30results about How to "Granular concentration" patented technology

The invention provides a preparation method of solid catalyst used in olefinic polymerization catalyst, the method synthetizes the solid catalyst of olefinic polymerization continuously by magnesium powder, simplifies the technology of preparing magnesium compounds solid firstly then preparing the solid catalyst of olefinic polymerization, reduces quantity of equipment needed in industrialization, has advantages of simple technics, easy operation, low industrializing installation cost, low production cost, easy controlled product quality. The ball solid catalyst of olefinic polymerization which D(50) is in range of 10-80 mum is produced through the method of the invention, the catalyst has particle sphericity height L/W<1.4 (L expresses the longest axle of the particle, W is the minimum axle of the particle), has advantages of high polymerization activity, hydrogen regulating sensibility, high isotacticity of the polymer, centralized particle-size distribution.

The invention relates to refine crystallization method for xylitol. Wherein, conveying the xylitol solution with mass concentration of 85-92% into crystallizer with original temperature of 65-85Deg; cooling and crystallizing; adding crystal seed to control refine crystallizing nucleation at temperature of 55-70Deg, holding for 15-60min; controlling cooling rate between 1Deg/hr-10Deg/hr during the process; the crystallization temperature is 30-45Deg, and the operation time is less than ten hours; centrifugal separating, cleaning, drying for 1-8h at temperature of 40-80Deg, finally, one obtains the product.

The invention relates to a preparation method of a cefotaxime sodium crystal. The preparation method comprises the following steps of: dissolving sodium acetate in a mixed solvent of organic solvent and water below 10-40 DEG C, wherein the volume fraction of organic solvent in the mixed solvent is 30-70%; adding cefotaxime acid, and stirring until the cefotaxime acid reacts in the solution; adding a cefotaxime sodium crystal in the solution, then adding elution agents with a feeding time of 2-8 hours, cooling to 5 DEG C below zero to 5 DEG C; and filtering, washing and drying a crystal slurry to obtain the cefotaxime sodium crystal. By the preparation method, the phenomenon of gelatinization frequently seen in the crystallization process of the cefotaxime sodium crystal is avoided, the size distribution of the products is centralized and the major particle size is adjustable from 5mu m to 60my m, the liquidity of the product is good, the process yield is higher than 87%, and the product purity is higher than 95.5%.

The invention provides a preparation method of spherical superfine gold powder for electronic materials. The preparation method includes the following steps: a), preparing a fulminic acid gold solution, b), preparing a reductant solution and a dispersant solution, c), preparing the gold powder through a reduction reaction and d), washing and drying the gold powder. The preparation method is simple and reasonable, the spherical superfine gold powder prepared according to the method has the advantages of high dispersibility, centralized granularity, small specific surface area and high tap density, and conductor paste made of the superfine gold powder has excellent electric conductivity and sintering characteristic and compact sintered membrane layers.

The invention relates to an excellent high alloy man made diamond sand manufacturing, using powder catalyst and graphite dust compressed under super high pressure and temperature to synthesize diamond. The synthesized pressure is lowered 2-10% compared to common synthesized pressure, with requirement for temperature matching and regulation at the same time, temporary stopping pressure being 80-92% of the synthesized pressure, with a gap of 0. 10-0. 15MPa and time interval 120-180s and pressure maintaining time being 5-20s. The synthesized man made diamond grains are mainly 170/200, 200/230, 230/270, 270/325, with 325/400 and 400/500 even finer diamonds. It uses the alloy diamond powder catalyst and bar making process. It also designs a set of high temperature super pressure synthesis according to low temperature and low pressure for the special selection of temporary shut pressure. The newly established process realizes the good effect the product.

The invention particularly relates to a method for producing industrial grade superior ammonium sulfate through coked coarse ammonium sulfate. According to the technical scheme, the method comprises the steps that the pH value of a coked coarse ammonium sulfate aqueous solution is adjusted through NaOH, activated carbon is further added, and the aqueous solution is filtered, so that a coked coarse ammonium sulfate crystallization mother solution is obtained; an acidity adjusting agent, a crystal habit modification agent and seed crystals are added to the mother solution and crystals are cultivated; finally, evaporative crystallization is conducted, so that ammonium sulfate crystals are obtained. The method for producing the industrial grade superior ammonium sulfate through the coked coarse ammonium sulfate has the advantages that the quality of a coked coarse ammonium sulfate product is remarkably improved, the particle size distribution of the ammonium sulfate product which is produced with the coked coarse ammonium sulfate serving as a raw material is concentrated, the average particle size is controllable, the surface is smooth, the purity is high, the liquidity is good, and the standard of an industrial grade superior product can be met.

Belonging to the technical field of boron carbide grinding, the invention in particular relates to a production process and production device of ultrafine boron carbide micropowder. The method includes the steps of: (1) crushing; (2) purification; (3) filter pressing; (4) drying; (5) dispersion; (6) grading; and (7) packaging. The production device includes a wet grinding machine, a first slurry pump, a slurry finished product tank, a second slurry pump, a slurry purification reaction tank, a filter press, a drying separation device and a vacuum packer that are communicated in order. Accordingto the invention, the process is simple, the production device is reasonable in design and easy to operate, the product cost is low, the dust production is small, the energy consumption is low, and the obtained boron carbide micropowder has high purity, finer grain size, a particle size of less than 0.5microm, large specific surface area, good fluidity, high stability and high sintering activity.

The invention discloses a high-purity tantalum rotating target material and a preparation method thereof. The preparation method comprises the steps that high-purity spherical tantalum powder is prepared through an induction plasma spheroidizing technology, then the high-purity spherical tantalum powder serves as a spraying raw material, a high-purity tantalum coating is prepared on the surface of a rotating substrate through a low-pressure plasma spraying technology, and the high-purity tantalum rotating target material is prepared. According to the method, the process difficulty is small, the method is not limited by the material and the size of the rotating substrate, the spraying applicability of the tantalum rotating target material is greatly improved, the thickness of the rotating target material can be easily and accurately controlled by adjusting the spraying time, a complex post-heat treatment process is avoided, the yield of the rotating target material is extremely high, and the manufacturing difficulty and the manufacturing cost of the rotating target material are reduced. The prepared high-purity tantalum rotating target material has the characteristics of high purity, low oxygen content, uniform and controllable coating thickness and high density, and is suitable for preparation and application of a high-purity tantalum sputtering film.

The invention relates to a method for preparing anhydrous betaine crystals with ultra-uniform granularity. An over-boiling explosion nucleation-cooling circulation method is adopted. The method comprises the steps: adding anhydrous betaine powder into a crystallizer, adding a solvent into the crystallizer, heating to completely dissolve the powder, and enabling the temperature of the solution to reach the boiling point of a crystallization system; rapidly cooling, and when crystal nucleuses are separated out of the crystallization system, adding a small amount of anhydrous betaine powder intothe crystallizer again to promote explosive separation of the crystal nucleuses from the crystallization system; continuously cooling the solution to room temperature; adding anhydrous betaine powderinto the crystallizer again, heating to dissolve the betaine powder until the temperature of the solution reaches the boiling point temperature of the crystallization system, and then cooling to roomtemperature; repeating the heating and cooling operations repeatedly until the mass of the crystal with 20-60 meshes is not lower than 99% of the total mass of the crystal; and cooling to the final temperature, filtering and washing the crystal, and drying to obtain the anhydrous betaine crystal product with ultra-uniform granularity.

The invention provides electromagnetic shielding silver paste for communication equipment and a preparation method thereof. The electromagnetic shielding silver paste is prepared from, by mass percent, 45%-60% of silver powder A, 5%-15% of silver powder B, 0.1%-2% of metal chelate and 20%-48% of organic carriers; and both the silver powder A and the silver powder B are silver powder which is low in bulk density, very concentrated in particle size and moderate in burning loss. The flake powder with low bulk density is very good in electrical property, the silver powder with very concentrated granularity has the advantages in dispersity, leveling property and uniformity; and the prepared silver paste is stable in performance in the long-time printing process. The metal chelate is a Schiff base titanium hydride metal chelate, so that the quick-drying performance of the low-temperature silver paste can be improved. The electromagnetic shielding silver paste prepared through mutual cooperation of the components not only has excellent printing performance and can meet low-temperature curing, but also has excellent quick-drying performance, and is stable in adhesive force and good in shielding effect in subsequent environmental testing.

The invention discloses a device and method for diamond micro-powder overflowing grading treatment. The device for the diamond micro-powder overflowing grading treatment comprises a cooling-water machine, an ultrapure water machine, a homogenizing tank, a mechanical measuring pump, a counterbalance valve, a one-way valve, a pulse damper, an overflowing cone, a discotic dispenser, a diversion column and a feeding pump. The device for the diamond micro-powder overflowing grading treatment is characterized in that dispersed diamond turbid liquid in the homogenizing tank is transported into the overflowing cone by the feeding pump, pure water produced by the ultrapure water machine is controlled by the cooling-water machine under the constant temperature, and the diamond particles with different particle sizes are flowed out of the overflowing cone by controlling the flow of ultra-pure water entering the overflowing cone through the measuring pump, so that the fine grading of the diamond micro-powder is realized. According to the device for the diamond micro-powder overflowing grading treatment, rapid and accurate grading of the diamond micro-powder with the different particle sizes can be realized, the production cycle is shortened, and the particle size distribution is concentrated.

The invention relates to a grinding fluid for silicon carbide wafer processing and a preparation method thereof, the grinding fluid comprises the following components by mass: 0.5-10 parts of diamond micro powder, 0.5-10 parts of a dispersant, 1-20 parts of a suspending agent and 50-98 parts of water; during preparation, the diamond micro-powder is taken into the dispersing agent and the suspending agent, water is added to form a two-phase mixture, the diamond micro-powder with coarse particles is separated and removed by utilizing the density difference of two-phase media through centrifugal separation, and the diamond micro-powder with more concentrated particle sizes is dispersed into the dispersing agent and the suspending agent, so that the grinding fluid for processing the silicon carbide wafer can be obtained. In the grinding fluid, the particle size of the diamond micro powder is more concentrated, and the number of coarse particles is far smaller than that of the diamond grinding fluid prepared by a traditional method, so that a silicon carbide wafer is effectively prevented from being scratched by large-particle diamonds.

The invention discloses a barite modifying and crushing assembly and a production device, and belongs to the field of barite processing. The assembly comprises a crushing chamber, a rotating disc, an air compressor, a modifying agent hopper and a drive device. The crushing chamber is provided with a crushing cavity. An air inlet and a modifying agent feeding inlet are formed in the bottom end of the side wall of the crushing chamber. The air compressor communicates with the air inlet. The modifying agent hopper comprises a conveying tube connected with the modifying agent feeding inlet and a hopper body connected with the conveying tube. The hopper body is provided with a sealing cover. A first regulating valve is arranged between the hopper body and the conveying tube. A second regulating valve is arranged between the conveying tube and the modifying agent feeding inlet. The rotating disc is arranged at the bottom of the crushing cavity and comprises a disc body and a plurality of propeller blades. The disc body is rotationally connected with the drive device. The propeller blades are uniformly distributed at the top of the disc body. The device comprises a barite screening assembly and the barite modifying and crushing assembly. A discharging outlet communicating with the crushing cavity is formed in the top of the crushing chamber. The barite screening assembly is arranged at the discharging outlet. The crushing efficiency is high, modifying can be performed, the process is saved, the product particle diameter is small, the product purity is high, and equipment loss is small.

The invention discloses an ultra-high molecular weight polyethylene resin and a preparation method thereof, particularly an ultra-high molecular weight polyethylene resin prepared by using an ultrasonic-treated supported titanium catalyst and a preparation method thereof, belonging to the technical field of high polymer materials. The preparation method comprises the following steps: by using an ultra-high molecular weight polyethylene catalyst as a main catalyst and alkyl aluminum as a cocatalyst, adding a polymerization solvent and an outer electron donor to carry out homopolymerization under non-hydrogen conditions by a slurry polymerization technique. The preparation method disclosed by the invention can easily implement industrialization, and has the advantages of favorable adjustability of technological conditions and high reaction kinetic stability of the catalyst. The ultra-high molecular weight polyethylene resin prepared by the method has the advantages of higher viscosity-average molecular weight and adjustable molecular weight, and effectively lowers the content of fine powder in resin granules.