How impurities weaken white fused alumina quality

In the smelting of white fused alumina, industrial alumina powder is used as raw material.  There always are some impurities in the crystallization process of white corundum during the smelting process. These impurities mainly include SiO2 (silicon dioxide), Na2O (sodium oxide), CaO (calcium oxide), Fe2O3 (iron oxide), and so on. They will directly affect the white-fused alumina quality.

When adopting white fused alumina for abrasive tools and refractory applications, the effect of SiO2 content on the properties of white fused alumina is mainly reflected in the toughness. For oilstone, vitrified bonded grinding wheels, high SiO2 may cause cracks and other defects. The content of Na2O content will affect the conversion rate of white corundum crystals to α-Al2O3 during the melting process. Therefore, the hardness and grinding performance of white fused alumina cannot get expectation.

White fused alumina with low impurities and high purity has the advantages of high hardness, high melting point, superior thermal properties (high temperature bending strength, compressive strength), and strong grinding power. High-quality white fused alumina with fewer impurities is more suitable for producing high-quality abrasive tools, refractory materials, abrasive materials, etc.