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 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 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 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.