Aluminum Oxide[Al2O3] Ceramic | Comprehensive analysis from production to application

        The main raw material of aluminum oxide is bauxite. Bauxite is an aluminum-containing ore, its main components are gibbsite (Al(OH)₃), boehmite (γ-AlO(OH)) and diaspore (α-AlO (OH)) and so on. Bauxite is distributed unevenly around the world, and countries such as Guinea and Australia have abundant bauxite resources. These bauxite ores usually require preliminary processing such as mining and crushing before entering the alumina production process.

Aluminum Oxide（Al2O3） Production method

        The Bayer process is one of the main methods for producing alumina. First, the bauxite is ground into pulp, and sodium hydroxide solution is added to carry out a dissolution reaction under high temperature and high pressure conditions. Aluminum oxide in bauxite reacts with sodium hydroxide to form sodium aluminate solution. The main reaction equation is as shown in the figure

        Then after steps such as dilution and cooling, the sodium aluminate solution decomposes and precipitates aluminum hydroxide. The chemical equation for the decomposition reaction is: 2NaAl(OH)₄ = Al₂O₃·3H₂O+2NaOH. Finally, aluminum hydroxide is calcined to obtain aluminum oxide, and the reaction equation is: 2Al₂O₃·3H₂O = 2Al₂O₃+3H₂O.

Properties of Aluminum Oxide（Al2O3）

Physical properties

        Alumina is a white powder solid, its hardness is second only to diamond, and its melting point is as high as 2054 °C. The density of alumina is 3.9-4.1g / cm3. According to the different crystal structures, alumina has a variety of crystal forms, such as α-alumina, γ-alumina and so on. Among them, α-alumina is the most stable crystal form, with high hardness, high wear resistance and good chemical stability ; γ-alumina has a large specific surface area and good adsorption performance.

Chemical properties

        Alumina has the properties of amphoteric oxides. It can react with acids, for example, the chemical equation of reaction with hydrochloric acid is: Al₂O₃+6HCl = 2AlCl₃+3H₂O; it can also react with bases, such as with sodium hydroxide: Al₂O₃+2NaOH = 2NaAlO₂+H₂O. This amphoteric property enables alumina to play an important role in different chemical environments

Application of Aluminum Oxide（Al2O3）

• Aluminum oxide is the main raw material for electrolytic aluminum production, providing a large amount of aluminum materials for many industries such as aerospace, automobile manufacturing, and construction.

• Alumina ceramics are an important special ceramic. Due to the characteristics of alumina such as high hardness, high wear resistance, high temperature resistance and good chemical stability, alumina ceramics are widely used in equipment anti-wear, bearings, spark plugs, etc.

3. Alumina is an excellent refractory material. α-alumina has a high melting point and good chemical stability, and is widely used in the manufacture of refractory bricks, refractory crucibles, etc.

4. High-purity alumina has important applications in the electronics industry. It can be used as a substrate material for integrated circuits because it has good insulation, high thermal conductivity, and a thermal expansion coefficient similar to silicon wafers.

5. Alumina can be used as a catalyst carrier. Due to its large specific surface area and appropriate pore structure, it can load active metal components and improve the activity and selectivity of the catalyst.

---

FAQ：

What is al2o3 also known as?

        Alumina is an important inorganic compound with the chemical formula of Al2O3. The alias of alumina includes   Alpha-alumina, corundum, alumina powder, aloxide and bauxite.

Is al2o3 covalent or ionic?

        The chemical bond of aluminum oxide is an ionic bond. In aluminum oxide, the electron transfer between aluminum atoms and oxygen atoms forms positive and negative ions, which are combined with each other through ionic bonds to form the structure of aluminum oxide crystals.

What is the correct name for the compound al2o3?

        The accepted name for this is alumina, also known as aluminum oxide.

What are some uses of aluminum oxide?

        Alumina is widely used in metallurgical industry, ceramic wear-resistant industry, refractory industry, electronics industry and chemical industry, etc.

---