49 results about "Ferrocyanide" patented technology

The present invention discloses a preparation method and production system for sodium nitroprusside. The preparation process comprises the following steps: first, reacting ferrocyanide with nitric acid to obtain a hydrogen nitroprusside aqueous solution; adding alcohol to the concentrated hydrogen nitroprusside aqueous solution to remove inorganic salts generated by the reaction, thereby obtaining a hydrogen nitroprusside alcohol solution; then, adding trisodium citrate to the hydrogen nitroprusside alcohol solution to react to obtain sodium nitroprusside and disodium citrate; separating and removing the citrate to obtain a sodium nitroprusside alcohol solution; and finally, concentrating, crystallizing, separating, and drying the sodium nitroprusside alcohol solution to obtain a sodium nitroprusside product. The present invention also provides a production system based on the preparation method. The production method of the present invention is simple to operate, operates under mild conditions, has a short production cycle, effectively prevents product oxidation, and has high purity. The obtained product is suitable for industrial production, and the production system requires less equipment and has low equipment requirements.

The invention discloses a method for preparing a sodium-rich boundary-rich iron-based prussian blue analogue (FePBA) through one-step hydrothermal synthesis assisted by sodium thiosulfate. The method specifically comprises the following steps: preparing a solution A and a Na4Fe (I I) (CN) 6 solution; the molar ratio of ferrocyanide to Fe ions in the solution B is 3: 4. And preparing a solution B to react with ferrocyanide to form FePBA. Adding sodium citrate to form a sodium and citrate-rich environment, then adding ferric iron salt, and fully stirring to chelate the added Fe < 3 + > with the citrate; and adding sodium thiosulfate after the step. Preparing a PVP (Polyvinyl Pyrrolidone) solution to play roles in dispersing FePBA and reducing agglomeration, and taking the PVP solution as a solution C; slowly dropwise adding the solution A and the solution B into the solution C at a constant speed by using a rubber head dropper to finally obtain a precursor solution, carrying out hydrothermal reaction for 6 hours at 110 DEG C, carrying out suction filtration on the obtained precipitate, and drying to obtain a FePBA sample. According to the invention, the time required for synthesis is greatly shortened, and the traditional coprecipitation of more than 24 hours is improved into rapid hydrothermal reaction of 6 hours.

The invention relates to the technical field of all-vanadium redox flow battery electrolyte additives, and discloses a Prussian-blue-like additive for a vanadium electrolyte as well as a preparation method and application of the Prussian-blue-like additive. Comprising the following steps: dissolving a first metal source, a second metal source and a structure stabilizer in an acid solution, and carrying out uniform dispersion treatment to obtain a uniform dispersion liquid I; dissolving ferrous cyanide salt and organic phosphonate in deionized water, and carrying out uniform dispersion treatment to obtain a uniform dispersion liquid II; performing continuous ultrasonic treatment on the uniform dispersion liquid II, and dropwise adding the uniform dispersion liquid I into the uniform dispersion liquid II to obtain a prussian blue-like precursor liquid; and carrying out heat treatment on the Prussian blue-like precursor solution to obtain the Prussian blue-like additive for the vanadium electrolyte. And the material can be used as an all-vanadium redox flow battery electrolyte additive to effectively improve the discharge capacity and the capacity retention ratio of the battery.

The invention provides a preparation method and application of oversized metal ferrocyanide, and relates to the technical field of nonferrous metallurgy. Comprising the following steps: preparing a DMF aqueous solution, and dividing the DMF aqueous solution into two equal parts which are respectively marked as a solution A and a solution B; soluble metal salt is added into the solution A, and the pH value is controlled to be 3-8; ferrocyanide is added into the solution B, and the pH value is controlled to be 3-8; dropwise adding the solution B into the solution A, and reacting to obtain a solution C; and filtering and drying the solution C obtained in the step 4 to obtain the metal ferrocyanide adsorbent. According to the method, N, N-dimethylformamide (DMF) is added as a surfactant in the process of preparing a metal ferrocyanide adsorbent by a conventional chemical precipitation method, and ferrocyanide is synthesized in one step. The oversized metal ferrocyanide adsorbent can be obtained by regulating and controlling the adding proportion of the ferrocyanide and water, and has a better adsorption effect.

The present disclosure relates to a kind of ferric phosphate and its preparation method and use, the preparation method includes the following steps: (1) mixing ammonium ferrocyanide and phosphorus source, obtain iron-phosphorus mixed solution;(2) the iron-phosphorus mixed solution obtained in step (1) is carried out spray pyrolysis, obtain solid particles;(3) the solid particles obtained in step (2) are broken, obtain ferric phosphate.The ferric phosphate provided by the present disclosure has higher purity, tap density and specific surface area, the preparation method can avoid using pH regulator and surfactant, reduce by-product production and cleaning step, greatly simplify production process, have higher industrial application value.

This invention discloses a cathode material, its preparation method, and its application, belonging to the technical field of cathode materials for sodium-ion batteries. The cathode material has a core-shell structure, with a core of sodium manganese ferrocyanide and a shell of potassium manganese ferrocyanide; a manganese ferrocyanide intermediate layer is also present between the core and the shell. The intermediate layer contains Mn... 2+ The ionic radius is greater than that of the Na core. + Larger K atoms, with higher valence states, can reduce lattice spacing, thus supporting the structure and improving the material's cycling stability while inhibiting the absorption of water molecules; the K atoms in the outer shell... + Not only can it provide capacity, but also K + The ionic radius is also larger than that of Na. + Larger and wider ion transport channels result in a more stable structure, which also helps reduce the material's water absorption. The presence of the aforementioned intermediate layer and outer shell significantly improves the structural stability of the cathode material during charge and discharge, reduces side reactions between the cathode and electrolyte, and enhances interfacial stability, cycle performance, and rate performance.

The invention relates to the field of compound preparation, and discloses a method for preparing alkali metal ferrocyanide by using iron powder as an iron source through a mechanochemical method, and the method comprises the following steps: mixing the iron powder with a solution containing alkali metal cyanide to obtain a mixture, and enabling the water content of the mixture to be not more than 50wt%, the alkali metal cyanide comprises sodium cyanide or potassium cyanide, the reaction time is short, the reaction temperature is low, the process of treating the raw materials in advance is omitted, hydrolysis of the sodium cyanide is reduced, side reactions are reduced, a small amount of NH3 is released in the complexing reaction process, and the method is suitable for industrial production. The yield is high, sulfate containing ferrocyanide is not produced as a byproduct, and unreacted metal residues are recycled. Compared with a traditional method, the method disclosed by the invention is low in production cost and high in added value of products, and has a relatively good industrial prospect.

The invention relates to an online recovery method for an electrolyte of an alkaline total-iron flow battery, and belongs to the technical field of flow batteries. Aiming at the problem of capacity fading caused by consumption of positive oxidation-state substances due to spontaneous reduction of positive ferricyanide into ferrocyanide and permeation of negative polyhydroxy organic ligands of an alkaline total-iron flow battery, a chemical and electrochemical coordinated regulation strategy is provided; and the concentration of the oxidation-state ferricyanide in the positive electrode electrolyte is dynamically monitored and accurately adjusted in the operation process of the battery. According to the method, dynamic balance regulation and control of oxidation state / reduction state substances in the electrolyte are realized through an in-situ chemical or electrochemical regeneration means on the basis of a positive and negative electrode capacity matching relationship, so that the positive electrode electrolyte is repaired on line, and quantitative and controllable capacity recovery of the alkaline all-iron flow battery is realized. According to the technology, the stable cycle life of the battery can be greatly prolonged, the problem of electrolyte failure caused by polyhydroxy ligand migration is solved, the maintenance cost is reduced, and a key technical support is provided for practicability of the alkaline all-iron flow battery in a large-scale energy storage system.

The invention relates to an aqueous magnesium ion battery positive electrode material and a preparation method thereof, and belongs to the technical field of battery materials, the positive electrode material is a HE-MnZnFePBA-coated CNT composite material, HE-MnZnFePBA is a Prussian blue analogue doped with three metals of manganese, zinc and iron, CNT is COOH-MWCNT, and HE-MnZnFePBA grows on the surface of COOH-MWCNT in situ. According to the HE-MnZnFe PBAatCNT composite positive electrode material and the preparation method thereof, the prepared HE-MnZnFe PBAatCNT composite positive electrode material is doped with Mn, Zn and Fe, the Mn element can improve the electrochemical activity of the material and provide high-capacity contribution, and the Zn element can enhance the lattice stability and inhibit structural collapse in the circulation process; meanwhile, due to the introduction of the carboxylated multi-walled carbon nanotubes, the conductivity of the material is remarkably improved, the ion transmission resistance is effectively reduced, and slow growth of crystals is realized by adopting a slow coprecipitation method and controlling the solution dripping rate, the reaction temperature and the reaction time; meanwhile, the excessive sodium ferrocyanide ligand can perform in-situ vacancy repair on the crystal, so that lattice defects are reduced, and the structural integrity of the material is improved.

The invention discloses a magnetic composite adsorption material with a core-shell structure, a preparation method of the magnetic composite adsorption material and application of the magnetic composite adsorption material in radioactive waste oil treatment, and belongs to the technical field of adsorption material preparation and radioactive waste treatment. The composite adsorbent (Fe3O4 (at) SiO2 (at) TiO2 (at) KTiFe (CN) 6) is of a core-shell structure, Fe3O4 is a magnetic core layer, SiO2 is a middle protective layer, TiO2 is a titanium source functional layer, and KTiFe (CN) 6 ferrocyanide on the outermost layer is a Cs < + > selective adsorption active layer. High-selectivity capturing of Cs < + > in an organic solvent matrix simulating radioactive waste oil and rapid magnetic separation after treatment are achieved. The design strategy effectively overcomes the ubiquitous problems of poor dispersibility, difficult recovery, limited applicability and the like in the application of the traditional ferrocyanide adsorbent in a non-aqueous system.

A preparation method of carbon-doped iron phosphate, comprising the following steps: (1) mixing ammonium ferrocyanide, a phosphorus source and pyridine oxide to obtain an iron-phosphorus mixed solution; (2) performing spray pyrolysis on the iron-phosphorus mixed solution obtained in step (1) to obtain solid particles; (3) crushing the solid particles obtained in step (2) to obtain carbon-doped iron phosphate; and further applying the carbon-doped iron phosphate obtained by the above preparation method to prepare lithium iron phosphate.

The application discloses a kind of alkaline full iron liquid flow batteries and preparation method of electrode material.Its characteristics are: the positive electrolyte of the alkaline full iron liquid flow battery is with ferrocyanide as active substance, one or both of NaOH and KOH as supporting electrolyte, the negative electrolyte is with 3-[N-N-bis (2-hydroxyethyl) amino]-2-hydroxypropane sulfonic acid and ferric chloride reaction to form complex iron as active substance, one or both of NaOH and KOH as supporting electrolyte to form the alkaline full iron liquid flow battery.The application increases the reaction active site of positive and negative electrode electrolyte active substance on the surface of electrode respectively, so as to improve the charge-discharge capacity of liquid flow battery.

The present invention discloses a method and application for organic enhanced stabilization of arsenic in arsenic ferrocyanide, which belongs to the field of wastewater treatment technology. The method comprises the following steps: adding an organic solution containing carboxyl groups to arsenic (III)-containing wastewater, adding a sulfate solution of appropriate concentration, adjusting the pH to less than 3, and then slowly adding a solution containing trivalent iron salt, wherein Fe 3+ ∶As 3+ ∶SO4 2‑ The ratio of arsenic to ferrous iron is 1.5:1:0.25, and the pH value is kept constant during the injection process; the mixture is heated and stirred to a temperature of 25-65°C, reacted for a period of time, and after the reaction is completed, the precipitate is separated. The present invention accelerates the mineralization rate through the strong complexation between organic matter and trivalent iron, achieving a trivalent arsenic removal rate of over 95%. The resulting arsenic nitrite has low leaching toxicity, controlling the leaching toxicity to below 5 mg / L for the first time. The process is simple, and the residual arsenic concentration in wastewater is reduced by approximately 50%, with broad prospects for practical application.

The invention discloses a novel method for recovering valuable metals in waste neodymium iron boron, and relates to the technical field of neodymium iron boron waste recovery. According to the method, the waste neodymium iron boron is subjected to acid leaching by adopting the inorganic acid as the leaching agent, so that iron and rare earth are fully dissolved in the leaching agent, impurities are removed through liquid-solid separation, ferrous cyanate is used as the iron precipitation agent, iron is separated out in the form of Prussian blue precipitation, rare earth is reserved in a liquid phase, efficient separation of iron and rare earth is achieved, and the method is suitable for industrial production. And the iron precipitation effect is obvious. According to the method, the Prussian blue precipitate obtained through the iron precipitation reaction reacts with the alkali liquor to generate alpha-FeOOH and the ferrocyanate solution, the alpha-FeOOH can be used as an adsorbent, a catalyst and an energy storage material for high-valued recovery after being dried, meanwhile, the generated ferrocyanate solution can be recycled, the production cost is reduced, and waste liquid is reduced.

The invention belongs to the field of nano material preparation, and particularly discloses a Fe5C2 powder nano material as well as a preparation method and application thereof. According to the preparation method, ferrous salt and potassium ferricyanide are mixed in proportion for reaction to prepare a precursor ferrous ferricyanide, and the precursor is carbonized and roasted in a reducing atmosphere to obtain the pure single-phase Fe5C2 powder nano material. The invention solves the problems of complex technology, harsh conditions, low product purity and the like in the preparation process of iron carbide, provides a simple and safe preparation method with strong process controllability, and provides a new way for research and application of iron carbide.

The invention relates to the technical field of preparation of inorganic-organic composite functional materials, and relates to a preparation method of an MFCs-coated E-ZrP composite adsorbent and a separation membrane thereof, and the method comprises the following steps: firstly, carrying out intercalation stripping on alpha-zirconium phosphate by using trihydroxymethyl aminomethane through a colloid assembly intercalation method to prepare a water-based E-ZrP dispersion liquid; then transition metal chloride and potassium ferrocyanide are sequentially introduced into the water-based E-ZrP dispersion liquid, metal ferrocyanide is generated through an in-situ reaction, and the MFCs-coated E-ZrP composite adsorbent is obtained; and blending the composite adsorbent with a high-molecular polymer, and preparing the MFCs-coated E-ZrP composite separation membrane by adopting a non-solvent induced phase separation technology. The composite adsorbent and the separation membrane prepared by the invention have high selective adsorption capacity and excellent structural stability on rubidium and cesium ions, and can be widely applied to the fields of separation and extraction of rubidium and cesium in salt lake brine, underground brine and geothermal water, removal of cesium ions in radioactive wastewater and the like.

The present invention relates to a preparation method and application of a nitrogen-doped carbon-supported copper-iron bimetallic catalyst. The preparation method comprises: 1) mixing ferrocyanide with water to obtain solution A; mixing a copper source compound, a reducing metal salt with water to obtain solution B; 2) mixing solution A in step 1) with solution B, reacting at a certain pH, washing and drying the product to obtain a metal-containing complex; 3) calcining the metal-containing complex obtained in step 2) under an inert atmosphere. The catalyst of the present invention exhibits excellent catalytic performance when applied to carbon dioxide electroreduction, and has the characteristics of high selectivity and high stability. In an alkaline electrolyte, CO2 can be selectively electrocatalytically reduced to CO at a low potential, and has a high current density. The preparation method has a simple operating process, low cost, mild reaction conditions, is a green process route, and has potential industrial application value.

The invention discloses a leaching method for reducing mercury leaching in mercury-containing gold ore, and belongs to the field of metal refining. The pH value of the mercury-containing gold ore pulp is adjusted to 11.5 or above, soluble ferrocyanate is added, and stirring and leaching are conducted. The concentration of CN <-> in the ore pulp is detected in the leaching process, and when the concentration of CN <-> is larger than 100 mg / L, a certain amount of soluble copper salt is added into the ore pulp to control the concentration of CN <-> to be smaller than 100 mg / L; and after leaching is finished, ore pulp is filtered to obtain a leaching pregnant solution of the mercury-containing gold ore, a leaching barren solution is obtained after precious metal in the pregnant solution is recycled, the Fe content in the leaching barren solution is detected, soluble ferrocyanate is supplemented according to the Fe content, and then the leaching barren solution returns to a leaching system to serve as slurry mixing water of the mercury-containing gold ore to be recycled. According to the method, the ferrocyanate which is safer and more environmentally friendly than cyanide is adopted as a leaching agent, compared with an existing method, the agent system is simplified, organic matter influencing the leaching index is not introduced, and leaching of Hg is greatly reduced.

Provided is a spinel-type lithium manganese oxide having improved long-term stability in charge-discharge cycles at high temperatures. SOLUTION: A spinel-type lithium manganese oxide containing ferrocyanide.

The invention discloses an energy storage module and an energy storage battery pack, and belongs to the technical field of energy storage battery preparation, the battery pack is composed of a positive electrode material, a negative electrode material, an electrolyte, a diaphragm and an auxiliary agent; the positive electrode material is prepared from a carbon quantum dot modified Prussian blue analogue; the Prussian blue analogue is composed of a precursor and a metal salt, the precursor is at least one of cobalt hexacyanoferrate and iron hexacyanoferrate, and the metal salt is a transition metal salt and an alkali metal salt; the carbon quantum dots are potassium citrate as a carbon source; the negative electrode material is prepared from a silicon-carbon composite material consisting of nano silicon, a pyrolysis carbon source, metallurgical silicon powder and a solvent; the electrolyte is sulfide solid electrolyte; the diaphragm is a ceramic coated diaphragm; the auxiliary agents are a conductive agent, a binder and a current collector. According to the energy storage battery pack, through material innovation and structural design, the defects of an existing energy storage battery are effectively overcome, and the energy storage battery pack has the advantages of being high in energy density, long in cycle life, rapid in charging and discharging, low in cost and high in safety.

This invention relates to the field of vanadium redox flow battery electrolyte additives, and discloses a Prussian blue-like additive for vanadium electrolytes, its preparation method, and its application. The method includes the following steps: dissolving a first metal source, a second metal source, and a structural stabilizer in an acidic solution and uniformly dispersing them to obtain a uniform dispersion I; dissolving ferrocyanide and an organophosphonate in deionized water and uniformly dispersing them to obtain a uniform dispersion II; subjecting uniform dispersion II to continuous ultrasonic treatment, and adding uniform dispersion I dropwise to uniform dispersion II to obtain a Prussian blue-like precursor solution; and heat-treating the Prussian blue-like precursor solution to obtain the Prussian blue-like additive for vanadium electrolytes. Using this additive as a vanadium redox flow battery electrolyte can effectively improve the battery's discharge capacity and capacity retention.

The synthesis and uses of organic hexacyanoferrates is provided. The synthesis of organic hexacyanoferrates includes steps of reacting potassium ferrocyanide or potassium ferricyanide with a nitrogen-organic compound and then collecting the crystals formed therefrom. Compounds of the formula R3Fe(CN)6 are formed from potassium ferricyanide (K3Fe(CN)6), Compound of R4Fe(CN)6 are formed from potassium ferrocyanide (K4Fe(CN)6). Compounds of the formula R3FeH(CN)6, are formed by reacting R3Fe(CN)6 with hydrazine. Compounds of the formula R3FeH(CN)6 are formed from tri-potassium hydrogen ferrocyanide (K3HFe(CN)6).

The invention provides a copper smelting slag separation tailing-based thallium removal agent and a preparation method thereof, and the copper smelting slag separation tailing-based thallium removal agent is prepared by taking a copper smelting slag separation tailing matrix and ferrocyanide as raw materials through pretreatment, functional modification and aftertreatment. Researches show that the perferrocyanide (Prussian blue and analogues thereof) shows extremely high selectivity and adsorption capacity on monovalent cations such as Tl < + > and Cs < + >. The cubic lattice structure provides channels with matched sizes, so that the ions can be specifically captured. The solid theoretical and technical basis is provided for efficient thallium removal by modifying the solid waste through ferrocyanide.

The invention relates to a strong alkaline total iron flow battery electrolyte and a preparation method thereof, the strong alkaline total iron flow battery electrolyte comprises a positive electrode electrolyte and a negative electrode electrolyte, the positive electrode electrolyte is a strong alkaline aqueous solution of ferrocyanate, the negative electrode electrolyte is a strong alkaline aqueous solution of iron salt and an organic ligand, the pH value of the positive electrode electrolyte is consistent with that of the negative electrode electrolyte, and the pH value of the positive electrode electrolyte is consistent with that of the negative electrode electrolyte. The pH is greater than or equal to 14.0. In the negative electrode electrolyte, an organic ligand is used as a complexing agent and forms a stable six-coordinate structure with iron ions, so that the stability of the negative electrode electrolyte is enhanced; the complexing constant of the organic ligand and iron is relatively large, so that the generation of ferric hydroxide precipitates in positive and negative electrolyte can be effectively inhibited even under an alkaline condition, and the stability of iron ions is improved; besides, the ligand molecules are large in size, the steric effect of the formed chelate is large, the transmembrane migration degree of iron ions / ferrous ions is reduced, the cycle life of the total-iron flow battery is greatly prolonged, and the total-iron flow battery can be widely applied to various aqueous flow batteries.

The present application relates to the technical field of comprehensive utilization of waste heat, and discloses a salinity gradient power generation apparatus and method, and a water-electricity co-generation apparatus thereof. In the salinity gradient power generation apparatus and method provided in the present application, an anode and a cathode respectively undergo hydrogen oxidation and reduction reactions, the anode consumes hydrogen, the cathode generates hydrogen, and the hydrogen circulates between the cathode and the anode by means of pipes without net consumption, thereby efficiently utilizing salinity gradient energy, achieving an environmentally friendly process, and producing no carbon emissions; compared with redox reaction systems using Fe2+ / Fe3+ or ferricyanide / ferrocyanide, the system is free from the limitation of concentration polarization; compared with redox systems based on water electrolysis, lower overpotential and higher efficiency are achieved; and a small amount of H2 is used, with no safety risk and no net consumption throughout the system. The water-electricity co-generation apparatus based on the salinity gradient power generation apparatus of the present application can make full use of waste heat to produce fresh water and generate electricity simultaneously, achieving high efficiency and pollution-free operation.

A sulfonated improved aqueous iron-based flow battery electrolyte with high solubility, belonging to the technical field of flow battery energy storage. To solve the problem of low solubility of the iron-based flow battery electrolyte, the present invention uses an asymmetric sulfonated ligand to chelate iron elements, and synthesizes a new type of iron-based flow battery electrolyte with high solubility, and the concentration of the active substance can reach more than 1.3 M at room temperature. The main components of the electrolyte are one or more iron salts, and an aqueous solution of a coordination compound formed by coordinating with 3-tris(hydroxymethyl)methylamino-2-hydroxypropanesulfonic acid (TAPSO), tris(hydroxymethyl)methylaminopropanesulfonic acid (TAPS), tris(hydroxymethyl)methylaminoethanesulfonic acid (TES) or its derivative chemicals. This electrolyte is compatible with ferrocyanide, can provide a voltage of more than 1.3 V, and exhibits excellent cycle stability while maintaining high solubility, creating new possibilities for the development and application of flow battery technology.

The present invention belongs to the field of inorganic advanced nanomaterial technology, and specifically relates to a method for preventing sodium chloride from crystallizing on the surface of a cathode in seawater electrolysis. The method includes at least one of the following two schemes: Scheme 1, the cathode is: a metal ferrocyanide, a metal ferrocyanide, a metal ferrocyanide-loaded material, or a metal ferrocyanide-loaded material; Scheme 2, one or more of ferrocyanide and ferrocyanide are added to the electrolyte. The present invention unexpectedly discovered that the crystal plane of this electrode is a (200) plane with a spacing of about 5 angstroms, while the main crystal plane of sodium chloride is a (200) plane with a spacing of 2.8 angstroms. The two crystal planes are symmetrically matched, but the lattices are not matched, resulting in difficulty for sodium chloride to adhere to the electrode surface. In addition, adding ferrocyanide or ferrocyanide to the electrolyte can also effectively limit the growth of some crystal planes of sodium chloride, thereby controlling the morphology of sodium chloride, making it difficult for it to solidify on the electrode surface, and greatly improving the anti-crystallization stability of the seawater electrolysis cathode.

The present invention discloses a method for preparing a highly selective hydrogen sensor load-type sensitive material, comprising the following steps: S1: adding ferrocyanide and polyvinyl pyrrolidone to a hydrochloric acid solution and uniformly mixing to obtain a mixed solution A; S2: sealing the mixed solution A and then heating it at 88°C to 888°C for 28h to 823h; S3: centrifuging the material obtained in step S2 and washing it multiple times with a mixed solution of ethanol and deionized water, and then dispersing it in an ethanol solution to obtain a mixed solution B; S4: adding a weighed weak acid conjugate base to the mixed solution B, stirring it at room temperature for 98min, then centrifuging, washing, and drying to obtain a precursor material; S8: heating the precursor material obtained in S4 to 888°C under air conditions and keeping it warm for 188min to obtain a loaded α-Fe2O3-based composite sensitive material. The preparation method is simple in process, highly repeatable, and low in cost. The hydrogen sensor made of the sensitive material has obvious advantages in selectivity and response speed.

The invention discloses a method for preparing Prussian blue from cyanidation tailing cyanide, and belongs to the technical field of cyanide. The preparation method of the prussian blue comprises the following steps: (1) putting cyanidation tailings into a ball mill, carrying out ball milling, then adding deionized water, and carrying out stirring and mixing, so as to obtain ore pulp; the method comprises the following steps: under a closed condition, adjusting the pH value to 2.5-3.5 by using sulfuric acid, reacting for 1-2 hours, dissolving ferrous sulfate heptahydrate in deionized water to obtain a ferrous sulfate aqueous solution, introducing HCN gas into the ferrous sulfate aqueous solution, adjusting the pH value to 9.5-10.5, and stirring for reacting for 1-2 hours to obtain ferrocyanide; (2) a cation collecting agent and ferroferric oxide powder are added into the ferrous cyanide salt, stirring and uniform mixing are conducted, then magnetic flotation separation is conducted, and Prussian blue concentrate is obtained; and the Prussian blue concentrate is filtered, washed and dried, and Prussian blue is obtained. The purity and yield of the Prussian blue prepared by the method disclosed by the invention are relatively high.

The application relates to a kind of basic zinc iron single liquid flow batteries, battery module is formed by one section single battery or two or more single batteries in series or / and parallel, an electrolyte storage tank, a set of electrolyte circulating pump and pipeline composition;Negative electrolyte does not flow, only positive electrolyte flows.Carbon felt as electrode;Graphite plate as current collector.Positive electrolyte is ferrocyanide and strong alkali aqueous solution, and negative active material is zinc salt or zinc oxide and strong alkali reaction generated slurry.The zinc iron single liquid flow battery of the application only needs a set of electrolyte circulating device, the structure is simplified, the failure rate of system operation is reduced, the system maintenance and control cost are saved;The concentration of negative active material is greatly improved, the loss of system is reduced, and the energy efficiency of system is improved.