Magnesite is one of the raw materials for refractories. Also known as magnesia refractory material, it refers to the material with MgO as the main component and periclase as the main crystal phase. Magnesia can be divided into sintered magnesia Fused magnesia Two major categories, today's edition of Yuzhengyang casting materials will briefly summarize sintered magnesia and fused magnesia in the following.

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.

Magnesia produced by smelting magnesite in an electric furnace at 2750 ℃ is called fused magnesia. Generally, it has very strong high temperature resistance, is not easy to be melted by alkaline substances, is not easy to be eroded by molten metals at high temperatures, and has excellent thermal conductivity at room temperature. The high refractory carbon magnesia brick (composed of graphite and fused magnesia) made from it as raw material is widely used in converter steelmaking and secondary refining. The smelting cycle is shorter, the furnace life is longer, and the quality of steel is improved. Compared with ceramics made from alumina, ceramics made from alumina have better high-temperature performance. In general, compared with sintered magnesia, fused magnesia has the advantages of larger grains and higher density, and can be used as high-quality raw materials for making magnesium refractory.