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Why does Alumina have to be calcined
- Sep 05, 2017 -

As we all know, Alumina includes 8 kinds of homogeneous special-shaped crystal, such as α, β, γ, rho, θ, kappa, ETA, and so on, its most widely used in industrial production is α, beta, γ, and Rho alumina. In the lattice of α-type alumina, the oxygen ions are tightly stacked in six square, and the al3+ is symmetrically distributed in the center of the eight-body ligand surrounded by oxygen ions, the crystal lattice can be very large, so the melting point and boiling point are very high. α-type alumina is insoluble in water and acid, and is the most stable phase of alumina. For the production of various ceramics, refractories, but also for grinding agents, fillers, etc., high-purity α-type alumina or production of man-made corundum, artificial ruby and sapphire raw materials. To form a alumina, it must undergo more than 1000 degrees of calcination, so that low-temperature alumina can be converted to α-crystalline alumina, that is, calcined alumina.