Liquid ammonia, also known as anhydrous ammonia, is a colorless liquid. As an important chemical raw material, ammonia is usually pressurized or cooled to obtain liquid ammonia, which is convenient for transportation and storage. Liquid ammonia is widely used in industry, which is corrosive and volatile, so the incidence of chemical accidents is quite high. Liquid ammonia is mainly used to produce fertilizers such as nitric acid and urea, and can also be used as raw materials for medicine and pesticides. In the national defense industry, liquid ammonia is used to make propellants for rockets and missiles. It can be used as ammoniation raw material for organic chemical products and also as refrigerant.