55results about How to "High adsorption selectivity" patented technology

The invention relates to a preparation method of an amino-functionalized metal organic framework material and application of the prepared material to separation of CO2 / N2 and CO2 / CH4. The preparation method comprises the following steps: dissolving adenine and copper nitrate trihydrate in N, N '-dimethylacetamide to obtain a first mixed solution; dissolving carboxylic acid and potassium carbonate in deionized water to obtain a second mixed solution; and adding the second mixed solution into the first mixed solution, carrying out stirring reaction, and carrying out vacuum drying on an obtained solid product to obtain the amino-functionalized metal organic framework material. The amino-functionalized metal organic framework material prepared by the invention has high CO2 adsorption selectivity and adsorption capacity, and also has good acid-resistant, alkali-resistant and water-resistant stability. The amino-functionalized metal organic framework material prepared by the preparation method disclosed by the invention is applied to industrial CO2 adsorption separation and has an excellent separation effect.

The invention discloses an anti-fouling high-voltage electrocatalytic activity polyvinylidene fluoride uranium adsorption material and a preparation method thereof, and belongs to the field of uranium adsorption materials.According to the adsorption material, dimethyl sulfoxide serves as a solvent, polyvinylidene fluoride serves as a substrate material, amidoximation polyacrylonitrile serves as a modified molecule, and B i4T i3O12 / SnO2 serves as filler, and after physical blending, the adsorption material is prepared into the high-voltage electrocatalytic activity polyvinylidene fluoride uranium adsorption material. The composition is prepared by a freezing phase inversion method. The adsorbing material disclosed by the invention has an excellent removal rate on uranyl ions and has an excellent antibacterial property.

The present invention relates to a method for preparing a attapulgite / molecular sieve composite adsorbent, comprising the following steps: (1) using NaX molecular sieve powder as a raw material, adding purified attapulgite, grinding, adding an aluminum source for crystallization, filtering, washing to a pH of 7 to 8, and drying to obtain a attapulgite / molecular sieve composite adsorbent precursor; (2) exchanging the composite adsorbent precursor obtained in step (1) with metal cations, and then filtering, washing, drying, molding, and activating to obtain the composite adsorbent. The composite adsorbent has a simple preparation method, a large adsorption capacity, and good selectivity. It can effectively adsorb and separate liquid mixtures, and has broad application prospects in selectively adsorbing and separating p-xylene from C8 aromatic isomers. The present invention also relates to a attapulgite / molecular sieve composite adsorbent and its application in adsorbing and separating p-xylene in mixed xylene.

The invention discloses a phosphate functionalized silicon-based solid adsorbent and application thereof, and belongs to the technical field of yttrium separation and purification, a preparation method comprises the following steps: step 1, synthesizing silicon-based resin particles SiO2-P by using spherical porous silicon dioxide as a solid-phase carrier and styrene as a raw material through an in-situ polymerization technology, and 2, synthesizing the phosphate-functionalized silicon-based solid adsorbent HDEHP / SiO2-P by using di (2-ethylhexyl) phosphate HDEHP as a raw material and utilizing a vacuum impregnation technology. Therefore, the phosphate functionalized silicon-based solid adsorbent and the application thereof are adopted in the invention. The phosphate can specifically and selectively extract trivalent yttrium ions, so that efficient separation of yttrium and strontium is realized, high-purity yttrium can be obtained through separation and purification after elution, and a solid adsorbent can be recycled.

The invention relates to the technical field of water treatment, and provides gel type imidazolyl anion exchange resin as well as a preparation method and application thereof. According to the method, the gel type styrene-divinyl benzene copolymer is taken as a matrix, and the adsorption selectivity of the gel type imidazolyl anion exchange resin on rhenium / technetium is regulated and controlled by grafting imidazole with alkyl side chains with different lengths, so that the removal rate of rhenium / technetium is increased. The gel type imidazolyl anion exchange resin provided by the invention has relatively high adsorption capacity on ReO4 <-> and TcO4 <->, high selectivity, wide applicable pH value and temperature range, strong acid and alkali resistance and irradiation stability, and wide application prospect.

The invention discloses a fly ash-based adsorbent as well as a preparation method and application thereof, and belongs to the technical field of adsorbent materials. The fly ash-based adsorbent is prepared from the following raw materials: modified fly ash, modified lignin, activated carbon, polyethylene glycol polyvinyl alcohol grafted copolymer, titanate and metal oxide. The coal ash is subjected to ball milling and acid modification treatment, and a surfactant is introduced, so that the adsorption sites and the adsorption efficiency of the coal ash are increased. Through the synergistic effect of the raw materials, the prepared fly ash-based adsorbent can efficiently adsorb fluorine ions in wastewater, and the fluorine ion removal rate can reach 99% after adsorption is performed for 30 min.

The invention discloses a process for separating copper and nickel from secondary nickel return materials, and relates to the technical field of hydrometallurgy, the process comprises the following steps: adding the secondary nickel return materials into alkali liquor for alkaline leaching, and filtering to obtain alkaline leaching liquor and alkaline leaching residues; adding the alkaline leaching residues into acid liquor for acid leaching, and filtering to obtain acid leaching liquor and acid leaching residues; adding the alkaline leaching solution into the acid leaching solution, stirring for reaction, and filtering to obtain filter residues and a neutralization solution; injecting the neutralization solution into adsorption equipment, performing desorption after adsorption is completed to obtain a copper ion desorption solution and a nickel ion desorption solution, and performing electrodeposition operation respectively to obtain copper metal and nickel metal; according to the method, the technical route of alkaline leaching, acid leaching, neutralization and adsorption separation is adopted, copper is selectively dissolved through alkaline leaching, nickel is dissolved through acid leaching, the pH is regulated in the neutralization process to achieve impurity separation, and finally graded adsorption of copper and nickel ions is conducted through a modified adsorbent.

The invention discloses a method for preparing a hydrophobic Ti / SiO2 coated composite aerogel desulfurization adsorbent by a micro-droplet template method and application of the hydrophobic Ti / SiO2 coated composite aerogel desulfurization adsorbent. The method comprises the following steps: mixing aliphatic hydrocarbon in which thiophene compounds are dissolved, which is used as a non-polar template agent solution and methyltriethoxysilane, which is used as a silicon source, with absolute ethyl alcohol and water to form a polar solution, stirring the non-polar template agent solution in a polar solvent to form hydrophobic SiO2 coated template gel containing a micro-droplet template, aging, doping a Ti element, and drying to obtain the hydrophobic SiO2 coated template gel containing the micro-droplet template. According to the present invention, the micro-droplet template is removed, drying is performed to obtain the hydrophobic Ti / SiO2-coated template composite aerogel desulfurization adsorbent, the hydrophobic Ti / SiO2-coated template composite aerogel desulfurization adsorbent is applied to adsorption simulation of thiophene compounds in aromatic hydrocarbons, and the result shows that the hydrophobic Ti / SiO2-coated template composite aerogel prepared by using the micro-droplet template method has good adsorption performance on thiophene sulfides, and when the aromatic hydrocarbon product has the polar substance, the hydrophobic Ti / SiO2-coated template composite aerogel desulfurization adsorbent has good adsorption performance on the thiophene sulfides. The adsorbent still has relatively high adsorption capacity and adsorption selectivity to thiophene sulfides, and has a good application prospect in the field of deep desulfurization of aromatic hydrocarbon products.

The invention discloses a low-alumina-silica-ratio bauxite direct flotation composite collecting agent and a preparation method thereof, and the method comprises the following steps: gradually adding an emulsifier into water, and stirring until the emulsifier is uniformly mixed to obtain an emulsifier solution; adding a fatty acid soap compound, a hydroximic acid compound and a co-emulsion into the emulsifier solution, and then heating, stirring and uniformly mixing to obtain a medicament mixed solution; and the agent mixed solution is placed in an ultrasonic cleaning machine or a stirring emulsifying machine, a synergist is added for a synergistic reaction, the solution is stirred to be uniform, and the composite collecting agent is obtained. The method is simple and easy to implement, the emulsifying effect can be improved, the production cost is reduced, the using amount of the collecting agent in the sorting process is reduced, mineral resources are saved and efficiently utilized, and the prepared collecting agent has the advantages of being excellent in selectivity, strong in collecting capacity, good in agent stability, resistant to low temperature and the like and is suitable for mineral separation of bauxite with the low aluminum-silicon ratio. The concentrate grade and recovery rate can be effectively improved, and the aluminum-silicon ratio of the concentrate is remarkably improved.

The invention discloses a Schiff base functionalized silica aerogel / benzo (a) pyrene molecularly imprinted material and application thereof, pyrene is used as a virtual template molecule, and Schiff base functionalized silica aerogel is added; adding a functional monomer, a cross-linking agent and an initiator; and preparing the Schiff base functionalized silicon dioxide aerogel / benzo (a) pyrene molecularly imprinted material by adopting a surface imprinting polymerization method. The silicon dioxide aerogel is used as a base material, and the adsorption efficiency of benzo (a) pyrene is enhanced through the porous structure and high porosity of the silicon dioxide aerogel. Schiff base groups are introduced to form strong interaction with benzo (a) pyrene molecules, so that the adsorption capacity is further improved. And by combining a molecular imprinting technology, holes highly matched with benzo (a) pyrene are formed on the surface of the Schiff base functionalized aerogel, so that the material is endowed with high selectivity. Pyrene is used as a virtual template, so that the use of benzo (a) pyrene is avoided, and the environmental risk and the material cost are reduced.

The invention discloses a preparation method and application of a high-entropy catalyst tellurium-selenium tungsten molybdenum sulfide, and belongs to the technical field of energy materials, the preparation method comprises the following steps: adding selenium powder into a hydrazine hydrate solution to form a solution A; dissolving sodium molybdate dihydrate, tungsten chloride and thiourea in the reduced graphene oxide suspension to form a mixed solution B; the solution A and the solution B are mixed together and stirred to obtain a solution C, and the solution C is transferred into a high-pressure kettle for a hydrothermal reaction; washing a product obtained by the reaction with deionized water, and freeze-drying after washing to obtain a black product A; and putting the product A at a leeward position of a tubular furnace, putting tellurium powder at a windward position of the tubular furnace, and performing annealing treatment in an argon-hydrogen environment to obtain the tellurium-selenium tungsten-molybdenum sulfide catalyst. According to the preparation method and application of the high-entropy catalyst tellurium selenium tungsten molybdenum sulfide, rapid transmission of electrons is facilitated, the transmission efficiency of ions and electrons is improved, and the dynamic performance of a battery is enhanced.

The invention discloses a magnesium-doped calcium carbonate adsorbent and a preparation method and application thereof, the chemical formula of magnesium-doped calcium carbonate is as shown in the following formula (1): MgxCa1-x (CO3), x represents the molar ratio of magnesium to calcium, 0 lt; xlt; and 0.200%. Compared with pure calcium carbonate, the adsorption rate of the adsorbent based on the magnesium-doped calcium carbonate material provided by the invention is greatly improved, so that passivation of the pure calcium carbonate in the early stage of adsorption is relieved. Under the condition of the same phosphorus adsorption amount, the adsorption rate of the adsorbent is obviously improved. Alternatively, under the same adsorption time, the phosphorus adsorption amount of the adsorbent provided by the invention is obviously improved. The adsorbent provided by the invention has good adsorption selectivity (competitive ion interference resistance), so that the adsorbent has high practical application value. In addition, as the preparation is simple and convenient and the cost is low, the compound can be used as an agricultural fertilizer slow-release agent, can maintain the phosphorus content in farmland for a long time, and is more beneficial to the growth of crops.

The application discloses a carbon dioxide adsorption material for electronic waste regeneration and a preparation method thereof. The carbon dioxide adsorption material is prepared from electronic waste nonmetal powder as raw material. On one hand, the electronic waste is pretreated to ensure that the electronic waste can be used in a high value mode; on the other hand, the electronic waste is converted into a high-performance adsorbent which is directly used for capturing carbon dioxide in industrial waste gas, so that one kind of waste is used to treat another environmental pollutant from the source. Not only is the difficulty in processing the nonmetal components of the electronic waste and the heavy pollution solved, but also a low-cost material is provided for carbon dioxide emission reduction, the production cost of the adsorbent is reduced, the unity of environmental benefits and economic benefits is realized, and the application is a typical practice of the circular economy concept.

A biochar-based ion-imprinted polymer material and its preparation method and application belong to the field of material preparation. The preparation method comprises: reacting a mixed solution containing a template and 4-vinylpyridine I to obtain a reaction system I, wherein the template is a metalloid compound or a heavy metal compound; adding biochar, a cross-linking agent, and an initiator to the reaction system I to carry out reaction II, washing, and drying to obtain a biochar-based ion-imprinted polymer material. When the material is used as a fixation / stabilization material for arsenic-containing soil remediation, it can be evenly distributed in the soil without causing agglomeration problems, can stably exist in a complex soil environment, has a good selective adsorption effect on free arsenic in the soil, and has a good short-term fixation effect. In addition, the material is a neutral material and has almost no effect on soil pH.

The invention discloses a preparation method of 2-amino-4-nitrophenol, belongs to the technical field of 2-amino-4-nitrophenol processing, and is used for solving the technical problems that in the prior art, the difficulty of recovering 2, 4-dinitrophenol from disperse blue wastewater is high, and the purity and the yield of 2-amino-4-nitrophenol need to be further improved. The method comprises the following steps: adding disperse blue production wastewater into a reaction kettle, stirring, and adding inorganic acid into the reaction kettle; according to the present invention, the adsorbent microspheres are prepared to adsorb the 2, 4-dinitrophenol in the disperse blue production wastewater, such that the process for recovering the 2, 4-dinitrophenol from the disperse blue wastewater is simplified, the purity and the regeneration rate of the regenerated 2, 4-dinitrophenol are improved, the composition of the catalyst solution and the reaction post-treatment method are optimized, and the 2, 4-dinitrophenol regeneration efficiency is improved. And the 2-amino-4-nitrophenol with high purity and high yield is prepared.

The invention belongs to the field of recycling of precious metal resources in environmental engineering, and particularly relates to a preparation method and application of an organic polymer sphere adsorbent. The amidoxime modified self-polymerized microporous polymer (AO-PIM-1) is prepared into the spherical adsorbent through a phase inversion method, and compared with other traditional adsorbents, the polymer sphere adsorbent is high in specific surface area and good in thermal stability and water stability and has a large number of functional groups with high combining capacity for Au ions. In a low-concentration Au solution, a good adsorption effect and excellent adsorption selectivity are still kept, and Au ions in electronic waste leachate can be well adsorbed and recycled.

The present application relates to the technical field of metal organic framework materials, in particular to a modified copper-based metal organic framework material, a preparation method and application thereof, and a sulfide removal method. The modified copper-based metal organic framework material comprises a metal organic framework formed by copper and an organic ligand, and silver doped on the metal organic framework; and the crystal surface of the modified copper-based metal organic framework material has long and narrow honeycomb-shaped pores. + and Ag + The modified copper-based metal organic framework material has suitable pore structures and rich adsorption sites for removing various organic sulfides, and the modified copper-based metal organic framework material has Cu + and Ag + which can adsorb sulfides through π bond action, and has a large adsorption capacity and high adsorption selectivity for sulfides (such as mercaptans, sulfides, thiophenes, etc.) as a desulfurization adsorbent.

The invention discloses a process for separating copper and nickel from secondary nickel return materials, and relates to the technical field of hydrometallurgy. The process comprises the following steps: adding the secondary nickel return materials to an alkali solution for alkali leaching, filtering to obtain an alkali leaching solution and an alkali leaching residue; adding the alkali leaching residue to an acid solution for acid leaching, filtering to obtain an acid leaching solution and an acid leaching residue; adding the alkali leaching solution to the acid leaching solution, stirring for reaction, filtering to obtain a filter residue and a neutralization solution; injecting the neutralization solution into an adsorption device, performing desorption after adsorption to obtain a copper ion desorption solution and a nickel ion desorption solution, and performing electrodeposition operations respectively to obtain copper metal and nickel metal. The invention adopts the technical route of alkali leaching-acid leaching-neutralization-adsorption separation, selectively dissolving copper by alkali leaching, dissolving nickel by acid leaching, regulating pH in the neutralization process to realize impurity separation, and finally performing graded adsorption of copper and nickel ions by using a modified adsorbent.

This invention discloses a polyphosphazene / MXene self-supporting electrode loaded with cobalt single atoms, its preparation method, and its application, belonging to the field of seawater uranium extraction technology. Ti3AlC2 powder is etched in an HCl-LiF mixed solution and then ultrasonically exfoliated to obtain Ti3C2T. x Nanosheet suspension; simultaneously, hexachlorocyclotriphosphazene, 4,4'-dihydroxydiphenyl sulfone, and cobalt salt were dissolved in a solvent, and triethylamine was added. A condensation reaction was then carried out under ultrasonication to obtain Co-PZS; then Ti3C2T x After the nanosheet suspension is uniformly mixed with Co-PZS and carbon fiber fabric, it is transferred to a hydrothermal reactor for hydrothermal reaction. The resulting hydrothermal reaction product is then dried and calcined to obtain a polyphosphazene / MXene self-supporting electrode loaded with cobalt single atoms. This electrode is used for the electrochemical adsorption of uranyl ions in the solution system and exhibits excellent comprehensive uranium extraction performance, with advantages such as high capacity, fast rate, strong selectivity, and good stability, meeting the application requirements of seawater uranium extraction.

The invention provides synthesis of a fluorine-doped ion sieve precursor Li1. 6Mn1. 6O4 and application of the fluorine-doped ion sieve precursor Li1. 6Mn1. 6O4 to adsorption and lithium extraction, and belongs to the technical field of lithium extraction of adsorbent brine. The synthesis method comprises the following steps: putting an ion sieve precursor Li1. 6Mn1. 6O4 and a fluorine-containing ionic liquid into water, uniformly stirring, carrying out a thermal reaction, naturally cooling, carrying out suction filtration, washing, and finally carrying out vacuum drying to obtain the fluorine-doped ion sieve precursor Li1. 6Mn1. 6O4, the molar ratio of fluorine to manganese is (0.05-0.8): 1. The synthesis method of the fluorine-doped ion sieve precursor Li1. 6Mn1. 6O4 has the advantages that the raw materials are wide, the doping process is simple and controllable, the doped raw materials can be recycled, the energy consumption is lower, and the fluorine-doped ion sieve precursor Li1. 6Mn1. 6O4 is greener and more environment-friendly; the fluorine-doped ion sieve H1. 6Mn1. 6O4 prepared from the precursor is stable in performance, and has great significance in reducing manganese solution loss and improving a brine lithium extraction process.

The invention relates to the field of chemical engineering, and discloses a method for preparing a carbon dioxide adsorption material by using a waste FCC catalyst, and the method comprises the following steps: S1, mixing and grinding the waste FCC catalyst containing an iron element, a silicon source, sodium hydroxide and a molecular sieve seed crystal; and S2, mixing the obtained mixture with water, and carrying out a crystallization reaction to obtain the carbon dioxide adsorption material with high selectivity on carbon dioxide. The waste FCC catalyst is recycled only through grinding and crystallization reaction, and the adsorbing material capable of adsorbing carbon dioxide with high selectivity is prepared. The recovery method is simple in process and lower in solvent energy consumption, and energy conservation and emission reduction are realized while resources are fully reutilized.

This invention relates to the field of mineral processing flotation reagents, specifically disclosing a high-efficiency collector for the flotation of sphalerite and its preparation method. The high-efficiency collector provided by this invention achieves synergistic enhancement of the functions of each component by compounding isopropyl xanthate, dialkyl dithiocarbamate, and mercaptoacetate, and introducing a designed and synthesized polymeric synergist. The three basic collector components together constitute a dense and stable primary hydrophobic adsorption layer. The introduced synergist, on the one hand, enhances the adsorption strength and selectivity on the surface of sphalerite through multiple functional groups; on the other hand, its grafted hydrophilic polymer chains can form steric hindrance at the mineral-water interface and regulate local hydrophilicity and hydrophobicity, thereby further optimizing the hydrophobic state of the mineral surface and inhibiting gangue inclusions. The composite reagent provided by this invention improves the recovery rate of useful minerals while ensuring concentrate quality.

The invention relates to an integrated recovery process of aromatic hydrocarbons in hydrogen peroxide oxidation tail gas, which specifically comprises the following steps: preheating the oxidation tail gas to 95-115 DEG C, introducing the oxidation tail gas into an adiabatic expansion machine for adiabatic expansion, reducing the pressure to 0.1-0.15 MPa, suddenly reducing the temperature to 3-7 DEG C, realizing energy recovery and power generation by using the Joule-Thomson effect, and condensing and separating out most aromatic hydrocarbons; and the condensed tail gas enters the activated carbon adsorption tower for deep adsorption, so that the aromatic hydrocarbon content in the finally discharged tail gas is less than or equal to 70mg / m. Through cooperation of process units, efficient recovery of aromatic hydrocarbons (the total recovery rate is greater than or equal to 95%), self-sufficiency of energy and even negative energy consumption operation (the unit tail gas treatment energy consumption is-5-0 kW.h / 1000 m) are realized, the stability and economical efficiency of an adsorption system are remarkably improved, and the technical problems of high energy consumption, low recovery rate and poor adsorption stability of a traditional cooling and adsorption process are solved.

The present application relates to oil and gas field development and environmental protection technical field, especially an aging oil demulsification treatment method, comprising: mixing fly ash and sodium hydroxide, then calcining, acid leaching, then mixing with oily sludge and ferroferric oxide, reduction reaction, mixing the reduction reaction product with 3-mercaptopropyl triethoxysilane, modification reaction, to obtain magnetic adsorbent; mixing aging oil, partial phosphate and water, stirring, standing and separating, to obtain pretreated aging oil; adding magnetic adsorbent, complexing agent, wetting reverse agent and demulsifier to the pretreated aging oil, stirring, then microwave irradiation treatment, magnetic separation, vortex separation and centrifugal dewatering, to obtain purified oil. The present application removes FeS particles by magnetic adsorbent, combines with multi-assistant component synergistic demulsification and multi-field coupling physical separation, destroys the stable emulsification system of aging oil, and the process is efficient, suitable for industrial demulsification treatment of high stability aging oil.

The invention discloses a zinc-based modified molecular sieve adsorbent for removing tetrafluoroethylene in carbonyl fluoride and application of the zinc-based modified molecular sieve adsorbent in an adsorber, and belongs to the technical field of adsorption materials for electronic-grade gas purification. The preparation method comprises the following steps: (1) soaking a 5A molecular sieve in an ammonium citrate aqueous solution, treating at 60-90 DEG C for 4-8 hours, and drying to obtain a pretreated molecular sieve; (2) putting the pretreated molecular sieve into a zinc source aqueous solution, reacting at 70-90 DEG C for 12-24 hours, and drying after the reaction is finished; (3) roasting the dried product in an air atmosphere for 6-10 hours; and (4) circularly carrying out the steps (1)-(3) for 1-5 times to obtain a finished product. The prepared zinc-based modified molecular sieve has the advantages of high adsorption selectivity, long penetration time, excellent regeneration performance and the like, and is suitable for a refining process of electronic-grade carbonyl fluoride (the purity is greater than or equal to 99.99%) in semiconductor manufacturing.

The invention relates to a lignin carbon modified hydrogen evolution reaction catalyst which is prepared by the following steps: 1) dissolving lignin in deionized water to obtain a solution B; 2) respectively dissolving nickel salt, manganese salt and molybdenum salt in the solution B to obtain a mixed solution C, adding the mixed solution C and the pretreated nickel-based carrier into a reaction kettle for hydrothermal reaction, cooling to room temperature after the reaction is finished, taking out reaction liquid in the reaction kettle, filtering, cleaning a filter cake, and drying to obtain a primary sample; and 3) performing high-temperature calcination on the preliminary sample prepared in the step 2) in a mixed atmosphere environment of hydrogen and argon to obtain the lignin carbon modified hydrogen evolution reaction catalyst. Lignin serves as a carbon source, nickel salt, manganese salt and molybdenum salt serve as metal sources at the same time, the lignin and metal ions are subjected to chelation through hydrothermal reaction synthesis, high-temperature calcination reduction is conducted, and the lignin carbon modified hydrogen evolution reaction catalyst is obtained. The prepared catalyst is simple in method, low in cost and high in activity.

The application discloses a preparation method of high-purity sodium nitrate in the technical field of inorganic chemical industry, and comprises the following steps: dissolving crude sodium nitrate in deionized water and heating and stirring to obtain a crude solution; pre-saturating and activating a multi-dimensional cerium tungsten titanium heteropoly acid salt grafted mesoporous silica-aluminum skeleton material in saturated sodium nitrate aqueous solution; adding the activated material into the crude solution to perform stirring reaction, and filtering to obtain a sodium nitrate mother liquor; performing vacuum concentration, natural cooling crystallization, centrifugal separation and drying on the mother liquor, so that high-purity sodium nitrate is obtained. The method can efficiently remove impurities in sodium nitrate, and the product has high purity.

The fluorine content of the fluorine-doped ion sieve precursor is 0.2%-2%, and the particle size of the fluorine-doped ion sieve precursor is 80-150 nm. The invention also discloses a preparation method of the fluorine-doped ion sieve precursor. The preparation method comprises the following steps: preparing a manganese and lithium metal salt solution A, and preparing a citric acid solution B and a fluorine-containing salt solution D; mixing the solution A and the solution B, heating and stirring to obtain a colloidal solution C; performing vacuum drying on the solution C to obtain a solid intermediate; grinding the solid intermediate, and calcining in a muffle furnace to obtain an ion sieve precursor marked as LMO powder; weighing LMO powder, putting the LMO powder into a reaction kettle, and adding the fluorine-containing salt solution D and deionized water; placing the reaction kettle in a muffle furnace for heat treatment to obtain precursor slurry; and carrying out suction filtration, washing and drying on the precursor slurry to obtain the fluorine-doped ion sieve precursor. According to the invention, the ion sieve precursor is doped with fluorine, so that the electron transmission path of disproportionation reaction is changed, and the problem of manganese solution loss of LiMn2O4 in the process of adsorbing and extracting lithium is solved.

The invention discloses a method for enhancing degradation of organic pollutants by using acid-modified hydrothermal carbon, which comprises the following steps: adding acid-modified hydrothermal carbon into a degradation system constructed by ferric salt and persulfate to degrade the organic pollutants in a water body, wherein the acid-modified hydrothermal carbon is prepared by taking biomass and an inorganic acid solution as raw materials and carrying out hydrothermal carbonization treatment. In the method disclosed by the invention, the adopted acid modified biochar has the advantages of rich surface oxygen-containing functional groups, multiple reducing components, rich pore structure, large pore diameter, large specific surface area and the like, shows very excellent adsorption capacity and catalytic reduction capacity on specific pollutants and Fe (III), and can obviously enhance the Fe (III) / Fe (II) circulation effect in a system; different types of organic pollutants in different environment media can be efficiently removed, the utilization rate of ferric salt can be remarkably increased, the treatment cost can be reduced, Fe (III) flocculent precipitation can be remarkably reduced, and the method is more environmentally friendly.

The invention relates to the technical field of lithium resource recovery, and particularly discloses a preparation method of a novel lithium ion sieve for extracting lithium from oil and gas field produced water. The preparation method of the novel lithium ion sieve comprises the following steps: step 1, mixing and oxidizing a manganese source and a lithium source according to a certain manganese-lithium ratio, drying, and calcining in a muffle furnace for the first time to obtain powder; and 2, uniformly mixing the water-soluble lanthanum salt in the step 1 according to a ratio, co-precipitating, calcining for the second time to obtain a novel lithium ion sieve precursor, and removing lithium from hydrochloric acid to obtain the novel lithium ion sieve for extracting lithium from the oil and gas field produced water. The stability is prominent by means of rare earth oxygen metal, the stability of lithium extraction of the novel lithium ion sieve in oil and gas field produced water is guaranteed, the loss rate of manganese is reduced to 1%, and the cycle adsorption frequency is increased.