51results about How to "Regular crystal form" patented technology

The present invention relates to is preparation process of nanometer spinel type ferrite powder. The spinel type ferrite has the general expression of MxM'yM' (1-x-y) Fe2O4, where, M,M' and M' are bivalent Mn,Zn,Co or Ni ion; x is 0-1, y is 0-1, and x+y is not greater than 1. The preparation process of the nanometer spinel type ferrite powder includes the following steps: weighing soluble salts of M,M', M' and Fe in certain weight proportion and adding them into deionized water solution of acrylic acid; adding deionized water solution of peroxide initiator; heating at 60-100 for complete polymerization; and drying, cooling, grinding and calcining in a muffle furnace. Compared with available technology, the nanometer spinel type ferrite powder of the present invention has the advantages of high dispersivity, homogeneous size within 8-50 nm, etc.

The invention discloses a preparation method of spherical aluminum hypophosphite. In the method disclosed by the invention, sodium hypophosphite reacts with aluminum sulfate; meanwhile, melamine cyanurate is added as a seed crystal in the earlier stage of reaction, and different dispersants are added to improve the dispersion effect. The spherical aluminum hypophosphite prepared by the method disclosed by the invention has the characteristics of small particle size, regular crystal form and the like, thus the drop of mechanical properties of plastics after the addition of a flame retardant is reduced. Meanwhile, by adopting the melamine cyanurate seed crystal as a synergist in the flame retardant, the flame retardance effect of aluminum hypophosphite after plastic addition is remarkably improved.

The invention relates to a method for synthesizing small-crystal-grain aluminum phosphate molecular sieves AlPO4-34. According to the method, pseudo-boehmite or aluminum isopropoxide is used as an aluminum source, phosphoric acid serves as a phosphorus source, tetraethylammonium hydroxide and morpholine serve as template agents, and hydrofluoric acid serves as a fluorine source. The small-crystal-grain aluminum phosphate molecular sieves AlPO4-34, which are high in crystallinity and regular in crystal form, are synthesized by a pre-crystallization and seed crystal adding method on the basis of using the conventional raw materials and the mixed template agent. The grain size is small, and the average grain size is smaller than 1.5 microns and is only 0.05 to 1 micron after conditions are optimized. According to the method, the crystallinity is high, the morphology is regular, and the grain size distribution is uniform.

The invention discloses a preparation method of nano-crystal boehmite, which comprises the following steps: (1) hydrolysis reaction: mixing distilled water and aluminum isopropoxide in a molar ratio of 50-150:1, heating to 70-90 ℃, react for 1~2h, filter the reaction product, and dry in an oven at 80-90℃ for 8-12h; (2) hydrothermal reaction, put the dried product in step (1) into a high-pressure reactor, and use distilled water as the reaction medium , the filling degree of the reactor is 60%-80%, the reaction temperature is 150-200°C, the reaction time is 4-12h, and the nano-crystal boehmite is obtained. The nano crystal boehmite product prepared by the invention has high crystallinity, regular crystal form, uniform particle size, simple dispersion condition and good dispersibility. And it has good water dispersibility, its dispersion condition is simple, the particle size distribution is uniform, and there is no obvious agglomeration phenomenon.

The invention belongs to the technical field of separation and purification of artemisinin, and concretely relates to an artemisinin separation and purification technology. The separation and purification technology comprises the following steps: S1, Sweet Wormwood Herb extract is concentrated, and undergoes press filtration to obtain first crude artemisinin crystals and a first mother liquor, thefirst mother liquor is concentrated under a reduced pressure to obtain a first artemisinin extract; S2, the first artemisinin extract is added to an alcohol-water solution, stirring is performed fordissolving and dispersing, and then separation is carried out to obtain a first alcohol-water extract and a second artemisinin extract; S3, the second artemisinin extract undergoes processes in step S2 to obtain a second alcohol-water extract and a third artemisinin extract; S4, the first alcohol-water extract and the second alcohol-water extract are mixed, and the obtained mixture is cooled and crystallized, and then undergo press filtration to obtain second crude artemisinin crystals and a second mother liquor; and S5, the first crude artemisinin crystals and the second crude artemisinin crystals are mixed, and are dissolved in an alcohol solvent, the obtained solution is filtered, and the obtained filtrate is heated, and then undergoes reduced pressure concentration, cooling, press filtration and drying to obtain refined artemisinin. The product obtained by the separation and purification technology has the advantages of high recovery rate, high purity and high crystal form quality.

The invention discloses a method for continuous crystallization of vitamin C. It includes the following steps: pump the ion-exchanged vitamin C aqueous solution into the first-stage crystallizer for vacuum evaporation and crystallization, and then continuously introduce the vitamin C evaporation concentrate produced in the first-stage crystallizer into the second-stage crystallizer for vacuum cooling Crystallization, after liquid-solid separation, crystal washing, centrifugation, and continuous discharge to obtain crude vitamin C crystals; after the crude vitamin C is dissolved in purified water, it is filtered and pumped into the third-stage crystallizer to realize continuous crystallization of high-quality vitamin C. After liquid-solid separation, crystal washing, centrifugation, and continuous discharge to obtain high-quality vitamin C crystals. The method adopted in the invention can realize the continuous crystallization of vitamin C and obtain coarse, uniform and neat crystal grains, which can not only improve product quality, but also reduce production cost.

A ZSM-5 molecular sieve, a preparing method thereof and applications of the molecular sieve are provided. The ZSM-5 molecular sieve is prepared through an amine-free system. A silica-alumina ratio of the ZSM-5 molecular sieve is 40-200. The ZSM-5 molecular sieve is prepared by adopting a nanometer thin-layer ZSM-5 molecular sieve having a high silica-alumina ratio as a crystal seed with the mole ratio of raw materials meeting a condition that the mole ratio of SiO2 to Al2O3 is 100:(0.04-2). Compared with molecular sieves synthesized under traditional template-free conditions, the ZSM-5 molecular sieve synthesized by the method is a molecular sieve having a high silica-alumina ratio (higher than 40). The silica-alumina ratio of the prepared flake ZSM-5 molecular sieve is adjustable in a large range (40-200).