Physical and chemical properties The pure product is a colorless transparent viscous liquid or orthorhombic crystal, odorless and very sour. Commercially available 85% phosphoric acid is a colorless, transparent or slightly light-colored, viscous liquid. The melting point is 42.35°C. When the boiling point is 213°C (loss of H2O), pyrophosphoric acid is generated. Heating to 300°C turns into metaphosphoric acid. Relative density d181.834. Soluble in water, soluble in ethanol. Its acidity is weaker than strong acids such as sulfuric acid, hydrochloric acid and nitric acid, but stronger than weak acids such as acetic acid and boric acid. It can stimulate skin inflammation and destroy body tissue. Concentrated phosphoric acid is corrosive when heated in porcelain. Hygroscopic.
Wet-process phosphoric acid is mainly used to manufacture various phosphates, such as ammonium phosphate, potassium dihydrogen phosphate, disodium hydrogen phosphate, trisodium phosphate, etc., and condensed phosphates. Refined phosphoric acid is used to make calcium hydrogen phosphate for feed. It is used for phosphating treatment of metal surface, preparing electrolytic polishing liquid and chemical polishing liquid for polishing aluminum products. In the pharmaceutical industry, it is used in the manufacture of oily sodium phosphate, iron phosphate, etc. It is also used in the manufacture of zinc phosphate as a dental filling adhesive. It is used as a catalyst for the condensation of phenolic resin, a desiccant for the production of fuels and intermediates. In the printing industry, it is used to prepare a cleaning solution for wiping off stains on offset color printing plates. Also used in the preparation of matchstick stains. In the metallurgical industry, it is used to produce phosphoric acid refractory mud to improve the service life of steelmaking furnaces. It is the coagulant of rubber slurry and the raw material for the production of inorganic binder. The paint industry is used as a metal antirust paint.
Phosphoric acid is packed in polyethylene plastic barrels, and the mouth of the barrels must be tightly sealed with inner and outer covers. The net weight of each barrel is 25, 30, 35kg, 330kg. When users have special requirements, supply and demand consultation. There should be obvious signs on the package, indicating: product name, specification, net weight, and the sign of "corrosive substances". It should be stored in a cool, ventilated warehouse. For high-concentration phosphoric acid in cold regions in winter, attention should be paid to heat preservation, to prevent freezing, and to prevent the container from breaking, prospering and leaking. It cannot be stored and transported together with alkalis, toxic substances and other corrosive substances. Protect from rain and hot sun during transportation. When loading and unloading, please handle it with care, and violent impact is strictly prohibited to prevent the packaging container from breaking.
