The magnesium oxide obtained 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.