Magnesia brick is a refractory brick with magnesite as raw material, peridotite as the main crystal phase, and MgO content between 80% and 85%. Its products are divided into metallurgical magnesia and magnesite products. According to different chemical compositions and application conditions, there are martin sand, ordinary metallurgical magnesia, ordinary magnesia brick, magnesia silica brick, magnesia alumina brick, magnesia calcium brick, magnesia carbon brick and other varieties. Magnesia refractory bricks are important products of basic refractory bricks. It has high fire resistance, good resistance to alkaline slag and iron slag. It is an important high-grade refractory brick. Mainly used in open-air furnace, oxygen converter, electric furnace, non-ferrous metal smelting and other industries.