Magnesium oxide (MgO) is commonly known as magnesia, magnesia and oxymagnesia. Density 2.94, light yellow or white powder. The melting point is 2852 C and the boiling point is 3600 C. Soluble in acid and ammonium salt, insoluble in water and ethanol. The specific surface area is 180 m2/g at 400 C. The specific surface area is only 3 m2/g at 1300 ~C. It is easily deliquescent in air. It belongs to pneumatic cementing material.


Light burnt magnesia is also called caustic bitter soil and active magnesia. Magnesium hydroxide (OH) 2, which is extracted from natural magnesite ore, brucite and seawater or brine, is calcined at 700 ~ 1000 (?) C to obtain light-burned magnesia.