48results about How to "Raise the average valence" patented technology

The invention relates to a kind of preparation craft of anode material of lithium ion battery: keep temperature in the stove equal through entering pump to make it into microcirculation; the anode material of lithium manganese oxide is made by agglomeration for two times; the characteristic of this craft is that, goes into the first agglomeration under the state short of lithium, enter air or oxygen through microcirculation during agglomeration; mix surplus lithium salts and outcome of ball milling for the first agglomeration equally, goes into agglomeration for second time to get lithium manganese oxide which is anode material of lithium ion battery. The invention improves reversibility of circulation and capability of high temperature of the anode material of lithium ion battery effectively and influence charge discharge capacity little. The craft of the invention is simple and practical, the cost is low and it is propitious to industrial production of scale. Lithium ion battery material made by this method can apply to field broadly such as mobile telephone, notebook computer,minitype of video recorder electromotion cars broadly and so on.

The utility model relates to float glass, batch of the float glass and a production method of the float glass. The compositions of the float glass include silicate glass basic oxide, and 0.01 to 2 percent of lithium oxide by weight and rare earth oxide, wherein, the rare earth is at least three kinds of lanthanum, cerium, yttrium, praseodymium and neodymium, which is sourced from the gangue of the rare earth. The batch of the float glass is mixed by the silicate glass basic raw material and the additives, in weight percent, 87.02-106.0:0.02-4. The additives are the lithium carbonate Li2Co3 and the gangue of the rare earth, and the batch is made into the float glass through a float-glass melting kiln. For the lithium oxide and the rare earth are added, the present invention reduces the melting temperature of the glass, which can be applied to the production of the large-scale float glass while satisfying the electrics, the calorifics, and the stable chemical performance. The float glass concerned in the present invention is more applicable to producing the chemical toughened glass.

The invention provides a preparation method of a gold-based catalyst for preparing vinyl chloride by an acetylene hydrochlorination method and the catalyst prepared by the method. According to the catalyst, an activated carbon is used as a carrier, a complex formed by gold and a nitrogen-containing ligand is a main active component, compared with other gold-based catalysts, green solvents such aswater, ethanol and the like are utilized to replace acidic solvents such as hydrochloric acid, aqua regia and the like in the catalyst preparation process, and the gold in a high valence state is stabilized by the complexation of the nitrogen-containing ligand with the gold, thereby improving the effectiveness of the catalyst. The catalyst has high activity and vinyl chloride selectivity in the reaction of fixed bed acetylene hydrochlorination to prepare the vinyl chloride, the preparation method is green and environmentally friendly, and the method has a great industrial application value.

The invention discloses a method for preparing sodium ion battery positive electrode materials with different crystal forms through lithium doping regulation and control. The chemical formula of the positive electrode materials is Na<0.7>Ni<x> Fe<y>Mn<1-x-y-z>Li O<2>, wherein x + y is more than 0 and less than or equal to 0.4, z is more than 0 and less than or equal to 0.4. The obtained material is a P2 phase material, a P2 / O3 mixed phase material or an O3 phase material by regulating the value of z, namely regulating the doping amount of Li. According to the invention, lithium is doped in a transition metal layer, so that a Na-O-Li structure can be formed to activate the oxidation-reduction reaction of oxygen, thereby providing additional capacity. The structure of the sodium-ion battery positive electrode material can be regulated and controlled by changing the lithium doping ratio, so that P2 phase, O3 phase and P2 / O3 mixed phase materials are obtained. The adopted co-precipitation method is simple and easy to implement, a material with regular morphology and uniform size can be obtained, and the obtained material has good electrochemical performance within the voltage range of 1.5-4.5 V.

The invention discloses lithium-ion power battery anode material lithium manganate and a preparation method thereof. The molecular formula of the lithium manganate is Li<1+x>Mn<2-y>TayO4 / zAl2O3, wherein 0<x<=0.2, 0<y<=0.2, and 0<z<=1.0. The preparation method includes the steps of proportionally mixing a lithium source compound, a manganese source compound and a tantalum element additive and subjecting the lithium source compound, the manganese source compound and the tantalum element additive to ball milling and high-temperature roasting to obtain the lithium manganate; and dispersing the lithium manganate in a dispersing agent, adding aluminum stearate for reaction to obtain precipitate, and finally subjecting the precipitate to two-section roasting, second annealing, cooling and sieving to obtain the lithium-ion power battery anode material lithium manganate. By means of a composite metal dual-doping mechanism, doping vario-property of two elements of tantalum and lithium is performed to the lithium manganate, a John-Teller effect is inhibited, and normal temperature and high temperature cycle performances of a lithium manganate material are greatly improved; and by means of sectional roasting and multi-time annealing processes, controllability of particle diameters and specific surface areas is achieved, tap density and processing performances of the material are improved, and simultaneously, oxygen defect levels during material sintering are effectively reduced.

The invention discloses a method for preparing a nitrogen-doped carbon nano array-ferronickel hydrotalcite oxygen evolution electrode and aims to solve the problems that in the prior art a nano arraystructure is not easily prepared from a nitrogen-doped carbon matrix, a hydrotalcite structure is easy to aggregate, and toxic and harmful substances are involved in a preparation method. The method comprises the following steps: (1) preparing a nitrogen-doped carbon nano array by using an ion injection method; and (2) by taking the nitrogen-doped carbon nano array, a platinum sheet and a silver / silver chloride electrode as a working electrode, a pair electrode and a reference electrode respectively, performing constant potential deposition, so as to obtain a nitrogen-doped carbon nano array-ferronickel hydrotalcite composite electrode. The nitrogen-doped carbon nano array-ferronickel hydrotalcite oxygen evolution electrode is prepared in a green and environment-friendly mode, regulation and control on a matrix surface structure is achieved, a good former basis is made for research on acquiring of hydrogen energy from water electrolysis, and thus the method is applicable to popularization and application.

A process is provided for converting an alkane to an oxygenated product by passing an alkane gas over a first fixed bed containing a higher valence bromide salt to produce an alkyl bromide, a hydrobromic acid, and a lower valence bromide salt. The alkyl bromide and hydrobromic acid are conveyed as a gas to a second fixed bed containing a metal oxide and are passed over the second fixed bed to produce the first bromide salt and the oxygenated product. The metal oxide in the second fixed bed is regenerated by passing oxygen over the second fixed bed producing the metal oxide and bromine. The bromine is conveyed as a gas from the second fixed bed to the first fixed bed. The first bromide salt of the first fixed bed is regenerated by passing the bromine over the first fixed bed producing the first bromide salt.

The invention belongs to the technical field of rare metal refining, and in particular, relates to a method for preparing porous titanium powder. The technical problem to be solved of the invention is to provide a method for preparing porous titanium; and the method comprises the following steps: a titanium raw material is added in an electrolyte for electrolysis to obtain the porous titanium powder on a cathode; the electrolyte is a mixture of titanium halide and molten salt; the molten salt is at least one of an alkali metal halide or a rare earth metal halide; and in electrolysis, an anode adopts an inert material or a metal material with more positive potential compared with titanium, and the cathode adopts a metal material. The method can prepare the porous titanium powder.

The invention discloses a low-sulfur-resistant low-temperature carbon-based denitration catalyst as well as a preparation method and application thereof, and belongs to the technical field of flue gasdenitration. The method comprises the steps: pretreating cocoanut active charcoal to obtain a sample AC; impregnating the sample AC in a nitric acid solution, and performing drying to obtain a sampleHAC; preparing a precursor Mn(NO3)2 solution and Fe(NO3)3.9H2O powder into a Mn / Fe-containing precursor mixed solution by adopting an isopyknic impregnation method, putting HAC into the solution, performing magnetic stirring, and performing drying to obtain a sample IAC; and carrying out medium-low temperature segmented calcination on the treated sample IAC to finally obtain the low-sulfur-resistant low-temperature carbon-based denitration catalyst sample. The preparation method is simple in process, low in preparation cost and energy consumption and environmentally friendly, the prepared catalyst has the advantages that the specific surface area of the carbon-based carrier is large, the pore structure is good, oxygen-containing functional groups are rich, and the reduction performance ofthe Mn / Fe active component NOx is excellent, and the low-temperature efficient flue gas denitrification performance of the composite carbon-based catalyst can be achieved.

The invention discloses a paraffin hydrofining catalyst and a preparation method thereof. A carrier of the paraffin hydrofining catalyst comprises aluminum oxide, layered clay and a Y-type molecular sieve; nickel and molybdenum are taken as active metal components; taking the mass of the paraffin hydrofining catalyst as a reference, the paraffin hydrofining catalyst comprises 2.0%-35.0% of molybdenum oxide, and 0.5%-20.0% of nickel oxide; the dispersity of the active metal components is as follows: IMo / IAl is 0.15-0.30, and INi / IAl is 0.07-0.15. The paraffin hydrofining catalyst is high in active metal utilization rate, high in active metal dispersity and high in activity.

The invention discloses a lithium-rich manganese-based positive electrode material capable of realizing accurate lithium preparation and a preparation method and application thereof. The preparation method comprises the following steps: S1, weighing corresponding soluble metal salts according to a proportion and mixing the soluble metal salts into a metal salt solution; S2, adding the metal salt solution, the precipitant solution and a complexing agent into a reaction kettle, reacting and filtering to obtain a precursor; S3, putting the precursor into a muffle furnace, and calcining in an air atmosphere; S4, mixing and stirring the precursor and a lithium source to obtain a mixture; S5, sintering the mixture in a muffle furnace. According to the method, the precursor of the lithium-rich manganese-based positive electrode material is oxidized and pre-sintered in the air, so that the hardness of the precursor is increased, the structure is more favorably maintained, the component structure is single, accurate lithium preparation is realized, residual lithium on the surface is reduced, and the stability of the structure is enhanced; compared with a conventional method, the method is efficient, economical and easy to operate, the process is easy to control, and the problem of deviation of the lithium preparation amount in a traditional method can be well solved.

The invention discloses a full-pH electrocatalytic hydrogen evolution molybdenum disulfide modified sulfur and molybdenum co-doped graphite-phase carbon nitride heterostructure material and a preparation method thereof. Firstly, melamine is taken as a precursor for synthesizing graphite-phase carbon nitride, and ammonium molybdate and thiourea are taken as metal sources; in the melamine polycondensation process, non-metallic elements are introduced through a two-step heat treatment method, metal atoms are anchored, generation of by-products is avoided, and the doping effect is adjusted by adjusting the adding proportion of metal and non-metal precursors; secondly, uniform growth of molybdenum disulfide nanosheets at nucleation sites on the surface of the substrate and strong coupling of the molybdenum disulfide nanosheets and a sulfur and molybdenum co-doped graphite phase carbon nitride material are realized by controlling the proportions of ammonium molybdate, thiourea and sulfur and molybdenum co-doped graphite phase carbon nitride by adopting a hydrothermal method. The method disclosed by the invention is simple to operate and good in repeatability, the formation and regulation of the structure can be efficiently realized, the effective transfer of active sites under different pH values can be realized, and the efficient proceeding of the electro-catalytic hydrogen evolution reaction is realized.

The invention discloses a Cr3<+>, Mg<2+>, Fe<3+> and F<-> co-doped layer-layer composite lithium-rich anode material xLi2MnO3.(1-x)LiMn0.5Ni0.5O2(x is not less than 0 and not more than 0.5). The Cr3<+>, Mg<2+>, Fe<3+> and F<-> co-doped layer-layer composite lithium-rich anode material is characterized in that a stoichiometric equation of the anode material is xLi2MnO3.(1-x)Li1+n-y(Mn0.5Ni0.5)1-m-n-pCrmMgnFepO2-yFy, wherein x is not less than 0 and not more than 0.5, m is not less than 0.01 and not more than 0.05, n is not less than 0.01 and not more than 0.05, p is not less than 0.01 and not more than 0.05 and y is not less than 0.01 and not more than 0.06. The preparation method comprises the following steps: adding soluble lithium compound, soluble manganese salt, soluble nickel salt, soluble magnesium salt, soluble chromium salt, soluble iron salt and lithium fluoride into deionized water according to the stoichiometric ratio of the molecular formula; adding tartaric acid of which the mol ratio is 1.5-2.5 times of the total amount of metal ions and uniformly and fully stirring until the mixture is dissolved; and condensing, gelating, drying, grinding, decomposing, tabletting and calcining the solution to obtain the Cr3<+>, Mg<2+>, Fe<3+> and F<-> co-doped layer-layer composite lithium-rich anode material. The prepared anode material has excellent circulation capacity holding capacity and magnification characteristic.

A method for treating compounds which contain reactive sulfur is disclosed, wherein the treatment produces compounds which contain sulfur in a non reactive form. The method is based on the use of an oxidizing compound selected from the group consisting of water soluble inorganic persulfates, water soluble inorganic and organic adducts of hydrogen peroxide and mixtures thereof. The method is particularly useful in preventing stress corrosion cracking of stainless steel and in preventing auto-ignition of pyrophoric iron sulfide.

The invention provides a multi-component stable thermal-corrosion-resistant zirconia coat material. The coat material is obtained through mixing a main agent with a stabilizer and carrying out ball milling, the main agent is ZrO2, the stabilizer is a mixture of Ta2O5, In2O3, Al2O3 and TiO2, the molar ratio of Ta2O5: In2O3: Al2O3: TiO2: ZrO2 in the multi-component stable thermal-corrosion-resistant zirconia coat material is x:x:x:x:(100-4x), and x is not greater than 4 and not lower than 2. Tetragonal phase ZrO2 is finally obtained through adopting Ta2O5, In2O3, Al2O3 and TiO2 as the stabilizer to stabilize ZrO2 in the invention. The multi-component stable thermal-corrosion-resistant zirconia coat material has an excellent Na2SO4-V2O5 molten salt corrosion resistance, and an excellent calcium magnesium aluminosilicate molten glass corrosion resistance.

The invention relates to the technical field of water quality purification, and provides a nucleation agglomeration induced granulation water treatment device for synchronously removing high-valence ions and organic matters. The water treatment device comprises a pre-oxidation tank, a coagulation reaction tank and a granulation sedimentation tank which are sequentially communicated, the coagulation reaction tank is assisted by a coagulant, so that the organic matters are in a micro-destabilization state; an alkaline substance and a nucleating agent are used as auxiliary materials, so that high-valence metal ions are in an ionic crystal state; then the water enters the lower part of the granulation sedimentation tank, under the action of a coagulant aid; the nucleating agent is preferentially combined with ionic crystal to form a crystal nucleus center; micro-destabilized organic matters are gathered outside the crystal nucleus center in a one-by-one attachment mode to form a densifiedgranulation body; in the process that water flows from bottom to top, the density of a granulation body is increased from bottom to top, then the granulation body with the large density is deposited at the bottom of the granulation sedimentation tank, the nucleation condensation induced granulation process is completed, and finally water with high-valence metal ions and organic matter synchronously removed is discharged from a water outlet.

The invention discloses a lithium manganate composite material and a preparation method thereof. The preparation method has the following advantages: 1) a natural lithium-bearing brine resource is comprehensively utilized as a lithium source, the usage amount of a refined lithium salt is reduced, and the material synthesis cost is substantially reduced; 2) the lithium source and a manganate source are uniformly distributed on an atomic level by an ion exchange method, a lattice matrix is easy to rearrange through short-range diffusion, the energy consumption is low during the synthesis process, a relatively low synthesis temperature and relatively short synthesis time are obtained, the grain distribution is uniform, and the polarization is reduced; 3) the constituent contents of lithium and magnesium are reasonably controlled by adjusting a pH value, lithium magnesium-doped type lithium manganate is prepared, the average valence state of manganate during the charge-discharge process is improved, a Jahn-Teller effect is effectively inhibited, and the cycle stability is improved; and 4) from the aspect of economic and environmental protection, the preparation method has more advantages than other schemes, and particularly, the preparation method has practical significance to extract lithium from a liquid-state lithium-bearing brine resource with a high magnesium-lithium ratio to synthesize a composite battery material.

The invention provides a method for recycling lithium manganese iron phosphate waste. The recovery method comprises the following steps: (1) mixing the lithium manganese iron phosphate waste with a first acid solution, introducing sulfur dioxide and oxygen, and carrying out oxidation leaching to obtain leached slurry; (2) the leaching slurry is subjected to copper removal treatment, and leaching residues and leaching liquid are obtained; (3) mixing the leaching residues obtained in the step (2) with a second acid solution, adjusting the pH value, and carrying out a first precipitation reaction to obtain ferromanganese phosphate; and carrying out lithium extraction treatment on the leachate obtained in the step (2) to obtain purified lithium salt. According to the recovery method provided by the invention, the oxidation effect is better, a large number of cation impurities are not introduced, all-component recovery of the lithium iron manganese phosphate battery positive electrode material can be realized, and a battery-grade purified lithium salt material and a precursor iron manganese phosphate product required by the battery-grade lithium iron manganese phosphate positive electrode material can be obtained; and the process cost is low, the added value of the product is improved, and the actual production requirement is better met.

The invention provides a novel nickel-iron bimetallic electrolysis water oxygen production catalyst. The valence state of nickel is high-valence +3 and + 4. An effective measure for improving the oxygen production performance of the catalyst is to improve the valence states of nickel and iron, especially the valence state of nickel, so as to obtain higher intrinsic activity; the invention providesthe method for preparing the high-valence nickel (+ 3 and + 4) iron bimetallic oxygen production catalyst under the condition of approximate normal temperature and normal pressure; the catalyst showsparticularly excellent oxygen production activity; and the preparation method is simple and suitable for large-scale production. According to the basic principle of the novel nickel-iron bimetallic electrolysis water oxygen production catalyst prepared by the method, the invention further provides a method for converting multivalent metal from low valence to high valence, so that besides the nickel provided by the invention, more low valence metal can be converted into high valence metal, so that different actual requirements can be met.

The invention relates to the technical field of lithium ion battery positive electrode materials, in particular to a modified nickel cobalt lithium aluminate positive electrode material and a preparation method and application thereof. The preparation method of the modified nickel-cobalt lithium aluminate positive electrode material comprises the following steps: mixing a nickel-cobalt-aluminum precursor, an oxidant and water, and performing pre-oxidizing to obtain a pre-oxidized nickel-cobalt-aluminum precursor; mixing the pre-oxidized nickel-cobalt-aluminum precursor with a lithium source, and carrying out first solid-phase sintering to obtain nickel-cobalt lithium aluminate; mixing the nickel-cobalt lithium aluminate, a binder, ammonium paratungstate and water to obtain slurry; and sequentially carrying out spray granulation and second solid-phase sintering on the slurry to obtain the modified nickel-cobalt lithium aluminate positive electrode material. The modified nickel-cobalt lithium aluminate positive electrode material prepared by the preparation method disclosed by the invention has relatively high specific capacity and relatively good cycling stability.

The invention discloses a hydrogenation regeneration method for waste lubricating oil. The method comprises the following steps: (1) distilling a pretreated raw material, namely waste lubricating oil;(2) feeding a lubricating oil fraction evaporated in the step (1) into a protective agent reactor for a reaction; and (3) feeding a product obtained after the reaction in the step (2) into a hydrogenation reactor filled with a hydrofining catalyst, and carrying out reacting to obtain lubricating oil base oil. The waste lubricating oil treated by the method can be used for producing standard lubricating oil base oil.

The invention discloses a sulfur-resistant monodisperse fusiform monatomic catalyst for denitration and a preparation method of the sulfur-resistant monodisperse fusiform monatomic catalyst. The preparation method comprises the following steps: firstly, weighing monodisperse fusiform iron oxide as a monatomic catalyst carrier; anchoring monatomic vanadyl on dopamine hydrochloride and adjusting a pH value by using a trihydroxymethyl aminomethane-hydrochloric acid solution to allow dopamine hydrochloride to undergo a polymerization reaction so as to tightly wrap an iron oxide carrier; carrying out high-temperature calcination to enable polydopamine to form carbon; and carrying out acid pickling to remove iron oxide so as to finally form the monodisperse fusiform monatomic vanadyl catalyst. Compared with other denitration sulfur-resistant catalysts, the monatomic oxygen vanadium disclosed by the invention has the advantages that the preparation cost of the catalyst is greatly reduced, and the catalytic capability of active substances can be exerted to the greatest extent; namely, the effect of an original commercial catalyst can be achieved by the catalyst accounting for only one thousandth of the dosage of the original commercial catalyst.

The invention discloses a paraffin hydrofining catalyst and a preparation method thereof. The catalyst is prepared by taking aluminum oxide as a carrier, and nickel and molybdenum as active metal components; taking the mass amount of the catalyst as a reference, the catalyst comprises 2.0%-35.0% of molybdenum oxide, and 0.5%-20.0% of nickel oxide; and the dispersity of the active metal componentsis as follows: IMo / IAl is 0.14-0.30, and INi / IAl is 0.07-0.15. The paraffin hydrofining catalyst is high in active metal utilization rate, high in active metal dispersity and high in activity.

The invention relates to the field of preparation of sodium-ion battery positive electrode materials, and particularly discloses an ion-synergetic high-performance sodium-ion battery positive electrode material and a preparation method thereof. The molecular formula of the positive electrode material is Na < x > Mn < 1-y > Ty < y > O < 2-z > N < z >, wherein T and N are nickel and fluorine elements respectively. 0.44 < = x < = 0.6, 0 < = y < = 0.3, 0 < = z < = 0.3, and y and z are not 0 at the same time. A manganese-based oxide material with a single tunnel-type structure is jointly constructed by Na, Mn, T, O and N, the appearance of the positive electrode material is of a uniform rod-shaped structure, the introduced T and N are important bases for realizing the single tunnel-type structure, sodium ion storage active sites are increased, the average valence state of manganese ions is improved, the stability of a lattice structure is enhanced, and the positive electrode material can be used for preparing a lithium ion battery. And the sodium ion migration dynamic behavior is enhanced, so that the positive electrode material has high charge-discharge capacity, excellent rate capability and long cycle life / high cycle stability.

The invention discloses lithium-ion power battery anode material lithium manganate and a preparation method thereof. The molecular formula of the lithium manganate is Li<1+x>Mn<2-y>TayO4 / zAl2O3, wherein 0<x<=0.2, 0<y<=0.2, and 0<z<=1.0. The preparation method includes the steps of proportionally mixing a lithium source compound, a manganese source compound and a tantalum element additive and subjecting the lithium source compound, the manganese source compound and the tantalum element additive to ball milling and high-temperature roasting to obtain the lithium manganate; and dispersing the lithium manganate in a dispersing agent, adding aluminum stearate for reaction to obtain precipitate, and finally subjecting the precipitate to two-section roasting, second annealing, cooling and sieving to obtain the lithium-ion power battery anode material lithium manganate. By means of a composite metal dual-doping mechanism, doping vario-property of two elements of tantalum and lithium is performed to the lithium manganate, a John-Teller effect is inhibited, and normal temperature and high temperature cycle performances of a lithium manganate material are greatly improved; and by means of sectional roasting and multi-time annealing processes, controllability of particle diameters and specific surface areas is achieved, tap density and processing performances of the material are improved, and simultaneously, oxygen defect levels during material sintering are effectively reduced.

This invention provides a method for recycling lithium manganese iron phosphate waste. The recycling method includes the following steps: (1) mixing lithium manganese iron phosphate waste with a first acid solution, introducing sulfur dioxide and oxygen, and performing oxidative leaching to obtain a leaching slurry; (2) subjecting the leaching slurry to copper removal treatment to obtain leaching residue and leaching solution; (3) mixing the leaching residue from step (2) with a second acid solution, adjusting the pH value to perform a first precipitation reaction to obtain manganese iron phosphate; and subjecting the leaching solution from step (2) to lithium extraction treatment to obtain purified lithium salt. The recycling method provided by this invention has a better oxidation effect, does not introduce a large amount of cationic impurities, can realize the full-component recovery of lithium manganese iron phosphate battery cathode materials, and can obtain battery-grade purified lithium salt materials and the precursor manganese iron phosphate products required for battery-grade lithium manganese iron phosphate cathode materials; and the process cost is low, which improves the added value of the products and better meets the actual production needs.

The invention belongs to the technical field of preparation of arsenic removal agents, and particularly relates to an arsenic removal agent and a preparation method thereof. The method comprises the following steps of uniformly mixing macroporous alumina, a molecular sieve and a magnesium-containing compound, molding with an alkaline solution, drying, and roasting to obtain a carrier, dissolving a lead-containing compound and a silver-containing compound in water, and adding an oxidizing agent to obtain impregnation liquid, and adding a carrier into the impregnation liquid, conducting impregnation, drying and roasting to obtain the arsenic removal agent. According to the method, an alkaline solution is used for sample forming, an alkaline active center is provided, a good coordination effect is achieved, and the prepared arsenic removal agent is more uniform in pore channel and higher in synergistic effect; and the oxidant is added, so that the valence state of the active component metal can be improved, the redox reaction is promoted, and the arsenic removal precision is improved.

The invention discloses a preparation method and application of a multivalent aptamer for detecting Salmonella based on HCR, which is characterized by comprising the following steps: 1) subjecting biotinylated hairpin DNA 1 and DNA 2 and biotinylated Salmonella aptamer to annealing pretreatment respectively; 2) mixing trigger chain DNA with biotinylated hairpin DNA 1 and DNA 2, reacting overnight at 37 DEG C to obtain an HCR skeleton solution, then adding biotinylated Salmonella aptamer to the HCR skeleton solution to react to obtain a multivalent aptamer solution for detecting Salmonella, and the detection method comprises the following steps: adding a Salmonella test solution to a high-adsorption enzyme label plate, then sequentially adding the multivalent aptamer solution for detecting Salmonella, streptavidin horseradish peroxidase and 3,3',5,5'-tetramethylbenzidine color developing solution, terminating the reaction after coloring in the dark, and quantitatively detecting the concentration of Salmonella in the test solution; the method has the advantages of high sensitivity and strong specificity.