Application of laser particle size analyzer in alumina (1)

As we all know, alumina is a compound with high hardness and is widely used in the manufacture of refractory materials, analytical reagents, adsorbents, catalysts, etc. Insoluble in water, easily soluble in strong acids and alkalis. The main component of rubies and sapphires is aluminum oxide, and they show different colors due to other impurities. In bauxite, the main component of aluminum ore, the content of aluminum oxide is high. Aluminum oxide is the reason why metallic aluminum is not easily corroded in the air. Pure metallic aluminum reacts easily with oxygen in the air to form a dense aluminum oxide film covering the aluminum surface exposed to the air. This aluminum oxide film prevents the aluminum from further oxidation. The thickness and properties of this oxide film can be enhanced through a process called anodizing (anodic corrosion protection). Aluminum is a good conductor of electricity and heat. The crystal form of aluminum oxide is suitable for use as abrasives and cutting tools due to its high hardness. Aluminum oxide powder is commonly used as a medium for chromatographic analysis.

Corundum powder has high hardness and can be used as abrasives, polishing powder, high-temperature sintered alumina, called artificial corundum or artificial gemstones, and can be used to make diamonds in mechanical bearings or watches. Alumina is also used as high-temperature refractory material to make refractory bricks, crucibles, porcelain, artificial gemstones, etc. Alumina is also a raw material for aluminum smelting. Calcining aluminum hydroxide can produce γ-Al2O3. γ-Al2O3 has strong adsorption force and catalytic activity, and can be used as an adsorbent and catalyst. The main component of corundum is α-Al2O3. Barrel- or cone-shaped trigonal crystal. It has glass luster or diamond luster. The density is 3.9~4.1g/cm3, the hardness is 9, and the melting point is 2000±15℃. Insoluble in water, acids and alkalis. High temperature resistance. Colorless and transparent ones are called white jade; red ones containing a trace amount of trivalent chromium are called rubies; blue ones containing ferrous iron, trivalent iron or tetravalent titanium are called sapphires; those containing a small amount of ferric oxide are dark gray or dark black. Called corundum powder. It can be used as bearings for precision instruments, diamonds, grinding wheels, polishing compounds, refractory materials and electrical insulators for watches. In addition to natural minerals, it can be produced by melting aluminum hydroxide with a hydrogen-oxygen flame. As can be seen from the above, the uses of modified alumina involve various aspects.