Magnesium oxide is commonly known as bitter soil, also known as magnesium oxide. Magnesium oxide is an alkaline oxide with the general properties of alkaline oxides and belongs to a cementitious material. White or light yellow powder, odorless, tasteless, non-toxic, is a typical alkaline earth metal oxide, chemical formula MgO, white powder, soluble in acid and ammonium salt solution. When exposed to the air, it is easy to absorb moisture and carbon dioxide and gradually become basic magnesium carbonate. The light product is faster than the heavy product. It combines with water to form magnesium hydroxide under certain conditions, showing a slightly alkaline reaction. The pH of the saturated aqueous solution is 10.3.