The main chemical component is MgO, the mineral component is periclase equiaxed crystal system, the density is 3.56～3.65g/cm, the Mohs hardness is 5.5, the melting point is 2800℃, and it volatilizes significantly at 1800～2400℃. Pure periclase is colorless. With the increase of Fe2O3 and CaO content, the color changes from light to dark, showing yellow, brown and dark brown. The periclase grain size increases with the increase of the calcination temperature and the extension of the holding time, and its hydration resistance and slag erosion resistance are also correspondingly enhanced. Light burnt magnesia powder

Impurities in magnesia come from dolomite, talc, tremolite, quartz, etc. in magnesite, so that magnesia contains SiO2, Al2O3, Fe2O3, CaO and other impurities (there is also B2O3 in seawater magnesia). These impurities reduce the high temperature strength of magnesia. If Fe2O3 is 1 and compared with Cr2O3, Al2O3, B2O3, the degree of influence is 1:3:11:70. In addition to periclase, the mineral phase in magnesia can form a variety of silicate minerals according to the ratio of CaO/SiO2.