37results about How to "Reduced purification process" patented technology

The invention relates to an oredressing method for pertinently reducing content of sesquioxide of iron and aluminum (R2O3) in the collophanite floatation process in advance. The process comprises the following steps of: (1) levigating raw collophanite until grains with the grain size of 0.038mm are more than or equal to 76 weight percent, and controlling the pulp mixing concentration to be 25-40 weight percent; (2) introducing ore pulp into a mineralizing agitation tank of a floatation machine, adding an agent for floating conventional mid-low grade collophanite for pneumatic flotation, ensuring that a spindle speed of the floatation machine is 1,800-2,100r / min, the floating aeration quantity is 0.05-0.10m<3> / h and the floating scraper speed is 20-30r / min, and obtaining phosphate concentrate subjected to rough concentration; and (3) controlling the pH of the phosphate concentrate subjected to rough concentration to be 4.5-5.5, adding a collector for removing R2O3, performing pneumaticflotation for 4 to 8 minutes, removing an impurity of R2O3 from foam, and obtaining base flow, namely a high grade phosphate concentrate product. By the method, the R2O3 content in the concentrate can be obviously reduced, the quality of the phosphate concentrate is improved, and production processes, flows and cost during purification in the subsequent acid making process can be reduced.

A preparation method for electron-grade hydrofluoric acid comprises the following steps: introducing an industrial waterless hydrogen fluoride liquid and pure water into a rectifying tower, so as to form hydrofluoric acid with a first concentration; then adding a hydrogen peroxide solution for obtaining arsenic and silicon impurities in hydrofluoric acid, and then performing rectification; condensing the hydrogen fluoride gas obtained through rectification to form a hydrofluoric acid liquid, performing first filtration, and performing absorbing by utilizing pure water to form hydrofluoric acid with a second concentration, and performing second filtration, so as to obtain the electron-grade hydrofluoric acid product; and absorbing tail gas with pure water, so as to prepare industrial-grade hydrofluoric acid. The preparation technology is simple, and no extra impurities are introduced; the prepared electron-grade hydrofluoric acid reaches international standard SEMI-C7 standard of semiconductor equipment and materials; the yield is high and the cost is low; and by employing one production process, the electron-grade hydrofluoric acid and analytically-pure-grade hydrofluoric acid can be both prepared.

The invention relates to a method for removing pigments and impurities in crude lactide. First, the temperature and pressure in the rectification tower are adjusted, and supercritical CO 2 into the rectification tower; then the crude lactide is crushed or heated and melted, and then sent into the rectification tower for decolorization and impurity removal; the product after rectification and CO 2 Separation to obtain de-impurity and decolorized lactide. The present invention uses supercritical CO 2 The combination of extraction and rectification process can not only effectively remove the pigment and impurities in the crude lactide, but also effectively reduce the operating temperature and difficulty of the rectification process, and reduce the coking, oxidation and polymerization of lactide caused by high temperature And side reactions such as mesization, to ensure the yield and quality of lactide products, is a purification method with high operational feasibility, simple separation process, and high-efficiency removal of impurities.

The invention discloses a method for preparing high-purity selenium through wet-process purification of crude selenium. The method comprises the following steps: a, slowly adding crude selenium into a sodium hydroxide solution at a uniform speed, wherein a liquid-solid mass ratio is 3-5: 1, reaction time is 1.5 to 2 h and complete dissolving and leaching of crude selenium are ensured; b, adjusting a pH value to 6.5 to 7.0 by using hydrochloric acid, adding sodium sulfide, then carrying out uniform mixing under stirring and carrying out standing to remove impurities; c, adjusting the pH value of an alkaline leaching solution obtained in the previous step to 1.0 to 1.5, carrying out ageing for 2.5 to 3 h and then carrying out solid-liquid separation after complete precipitation of selenium; d, oxidizing leached fine selenium by using a sodium sulfite solution, carrying out sufficient stirring and then successively carrying out standing and filtering so as to obtain a selenium-rich solution; and e, slowly adding sulfuric acid into the selenium-rich solution, and successively carrying out acidification and reduction, filtering, washing and drying so as to prepare high-purity selenium. The method provided by the invention realizes preparation of high-purity selenium through two-step leaching and wet-process purification of crude selenium, shortens the purification flow of selenium, improves recovery rate, reduces production cost and mitigates limitation of large-scale production.

The invention discloses a synthesis method of active cyclic octapeptide Reniochalistatin E and an analogue thereof. A complete synthesis method of the cyclic octapeptide disclosed by the invention adopts a polypeptide solid phase synthesis method, and the synthesis time and purification processes are greatly shortened; in order to prevent the condition that hydrogen on tryptophan indole nitrogen possibly causes decrease of a connection rate and increase of by-products, tryptophan with protection of carbonyl tert-butyl (Boc) on indole is adopted as a raw material, and finally, after cyclizationis finished, a TFA / DCM solution with a high volume ratio is adopted for removing Boc protection to obtain a final product. Compared with traditional condensation reagents and cyclization reagents, condensation reagents DEPBT and DIEA and a cyclization reagent PyBOP adopted by the invention have the advantages of greatly reducing racemization caused by reaction processes and reducing toxicity hazards to the body of a user. The product obtained by the synthesis method provided by the invention is simple in synthesis process, low in raw material cost, mild in reaction condition, high in purity and easy to industrialize, and has broad market prospects.

The invention relates to a production method for high-purity polysilicon and production equipment for producing the high-purity polysilicon by the production method, wherein the production method comprises the following steps: preparing a silicone material, smelting a packaging material, deslagging, smelting silicon refining, casting silicone fluid slag, deairing silicone fluid in vacuum, directionally solidifying, discharging silicon ingots, and peeling and cutting, wherein the silicone material used in the silicone material preparation step is metallurgy level of reduction silicon; and a heating mode adopted in the silicon material smelting step comprises chemical combustion heating. The production equipment comprises at least more than three same ladle structures used for a smelting ladle and a refining ladle, wherein one ladle is used for smelting operation, one ladle is used for refining operation, and another ladle is used for repairing, preheating or loading operation. The production method and the production equipment can produce the high-purity polysilicon on large scale and at low cost.

The invention relates to a continuous purification method of high-purity tungsten hexafluoride, belonging to the field of fluorine-containing fine chemical separation technology. In the method, the impurity gas is firstly sublimated into a solid through a low-temperature purification tower, and then the tungsten hexafluoride with a purity of 99.9999 vol% is obtained through high-efficiency rectification by adjusting the rectification process parameters. The method of the invention can realize the purification of crude tungsten hexafluoride gas with a purity of more than 30 vol%, has wide application range, strong operability, high yield, low cost, high efficiency and is easy for large-scale production.

The invention provides a method for reclaiming anthranilic acid from methyl anthranilate wastewater, the method is to carry out separation treatment and extraction treatment to methyl anthranilate wastewater, then obtain sodium anthranilate solution, and then Anthranilic acid was obtained after purification. In the present invention, the property that anthranilic acid is soluble in hot water and slightly soluble in cold water is used for purification, which reduces the addition of other substances and the purification process, reduces the cost of purification, and is economical and environmentally friendly.

The invention discloses a production device and production method of electronic grade hydrofluoric acid. The raw material industrial anhydrous hydrogen fluoride is first vaporized through an evaporator and then transported to a purification tower, and high-purity hydrogen fluoride gas is obtained through rectification; The tower is absorbed with a certain concentration of hydrofluoric acid in the liquid phase to obtain crude electronic grade hydrofluoric acid; finally, the finished electronic grade hydrofluoric acid is obtained by ultra-pure filtration. The invention overcomes the technical problems of small output and low purity in the prior art, and the production process meets the requirements of environmental protection, and is suitable for industrialized large-scale production.

The present application relates to the field of water treatment, in particular to a rainwater treatment system. The rainwater treatment system includes a discharge pipe, a sewage pipe and a rainwater pipe. A transfer station is arranged between the discharge pipe, the sewage pipe and the rainwater pipe. One end of the pipe away from the road is fixedly connected and connected with the transfer station, one end of the sewage pipe is fixedly connected and connected with the transfer station, and the other end is connected with the sewage treatment plant. Open and close at the same time, a conversion device for switching the open and closed states of the rainwater pipe and the sewage pipe is arranged between the rainwater pipe and the sewage pipe. In the present application, the change of the open state of the rainwater pipe and the sewage pipe is realized, the diversion of sewage and rainwater is realized, the process of purifying the rainwater in the sewage treatment plant is shortened, and the effect of reducing the waste of power consumption of the sewage treatment plant is achieved.