Alumina is aluminum oxide, commonly known as bauxite, or corundum, it is a white powder, insoluble in water. Alumina has a wide range of application fields and has very obvious characteristics. Now, alumina has been deeply used in all aspects of life.
Characteristics of alumina
The hard coating of alumina has the characteristics of a high melting point, high hardness, excellent thermal and chemical inertness, and so on. The specific performance is:
1. Good thermal stability, that is, when used at high temperatures, it can still maintain the same performance.
2. Stable chemical properties, resistant to organic solvents, chlorides, and strong acid, and strong alkali solutions, and not easily degraded by microorganisms.
3. It has high strength and can operate under a large pressure gradient without being compressed and crept, so its mechanical properties are good.
4. Compared with the polymer film, there will be no aging phenomenon. As long as it is not damaged, it can be used for a long time.
The main use of alumina
1. Used as a catalyst and catalyst carrier, it is the main catalyst and carrier in the petroleum refining and petrochemical industry. It is also used as a dehumidifying agent for air and other gases, and a deacidifying agent for transformer oil and turbine oil.
2. Industrial high-temperature furnaces such as heating furnaces and soaking furnaces for forging. It can be used as sealing material and filling material. It can also be used as reinforcing fiber for reinforcement, the lining of a kiln, calciner of electronic components (IC board, ferrite), etc.
3. Alumina fiber is mainly used in high temperature insulation materials and reinforced composite materials. Alumina short fiber has outstanding high temperature resistance, and can be compounded with resin, metal or ceramics to prepare high-performance composite materials, and to manufacture industrial high-temperature furnaces such as heating furnaces, kiln linings, and electronic component calciners. Due to its small density, good heat insulation and small heat capacity, it can not only reduce the mass of the furnace body, but also improve the temperature control accuracy, and the energy saving effect is remarkable. The energy-saving effect of alumina fiber in high-temperature furnaces is better than that of general refractory bricks or high-temperature coatings. When it is used to strengthen metal, it has no chemical effect with metal and has good corrosion resistance, so alumina fiber is a reinforcing fiber for metal. It can also be used to weave fiber products of various shapes such as non-woven fabrics, braided belts, and ropes.
4. Used in the manufacture of industrial high-temperature furnaces such as heating furnaces and soaking furnaces. Used as sealing material, filling material, reinforcing fiber for FRM, kiln lining, and calciner for electronic components (IC substrate, ferrite), etc.
5. Used in chemical fiber filler, also used in abrasives of cosmetic facial creams, toothpaste abrasives, metallurgy, and chemicals.
6. Used in the preparation of analytical reagents, dehydration adsorbents for organic solvents, abrasives, and low-melting lead glass.
7. Alumina is the most commonly used filling material in chromatography, which is acidic, alkaline and neutral. It is a reagent that can catalyze dehydration, elimination, addition, condensation, epoxide ring opening, oxidation and reduction reactions. For homogeneous reactions, the reaction conditions are usually milder and more selective.
8. Addition and condensation reactions Whether it is an electrophilic reaction or a nucleophilic reaction, alumina can promote the addition reaction of various heteroatoms. Alumina can also cause intramolecular addition of hydroxyl and alkoxy groups to generate the corresponding alkenes. Under the action of alumina, the aldol condensation reaction, Michael reaction and Wittig reaction between aldehydes and methylene compounds of different activities are often carried out under solvent-free and mild conditions.
9. Alumina is beneficial to reactions controlled by orbital symmetry such as the Diels-Alder reaction, olefin reaction, and Carroll rearrangement. These reactions are mild and highly stereoselective.
10. Alumina can catalyze many rearrangement reactions. Activated alumina causes the Beckmann rearrangement of O-sulfonyl oxime to generate the expected amide, while basic alumina generates the corresponding oxazoline. Under the action of alumina, β, γ-unsaturated ketones can be isomerized into conjugated ketones, alkynes into olefins, and olefins into conjugated di-enols. Alumina facilitates the hydrolysis of primary alcohol acetates, deacylation of imides, hydrolysis of sulfonyl oximes, and dealkoxycarbonylation of β-ketoesters and carbamates.
In the end
Alumina is widely used in the industrial field. In addition to the above applications, alumina can also be used to strengthen metals. It has a good fusion with metals and does not chemically react with metals. It is an ideal metal reinforcement fiber. Jinbangch has many years of experience in producing alumina and can provide you with high-quality alumina. Welcome to contact us for consultation.