214results about How to "Short crystallization time" patented technology

The invention relates to a method for preparing an epoxide and mainly resolves the problems in the prior art such as the low activity of catalysts for production of the epoxide, poor effect of mass transference, and high cost of production. The invention well resolves the problems through adopting the technical proposal which selects cheap organic amine as a template with shorter crystallization time, carries titanium through posterior synthesis in the presence of inertia gas, grafts inorganic titanium to silicon dioxide framework with a hexagonal mesoporous structure to form a substance of active titanium with four coordinating structure, and carries out alkylation treatment to produce a catalyst of the epoxide. The method provided by the invention can be applied to the industrialized production of the epoxide.

The invention provides a preparation method of a small grain ZSM-35 molecular sieve. The method comprises the following steps: uniformly mixing a silicon source, an aluminum source, an alkaline source, a template and water to obtain a colloid liquid, the molar ratios of which are as follows: SiO2/Al2O3=18.5-28.6, template/SiO2=0.81-1.25, OH<->/SiO2=0.03-0.18 and H2O/SiO2=10-26; firstly crystallizing the colloid liquid for 5-30 hours at 15-80 DEG C and then continuously crystallizing for 10-30 hours at 150-200 DEG C; and filtering, washing and drying to obtain the small grain ZSM-35 molecular sieve. According to the preparation method, by using cheap ethidene diamine as the template, the crystallizing process is controlled to synthesize the small grain ZSM-35 molecular sieve by adding seed crystals and crystallizing in two stages, so that the grain size reaches about 0.5 micron at minimum.

The invention provides a method for synthesizing SAPO-5 by using diethylamine as template and recovering the template of the SAPO-5. The structural formula of the SAPO-5 is represented by aR x (SixAlyPz)O2, wherein, the x, y and z are a molar fraction of Si, a molar fraction of Al and a molar fraction of P respectively, and meet a relation of x+y+z =1; the R is the template; and the a is the mole number of the template, and a is between 0.5 and 2.5. The invention is characterized in that: the template adopts the diethylamine or mixture of nitrogenous organic substances mainly containing the diethylamine ; and the method comprises the following steps of: weighing the template, a silicon source, an aluminium source, a phosphorus source and water according to the mole amount of H2O on a molecular sieve with meshes between 0 and 500; preparing gel through sufficiently mixing and stirring the materials; crystallizing the gel at a temperature of between 160 and 350 DEG C with a reaction time not shorter than 0.1 hour; filtering, washing and drying after complete crystallization, and performing drying under a temperature of between 25 and 120 DEG C; heating up the gel to a temperature not higher than 250 DEG C after molecular sieve synthesis, and condensing and volatilizing diethylamine template which can be reused. The method has the advantages of simple preparation method, low cost and high product yield.

The invention relates to a method for synthesizing MCM-22 molecular sieve. The method comprises the following steps of: preparing gel consisting of a silicon source, an aluminum source, an organic template agent, halogen compounds, alkali and water; then crystallizing the gel; and performing the traditional steps of filtering, washing, drying and roasting so as to obtain product of the MCM-22 molecular sieve, wherein the organic template agent can be dimethyleneimine, and also can be a mixed template agent composed of the dimethyleneimine and one or more than one of hydrocarbon, organic amine, alcohol and ketone. Compared with the prior art, the method has the advantages of low crystallization temperature, short crystallization time, high yield coefficient of product, high product quality and the like. The MCM-22 molecular sieve produced according to the invention has excellent catalytic performances of catalytic cracking, olefin alkylating, benzene alkylating and the like.

The invention provides a synthetic method for NaY zeolite with a high silica-alumina ratio. The method comprises the main steps: according to the proportioning requirement of a directing agent to uniformly mix a silicon source, an aluminium source and water, and ageing at 15 DEG C-60 DEG C for 0.5-120 h, so as to prepare the directing agent; according to the proportioning requirement of a gel reaction mixture to adding the directing agent and an alkaline solution into a silicone source at 10 DEG C-90 DEG C, stirring for 1 h-80 h, and stirring uniformly to obtain the gel reaction mixture; performing crystallization on the gel reaction mixture at 80-120 DEG C for 10-50 h, and then filtering, washing and drying to prepare NaY zeolite. The method does not employ a template, the preparation of the directing agent is mild in temperature, NaY zeolite with high crystallization degree and the high silica-alumina ratio is synthesized at a relatively short crystallization time. Also the method is capable of replacing conventional production technology without changing current apparatuses for industrial production, and has great important meaning on improving performances of catalytic cracking catalysts.

The present invention relates to a Li₂O-Al₂O₃-SiO₂ system ultra-low expansion coefficient high-transparency glass-ceramic and production method of the products. Calculated by weight percentage, the ultra-low expansion coefficient high-transparency glass-ceramic is composed of 3.2 to 4.6 percent of Li₂O, 18.0 to 23.6 percent of Al₂O₃, 64.1 to 69.4 percent of SiO₂, 0.3 to 0.8 percent of MgO, 0.8 to 2.5 percent of BaO, 0.3 to 0.8 percent of R₂O, 0.01 to 0.4 percent of Y₂O₃, 1.8 to 2.5 percent of TiO₂, 1.6 to 2.4 percent of ZrO₂, 1.1 to 1.8 percent of P₂O₅, 0.6 to 1.5 percent of Sb₂O₃, 0.3 to 1.0 percent of NaCl and 1.0 to 2.0 percent of NH₄NO₃. The heat-resistant glass plates and heat-resistant glass products can be manufactured by using the formula and the corresponding forming die. The present invention has the advantages that the production technique is simple, the produced products have low expansion coefficient, good transparency, high thermal impact temperature, high strength, have constant transparency when being used under the temperature of 700 Celsius system for a long time, the products have long service life, etc.

The invention discloses a high-density rapid synthesizing method of ZSM-5 zeolitic molecular sieve, which is characterized by the following: adopting water glass or silicasol as silicon source, and aluminum sulfate, aluminium chloride, aluminum nitrate as aluminum source and short-chain organic amine as mould agent; adding ZSM-5 as seed to crystallize according to normal water-heat synthesizing method. The invention shortens crystallizing time, which reduces manufacturing cost effectively.

The invention discloses a method for purifying tebipenem by recrystallizing. Acetone and isopropyl ether are adopted as recrystallizing solvents, the operation is simple, heating or cooling equipment is not required, crystallization is realized at room temperature, crystallization time is short, and recrystallization yield is high and over 75 percent, so that the method is suitable for industrialproduction, the recrystallized product has short melting range, high purity which is over 99.9 percent by virtue of HPLC (high performance liquid chromatography) detection, and can be used as a raw material medicament in accordance with requirements to prepare a medicinal preparation for safe administration of patients.

A chalcogenide material and chalcogenide memory device exhibiting fast operation (short set pulse times) over an extended range of reset state resistances. Electrical devices containing the instant chalcogenide materials permit rapid transformations from the reset state to the set state for reset and set states having a high resistance ratio. The instant devices thus provide for high resistance contrast and improved readability of memory states while preserving fast operational speeds for the device. The chalcogenide materials include materials comprising Ge, Sb and Te in which the Ge and/or Te content is lean relative to the commonly used Ge₂Sb₂Te₅ chalcogenide composition. In one embodiment, the atomic concentration of Ge is between 11% and 22%, the atomic concentration of Sb is between 22% and 65%, and the atomic concentration of Te is between 28% and 55%. In a preferred embodiment, the atomic concentration of Ge is between 15% and 18%, the atomic concentration of Sb is between 32% and 35%, and the atomic concentration of Te is between 48% and 51%.

The invention discloses a preparation method for an SCR catalyst for purifying oxynitride in motor vehicle exhaust .The preparation method includes the steps of preparation of an SSZ-13 molecular sieve, preparation of a Cu-SSZ-13 catalyst and preparation of an integrated SCR catalyst .The preparation method is simple, production cost is lowered, SSZ-13 crystallization time is short, crystallization is relatively pure, HN3-SCR catalytic activity is high, and the purification rate of oxynitride in motor vehicle exhaust is high.

The invention discloses a method for gathering/recovering VE (Vitamins E), squalene and polyunsaturated fatty acids from the deodorized distillate of plant oil. Specifically, the method comprises the following steps: adopting urea and a solvent as addition agents; mixing the addition agents with the distillate so as to dissolve the addition agents in the distillate; carrying out flexible packaging, vacuum degassing and sealing; applying a super high pressure for quickly crystallizing and agglomerating saturated fatty acids, monounsaturated fatty acids, fatty hydrocarbons, sterols and the like in the distillate; adsorbing a large quantity of impurities with an inclusion compound; carrying out pressure filtering and separating to obtain filter residue and filtrate; removing the solvent from the filtrate to obtain the VE, squalene and polyunsaturated fatty acids with high concentration. According to the method, the recovery rates of the VE, squalene and polyunsaturated fatty acids are all more than 80%, and neutral oil can be reserved.

The invention relates to a method for preparing a molecular sieve ZSM-5 by preparing a precursor glue solution, crystallizing, filtering, drying and roasting. The invention adopts two crystallization methods, one method comprises the following steps of: directly illuminating the precursor glue solution in a sealed container by adopting a microwave field, and crystallizing by utilizing the coaction of the microwave effect and the autogenous hydrothermal pressure of the glue solution; and the other method comprises the following steps of: heating the precursor glue solution in the sealed container by adopting saturated steam for crystallization treatment, wherein the heating and the crystallization treatment can be simultaneously carried out in the microwave field. The saturated steam for the crystallization treatment is crystallized at 170-180 DEG C for 1-6h, 1-10 percent by weight of inoculating seeds are added after aging the precursor glue solution and before crystallizing the precursor glue solution which is prepared by adopting a template-free preparation method. The method of the invention has the following advantages of simple and practical process and uniform temperature in the crystallization process, obtains the molecular sieve with high crystallinity, pure crystal phase, controllable grain size, wider range and short crystallization time, can improve the production efficiency, decrease the cost and save energy.

The invention discloses a method for ultrasonically crystallizing rebaudiosideA, which comprises the following steps of: charging stevioside and dissolvent according to the quality volume ratio (kg:L) of 1:4-10; stirring, charging and heating to be the temperature of 40-80 DEG C; constantly keeping the temperature at 30-90 minutes; fast reducing the temperature to be 10-25 DEG C with the velocity of 5-15 DEG C per minute; sequentially statically crystallizing and recrystallizing for 3-12 hours, wherein the ultrasonic wave is adopted to perform auxiliary crystallizing and recrystallizing during statically putting; stirring and performing the ultrasonic wave for 5-15 minutes every 30-90 minutes; and performing solid-liquid separation, dissolution in a washing way, membrane separation, reduced pressure distillation and spray drying to the recrystallized crystalloid to obtain the high-purity rebaudiosideA. The method has the crystallizing time of only 6-24 hours, the rebaudiosideA yield which is more than 75%, even crystallizing grains, and the rebaudiosideA purity which reaches up to be more than 95%, meets the standards of American FDA, can be produced on a large scale, and has obvious effect.

The invention relates to a preparation method of a total-silicon molecular sieve Silicalite-1 having the high hydrogen bond silicon hydroxyl content. The preparation method comprises: (1) mixing a silicon source, a templating agent and water, stirring into a gel, and adjusting the pH value of the gel to 7.5-11.5; and (2) crystallizing the gel of the step (1), washing the crystallized product, separating, and calcining to obtain the total-silicon molecular sieve Silicalite-1, wherein the crystallization comprises the two crystallization processes, the first crystallization process comprises that the crystallization is performed for 1-10 h at a temperature of 60-120 DEG C, and the second crystallization process comprises that the crystallization is performed for 3-24 h after the temperature is increased to 150-200 DEG C. According to the present invention, the total-silicon molecular sieve Silicalite-1 prepared by the preparation method has the high hydrogen bond silicon hydroxyl content, and further maintains high crystallinity, good thermal stability, and good hydrothermal stability of the molecular sieve.

The invention provides a method for promoting Beta molecular sieve synthesis. According to the method, a silicon source, an aluminum source, inorganic alkali, a microporous template agent and crystalgrowth promoters R are sufficiently mixed; the obtained gel is subjected to short-time hydrothermal crystallization for fast preparing a Beta molecular sieve. The synthesized product is formed by stacking and connecting primary nanometer particles; the primary particle diameter is 10 to 30nm; the synthesis process is fast; the materials can be directly crystallized for 10 to 60 hours at the propertemperature; the crystal growth promoters are 2-pyrrolidone, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone or N-isopropyl-2-pyrrolidone or a mixture of the 2-pyrrolidone, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N-isopropyl-2-pyrrolidone. The cheap crystal growth promoters are used for fast preparing the Beta molecular sieve by a one-step method; the conventional crystal seed method is replaced for fast obtaining the Beta molecular sieve; the method belongs to the economic and fast Beta molecular sieve obtaining method. In addition, the prepared Beta molecular sieve also has the excellent catalyst performance; high isobutene conversion rate and tert-butylamine selectivity are shown in the isobutene amination reaction.

The invention relates to the field of synthesis of N-acetoacetanilide type compounds, and in particular relates to a crystallization method of N-acetoacetanilide. According to the crystallization method, gradient cooling is performed on materials by introducing a condensation medium into a cooling tube of a reaction kettle. The crystallization method disclosed by the invention is short in crystallization time, simple in operation step, capable of achieving automation and standardization and capable of improving the yield and purity of products, the particle sizes of product crystals are uniform and consistent, the phenomenon of agglomeration is further reduced, and the agglomeration time is greatly prolonged.

The invention discloses a high shearing force preparation of microcrystalline lactin, including steps of: (1) mixing solid lactin and water with a certain proportion, stiring and heating until the latin is fully dissolved; (2) cooling the latin solution to a predetermined temperature to obain hypersaturate solution of latin; (3) turn on a shear in a crystallizer, to stimulate crystallization of the solution by high shear force; (4) fast separating latin crystal from mother liquid by continuous centrifuge; (5) drying obtained latin crystal; (6) product of microcrystalline lactin is obtained by screening. The invention not only stimulate crystallization of mother liquid by shearing force, in order to realize control of the crystal forming process, and obtain product with centralized grain-size distribution, but also avoids mechanical crushing in the preparation, so that crystal structure is protected, and generation of non-crystal granular is also avoided. Further, the invention combines centrifugal and vibrating drying, thus crystal exhibit excellent fluidity and dispersity, and crystallization time is short.

The invention relates to a circulating typed mould. The invention contains a crystallization container and a cooling interlayer which is arranged around the crystallization container. A stirring rod is arranged inside the crystallization container. A liquid inlet and a liquid outlet are arranged on the crystallization container. A circulating pipeline is arranged between the liquid inlet and the liquid outlet. Middle pools of the water overflow port are arranged in turn on the circulating pipeline, which are used for storing high-level tank and condenser of crystal initial solution. A circulating pump is also arranged on the circulating pipeline. A crystal liquid outlet is arranged on the lower part of the crystallization container. The crystal liquid outlet is communicated with a crystal groove. The crystal groove has a mother liquor back-in-tank pipeline which is communicated with the crystallization container. A vacuum pump is arranged on the mother liquor back-in-tank pipeline. The mother liquid of the circulating typed mould circulates back into the crystallization container, which makes the invention has high efficiency and low energy consumption.