Sintered magnesia is a sintered block obtained by calcining natural magnesite MgCo3 at high temperature, which is crushed and screened. Or magnesium oxide raw material obtained by fully sintering magnesium hydroxide prepared from seawater or brine at 1450-1900 ℃. Generally speaking, sintered magnesia refers to the product obtained by calcining magnesite as raw material. Because of the high sintering temperature and good sintering degree of magnesia, sintered magnesia is also called dead burned magnesia to distinguish it from light burned magnesia. It is the raw material for producing ordinary magnesia bricks and amorphous refractories.

Fused magnesia It is a magnesia raw material made of natural magnesite, light burned magnesia powder or sintered magnesia by melting at 2750 ℃ in an electric arc furnace. Its strength, corrosion resistance and chemical inertia are better than those of sintered magnesia. Periclase has large grain size, compact structure, good slag resistance and high temperature volume stability. It is replacing sintered magnesia more and more in magnesia and magnesia carbon refractories. It is a good raw material for high-grade alkaline bricks, carbon containing products and amorphous refractories.