Silicon modified alumina nano disperser

Activated alumina is a porous material with high specific surface area, large pore volume, and special surface properties, which is widely used in catalysis, adsorption, and other fields. However, when activated alumina is applied in certain high-temperature environments, especially high-temperature water vapor environments, sintering and phase transformation occur, resulting in a significant reduction in its specific surface area and pore volume. Its high-temperature stability and hydrothermal stability often cannot meet the requirements. Improving the thermal stability of alumina materials is of great significance. At present, the main method to improve the thermal stability of alumina is to introduce other elements for doping and modifying alumina.

The conventional preparation method for modifying alumina using existing technology is the impregnation method, which usually uses an organic solvent solution of silicone grease to impregnate the alumina solid. But this often leads to uneven impregnation and uneven composition of the modified alumina obtained; Or the method of adding silicon, precipitant or gelling agent to alumina slurry (suspension of alumina and water) to form precipitation or sol gel,However, due to the tendency of aluminum oxide to agglomerate in water, the uniformity of the mixture cannot be guaranteed, resulting in uneven distribution of aluminum oxide and silicon obtained.

A silicon modified alumina and its preparation method and application, wherein the modification of alumina with silica sol comprises: (1) acidifying and dissolving the pseudo boehmite slurry with inorganic acid to obtain a pseudo boehmite sol; (2) Add silica sol to the pseudo boehmite sol to obtain a * * mixture; (3) According to different requirements for the improvement of surface B acid content and pore volume of alumina, adjust the pH value of the * * mixture within the range of pH=111, and then react for a period of time under heating conditions to obtain a second mixture; (4) Crystallize the second mixture to obtain a third mixture; (5) The third mixture is filtered, washed, dried, and calcined to obtain silicon modified alumina. By adjusting the pH value of the mixture, a flexible transition can be achieved between focusing on improving pore volume and focusing on improving B acid content.

The following steps are as follows: add surfactants, gamma alumina powder, and silicon containing organic compounds in water in sequence,Wet crushingForm a dispersion, dry, and roast; Among them, the weight ratio of the silicon containing organic compound to the gamma alumina powder, calculated as silicon dioxide, is 1:10-50. The method provided by the present invention is simple and easy to implement, which can uniformly modify silicon and obtain silicon modified alumina with uniform composition. The obtained silicon modified alumina has a large pore volume and specific surface area, especially with good thermal stability, and can still maintain a high specific surface area and pore volume after high-temperature calcination. The silicon modified alumina prepared by this method has good application prospects under high temperature, especially high temperature and high humidity conditions.

The three-stage high shear dispersion machine is mainly used for the production of micro lotion and ultra-fine suspension lotion. Since three groups of dispersion heads (stator+rotor) in the working chamber work at the same time, after high shearing, the lotion drops are more delicate and the particle size distribution is narrower, so the stability of the generated mixed liquid is better. The three sets of dispersing heads are easy to replace and suitable for different process applications. The different models of machines in this series have the same line speed and shear rate, making it very easy to scale up production. It also meets the CIP/SIP cleaning standards and is suitable for food and pharmaceutical production.

High rotational speed and shear rate are important for obtaining ultrafine suspension lotion. According to some industry specific requirements, its shear rate can exceed 15000rpm, and the rotor speed can reach 44m/s. Within this speed range, turbulence caused by shear forces combined with specially developed motors can reduce the particle size range to the nanometer level. The shear force is stronger, and the particle size distribution of lotion is narrower.

The following is a model table for reference:

Silicon modified alumina nano disperser