35results about How to "Low extraction efficiency" patented technology

The invention relates to a production method of 2,3-dichloropyridine, solving the problem that byproducts are easily generated through 2-position chlorination reaction so as to cause the final product quality to be instable, for example, intermediate purification is carried out but yield and environment are influenced, and the working efficiency is reduced. The production method of the 2,3-dichloropyridine comprises the following steps: 1) carrying out degradation reaction: hydrolyzing 2-chloro nicotinamide used as a starting material, and carrying out solid-liquid separation to obtain 2-chlorine-3-aminopyridine; and (2) successively carrying out diazotization reaction and 3-position chlorination reaction: successively carrying out diazotization reaction and 3-position chlorination reaction on 2-chlorine-3-aminopyridine to obtain 2,3-dichloropyridine. The production method has the beneficial effects that (1) the difficulty that the byproducts are easily generated because 2-position chlorination is successfully avoided, thereby ensuring the quality of the intermediate product 2-chlorine-3-aminopyridine; and (2) because the intermediate product 2-chlorine-3-aminopyridine is not dissolved in strong basic aqueous solution, the product can be directly taken out by vacuum filtration, and is easy to purify.

The invention relates to a method for preparing lactic acid and lactide through dehydration extraction. The method comprises the following steps: 1) mixing a crude lactic acid solution with an organicsolvent to obtain a mixed solution to be treated; and 2) evaporating and concentrating the to-be-treated mixed solution, removing moisture to obtain an organic solvent dissolved with lactic acid, andcarrying out extracting to obtain lactic acid in the organic solvent. The lactic acid production method is short in process route and convenient to operate, and the obtained lactic acid is high in purity. When the method is used for producing lactide, a high-quality lactide product can be obtained without complex processes such as lactic acid refining and the like; product yield is high, environmental pollution is small, and complex operation in a traditional lactide production process is avoided.

The invention provides a liquid chromatography-mass spectrometry method for rapidly detecting the content of beta-agonists. The liquid chromatography-mass spectrometry method comprises the following steps: pretreating a sample, namely, sequentially adding water and an organic extracting solution in the sample for extracting a beta-receptor stimulant; then adding a salting-out agent and a water removing agent to ensure that the organic extracting solution and a water phase demix, centrifuging to obtain a first supernate, adding an adsorbing agent in the first supernate for purification, centrifuging to obtain a second supernate, concentrating, re-dissolving and filtering the second supernate to prepare a sample to be detected; and then detecting the beta-receptor stimulant contained in an animal-derived food by adopting an ultra-high performance liquid chromatography-triple quadrupole mass spectrometer. According to the sample pretreatment method suitable for liquid chromatography-mass spectrometry detection, provided by the invention, interfering molecules are removed through extraction and purification so that high accuracy is achieved in sample detection.

The invention discloses a method for continuous fractional separation and purification of effective ingredients of star anise, and relates to purification of a natural product of star anise. The invention provides a method for continuous fractional separation and purification of the effective ingredients of the star anise, which can ensure the extraction efficiency of a target product, has low production operating cost, high solvent recovery rate and obviously low energy consumption, and is suitable for large-scale production. The method comprises the following steps of: extracting star aniseoil; extracting star anise oil resin; separating anethole from anisaldehyde; performing microbial conversion on shikimic acid; and extracting and separating the shikimic acid. On the basis of extracting the star anise oil resin and separating the anethole from the anisaldehyde, the shikimic acid is extracted and separated from extraction residue, products with high added value, such as shikimi fruit, the anethole and the anisaldehyde are obtained, and the extraction efficiency of the target product is ensured.

The invention discloses a method for extracting cobalt from tailings. After termination, add alkali to remove excess inorganic acid impurities; (2) separate the mixture obtained in step (1) from solid to liquid, and take out all the separated liquid as mixed liquid I for later use; (3) separate the solid obtained from step (2) from solid to liquid The tailings powder is crushed to a maximum particle size of 0.8-1.6mm, and the pulverized tailings powder is added to an inorganic acid solution for leaching. After the leaching reaction is terminated, alkali is added to remove excess inorganic acid impurities; (4) the mixture obtained in step (3) Separation of solid and liquid, take out all the separated liquid as mixed liquid II for later use. The invention has the advantages that it can overcome the disadvantages of the prior art, and the method design is reasonable and novel.

The invention discloses a lidocaine-based hydrophobic deep eutectic solvent, a preparation method and application thereof, and belongs to the technical field of extraction, separation and enrichment of large cationic compounds. The main points of the technical scheme of the present invention are: a hydrophobic deep eutectic solvent based on lidocaine, which uses lidocaine as a hydrogen bond acceptor and n-octyl p-hydroxybenzoate as a hydrogen bond The donor is synthesized according to the molar ratio of 1:0.25~3. The invention also specifically discloses the preparation method of the lidocaine-based hydrophobic deep eutectic solvent and its application in extracting rhodamine B, methyl violet or / and malachite green in aqueous solution. When the hydrophobic deep eutectic solvent prepared by the invention is used as an extractant, it has the advantages of simple synthesis, stable performance, low toxicity, high extraction efficiency and the like.

The invention provides a process for extraction refining amygdalin which consists of, disintegrating the plant raw material containing rich bitter apricot seed into powder, removing the grease from the raw material powder by using CO2 as extracting agent, carrying out decompression segregation to the carbon dioxide containing vegetable fat, charging alcohol into ground-slag containing bitter apricot seed glycosides by the solid-to-liquid ratio of 1 : 3-10, agitating, filtering by suction to obtain the filter liquor, distilling and drying the filter liquor to obtain crude product of bitter apricot seed glycoside, dissolving the bitter apricot seed glycoside into ethanol, low temperature crystallizing, filtering and drying to obtain the high purity bitter apricot seed glycosides.

The invention discloses a display panel, a manufacturing method thereof and a display device, wherein the display panel is divided into a display area and a non-display area surrounding the display area, the display area includes an edge area and a non-edge area, and the edge area of ​​the display area and the non-display area The regions are connected and surround the non-edge area; the display panel includes a light extraction layer, and the thickness of the light extraction layer in the edge area of ​​the display area is greater than that in the non-edge area of ​​the display area, which can make the light extraction efficiency in the edge area of ​​the display area higher. In the non-edge area of ​​the display area, the light extraction efficiency is relatively low, and the light output in the edge area of ​​the display area is enhanced by increasing the thickness of the light extraction layer in the edge area of ​​the display area, so that the brightness of the edge area increases, and then the non-edge area is reduced. The brightness difference between the edge area and the edge area makes the brightness of the edge area of ​​the display panel tend to be consistent with the brightness of the non-edge area, which improves the display uniformity of the display panel, thereby improving the display effect.

The invention provides a preparation method of lespedeza total flavone. The preparation method comprises the following steps: an extraction step: taking lespedeza powder, and extracting the lespedeza powder by adopting a supercritical fluid extraction method by taking supercritical fluid CO2 as an extracting agent and an organic solvent as an entrainer to obtain a lespedeza extract; and a purification step: purifying the lespedeza extract by adopting an adsorption chromatography, performing elution by using an organic solvent mixed solution as an eluting agent to obtain an eluant, and then removing the eluting agent from the eluant to obtain lespedeza total flavone. According to the method, the supercritical fluid extraction method is adopted to extract the lespedeza powder, so that double effects of extraction and separation can be achieved, and the extraction efficiency is high; and the adsorption chromatography is adopted to separate the obtained extract, so that the impurities in the extract can be effectively removed, flavone active substances in lespedeza can be kept, the separation efficiency is high, and the obtained lespedeza total flavone is high in purity.

The invention discloses a method for recovering sulfur, lead, zinc and silver from oxygen-rich direct leaching residues of zinc concentrate or lead and zinc mixed ores by virtue of ultrasonic wave intensification, belonging to the field of comprehensive recycling of non-ferrous metal metallurgy. The method disclosed by the invention comprises the following steps: by using tetrachloroethylene or trichloro ethylene as a solvent, extracting elemental sulfur from the oxygen-rich direct leaching residues of zinc concentrate or lead and zinc mixed ores, which are dried, ground, and sieved by virtue of ultrasonic wave intensification, preserving heat and filtering, after naturally cooling and forcibly cooling the filtrate and filtering to obtain a sulfur product, and returning a regenerated sulfur extraction agent to a sulfur extraction step; and enriching zinc, lead and silver in the residues, wherein the residues can be directly fed to a lead system to recover zinc, lead and silver, or the residues are firstly leached to recover zinc, filter residues are fed to the lead system to recover silver, and zinc-containing filtrate is returned to a direct leaching system. The method disclosed by the invention is simple, energy-saving and high in sulfur recovery rate and product quality. The sulfur extraction process is sealed, so that the method is free from environmental pollution and is particularly suitable for comprehensively utilizing normal pressure / high pressure oxygen-rich direct leaching residues of zinc concentrate or lead and zinc mixed ores.