Alumina

Alumina products can generally be divided into three major categories based on the mineral phase and the form of aluminum oxide present.

• Alumina hydrates: including bauxite, diaspore, kyanite, monohydrate alumina, and hard bauxite monohydrate, etc.
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• Transition phase alumina: Includes r-Al2O3, η-Al2O3, x-Al2O3, θ-Al2O3, ρ-Al2O3, etc. The first two types of alumina can be sintered at high temperatures and will eventually transform into stable α-Al2O3.
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• Stable Phase Aluminum Oxide: Primarily α-Al2O3.

Additionally, aluminum oxide can be categorized into metallurgical grade aluminum oxide and non-metallurgical grade aluminum oxide based on its application.

1. Fire-resistant materials: Aluminum oxide boasts a high melting point and excellent fire-resistant properties, commonly used as fire-resistant materials, such as refractory bricks, crucibles, and pipes.
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3. Alumina ceramics: Known for its excellent mechanical strength and high-temperature stability, alumina is commonly used as ceramic material, such as ceramic knives, ceramic rolls, ceramic plates, and more.
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5. Electronic Components: Aluminum oxide, with its high dielectric constant and low loss, is commonly used as electronic components, such as capacitors and inductors.
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7. Coating Material: Aluminum oxide boasts excellent wear and corrosion resistance, commonly used as a coating material, such as ceramic coatings and corrosion-resistant coatings.
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9. Catalysts and Catalyst Carriers: Aluminum oxide boasts a large specific surface area and excellent thermal stability, commonly used as a catalyst and catalyst carrier, such as in automotive exhaust purification catalysts and catalyst carriers.
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11. Other Applications: Aluminum oxide can also be used in the manufacture of artificial gemstones, optical instruments,MedicalIn fields such as biology. For example, α-Al2O3 is used in the manufacturing of rubies and sapphires, while γ-Al2O3, due to its porosity and excellent adsorption properties, is widely applied in the catalyst and adsorbent fields.