Other Uses for Phosphoric Acid
- Along with the establishment of phosphate fertilizers and phosphorous from mined phosphate rock, two new product streams were beginning to develop based on pure phosphoric acid. The first was phosphoric acid as a metal treatment and the second was food phosphates.
- William A. Ross, a captain in the Royal Regiment of Artillery, discovered that phosphoric acid applied to a clean surface of iron produced a coating that would “preserve the iron, steel or metal so treated from the injurious action (in the shape of rust or other oxide) of water or damp air or perspiration” and was granted a patent in 1869.
- Baking powders were developed in the mid 19th century to provide carbon dioxide to aerate the dough making it rise on both mixing and baking; this function has been carried out for thousands of years by yeast. Early baking powders were based on sodium bicarbonate and potassium bitartratate (cream of tartar, a by-product of brewing or sour milk) and were later reformulated using monocalcium phosphate which was made by reacting charred bones with sulfuric acid.
- Among the pioneers in wet-process phosphoric acid was the Stauffer Chemical Company, where a process was developed in 1897 for acidulating bones from the Chicago stockyards to make acid for use in the manufacture of calcium leavening agents.
Ref: R. Gilmour – Phosphoric Acid, Purification, Uses, Technology & Economics (Boca Raton, FL, CRC Press, 2014)Next: Phosphorous Production – 20th Century »