204 results about "Crystallization temperature" patented technology

The invention relates to the technical field of formaldehyde copolymer production, and discloses a trioxymethylene static crystallization separation method which comprises the following steps: S1, cooling crystallization: the crystallization temperature is 25-30 DEG C, and the crystallization time is 3-4 hours; s2, discharging mother liquor; s3, sweating, wherein the sweating temperature is 50-55 DEG C, and the sweating time is 2-2.5 h; and S4, melting to obtain a high-purity product. According to the invention, the characteristic that the solubility of trioxymethylene is reduced along with temperature reduction is utilized, and separation and purification are realized through temperature gradient regulation and control. The content of trioxymethylene in the prepared finished product reaches 94-96% and is higher than that in the prior art by 90-92%, the formaldehyde content is only 0.1-0.2%, and the impurity content is lower.

The invention relates to the technical field of composite adsorption material preparation, and discloses a salt lake lithium extraction titanium system composite adsorption resin preparation technology, which comprises: placing a macroporous organic resin matrix loaded with a titanium lithium source and maintaining a solvent saturation state in a closed reaction kettle, and carrying out a reaction under an inert gas and initial pressure atmosphere, according to the preparation method disclosed by the invention, the problem that a traditional powdery ion sieve is easy to break and lose is solved by utilizing the anti-wear characteristic of an organic resin framework; and meanwhile, an in-situ composite interface realized by the process inhibits pulverization attenuation of active components in circulation, and ensures long service life and structural integrity of the material.

This invention discloses a method for preparing crystalline aluminum phosphate from aluminum polishing waste liquid, comprising the following steps: Step S1. Adding water and alkali to the aluminum polishing waste liquid, adjusting the pH to 2-5, to obtain a mixed solution; Step S2. Taking the mixed solution obtained in Step S1, filtering, to obtain an amorphous precipitate; Step S3. Taking the precipitate from Step S2, washing, to obtain a washed precipitate; Step S4. Adding water to the washed precipitate from Step S3 and transferring it to a hydrothermal reactor for crystallization, to obtain crude aluminum phosphate; Step S5. Taking the crude aluminum phosphate from Step S4, filtering, washing, and drying, to obtain crystalline aluminum phosphate; wherein, in Step S4, the crystallization temperature is 160-210℃, and the crystallization time is not less than 3 hours. This method is simple, easy to operate, and the reaction conditions are easy to control. It not only solves the environmental problems encountered in the chemical polishing process of aluminum materials, but also improves the industrial value of aluminum polishing waste liquid.

The application provides a method for preparing calcium sulfate hemihydrate whiskers by using a low water activity system, and belongs to the technical field of calcium sulfate hemihydrate whiskers. The method comprises the following steps: aging, washing and drying treatment are performed on phosphogypsum raw materials to obtain modified phosphogypsum; inorganic salt, alcohol for reducing water activity and deionized water are mixed to obtain a mixed solution; the mixed solution is heated to a crystallization temperature, and then the modified phosphogypsum and a polyhydroxy alcohol crystallization regulator are added to perform a crystallization reaction; after the crystallization reaction is completed, solid-liquid separation, washing and drying are performed to obtain calcium sulfate hemihydrate whiskers. The method has simple process conditions and a controllable crystallization process, and can stably prepare calcium sulfate hemihydrate whiskers with a high length-diameter ratio.

Provided are a polyethylene having excellent processability and capable of reducing an injection molding defect rate, and a method of preparing the same. The polyethylene has an integral value in the region where the Log Mw is 5.5 or more in a GPC curve, wherein the x-axis is log Mw and the y-axis is dw / dlogMw, of 9% or less of the total integral value: and has a ratio (Tc10 / Tc40) of a crystallization temperature (Tc10) measured at a cooling rate of 10° C. / min to a crystallization temperature (Tc40) measured at a cooling rate of 40° C. / min of less than 1.04.

The invention relates to a process for recycling a particulate semi-crystalline polyamide, the initial particulate semi-crystalline polyamide having already been used in a layer-by-layer printing process, the process comprising: - a step of contacting the initial particulate semi-crystalline polyamide with water and at least one acid; - a step of heating the initial particulate semi-crystalline polyamide to a temperature above Tc – 20°C and below Tf, Tc denoting the crystallization temperature of the initial particulate semi-crystalline polyamide and Tf being the melting temperature of the initial particulate semi-crystalline polyamide, and - a step of collecting the treated particulate semi-crystalline polyamide, in which the treated particulate semi-crystalline polyamide has an inherent viscosity lower than the inherent viscosity of the initial particulate semi-crystalline polyamide.

This invention discloses a method for removing BQB impurities from aripiprazole raw material. This method involves controlling the reaction solvent and post-reaction processing during aripiprazole synthesis. By rationally controlling the ratio of reaction solvent to water, the post-treatment temperature, the crystallization temperature, and the time, BQB impurities can be effectively removed. This invention features a simple process and high removal efficiency. Compared to existing technologies, this invention operates under milder conditions and requires less sophisticated equipment, making it suitable for industrial production.

The invention relates to an easy-to-disperse high-performance organic carboxylate nucleating agent and a synthesis method and application thereof, and the method comprises the following steps: adding an organic acid or an anhydride compound and an organic solvent into a container equipped with a stirrer and a reflux condenser according to a predetermined ratio, and stirring and mixing to form slurry; raising the temperature and stirring to prepare a precursor; adding the fatty acid metal salt into another organic solvent solution according to a preset ratio, and uniformly stirring to obtain a fatty acid metal salt suspension solution; dropwise adding the mixture into a container with a nucleating agent precursor, filtering a product after reaction, and drying and crushing the product; the nucleating agent is obtained. Fatty acid can form a coating surface layer, so that agglomeration of super particles of the nucleating agent is prevented, the dispersion effect of the nucleating agent is enhanced, a prepared plastic product shows a lower haze value and a higher crystallization temperature, the use convenience is improved, and the application field is widened.

A method for reducing or eliminating Si contained in an aluminum alloy including: holding the aluminum alloy and Sn at a melt temperature at which the aluminum alloy and Sn are melted; lowering the melt temperature, and holding the aluminum alloy and Sn at a Si crystallization temperature at which solid Si is crystallized while maintaining a molten state of Sn and Al, and separating the solid Si; and further lowering the temperature and holding the aluminum alloy and Sn at an Al crystallization temperature at which Al is crystallized and Sn is in the molten state, to separate and recover solid Al.

The application discloses a solid selenium diffusion process and application thereof in antimony-based solar cells. Advantages of the solid selenium diffusion process are as follows: 1) the evaporation temperature and annealing crystallization temperature of selenium are very low (about 200 DEG C), so that the temperature of the solid selenium diffusion process is much lower than that (about 350 DEG C) of a conventional selenization process based on selenium vapor; 2) a high-quality antimony selenide interface layer can be prepared by using the process, the interface band structure between an absorption layer and a back electrode can be optimized, and the carrier transport of the device can be improved; 3) the solid selenium diffusion process is highly compatible with a full-vacuum process of the antimony-based solar cell, and can realize full-process physical preparation, and is suitable for large-area industrial manufacturing; and 4) the full-inorganic photovoltaic device prepared by using the solid selenium diffusion process has the advantages of low material cost, environmental friendliness, high stability and the like, and the indoor photovoltaic efficiency of the prepared device is as high as 12.00%, and the device has a wide application prospect in the field of indoor photovoltaic.

The invention discloses a Y-type molecular sieve and a preparation method thereof, a catalyst and a preparation method thereof, and a Fischer-Tropsch wax hydrocracking method, and belongs to the technical field of chemical engineering. The method comprises the following steps: S1, mixing a first alkali source, a first aluminum source, a first silicon source, first water and a template agent to obtain a first mixed solution, and pre-crystallizing to obtain a seed crystal guiding agent; the pre-crystallization temperature is 15-35 DEG C, the pre-crystallization time is 24-60 hours, and the template agent is poly (diallyldimethylammonium chloride); s2, mixing a second alkali source, a second aluminum source, a second silicon source and second water to obtain mother liquor; mixing the guiding agent and the mother liquor to obtain initial gel; crystallizing the initial gel to obtain an alkali metal Y-type molecular sieve; and S3, mixing the alkali metal Y-type molecular sieve with an ammonium-containing solution, carrying out ammonium ion exchange treatment to obtain a first Y-type molecular sieve, and carrying out first roasting treatment to obtain a second Y-type molecular sieve. The particle size of the molecular sieve is smaller than 520 nm, and the silica-alumina ratio is larger than 6.5.

The application discloses a kind of dry treatment desulfurization wastewater system and process flow, high-temperature hot flue gas of boiler induced draft fan outlet is used, dust removal is entered into evaporator coil heat exchange to realize brine concentration, and cooperate with damper to realize temperature rise in evaporator and reach crystallization temperature requirement, by concentrated liquid direct injection high-temperature air duct to carry out vapor-solid separation, then into dryer to carry out gas-solid high-temperature cyclone separation.The application is more reasonable in arrangement, has lower maintenance cost, has wider applicability in finished product production, has higher economic benefit, especially avoids chloride crystalline salt pollution ash, so that ash and chloride crystalline salt can be collected and utilized separately.

The invention discloses a quaternized thiophene polymer and a preparation method thereof.The structural formula of the quaternized thiophene polymer is shown in the specification, the quaternized thiophene polymer structurally contains a C6 alkyl chain and a quaternary ammonium salt long chain containing a polar group, the polymer can be endowed with good alcohol solubility, then the environment-friendly solvent processing characteristic can be achieved, and meanwhile, the quaternized thiophene polymer can be used for preparing a solvent. And the crystallization temperature and the melting point of the polymer can be reduced, so that the melting processing characteristic at lower temperature can be realized.

A method for producing a porous ceramic structure, comprising the following: a) Making kneaded clay by kneading a raw material; b) Obtaining a pressed body by shaping the kneaded clay and c) Firing of the pressed body, wherein the raw material contains the following: Cordierite; Cer and iron and / or manganese and / or cobalt, wherein the process c) forms a porous ceramic structure comprising a porous structural body formed essentially of cordierite, cerium-containing particles firmly attached to the structural body, and metal oxide particles each firmly attached to an inside of a pore in the structural body, wherein the metal oxide particles are particles of an oxide having a spinel structure containing iron and / or manganese and / or cobalt, The process c) includes the following: c1) Raising the temperature of the pressed body to a first temperature that is less than or equal to a liquid phase formation temperature; c2) Increasing the temperature of the pressed body from the first temperature to a second temperature that is higher than the liquid phase formation temperature and lower than a crystallization temperature of the metal oxide particles; c3) Increasing the temperature of the pressed body from the second temperature to a third temperature which is greater than the crystallization temperature and less than or equal to a maximum temperature; and c4) Maintaining the temperature of the press body at the maximum temperature for a specified period of time, and wherein a rate of temperature increase in process c2) in the range of 100 °C / h to 200 °C / h.

The invention relates to a fiber-reinforced tape comprising a thermoplastic composition comprising a propylene-based polymer and a plurality of continuous glass fibers dispersed in the thermoplastic composition, wherein each of the plurality of continuous glass fibers extends in the longitudinal direction of the tape, wherein the thermoplastic composition has a crystallization temperature determined by differential scanning calorimetry according to ISO 11357-3 using a heating rate of 10˚C / min and a cooling rate of 10˚C / min of at least 122.0 ⁰C.

A method for increasing the BEMT content in a composition comprising 2,4-bis[4-(2-ethylhexyloxy)-2-hydroxyphenol]-6-(4-methoxyphenol)-1,3,5-triazine (BEMT), the method comprising the steps of: a) providing a composition comprising BEMT and impurities; b) dissolving the composition in a solvent mixture at a first dissolution temperature to produce an unsaturated BEMT solution, wherein the solvent mixture comprises at least one polar solvent; c) lowering the temperature of the unsaturated BEMT solution to a saturation temperature, wherein the saturation temperature is below the first dissolution temperature, to produce a saturated BEMT solution; d) further lowering the temperature of the first saturated BEMT solution to a first crystallization temperature, wherein the first crystallization temperature is below the saturation temperature, thereby producing a supersaturated BEMT solution; e) during step d), adding BEMT seed crystals in an amount ranging from 0.00001 wt.-% to 20 wt.-% relative to the total weight of the composition to the supersaturated BEMT solution to produce a first BEMT suspension comprising BEMT particles; f) a) Heating the first BEMT suspension to a second dissolution temperature to produce a second BEMT suspension containing fewer BEMT particles than the first BEMT suspension, wherein the second dissolution temperature is higher than and lower than the first crystallization temperature; g) Cooling the second BEMT suspension to a second crystallization temperature to produce a final BEMT suspension containing BEMT particles larger than those in the first BEMT suspension; h) Separating these BEMT particles from the final BEMT suspension, wherein the second crystallization temperature is lower than the first crystallization temperature.

The invention relates to a method for preparing polypropylene fibers by high-power stretching oriented crystallization, which comprises the following steps of: pretreating raw materials, melting, plasticizing and accurately metering, spinning and forming, and treating by using a three-section temperature control channel: enabling nascent fiber trickles to enter a temperature-controllable channel of a high-temperature slow cooling area, a medium-temperature oriented crystallization area and a low-temperature shaping area which are sequentially arranged from top to bottom; the areas are independently controlled in temperature and have a synergistic effect. According to the method disclosed by the invention, through coordinated regulation and control of three-section type temperature gradient and high-power stretching, a molecular chain is fully unwound and stretched in a high-temperature region firstly, and then is subjected to high-power stretching induction in an optimal crystallization temperature region to form a perfect crystal structure with high orientation, high crystallinity and narrow grain size distribution, so that high-strengthening structures such as shishkebab shish-kebab crystals and extended-chain crystals can be stably obtained; and the tensile strength and the initial modulus of the prepared polypropylene fiber are remarkably improved, the dry heat shrinkage rate is greatly reduced, the mechanical property and the dimensional stability are far superior to those of traditional process products, and the strict requirements of high-end industrial textiles are met.

The utility model relates to the field of dexamethasone production, in particular to a crystallization device for dexamethasone production, which comprises a treatment box, the device further comprises an L-shaped plate, a filter plate, a through groove, a baffle, a rotating shaft, a crystallization plate, a temperature control plate, a drainage groove, a sliding assembly, a mounting bracket, a water pump, a spray head, a guide pipe and a suction head; the treatment box is arranged, the liquid medicine is added into the treatment box, the water pump conveys the liquid medicine to the position of the spray head through the suction head and the guide pipe during operation, the liquid medicine falls on the surface of the crystallization plate in a dripping mode, and the temperature control plate can adjust the temperature of the crystallization plate so that the crystallization plate can be kept at the crystallization temperature. Due to the arrangement of the drainage groove, the flowing uniformity of the liquid medicine can be improved, part of the liquid medicine can be crystallized and left on the surface of the temperature control plate in the flowing process, the uncrystallized liquid medicine flows back to the bottom of the treatment box again after being filtered by the filter plate, and then is circulated through the water pump, so that circulating crystallization of the dexamethasone liquid medicine is realized, and the crystallization quality is improved.

An electrophotographic belt can suppress a decrease in electric resistance and a decrease in the crack resistance even when being repeatedly used for a long period of time. The electrophotographic belt including at least a base layer, wherein the base layer contains a polyether ether ketone resin, which is a thermoplastic resin, and carbon black, the content of the carbon black is 18 to 30 mass % with respect to the mass of the base layer, the base layer has a moisture content of at least 0.50 mass % as measured from a sample cut out from the base layer, and a crystallization temperature of the base layer during cooling is not higher than 288.0° C. that is measured in differential scanning calorimetry.

The application relates to the technical field of transparent glass ceramic preparation, in particular to a Ca 1.46 Ti 1.38 Nb 1.11 O7 crystal phase transparent glass ceramic and a preparation method and a transparent luminescent material 1.46 Ti 1.38 Nb 1.11 O7 crystal phase transparent glass ceramic is prepared by taking calcium salt, Na salt, B source and Nb, Ti and Sb oxides as raw materials, heating the raw materials to be molten into a liquid state, performing annealing treatment after solidification forming to obtain transparent glass; the transparent glass is subjected to crystallization at 600-640 DEG C and is kept for 1-2 hours to generate Ca 1.46 Ti 1.38 Nb 1.11 O7 crystal phase, and Ca 1.46 Ti 1.38 Nb 1.11 O7 crystal phase transparent glass ceramic is obtained. By adjusting the raw material composition and the crystallization temperature, a specific crystal phase and a crystal field environment can be formed, which can provide a doping site for rare earth ions and is beneficial to improving the luminescent intensity after doping.

Disclosed is a polyolefin resin composition for use in the production of a single-layer dry porous membrane having excellent melting and closing properties, and a porous membrane using the same. The present invention provides a polyolefin resin composition for a porous membrane, comprising: 30 to 70 wt% of a high-density polyethylene having a melt flow index (190°C, 2.16 kg load) of 0.1 to 5 g / 10 min, a crystallization temperature of 115 to 125°C, and a crystallinity of 75% or more; and 30 to 70 wt% of a high-crystalline polypropylene having a melt flow index (230°C, 2.16 kg load) of 5 to 20 g / 10 min.

The application belongs to the technical field of aluminum smelting, and specifically provides a method for detecting initial crystallization temperature of electrolyte, which comprises the following steps: preparing electrolyte powder from electrolyte to be detected, melting the electrolyte powder to obtain liquid electrolyte; gradually reducing the temperature of the liquid electrolyte, and measuring the viscosity of the liquid electrolyte to obtain the viscosity value of the current temperature every time the temperature is reduced by a preset temperature; drawing a viscosity curve of the liquid electrolyte based on the viscosity values of various temperatures, wherein the viscosity curve is used to represent the relationship between the viscosity of the liquid electrolyte and the temperature; and determining the initial crystallization temperature of the electrolyte to be detected based on the viscosity curve. The technical scheme provided by the application can improve the accuracy of the detection of the initial crystallization temperature of the electrolyte.

A method for producing a 3D item (1) by means of fused deposition modelling of 3D printed material (202) on a receiver item (550), wherein the 3D item (1) comprises a plurality of layers (322) of 3D printed material (202); wherein: (a) the printable material (201) comprises a semi-crystalline polymer; (b) the 3D printable material (201) has (i) a melting temperature range, ranging from a first melting temperature TM1 to a second melting temperature TM2, wherein TM2>TM1, and (ii) a crystallization temperature range, ranging from a second crystallization temperature Tc2 to a first crystallization temperature Tci, wherein TC2>TC1; (c) the 3D printing stage comprises guiding the 3D printable material (201) through a printer nozzle (502) at a nozzle temperature TN; wherein TN>TM2; (d) the method comprises during a first sub-stage of the 3D printing stage: depositing 3D printable material (201) on the receiver item (550) having a first receiver item temperature TB1, to provide n1 first layers (1322) on the receiver item (550); wherein TB1>TM2; (e) the method comprises during a second sub-stage of the 3D printing stage: cooling n12 first layers of the n1 first layers (1322) and selecting a second receiver item temperature TB2 of the receiver item (550), wherein TN2<TB1; and (f) the method comprises during a third sub-stage of the 3D printing stage: depositing 3D printable material (201) on the previously deposited n1 first layers (1322), to provide n2 second layers (2322) thereon.

This invention discloses a kinetically controlled method for preparing hierarchical porous molecular sieves, belonging to the field of catalyst preparation technology. It employs a two-step crystallization method: first, nucleation occurs at low and ultra-low H2O / SiO2 molar ratios; then, after the low-temperature phase, water is added, followed by rapid growth at high temperature and high H2O / SiO2 molar ratios. The solid-phase and liquid-phase crystallization mechanisms in the synthesis system work in succession to prepare hierarchical molecular sieves. This invention, without adding any mesoporous pore-forming agents, only modulates the crystallization temperature and the H2O / SiO2 molar ratio of the synthesis system to kinetically control the crystallization mechanism, resulting in molecular sieves with higher catalytic performance than those obtained using traditional methods. Furthermore, it overcomes the drawbacks of traditional hierarchical porous molecular sieve preparation processes, such as high cost, high calcination energy consumption, poor mesopore connectivity, and severe contamination from pore-forming agents.

The invention relates to a method for recycling a particulate semicrystalline polyamide, wherein the initial particulate semicrystalline polyamide has already been used in a layer-by-layer printing process, the method comprising: a step of bringing the initial particulate semicrystalline polyamide into contact with water and at least one acid, a step of heating the initial particulate semicrystalline polyamide to a temperature higher than Tc - 20°C and lower than Tm, Tc denoting the crystallization temperature of the initial particulate semicrystalline polyamide and Tm being the melting temperature of the initial particulate semicrystalline polyamide, and a step of collecting the treated particulate semicrystalline polyamide, wherein the treated particulate semicrystalline polyamide has an inherent viscosity lower than the inherent viscosity of the initial particulate semicrystalline polyamide.

A method for preparing acrylic acid, the method including a multi-stage crystallization process performed by two or more crystallization units that are connected in series, and each includes a crystallizer and a solid-liquid separator, wherein a first stage crystallization unit among the two or more crystallization units includes a crystallizer having a crystallization temperature of −20 to −10° C.

The application designs and synthesizes a nucleating agent with good compatibility with recycled polyethylene terephthalate. The nucleating agent can effectively solve the technical problems of slow crystallization rate and poor heat resistance of recycled polyethylene terephthalate. The nucleating agent is simple to synthesize, has good effect, can effectively improve the crystallization temperature, crystallization rate and heat distortion temperature of recycled polyethylene terephthalate, and further promotes the wide application of recycled polyethylene terephthalate.

This invention relates to the fields of materials science and chemistry, and discloses a method for preparing a metal ion-doped defective FER molecular sieve. The method includes a molecular sieve using Cu and Co as doping ions, with a basic framework of a defective FER molecular sieve having a silicon-to-aluminum ratio of 30-40. The molecular sieve is based on the mass of the defective FER molecular sieve, and the mass percentage of the doping ions is 3-5%. This invention employs a two-step synthesis method. The first step involves hydrothermal crystallization to synthesize a pre-crystallized FER molecular sieve. The second step increases the hydrothermal crystallization temperature, causing the unstable molecular sieve structure to transform into a high silicon-to-aluminum ratio defective crystal form under high temperature and pressure, while simultaneously introducing heteroions into the molecular sieve framework. Compared to traditional techniques, this method can achieve a larger doping amount and is simpler with readily available raw materials. Its application in the catalytic synthesis of ethylene glycol dimethyl ether from ethylene glycol and methanol can achieve high conversion rates and high selectivity, demonstrating significant economic value and market potential.

The invention provides a molecular sieve crystallization kettle and a device and method for preparing a molecular sieve, the molecular sieve crystallization kettle comprises a crystallization kettle body and a crystallization kettle cover, the crystallization kettle body comprises a base and a side wall, the crystallization kettle cover is provided with a material inlet, the outer edge of the crystallization kettle cover is in close contact with the inner wall of the side wall of the crystallization kettle body, and the material inlet is communicated with the material inlet. Moving parts which are matched with each other and can enable the crystallization kettle body and the crystallization kettle cover to move up and down relative to each other are arranged on the contact surface of the outer edge of the crystallization kettle cover and the inner wall of the side wall of the crystallization kettle body. According to the molecular sieve crystallization kettle, gel can be flatly laid in the crystallization kettle in a cake shape in the crystallization process, the heating area is large, the temperature of the gel at different positions is uniform, and the gel can rapidly reach the specified crystallization temperature in a short time, so that the gel obtains a higher heating speed and a smaller internal temperature difference; the crystallization process of the molecular sieve is facilitated, the crystallization time is shortened, the product quality is improved, and the grain size is reduced.

The invention discloses a liquid crystal polyester composite material as well as a preparation method and application thereof. The liquid crystal polyester composite material comprises the following components in parts by weight: 82-115 parts of liquid crystal polyester; 8-15 parts of a flaky filler; 3-10 parts of a spherical filler; 0.2 to 1.2 parts of fibrous filler; wherein the difference value between the melting point and the crystallization temperature of the liquid crystal polyester composite material is greater than or equal to 48 DEG C; the melt viscosity of the liquid crystal polyester composite material is less than or equal to 15 PaS. According to the invention, fillers with different morphologies are added into the liquid crystal polyester, and the melt viscosity and the temperature difference between the melting point and the crystallization temperature of the liquid crystal polyester composite material are regulated and controlled, so that the liquid crystal polyester composite material has better heat-conducting property and better flowing property.