CAS: 7664-38-2
Properties: Colorless, odorless, sparkling liquid or transparent, crystalline solid, depending on concentration and temperature. At 20C the 50 and 75% strengths are mobile liquids, the 85% is of a syrupy consistency, and the 100% acid is in the form of crystals, d1.834 (18C), mp 42.35C, loses 1/2/ H2O at 213C (to form phosphoric acid), soluble in water and alcohol, corrosive to ferrous metals and alloys.
Derivation: (1) Action of sulfuric acid on pulverized phosphate rock; (2) action of hydrochloric acid on phosphate rock, with extraction by tributylphosphate; (3) by heating phosphate rock, coke, and silica in an electric furnace, burning the elemental phosphorus produced, and then hydrating the phosphoric oxide (furnace acid).
Grade: Agricultural, technical (50, 75, 85, 90, 100%), food (50,75, 85%), NF (85-88%), FCC (75-85%).
Hazard: Toxic by ingestion and inhalation, irritant to skin and eyes.
Use: Fertilizers, soaps and detergents, inorganic phosphates, pickling and rust proofing metals, pharmaceuticals, sugar refining, gelatin manufacture, water treatment, animal feeds, electropolishing, gasoline additive, conversion coatings for metals, catalyst for ethanol manufacture, lakes in cotton dyeing, yeasts, soil stabilizer, waxes and polishes, binder for ceramics, activated carbon, in foods and carbonated beverages as acidulant and sequestrant, laboratory reagent.