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    The Main Application of Aluminum Oxide Powder
    Hits:   Date:2020-06-03  
    Corundum powder with high hardness can be used as abrasive, polishing powder, high-temperature sintered alumina, called artificial corundum or artificial gemstone, and can be used to make diamonds in mechanical bearings or watches. Alumina is also used as a high-temperature refractory material for making refractory bricks, crucibles, porcelain, artificial gems, etc. Alumina is also a raw material for aluminum smelting.
    Calcined aluminum hydroxide can produce γ-. γ-Al₂O₃ has strong adsorption and catalytic activity, and can be used as adsorbent and catalyst. The main component of corundum is α-Al₂O₃. Barrel or cone-shaped trigonal crystals. There is glass luster or diamond luster. The density is 3.9~4.1g/cm3, the hardness is 9, the melting point is 2000±15℃. It is insoluble in water, acid and alkali. High temperature resistance.
    Colorless and transparent ones are called white jade, red with trace trivalent chromium is called ruby; blue with ferric iron, trivalent iron or tetravalent titanium is called sapphire; dark gray and dark black with a small amount of ferric oxide Called corundum powder. Can be used as bearings for precision instruments, diamonds, grinding wheels, polishing agents, refractory materials and electrical insulators for watches and clocks. Colorful can be used as decorative gems. The material of artificial ruby ​​single crystal can make laser. In addition to natural minerals, aluminum hydroxide can be produced by melting oxyhydrogen flame.
    Aluminum oxide powder has the chemical formula Al₂O₃ with a molecular weight of 101.96. The main component of bauxite. White powder. With different crystal forms, the common ones are α-Al₂O₃ and γ-Al₂O₃. Corundum in nature is α-Al₂O₃, hexagonal close-packed crystals, the melting point of α-Al₂O₃ is 2015±15℃, density is 3.965g/cm3, hardness is 8.8, and it is insoluble in water, acid or alkali. γ-Al₂O₃ is a cubic close-packed crystal, insoluble in water, but soluble in acid and alkali.
    The main components of ruby ​​and sapphire are aluminum oxide, which shows different colors due to other impurities. Sapphire contains iron oxide and titanium oxide and appears blue.
    1. Among the main components of bauxite, aluminum oxide, the content of alumina is the highest. Industrially, bauxite is purified into alumina by the Bayer process, and then transformed into aluminum metal by the Hall-Heroult process.
    2. Aluminum reacts with oxygen in the air to form a dense aluminum oxide film covering the aluminum surface exposed to the air.
    3. Aluminum is a good conductor of electricity and heat. Because of its high hardness, the crystal form of alumina is suitable for abrasive materials and cutting tools.
    4. Alumina powder is often used as a medium for chromatographic analysis.
    5. In August 2004, scientists working at 3M in the United States developed an alloy made of aluminum and rare earth elements to make a strengthened glass called transparent alumina.