rich ferric sodium pyrophosphate positive electrode precursor with high sodium content, uniform element distribution and uniform phase can be prepared, the sodium-rich ferric sodium pyrophosphate positive electrode precursor is low in gas production rate in the subsequent sintering process, and the sodium-rich ferric sodium pyrophosphate positive electrode material with high compaction density can be prepared.

The invention belongs to the technical field of adsorbents, and discloses a core-shell structure composite material as well as a preparation method and application thereof. Ferroferric oxide is loaded on biochar by coprecipitation of ferric salt, ferrous salt and biochar, amination modification is performed by using polyethyleneimine, and a COF shell layer is prepared in situ by using a magnetic core. The shell layer is chemically connected with the magnetic core, and is coated by the COF shell, so that the structural stability is improved, the porous structure of the biochar is not easy to collapse, and the magnetic particles are not easy to fall off; the shell contains sulfonic acid groups, has electronegativity, and is combined with metal ions through electrostatic interaction, so that the adsorption sites of the adsorbent are increased. Meanwhile, the COF shell is of a porous structure, the specific surface area is large, the COF shell has the adsorption effect on metal ions, more adsorption sites are provided for the metal ions through the multiple adsorption effects of the COF shell and the magnetic core, and the removal rate is effectively increased.

The present invention discloses a carbon-coated one-dimensional ferrous fluoride positive electrode material and its preparation method and application, comprising the following steps: A. mixing iron powder or soluble ferrous salt with fluorosilicic acid aqueous solution or fluorosilicate solution, centrifugally separating the supernatant and evaporating to obtain ferrous fluoride silicified powder; B. dissolving ferrous fluoride silicified powder and polyvinyl pyrrolidone in a deionized aqueous solution of ethanol to obtain a mixed solution; C. preparing an electrostatic spinning material by electrostatic spinning; D. placing the electrostatic spinning material in air or oxygen for pre-oxidation, and then carbonizing it in an inert atmosphere, and taking it out. The present invention, without introducing an additional fluorine source, uses liquid phase reaction to synthesize precursors, electrostatic spinning composites and high-temperature solid phase reactions to embed transition metal fluorides into conjugated polymers, and uses the nano properties, conductivity and structural toughness of one-dimensional carbon materials to improve the electrochemical activity, intrinsic conductivity and structural stability of transition metal fluorides, thereby comprehensively improving the electrochemical properties of transition metal fluorides.

The invention discloses a treatment method of an electrolyte after wet crushing of a waste lithium ion battery. During crushing, an alkaline solution is sprayed out of a spraying opening located above a shearing opening to completely cover the waste lithium ion battery crushed material, a hydrolysis reaction is carried out under the cooperation of ultrasonic waves, and waste water, a pole piece mixture, a shell pile head, a diaphragm and the like are separated out through hydrodynamic force. The method comprises the following steps: adding dilute acid into wastewater to adjust the pH value, adding bivalent iron salt and hydrogen peroxide, performing Fenton oxidation and mineralization on an organic solvent in the wastewater under the synergism of ultrasonic waves, then adding an alkali metal salt solution to adjust the pH value, and filtering and separating to obtain filtrate and ferric hydroxide precipitate; adding alkali into the filtrate twice to adjust the pH value for precipitation, and filtering to separate valuable precipitate and filtrate; and adding dilute acid into the ferric hydroxide precipitate for dissolving, and then adding a reducing agent to obtain a ferrous salt solution which is circularly used for Fenton reaction. According to the method, hydrolysis, Fenton oxygenolysis, mineralization of the organic electrolyte and regeneration and recycling of the ferrous salt are adopted, and the method is suitable for large-scale and low-cost treatment of the electrolyte in the waste lithium ion battery.

The invention relates to the technical field of soil remediation, and discloses a soil remediation material for targeted adsorption of perfluoroalkyl acid organic pollutants and a preparation method of the soil remediation material. The soil remediation material is prepared from the following raw materials: microorganisms, a porous carrier, cationic gel, anionic gel and ferrite, wherein the microorganisms have the capability of driving a nitric acid reduction-ferrous oxidation process. According to the soil remediation material provided by the invention, the microorganisms with the capability of driving the nitric acid reduction-ferrous oxidation process, the porous carrier, the cationic gel, the anionic gel and the ferrite are used as raw materials, and the mechanical strength change of the material in different application stages is dynamically regulated and controlled through the valence change of iron ions and the mineralization process of the microorganisms; according to the soil remediation material disclosed by the invention, the miscibility of the soil remediation material and soil and the specific adsorption of the medium-short-chain perfluoroalkyl acid are enhanced, and meanwhile, the conversion of pollutants from an extractable state to a non-extractable state can be promoted, so that the deep fixation of the pollutants is realized, and the secondary release risk after fixation is reduced.

The invention discloses an electrochemical preparation method and application of a superfine platinum particle modified nickel-iron double hydroxide nanosheet array, and belongs to the technical field of water electrolysis. The preparation method comprises the following steps: in a three-electrode system, taking a mixed solution of nickel salt and ferrous salt as an electrolyte, and carrying out electro-deposition by adopting a constant potential deposition method to obtain a carbon cloth material for in-situ growth of a ferro-nickel hydroxide nanosheet array; and then in a two-electrode system, a mixed solution of chloroplatinic acid and potassium hydroxide is used as an electrolyte, and electro-deposition is performed by adopting a constant current deposition method, so that uniform loading of superfine platinum particles on the surface of the ferro-nickel double hydroxide nanosheet array is realized. The superfine platinum particle modified nickel-iron double hydroxide nanosheet array prepared by the preparation method disclosed by the invention can show excellent catalytic activity and stability in hydrogen production by alkaline electrolysis of water.

The invention provides a preparation method of doped iron phosphate with a high iron-phosphorus ratio and a specific crystal structure, and relates to the technical field of lithium ion, the preparation method comprises the following steps: S1, respectively preparing a ferrite solution, a phosphorus salt solution, a hydrogen peroxide solution and a phosphoric acid solution; s2, adding a pure water base solution into a reaction kettle, adding a phosphorus salt solution and a ferrite solution at the same time, and reacting to obtain blue-green slurry A; s3, adding a phosphoric acid solution, heating to T1, adding a hydrogen peroxide solution, and reacting to obtain white slurry B; s4, heating the white slurry B to T2, and keeping the temperature to obtain white slurry C; s5, flash evaporation calcination; on one hand, the diffusion path of lithium ions is shortened by utilizing the characteristic that the ratio of iron to phosphorus in iron phosphate is favorable for refining the particle size of lithium iron phosphate; on the other hand, a specific iron phosphate crystal structure is utilized to reduce the Li / Fe mixed arrangement phenomenon occurring in the lithium iron phosphate sintering process; meanwhile, impurity elements are doped into the iron phosphate precursor to broaden the transmission path of lithium ions and improve the electron conductivity.

The invention relates to the technical field of mine waste liquid treatment, in particular to a method for treating acid mine waste water containing iron ions. The method comprises the following steps: carrying out reduction reaction on acid mine wastewater containing iron ions by using an iron-containing reducing agent to obtain a mixture; carrying out solid-liquid separation on the mixture to obtain a ferrous ion solution; performing membrane treatment on the ferrous ion solution to obtain a concentrated solution; and carrying out crystallization reaction on an alcohol solventing-out agent, a ferrite seed crystal and the concentrated solution to obtain crystal slurry containing ferrite crystals. According to the method, reduction reaction, solid-liquid separation, membrane treatment and crystallization reaction are combined, so that the purity of an iron product obtained by treating the acid mine wastewater containing iron ions can be synchronously improved to 95% or above, and the recovery rate can be synchronously improved to 94% or above.

The invention belongs to the field of field remediation functional materials, and particularly relates to a preparation method and application of a chelating iron agent for remediation of organic contaminated soil. The preparation method comprises the following steps: firstly, preparing a chelating agent aqueous solution, adding ferrite under a continuous stirring condition to carry out chelation reaction, then adding organic acid to carry out stabilization treatment, finally adding an activating auxiliary agent fulvic acid, uniformly mixing, and adjusting the pH value of the solution to a required value to obtain the chelating iron agent. The chelating iron agent can be used for activating an oxidizing agent during in-situ / ex-situ remediation of an organic polluted site, and has the advantages that the chelating iron agent is environment-friendly, the ferrous ion stability is good, the contact reaction with the oxidizing agent is mild and controllable, iron precipitates are not easy to form, and the growth and metabolic activity of indigenous organisms are stimulated.

The invention discloses a treatment method of electroplating wastewater, and belongs to the technical field of electroplating wastewater treatment. The process comprises the following steps: electrically adjusting the pH value of the electroplating wastewater to 2.5-4.0, adding ferrite, adopting a Ti / PbO2 anode and a graphite cathode, controlling the current density to 15-30mA / cm, introducing air, reacting for 40-80 minutes, and adjusting the pH value to 6.0-7.0 after the reaction; introducing the wastewater into a chelating resin column, wherein the chelating resin is an amino phosphonic acid type or iminodiacetic acid type; the method comprises the following steps of: introducing into a built-in filter column, loading two layers of recrystallized silicon carbide honeycomb ceramic membranes in the filter column in parallel, performing cross-flow filtration under the conditions that the operation pressure is 0.8-2.0 MPa, the temperature is 25-40 DEG C and the cross-flow velocity is 1.5-3m / s, and collecting permeate; the permeate liquid is used for backwashing every 8-12 hours of operation. According to the method, heavy metal ions in the electroplating wastewater can be effectively removed, and the treatment efficiency of the electroplating wastewater is improved.

The embodiment of the specification provides a preparation method of amination modified magnetic beads, and the preparation method comprises the following steps: mixing ferric salt, a ferrous salt aqueous solution and a dextran aqueous solution for reaction to obtain dextran magnetic beads; then adding an epichlorohydrin solution into the glucan magnetic beads to react for a certain time, and then adding an amination reagent to react for a certain time to obtain amination modified magnetic beads; the embodiment of the invention also provides a magnetic bead for cell sorting and cell activation, and a target cell sorting and target cell activation method. The cell sorting magnetic bead provided by the invention is high in cell sorting purity, high in sorting recovery rate and high in cell viability; the activation magnetic bead provided by the invention has a good activation effect, and activated cells can be amplified at high times.

The invention relates to the technical field of underground water remediation, in particular to a biochar-loaded pyrrhotite composite remediation agent as well as a preparation method and application thereof. The preparation method of the biochar-loaded pyrrhotite composite repairing agent provided by the invention comprises the following steps: S1, crushing, pyrolyzing, cooling, grinding and sieving carbon-based biomass to obtain a BC material; s2, dissolving ferric salt, ferrous salt, a sulfur source and a BC material, uniformly stirring, heating, cooling to room temperature, washing and drying to obtain a composite repairing agent; in the composite repairing agent, the molar ratio of Fe7S8 to BC is 1: (1-5). According to the method provided by the invention, Fe7S8 is uniformly dispersed and loaded on the surface of BC with a unique pore structure (agglomeration is effectively relieved) through a simple and convenient one-pot solvothermal synthesis method.