32results about How to "Reduce the number of crystallization" patented technology

The present invention relates to a crystallization method of abamectin B 1a. Said method includes the following steps: using crystallization solvent n-butanol to stir and dissolve primary crude powder of abamectin B 1a at 75-100deg.C to saturation, filtering while the saturated solution is hot to obtain clear hot-saturated solution; slowly cooling said solution to that when the supersaturation degree is 1-3, adding crystal seeds, constant stirring for 20-60min, its stirring speed is 120-300rpm, and cooling to make crystallization, fitering crystal slurry or centrifugally-separating said crystal slurry, washing crystal and drying so as to obtain the invented abamectin B 1a.

The invention relates to a production process of abamectin fine powder. The production process method comprises the steps: extracting fermentation liquid filter cake with sec-butyl acetate for three times; combining organic-ester-phase extracts, adding tetrabutyl ammonium bromide aqueous solution for washing, and filtering, concentrating filtrate, and cooling and crystallizing to obtain once crude product; and dissolving the once crude product with ethanol, filtering, naturally cooling to room temperature, adding water at a volume ratio of ethanol to water being (7 : 1)-(4 : 1) for dilution crystallization, washing and drying to obtain the abamectin fine powder product. By adopting the method, the abamectin crystal product with higher purity and yield can be obtained; and compared with the traditional methods, the method has the advantages that the crystallizing time is shorter, the repeated crystallizing frequency is reduced and the production cost is low, thereby being a low-cost and high-efficiency production process of the high-purity abamectin fine powder.

The invention discloses a preparation method of griseofulvin. The preparation method comprises the following steps of: A, heating griseofulvin fermentation liquor, adding calcium oxide to adjust the PH, carrying out solid-liquid separation by using a sheet frame, adding calcium oxide to a filter cake to granulate, and extracting by using acetone to obtain a griseofulvin acetone extracting solution; B, decoloring the griseofulvin acetone extracting solution by using an active carbon column to obtain a griseofulvin decoloring solution, feeding the decoloring solution into a concentration tank, and crystallizing by concentrating to obtain wet griseofulvin crystals; and C, washing the wet griseofulvin crystals once by using a dichloromethane and ethanol mixed solution while stirring, then washing the wet griseofulvin crystals once by using medicinal ethanol with the concentration of 95 percent while stirring, drying the crystals by using a vacuum drier, and carrying out superfine grinding on the dried crystals to obtain the griseofulvin product. Compared with a traditional preparation method, the preparation method disclosed by the invention has the advantages that the crystallization times in the process of preparing the griseofulvin in the prior art is reduced, the yield loss caused by recrystalization of griseofulvin is effectively avoided, the total yield of the griseofulvin is improved by 7-10 percent, and the production cost is greatly reduced.

The invention relates to a ganciclovir recovery method, which comprises the steps that ganciclovir mother solution is concentrated, alkaline solution is added to adjust pH value to 10.0-13.5, temperature is kept to be constant at 20-60 DEG C for 10-60 minutes, active carbon is added and agitation is conducted for 1-3h, filtration is conducted, organic solution is added in filtrate to precipitate white crystals, filtration is conducted, filter cakes are dissolved in deionized water, hydrochloric acid is added to regulate pH value to 5-6, solid sediment is precipitated, after the solid sediment is heated and dissolved, the temperature of the solid sediment is slowly decreased by 0-30 DEG C to precipitate crystals, and the crystals are filtered and dried to obtain high-purity ganciclovir products. Compared with the prior art, the invention has the advantages of simple operation, high yield, low cost, no pollution and the like.

The invention relates to an analyzer producing the polylactic and the producing process of producing the polylactic adopting the analyzer , characterized in that it is composed by the composite containing the strontium and the aluminium namely the compound system of the bimetal o-oxo bridge alkoxylating compound and the benznene sulfonic acid; the mol content of the said bimetal o-oxo bridge alkoxylating compound is 40-90 percent; the process of producing the polylactic adopting the analyzer : (1)the lactide of the melting range of 92-108 degree is embedded in the reactor and chilled, heated up; (2) it is vacuumized to dewater fully on the N2 condition; (3) the definite proportion of the composite catalyst mixing agent of the Sr and aluminium are added and mixed equably; (4) the air of the reactor is displaced by the highly pure nitrogen gas in order to keep the positive pressure; (5) It is mixed and heated up and the reaction can be finished within 4-16 hours. Because of adopting the analyzer to the production, the puzzle of the high purify requirement of the gathering monocase lactide needed by the existing ring-opening polymerization; so the reaction time is shortened, the producing rate is improved and the producing cost is reduced.

The invention discloses a purification method of sucralose-6-ethyl ester. The purification method comprises the following steps: a preparation step: obtaining an ethyl acetate saturated solution of crude sucralose-6-ethyl ester heated to a preset temperature; a gradient crystallization step: cooling crystallizing and filtering the saturated solution for multiple times, dropwise adding a low-polarity solvent into the solution in each cooling crystallizing process to gradually reduce the polarity of the solution system during crystallizing, and collecting a sucralose-6-ethyl ester crude product obtained by multiple times of crystallization and filtration; and a purification step: recrystallizing and purifying the collected sucralose-6-ethyl ester crude product by using a mixed solution of ethyl acetate and a low-polarity solvent to obtain a sucralose-6-ethyl ester fine product with higher purity. On the basis of cooling crystallization of sucralose-6-ethyl ester by using ethyl acetate as an initial solvent, the polarity of the mixed solvent is reduced by gradually adding a low-polarity solvent, so that the effectiveness of impurity separation in each gradient stage is improved, the product yield is high, and the product quality is good.

The invention discloses a method for treating solid wastes of fluoroethylene carbonate ester. The method comprises the following steps: 1) heating and decomposing fluoroethylene carbonate ester drogsin infrared equipment at a certain temperature; 2) adding a proper amount of hot water with a certain amount of potassium hydroxide into the decomposed drogs, performing stirring dissolution, performing concentration, and performing primary crystallization in a normal-temperature environment; 3) draining off water of a primary crystal, adding the primary crystal into clean water, performing heating to a certain temperature, performing stirring dissolution, performing concentration, and performing secondary crystallization in a normal-temperature environment; and 4) drying a secondary crystal in the infrared equipment at a certain temperature, so as to obtain a byproduct potassium chloride. By adopting the method for treating solid wastes of fluoroethylene carbonate ester, the infrared equipment is adopted for preheating, uniform heating can be implemented, the heating speed is rapid, organic matter in the solid drogs can be removed, caking is not easily caused, in addition, crystallization times can be reduced, treatment steps can be reduced, and the treatment cost can be correspondingly reduced.

The invention discloses a seed crystal addition and atmosphere protection device for preparing high-purity gallium through the crystallization method. A threaded hole is formed in the center of an end cover, and a lifting rod is a threaded rod and installed on the end cover through the threaded hole in the center of the end cover. The end cover is connected and matched with the top end of a crystallizer in a sealed mode. A support is connected to the lower end of the lifting rod, the lower ends of vertical through pipes are fixedly connected to the support, and the upper ends of the vertical through pipes are located above the end cover through through holes formed in the end cover. Supporting feet are arranged at the outer end of the support and matched with the inner wall of the crystallizer in a contact mode. An air inlet hole way is formed between the end cover and the support. The lifting rod can be solid or hollow; when the lifting rod is hollow, the central hole way of the lifting rod is the air inlet hole way. A handle is arranged at the upper end of the lifting rod. The supporting feet are uniformly arranged. The end cover and the crystallizer are matched in shape. According to the invention, the seed crystal addition process can be effectively simplified, the production cycle can be shortened, the influence of the production environment atmosphere to the purification process can be effectively avoided, and the production cost can be saved.

The invention relates to a purification method of puerarin and belongs to the technical field of traditional Chinese medicine extraction. The purification method comprises the steps of 1, condensing in vacuum, puerarin elution under the temperature of 60-100 DEG C and vacuum degree of 0.04-0.09 MPa until puerarin concentration is 0.15 kg/L; 2, adding 2 L of the condensed puerarin elution into 0.2-1.0 kg of alumina, and adsorbing by stirring for 10-30 min; 3, filtering, and washing the alumina to obtain puerarin solution; 4, subjecting the puerarin solution of step 3 to septuple crystallizationto obtain puerarin having the content of greater than 99%. The purification method has the advantages that the purification method is scientific and reasonable and is simple and feasible, the purification method of puerarin is greatly simplified, production cost is reduced, and high-purity puerarin is obtained.

The invention provides a preparation method for D-mannose crystals. The method includes adding activated carbon into mannose slurry to perform heating and discoloration, then performing desalination and purification, performing evaporation and concentration, and soaking in absolute ethyl alcohol for purification and drying to obtain high-purity crystal D-mannose. By the aid of the method that the activated carbon is used for discoloration and electrodialysis desalination, evaporation and concentration are performed until the slurry is almost oven dry and the absolute ethyl alcohol is used for soaking the obtained crystals, the problems of viscous mother liquid, small crystals, low yield and the like in the existing D-mannose crystallization process are solved. On the basis of the traditional technology, an advanced electrodialysis desalination technique replaces ion exchange, crystallization time ranges from 20 hours to 30 hours, a technological process is shortened, and energy conservation and consumption reduction are achieved; crystallization times are decreased, and crystallization yield of the mannose crystals is increased.

The invention discloses a sucralose-6-ethyl ester purification method which comprises the following steps: a secondary water boiling step: taking sucralose-6-ethyl ester mother liquor subjected to water boiling and negative pressure treatment, adding a preset proportion of water into the sucralose-6-ethyl ester mother liquor, fully stirring and heating for water boiling, and after stirring and water boiling for a preset time, filtering to obtain a filtrate; carrying out solid-liquid separation to obtain a secondary water boiling mother solution in which sucralose-6-ethyl ester is dissolved; a phase separation extraction step: standing the secondary water boiling mother liquor for phase separation, taking an upper phase after phase separation, extracting by using an alkane extraction agent at a preset temperature, and removing residual white oil in the upper phase; a recrystallization purification step: evaporating the lower effluent obtained after extraction to obtain a solid, and purifying the solid through recrystallization to obtain sucralose-6-ethyl ester; and a recycling step: separating the extracted upper-layer effluent, recycling the alkane extraction agent, and recycling the alkane extraction agent to the split-phase extraction step for use. The method is simple, efficient and low in cost, trace white oil can be effectively removed, and the purity of sucralose-6-ethyl ester is improved.

The purpose of the present invention is to disclose a camptothecin separation and purification method, particularly a technology for preparing high-purity camptothecin by using diatomaceous earth filtration, membrane separation technology, macroporous adsorption resin column chromatography adsorption and chromatography column preparation integration purification. With the method of the present invention, the problems that the selectivity of extraction and adsorption on the target compound is low, the purity of the prepared camptothecin is not high, and the multiple extraction-recrystallization way has disadvantages of high organic solvent consumption, labor consuming, time consuming, poor economy, high industrial production and serious environmental pollution are solved.

The invention discloses a preparation method of an argatroban intermediate, belonging to medicine preparation. The invention particularly relates to the field of preparation of medicine intermediates,and especially relates to an enzyme resolution preparation method for an important argatroban intermediate, namely ethyl (2R,4R)-4-methyl-2-piperidinecarboxylate L-tartrate. The invention aims at overcoming the defects of excessive crystallization times and low yield of the existing process, and provides the preparation method, which is simple in research, design and operation, good in selectivity, high in yield and easier for industrial production, for the argatroban intermediate ethyl (2R,4R)-4-methyl-2-piperidinecarboxylate L-tartrate. The preparation method is a brand-new preparation method.