sric acid, also known as orthosric acid, is a common inorganic acid with a chemical formula of H3PO4 and a molecular weight of 97.995. sric acid is not volatile, not easy to decompose, has almost no oxidizing properties, and has the properties of an acid. It is a three-basic weak acid. Its acidity is weaker than hydrochloric acid, sulfuric acid, and nitric acid, but stronger than acetic acid, boric acid, etc. sric acid deliquesces easily in the air. When heated, it will lose water to obtain pyrosric acid, and then further lose water to obtain metasric acid. sric acid is mainly used in rmaceutical, food, fertilizer and other industries, including as a rust inhibitor, food additive, dental and orthopedic, EDIC corrosive, electrolyte, flux, dispersant, industrial corrosive, fertilizer raw material and component for household cleaning products, and also Can be used as chemical reagent.