14results about How to "High separation selectivity" patented technology

The invention relates to the technical field of membrane separation, in particular to a functional group regulated covalent organic framework (COF) membrane and a preparation method thereof, and relates to application of the membrane in selective separation of monovalent cations. The preparation method comprises the following steps: condensing a polyaldehyde monomer and aromatic diamine with different side chain substitutions on an interface through oil-water-oil three-phase interface micro-fluidic dripping to generate a two-dimensional COF nanosheet, carrying out ultrasonic dispersion, carrying out vacuum filtration, self-assembling on a porous substrate, and drying to obtain a continuous separation layer with the thickness of 50-150nm. The functional group can regulate and control pore channels and surface charges, flux and selectivity of monovalent cations such as Li < + > can be adjusted, effective separation is kept at the pH of 3-11, and the functional group is suitable for lithium salt extraction and electrolyte purification.

The application belongs to the technical field of nuclear fuel cycle and nuclear waste liquid treatment. The application reports a kind of carboxyl-substituted o-phenanthroline water-soluble ligand based on selective masking of part of trivalent actinide under high acidity conditions, and under optimal conditions, the separation coefficient of trivalent europium can reach 120 in 1.5M nitric acid; the separation coefficient of trivalent cerium can reach 4.4. The single crystal structure of the complex is a double metal dimer structure, which guarantees the high acidity tolerance and high selectivity of the ligand. The synthesis of the ligand involved in the application is simple, the extraction efficiency is high, and the extraction mode is novel; the related content will greatly promote the design and performance optimization of water-soluble lanthanum, lanthanum, actinium and actinium separation ligand.

The invention discloses a method for removing high-valence ions and organic matters in a lithium-rich solution of brine, which comprises the following steps: carrying out first nanofiltration separation on the lithium-rich solution with the pH value of 3.0-6.0, carrying out second nanofiltration on a first trapped fluid to further separate and recover lithium, and carrying out third nanofiltration on the first trapped fluid and a first permeate to realize deep removal of the high-valence ions and the organic matters. According to the invention, three-stage nanofiltration is subjected to series-parallel configuration and design, so that the separation effect of lithium ions, foreign ions and organic matters is improved; an electric field is arranged to strengthen the nanofiltration process driven by pressure, the solute hydration state difference and the mass transfer rate are enhanced, and the separation performance is improved. According to the method provided by the invention, the removal rate of high valence ions in the lithium-rich liquid is gt; 99.9%, and the organic matter removal rate gt; and the lithium ion flux is improved by more than 20%. The process and the strengthening measure are a separation method with high universality, impurity ions and organic matters in different types of lithium-rich solutions can be removed, and large-scale industrial popularization is facilitated.

This invention discloses a method for preparing dehydroabscisic acid locust bean gum ester-bonded silica microspheres. The method uses dehydroabscisic acid locust bean gum ester (DLE) as a functional monomer. By adjusting the degree of substitution of DLE (0.001–2.5), an esterification reaction is carried out with a silica derivative to obtain dehydroabscisic acid locust bean gum ester-bonded silica microspheres (DLE@SiO231). These microspheres are then treated with a blocking agent to obtain blocked microspheres (DLE@SiO231M). The resulting microspheres have a particle size of 2–10 μm, an average pore size of 2–70 nm, and a specific surface area of ​​50–600 m². 2 The material exhibits uniform particle size and high mechanical strength. It can be used as a packing material for high-performance liquid chromatography (HPLC) columns or for solid-phase extraction. Due to the introduction of DLE (dihydrolamine), it possesses amphiphilic properties and demonstrates excellent selective separation capabilities for saponin drugs, showing broad application prospects in the field of drug separation and purification.

This invention discloses a highly selective polyamide acid-resistant nanofiltration membrane containing telrogalg bases and its preparation method, comprising: firstly, using haloaniline monomers and aldehyde monomers as raw materials, synthesizing a telrogalg-based halobenzene intermediate under acidic conditions; then reducing the intermediate to prepare a telrogalg-based phenylenediamine (PDA-TB) functional monomer; subsequently, dissolving it together with polyethersulfone in a polar solvent to prepare a casting solution, which is then coated onto a nonwoven fabric. A polyethersulfone-supported substrate membrane rich in PDA-TB is prepared through a non-solvent-induced phase inversion. Next, a polyacrylamide organic phase solution is brought into single-sided contact with the substrate membrane surface, and a PDA-TB and polyacrylamide interfacial polymerization reaction is performed to prepare a highly selective polyamide acid-resistant nanofiltration membrane containing telrogalg bases. Compared with conventional piperazine amide nanofiltration membranes, the nanofiltration membrane prepared by this invention exhibits significantly improved acid resistance, narrower pore size distribution, and higher separation selectivity, and has broad application prospects.

The invention relates to the technical field of materials, and discloses a polysulfone ether porous membrane as well as a preparation method and application thereof. The polysulfone ether porous membrane comprises a first polymer layer and a second polymer layer which are overlapped with each other, the average pore size of the first polymer layer is 55-245nm, and the porosity is 18-30%; the average pore size of the second polymer layer is 10-18 microns, and the porosity of the second polymer layer is 70%-85%; wherein the surface porosity of the polysulfone ether porous membrane is greater than or equal to 28%. The polysulfone ether porous membrane provided by the invention has an asymmetric structure, and the polysulfone ether porous membrane has an open bicontinuous structure surface, has excellent high surface porosity characteristics and high CH4 permeation rate characteristics, has relatively high permeability and selectivity to VOCs, and can be used for preparing a porous membrane for the VOCs. The composite film formed by using the composite film as a porous support layer has high separation efficiency and selectivity, can effectively adsorb and remove harmful gases such as VOCs and the like, and improves the treatment efficiency.

The invention discloses application of a halogenated organic oxidant in iron oxide ore flotation, and belongs to the technical field of mineral flotation. The iron oxide ore flotation specifically comprises the steps that after ferrous minerals are smashed and subjected to size mixing, the oxidizing agent is added for oxidation, then a collecting agent and a foaming agent are added, and concentrate is obtained after flotation. The halogenated organic oxidizing agent can greatly improve the floatability of iron oxide ore, can achieve efficient flotation of the iron oxide ore under mild conditions, and has the outstanding advantages of being good in selectivity, high in recovery rate, small in dosage, environmentally friendly and the like.

This invention provides a method for separating and extracting lead-212 and bismuth-212 from monazite-processed radium slag dissolution solution, belonging to the field of medical radioisotope preparation technology. The method uses monazite-processed radium slag dissolution solution containing radium-228 decay chain substances as raw material. First, halide ions are added to the raw material and the acidity is adjusted to obtain an acidic radium slag dissolution solution. Then, the solution is pretreated with an anion exchange resin column to remove impurities. After static decay, a decay solution containing lead-212 and bismuth-212 is generated. Utilizing the halogen content and acidic environment of the solution itself, the solution is selectively adsorbed again by an anion exchange resin column. Subsequently, elution is performed using a desorption reagent, and the medium conditions are readjusted for repeated adsorption and desorption, ultimately yielding a high-purity and high-specific-activity lead-212 and bismuth-212 finished desorption solution. This invention can efficiently extract lead-212 and bismuth-212 with fast extraction speed, high recovery rate and purity, and is less likely to cause organic pollution in the product.

This invention discloses an anion-pillared ultraporous membrane, its preparation method, and its application in the separation of low-carbon hydrocarbons. The ultraporous membrane exhibits stable properties and excellent separation selectivity and permeation flux. Preparation method: A polymer with hydrogen-bonded groups is spin-coated onto a substrate, dried to form a film, the substrate is modified, and then an inorganic anion-pillared ultraporous material layer is grown in situ on the substrate surface to obtain the ultraporous membrane. The inorganic anion-pillared ultraporous material layer is formed by the self-assembly of metal ions, inorganic anions, and flexible ligands through coordination bonds; the metal ion is Cu. 2+ Zn 2+ At least one of the following; the inorganic anion is SiF6. 2‑ GeF6 2‑ At least one of the following; the flexible ligand is at least one of 4,4'-bipyridine sulfide and 4,4'-bipyridine sulfoxide.

The invention discloses a system and a method for extracting helium from natural gas at normal temperature. The system comprises a first membrane separation unit, a second membrane separation unit, a catalytic circulation dehydrogenation unit, an isobaric drying unit, a first pressure swing adsorption unit, a second pressure swing adsorption unit and a purification unit which are sequentially connected, and the performance of the first membrane separation unit is superior to that of the second membrane separation unit. Aiming at the problems of relatively complicated process flow, more power equipment, high operation energy consumption and high comprehensive cost of helium extraction when a traditional helium extraction technology is adopted for low-grade helium-poor natural gas, the application only adopts relatively simple process integration technologies such as two-stage membrane separation, catalytic circulating dehydrogenation, isobaric drying, two-stage pressure swing adsorption separation and purification and the like; helium is extracted from natural gas with high efficiency and low cost, and a high-purity helium product is prepared.

The invention provides a purification method and a purification system for a long-chain alkyl mercaptan azeotrope, and belongs to the technical field of azeotrope separation and purification. According to the method, a Cu < 2 + > modified MFI type molecular sieve is used as an adsorbent and is filled in a fixed bed adsorption tower. In the adsorption step, straight-chain alkyl mercaptan can enter a molecular sieve pore channel and is adsorbed by Cu < 2 + > specific complexation, and branched-chain alkyl mercaptan is not adsorbed due to steric hindrance, so that a material rich in branched-chain alkyl mercaptan is obtained; in the regeneration step, a thermal medium is introduced for desorption and recovery of high-purity linear alkyl mercaptan; and in the cooling step, inert gas is introduced to recover the adsorption tower to the adsorption preparation state. By utilizing the synergistic effect of double mechanisms of size screening and chemical complexing, efficient and continuous separation can be realized at normal temperature and normal pressure, the purity of the straight-chain alkyl mercaptan product is not lower than 99.5%, and the method has the advantages of low energy consumption, stable operation and high product yield.

The invention relates to the technical field of flotation agents, in particular to a steric hindrance group mixed flotation agent and application of the steric hindrance group mixed flotation agent to flotation separation of quartz and feldspar. According to the technical scheme, the steric hindrance group mixed flotation agent is composed of dodecyl dimethyl benzyl ammonium bromide (BDAB) serving as a collecting agent and sodium dodecyl benzene sulfonate (SDBS) serving as an inhibitor, and the mass ratio of the sodium dodecyl benzene sulfonate to the dodecyl dimethyl benzyl ammonium bromide is 1: 1.1-1: 1.5. According to the neutral flotation method, efficient separation of quartz and feldspar can be achieved under the normal-temperature condition, and environmental pollution and equipment corrosion are avoided; the adopted composite flotation agent is low in toxicity, good in water solubility and small in dosage, the separation selectivity is remarkably improved through sequential addition and steric hindrance synergistic effect, high-grade quartz and feldspar concentrate can be obtained through one-time flotation, the technological process is simple and stable, implementation is easy, and the method is suitable for resource utilization of silicate tailings.

The invention belongs to the technical field of membrane separation, and relates to an octyl modified siloxane pervaporation membrane. Octyl in the membrane serves as long-chain alkyl, the solubility parameter of the octyl is closer to that of ethyl alcohol, and the octyl has high selective adsorption capacity on ethyl alcohol and can effectively and preferentially adsorb ethyl alcohol molecules. Meanwhile, due to the introduction of octyl, the steric hindrance and hydrophobic interaction among PDMS molecular chains are increased, and the excessive swelling phenomenon, easily occurring in an ethanol-water mixture, of PDMS is favorably inhibited; and a polymer cross-linked network can keep a more stable structure under an operation condition, the screening function of the polymer cross-linked network can be better played, the accompanying permeation of water molecules is reduced, and the separation selectivity is improved. In addition, the strong hydrophobicity of octyl further reduces the dissolution and diffusion tendency of water molecules in the membrane. The method for molecular design through side chain chemical modification directly aims at the structural limitation of traditional PDMS, and effectively and synergistically improves the separation factor and selectivity of the membrane.