39results about How to "Control crystal form" patented technology

The invention relates to a preparation method of fine aspirin crystals, belonging to the field of medical and chemical engineering. The preparation method comprises the following steps: (1) putting salicylic acid, acetic anhydride and fine aspirin crystal mother liquor into a dissolving tank to be stirred, and after rising the antipyretic temperature to 80-90 DEG C to dissolve, preserving the temperature for 1-2 hours to obtain hot liquor; (2) adding acetic anhydride, fine aspirin crystal mother liquor or the mixture of acetic anhydride and fine aspirin crystal mother liquor into a crystallizing tank to stir to obtain cold liquor; (3) filtering the hot liquor after preserving temperature to the crystallizing tank, controlling the temperature of the crystallizing tank in the filtering process to gradually rise, after preserving temperature after filtering, and then cooling and carrying out centrifugal separation to obtain solid state fine aspirin crystals. The obtained fine aspirin crystals mother liquor is recycled to the steps (1) and (2). According to the method provided by the invention, the crystal form, the uniformity and the granularity which are fine aspirin crystals are effectively controlled, so that the preparation method is environment-friendly, and the product yield is improved and the production cost is lowered.

The invention relates to an adsorbent for efficiently adsorbing sulfate ions in water, and a preparation method thereof. In the prior art, the removal efficiency of the sulfate ions in the industrialwastewater is not high. A purpose of the present invention is mainly to solve the problem in the prior art. According to the technical scheme, a hydrotalcite-like structure CaxMn6-xFe2(OH)18.4H2O as an adsorbent is prepared by combining co-precipitation and hydrothermal treatment, and x is 3-5.5. With the technical scheme, the problem in the prior art is well solved. According to the present invention, the adsorbent prepared by the method can efficiently remove sulfate ions from water, and can be used in the field of environmental protection.

This fine particle production method involves a dissolving step in which a stirrer having a rotating stirring blade is used to dissolve at least one type of fine particle raw material in a solvent to obtain a fine particle raw material solution, and a precipitation step in which the fine particle raw material solution and at least one type of precipitation solvent for precipitating the fine particle raw material from the fine particle raw material solution are introduced between at least two treatment surfaces which are arranged oppositely one another, can move closer to and farther apart from one another, and at least one of which can rotate relative to the other, and the fine particle raw material solution and the at least one type of precipitation solvent are mixed in a thin film fluid formed between the at least two treatment surfaces, and the fine particles are precipitated. The stirring energy is determined by the stirring time conditions of the stirrer, the circumferential velocity conditions of the stirring blade, and the temperature conditions of the fine particle raw material solution, and in the dissolving step, the stirring energy is varied by changing at least one of the aforementioned conditions, and by changing the stirring energy, the degree of crystallization and the crystal form of the fine particles obtained in the precipitation step are controlled.

The invention discloses an adsorbent for removing nitric oxide in fluid as well as a preparation method and application of the adsorbent. The composition of the adsorbent is Ni<x> Mg<6-x>Fe<2>O<9> or Ni<x>Mg<6-x> Al<2>O<9>, wherein x is equal to 1-6. The preparation method of the adsorbent comprises the following steps of: dropwise adding an alkaline solution into a solution containing nickel, magnesium and iron or aluminum to carry out precipitation reaction, and then carrying out hydrothermal crystallization, drying, roasting and the like to obtain the adsorbent. The adsorbent has the characteristics of high efficiency of removing nitrogen oxide in fluid, simple preparation method, environment-friendly and pollution-free production process, simple operation and the like.

The invention relates to an adsorbent for efficiently adsorbing phosphate ions in water and a preparation method thereof. The invention mainly solves the problem of low removal efficiency of phosphate ions in industrial wastewater existing in the prior art. The present invention adopts the method of co-precipitation and hydrothermal treatment to prepare the metal composite Ca x Mg 6‑x Fe 2 (OH) 18 ·4H 2 O or Ca x Mg 6‑x Al 2 (OH) 18 ·4H 2 O, where x=1-5 is the technical solution of the adsorbent, which better solves this problem. The adsorbent prepared by the method of the invention has the characteristics of high efficiency in removing phosphate ions from water, and can be used in the field of environmental protection.

The invention relates to an adsorbent for efficiently removing arsenite ions in water and a preparation method thereof, and relates to an adsorbent for efficiently adsorbing arsenite ions in water and a preparation method thereof. It mainly solves the problem of low removal efficiency of arsenite ions in wastewater solution existing in the prior art. The present invention adopts the method of co-precipitation and hydrothermal treatment to prepare the metal composite Cu x Mn 6‑x La 2 (OH) 18 .4H 2 O or Cu x Mn 6‑x Fe 2 (OH) 18 .4H 2 O, where x=2-5 is the technical solution of the adsorbent, which better solves this problem. The adsorbent prepared by the method of the invention has the characteristics of high removal efficiency of arsenite ions in water, and can be used in the field of environmental protection.

The present invention is a silicon carbide smelting method, the steps of which are as follows: carry out the following treatment on the selected silicon carbide which will be used as the seed crystal: crushing treatment and screening treatment, selecting silicon carbide with a particle size of 3 to 8 millimeters and adopting pickling method Carry out purification treatment, and then rinse with pure water; place 0.1%~5% 6H silicon carbide seed crystals within 0~10cm, and place 0.3%~8H 6H silicon carbide seed crystals within 10cm~25cm, centering on graphite electrodes. %, place 1%~10% 4H silicon carbide seed crystals within the range of 25cm~40cm. The method of the invention has reasonable design and strong operability. By adding seed crystals in silicon carbide smelting, the growth efficiency of silicon carbide can be effectively improved, the crystal form of silicon carbide can be effectively controlled, and energy consumption can be reduced.

The invention relates to a modified high belite cement and a method for improving the early strength of the high belite cement, aiming at solving the technical problem of low early strength of the existing high belite cement. The present invention is to add nano indium oxide to high belite cement according to the mass ratio of high belite cement:nano indium oxide=9~4999:1 and mix evenly, the added nano indium oxide can excite C 2 The activity of S in the early stage can accelerate the hydration rate, generate more gels, regulate the crystal form of hydration products, and improve the early strength of high belite cement. The invention not only effectively solves the problem of high energy consumption in the cement industry, but also provides a simple and easy method for improving the early strength of high belite cement, which has low production cost and is easy to popularize.

A process for preparing Co3O4 includes such steps as dissolving Co in nitric acid, hydrochloric acid or sulfuric acid to generate cobolt nitrate (or sulfate, or chloride), dissolving precipitant and complexing agent in deionized water to prepare saturated solution, adding the prepared to solution to reactor, regulating pH=4-5.5, adding complexing precipitant at 35-100 deg.c while stirring, reacting, filtering, washing with deionized water at temp higher than 90 deg.C, calcining at 300-1000 deg.C for 5-25 hr, pulverizing and classifying.

The invention discloses a method for preparing SrHfO3:Ce super-microsphere luminescent powder by adopting a monohydric alcohol thermal method and relates to a method for preparing luminescent powder. The method is characterized in that high-purity Sr(NO3)2, HfOCl2.8H2O, Ce(NO3)3.6H2O are used as raw materials, KOH is used as a mineralizing agent, and alcohol / water mixed solution is used as a reaction solvent; the correlated conditions of the preparation process comprise: preparation of materials, adding and mixing of the mineralizing agent, hydrothermal reaction, filtering, washing and drying, wherein the content of Ce in the SrHfO3:Ce uminescent powder is between 0.1mol% and 1.5mol%. The method for preparing the SrHfO3:Ce uminescent powder is simple in process, and good in appearance and particle diameter controllability of the super-microsphere particles. Besides, the super-microsphere powder prepared by the method is an important raw material of a ceramic scintillator substrate material and can be burnt into sparkling transparent ceramic with excellent optical performances.

The invention discloses a preparation method of a modified nickel hydroxide positive electrode material. The preparation method comprises the following steps: 1, obtaining a positive electrode through an electrochemical method or a chemical coprecipitation method; and 2, coating the positive electrode with the conductive material through an electrochemical method or a solid-phase polymerization method. The positive electrode material prepared by the method has the characteristics of high conductivity, excellent cycle performance, high capacity, high magnification and the like.

The invention discloses a water purifier with an ultrafiltration membrane. The water purifier comprises a filtration tank, wherein the top of the filtration tank is provided with a water inlet, and the bottom of the filtration tank is provided with a water outlet; the filtration tank is internally provided with an activated carbon filtration layer and an ultrafiltration membrane filtration layer. A preparation method of an Al2O3-PVA ultrafiltration membrane comprises the following steps: firstly preparing Al2O3 sol, then preparing an Al2O3-PVA casting membrane solution, and finally solidifying to obtain the ultrafiltration membrane. According to the preparation, PVA is modified by use of Al2O3, and cerium ions are doped, so that the crystal form, particle morphology, pore size and distribution, membrane thickness and the like of the membrane can be effectively controlled, and thus the ultrafiltration membrane has an excellent retention rate on impurities in water and excellent acid and alkali resistance property, and has certain bactericidal performance. The water purifier with the ultrafiltration membrane, provided by the invention, is simple and reliable in structure, good in purification effect and beneficial to large-scale popularization.

The invention discloses a method for preparing phase-change microcapsules by a hydrothermal method, comprising: preparation of phase-change material emulsion; dropping bismuth salt solution into the phase-change material emulsion, stirring, and then adding tungstate solution or borax solution Drop into the phase change material emulsion, stir, and in the process of stirring, use ammonia water to adjust and adjust the phase change material emulsion to be neutral, and obtain the phase change material emulsion containing the shell precursor; the phase change material emulsion containing the shell precursor Adding it into a hydrothermal reaction kettle for hydrothermal reaction; cooling the system after the hydrothermal reaction to room temperature, taking out the phase-change microcapsules, washing with deionized water, and drying to obtain the phase-change microcapsules. The invention adopts the hydrothermal method in the preparation of phase change microcapsules, which has the advantages of simple reaction, adjustable temperature and controllable product morphology; meanwhile, organic solid-liquid phase change material is used as the core material, which is an inorganic material with radiation protection function As the shell material, the prepared phase change microcapsules have dual functions of phase change energy storage and radiation protection.

Provided is a method for producing fine particles, comprising: a dissolving step of dissolving at least one kind of fine particle raw materials in a solvent using a stirrer having a rotating stirring blade to obtain a fine particle raw material solution; At least one of the precipitated solvents and the fine particle raw material solution are introduced between at least two processing surfaces that are oppositely arranged, accessible and / or separate, and at least one of them rotates relative to the other. This is a precipitation step in which fine particles are precipitated by mixing in the thin film fluid formed between the treatment surfaces. In the above-mentioned dissolving step, the stirring energy specified by the stirring time conditions using the stirrer, the peripheral speed conditions of the stirring blades, and the temperature conditions of the fine particle raw material solution is increased or decreased by changing at least one of the above conditions. , by increasing or decreasing the stirring energy, the crystallinity and crystal form of the particles obtained in the precipitation step are controlled.

The invention relates to a preparation method of rare earth polishing powder containing fluorine and phosphorus, which is characterized in that it comprises the following steps: precipitation, fluorine-phosphorus compound additive treatment, roasting, crushing and classification. In the present invention, fluorine and phosphorus elements are added at the same time when the polishing powder precursor is synthesized, which can effectively control the crystal form of the polishing powder and make it have certain crystal defects, thereby obtaining better polishing performance, higher grinding ability, and surface accuracy. better.

The invention relates to a preparation method of fine aspirin crystals, belonging to the field of medical and chemical engineering. The preparation method comprises the following steps: (1) putting salicylic acid, acetic anhydride and fine aspirin crystal mother liquor into a dissolving tank to be stirred, and after rising the antipyretic temperature to 80-90 DEG C to dissolve, preserving the temperature for 1-2 hours to obtain hot liquor; (2) adding acetic anhydride, fine aspirin crystal mother liquor or the mixture of acetic anhydride and fine aspirin crystal mother liquor into a crystallizing tank to stir to obtain cold liquor; (3) filtering the hot liquor after preserving temperature to the crystallizing tank, controlling the temperature of the crystallizing tank in the filtering process to gradually rise, after preserving temperature after filtering, and then cooling and carrying out centrifugal separation to obtain solid state fine aspirin crystals. The obtained fine aspirin crystals mother liquor is recycled to the steps (1) and (2). According to the method provided by the invention, the crystal form, the uniformity and the granularity which are fine aspirin crystals are effectively controlled, so that the preparation method is environment-friendly, and the product yield is improved and the production cost is lowered.