32results about How to "Lower the nucleation barrier" patented technology

The invention provides a gas-phase magnesium purification method based on a pure iron filter material. The method uses a pure iron filter material to filter magnesium vapor. On the one hand, pure iron will not react with magnesium vapor and will not bring new impurities to the system; on the other hand, the impurities Al and Mn in magnesium vapor have special affinity with iron and can form a stable solid solution with iron ; At the same time, pure iron can be used as the nucleation site of some impurities in the magnesium vapor, lowering the nucleation energy barrier, allowing some impurities to deposit in advance, and removing impurities. The method provided by the invention can be applied to industrial large-scale gas-phase magnesium purification, and the production efficiency of magnesium purification can be increased by an order of magnitude by increasing the temperature, so that the content of impurity Mn in the magnesium raw material is reduced to below 10 ppm, and the content of Al is reduced to below 10 ppm. The Ca content is reduced to below 20ppm, and at the same time, non-metallic impurity elements such as F, Cl, and S can be removed to obtain magnesium with a purity of more than 99.99%.

The invention provides a gas-phase magnesium purification method based on an elemental silicon filter material. The method uses an elemental silicon filter material to filter magnesium vapor. Within a certain range of temperature and vacuum, elemental silicon does not react with magnesium vapor on the one hand, and will not bring new impurities to the system; on the other hand, Ca, Al, and Mn in elemental silicon and magnesium vapor have special properties. Affinity can form a more stable solid solution with silicon; at the same time, elemental silicon can be used as the nucleation site of impurities in magnesium vapor, lowering the nucleation energy barrier, allowing some impurities to deposit in advance, and removing impurities. The method provided by the invention can be applied to large-scale industrialized gas-phase magnesium purification, and the production efficiency of magnesium purification can be increased by an order of magnitude by increasing the temperature, so that the Mn content of impurities in the magnesium raw material can be reduced to below 4ppm, and the Al content can be reduced to below 10ppm. The Ca content drops below 10ppm, and the purity of the obtained magnesium is above 99.99%.

The invention relates to a feedback control method for crystal product granularity in the dilution crystallization process. The method includes the specific steps: estimating the sum of crystal granules according to expected average grain diameter of crystal products, comparing the sum of crystal granules N in crystallization mother liquor measured through an on-line granularity measurement apparatus in real time with the sum of crystal granules Ns specified in production, and synchronously controlling feeding rate of a crystal breaking system, dilution agent and solvent till the crystal products with expected granularity distribution are produced. Compared with the conventional granularity control method in the dilution crystallization process, the method has the advantages that the crystal products with expected granularity distribution can be produced automatically and conveniently as required by only regulating one parameter of the specified sum of crystal granules Ns without re-optimizing new process parameters and the grinding and screening process through plenty of experimental operation, and a granularity controllable regulation function of producing the crystal products with specified granularity distribution as required is realized.

The invention discloses a pre-prepared alloy powder type flux-cored wire and a self-protection open arc surfacing welding method of a high-chromium alloy. The adopted technical scheme lies in that a cold rolled thin steel strip manufactured through low-carbon steel H08A as an outer coating, high carbon ferro-chrome, ferrosilicon, graphite and other metal powder are blended inside the coating to form a powder core of the flux-cored wire, and high carbon ferro-chrome, ferroboron, ferrosilicon and reduced iron powder are blended to form pre-prepared alloy powder; and before welding, the alloy powder is placed on a welding bead in advance, the surfacing welding current control value is set, a regulating melt mode combined with the mass of the pre-prepared alloy powder type flux-cored wire is set, a nonhomogeneous melt containing liquid high carbon ferro-chrome atom clusters formed through melting high carbon ferro-chrome particles is formed, and the concretionary high-chromium alloy which adopts the liquid high carbon ferro-chrome atom clusters as component donors, nucleates and grows into primary M7C3 abrasion-resistance phases is formed. According to the method, the problems that the source of components of surfacing welding alloys is single and the chromium content of the surfacing welding alloys is not liable to increase are solved, and the method is widely applied to surfacing welding manufacturing and repairing of parts with the requirement of abrasive wear resistance.

The invention discloses a preparation method and application of a modified metal lithium negative electrode current collector. The method comprises the following steps: step 1, adding a halogen salt into a solvent, stirring and mixing evenly to obtain a halogen salt solution; step 2, The current collector to be modified is placed in the brine salt solution prepared in step 1 for soaking modification treatment. The present invention improves the lithium affinity of the surface of the metal lithium negative electrode current collector through a simple current collector surface modification treatment method, avoids dendrite growth, and thereby realizes the practical application of the lithium metal battery. The preparation method is simple to operate, low in energy consumption, and can be operated on a large scale, and can modify the current collector with the array / coating layer grown on the surface. The lithium metal battery with good cycle stability and safety performance can be prepared by using the modified metal lithium negative electrode collector of the present invention, and the practical process of high specific energy lithium metal battery is promoted.

The invention relates to the technical field of building materials, in particular to a calcium silicate hydrate early strength agent and a preparation method thereof. The preparation method of calcium silicate hydrate early strength agent comprises the following preparation steps: 1) preparation of calcium liquid; 2) preparation of silicon liquid with silicate as silicon source; 3) synthesis of calcium silicate hydrate: polyoxo The dispersant solution compounded with ethylene (5) nonylphenyl ether and cyclohexane was placed in a shear stirring mixing device, kept stirring at room temperature, and added the prepared calcium liquid and silicon liquid, and then used alkaline The solution adjusts the pH value of the mixed solution, maintains constant temperature and stirs, and obtains white calcium silicate hydrate gel; washes the obtained white calcium silicate hydrate gel by centrifugation, and then dries in a vacuum drying oven to obtain hydrated silicic acid Calcium early strength agent. After the calcium silicate hydrate accelerator prepared by the above preparation method is mixed into cement, it can promote the hydration of cement, significantly shorten the setting time of cement, and improve its early strength at the same time, which has important practical application value in the field of construction.

The invention discloses a preparation method for a polybutylene succinate / graphene-molybdenum-disulfide-like nanocomposite material. The preparation method comprises the following steps: adding molybdenum disulfide powder to mixed liquid of butanediol and water, and centrifugally separating after the room temperature liquid phase ultrasonic treatment; adding a succinic acid to upper deep green liquid obtained by the centrifugal separation, strongly and mechanically stirring until no water is generated in 150-225 DEG C of the temperature under the nitrogen protection, to obtain a terminal hydroxyl prepolymer containing the graphene-molybdenum-disulfide-like; rapidly adding a catalyst to the terminal hydroxyl prepolymer under the stirring condition, and warming to 210-250 DEG C, and vacuumizing to 50-250 Pa, continuously stirring until the obvious pole-climbing occurs, and ending the reaction, to obtain the polybutylene succinate / graphene-molybdenum-disulfide-like nanocomposite material.The composite material is capable of improving the crystallization temperature of the polybutylene succinate, shortening the crystallization time, and refining the crystal grains of the polybutylenesuccinate.

The invention discloses a preparation method, product and application of a composite material. The method impregnates a precursor solution into polymer particles, realizes the in-situ loading of MOFs in one-time molding, and adjusts the concentration and addition of metal salts and organic ligands. The structure of porous composites can be designed by means of regulators, and the crystal size of MOFs can be controlled. The composite material prepared by this method can take advantage of the spatial structure of the polyacrylamide material with interconnected hierarchical pore structure, combined with the active amino groups on the pore wall, to realize the uniform spreading of the nano-MOFs layer, and greatly improve the transmission of the material in the water vapor trapping. The mass rate and adsorption efficiency can be applied to water vapor capture in different humidity environments. The method has the advantages of simple preparation method, easy molding and high mechanical strength, and is suitable for industrial production.

The invention provides an application of a pure iron filter material in gas-phase magnesium purification. In the process of gas-phase magnesium purification, magnesium vapor passes through the pure iron filter material, and impurities Al and Mn in the magnesium vapor form stable ions with iron in advance before the magnesium condenses. solid solution, so as to remove the magnesium vapor; in addition, the pure iron filter material can be used as the nucleation site of some impurities, reduce the nucleation energy barrier of some impurities, thereby providing attachment sites for these impurities, so that the impurities are condensed and enriched in advance , out of the magnesium vapor system; and the pure iron filter material can also remove part of the impurities through physical adsorption; the pure iron filter material of the present invention can effectively remove the impurities in the magnesium vapor through various effects, greatly improving the magnesium content. Purity, the purity of the obtained magnesium is above 99.99%. The gas-phase magnesium purification production system comprising pure iron filter material provided by the present invention has a simple structure, is convenient to set up, is suitable for large-scale industrial production, can effectively improve the efficiency of magnesium purification, and reduce the cost of magnesium purification.

The invention provides the application of elemental silicon filter material in gas-phase magnesium purification. In the gas-phase magnesium purification process, magnesium vapor passes through the elemental silicon filter material. In a certain range of temperature and vacuum degree, elemental silicon will not interact with magnesium vapor on the one hand. The reaction will not form a more stable substance with magnesium in thermodynamics, and will not bring new impurities to the system; on the other hand, the impurities Mn, Al, and Ca in silicon and magnesium vapor have special affinity and can form more Stable solid solution, so as to achieve removal; at the same time, elemental silicon can be used as the nucleation site of certain impurities in magnesium vapor, lowering the nucleation energy barrier, allowing certain impurities to deposit in advance, thereby achieving removal. The invention can effectively remove impurities in the magnesium vapor through the function of the elemental silicon filter material, greatly improve the purity of the magnesium, and the purity of the obtained magnesium is above 99.99%. The production system provided by the invention is suitable for large-scale industrial production, can effectively improve the efficiency of magnesium purification, and reduce the cost of magnesium purification.

The invention relates to the manufacturing method of a metal nanostructure array based on interface induction growth. The method comprises the following steps of 1, cleaning a substrate; 2, transferring a template, and transferring an ultrathin porous alumina template to the cleaned substrate; adjusting an adhesive force, standing a sample acquired from the step2 for several hours so that an adhesive force portion between the template and the substrate is relaxed, or through low temperature annealing, strengthening the adhesive force between the template and the substrate; 4, depositing metal,and depositing the metal on the surface of the sample obtained from the step3 by using a physical vapor deposition method; and 5, peeling the template, after the deposition is completed, using an adhesive tape to peel the template so that an ordered metal nanostructure array is left on the surface of the substrate, wherein under an adhesive force relaxation condition, an ordered nano-pore array is acquired, and under an adhesive force strengthening condition, an ordered nano-ring array is acquired. The technology of the method is simple, cost is low, and the method can be expanded to a waferscale.