Refractory products with periclase as main mineral component. According to the composition of raw materials, it can be divided into: Magnesia brick made of magnesia brick and Magnesia brick made of magnesia brick and Magnesia brick made of magnesia brick and Magnesia brick made of Magnesia brick and Magnesia brick made of magnesia brick and alumina brick added with a small amount of special grade bauxite or industrial alumina, magnesia-carbon brick added with a certain amount of graphite powder, magnesia-silica brick made from poor quality high Silica Magnesia. Compared with other refractory bricks, magnesia bricks have higher refractoriness, which can reach over 2000 °C, higher load softening temperature and higher high temperature mechanical strength, it also has good resistance to chemical attack of basic slag containing iron oxide and calcium oxide. But generally the thermal stability is poor. The content of magnesium oxide in the products is about 85% . The al2o3 content is 5% ~ 10% , the basic Refractory with periclase as the main crystal phase and magnesia-alumina spinel as the secondary crystal phase (as the main binding phase) . The apparent porosity is generally 15 ~ 18% . The Coefficient of thermal expansion is 10.6 × 10-6 °C. The thermal shock resistance of magnesia-alumina brick is better than that of Magnesia brick. Because the spinel with higher melting point is distributed in the Matrix, its high temperature strength is higher, and the load softening temperature is above 1580 °C. Slag resistance is also good. In general, high-quality sintered Magnesia is used as granular material, and the fine powder composed of Magnesia mixed with raw bauxite or lightly burned bauxite clinker or industrial alumina is mixed, shaped and fired.