Magnesium oxide is one of the magnesia chemical materials. Magnesium oxide is classified into light-burned magnesium oxide and dead-burned magnesium oxide according to the calcination production process. The light-burned magnesia currently used in the magnesite industry refers to the magnesia formed by calcining the compound of magnesite ore at 700-900°C, which is also active magnesia, chemical formula MgO, relative molecular mass 40.30, melting point 2800°C, odorless , tasteless, non-toxic, insoluble in pure water and organic solvents, the solubility in water increases due to the presence of CO2, and can be dissolved in acid or ammonium salt solution. It is easy to get wet and can gradually absorb CO2 and moisture to form magnesium carbonate double salt in the air.