Historical Usage

• Soda ash has been used since ancient times. The Egyptians used it to make glass ornaments and vessels as early as 3,500 B.C. The early Romans used soda ash to bake bread, to make glass and for medicinal purposes. Soda ash was obtained from specific mineral deposits and from plants. The extraction of the substance from the ashes of plants led to its common name.
  
  

LeBlanc Process

• In 1791, Nicolas LeBlanc, a French physician, developed a process for synthetically producing soda ash. It involved two stages: the production of sodium sulfate from sodium chloride, followed by the reaction of the sodium sulfate with coal and calcium carbonate to produce sodium carbonate, or soda ash. The process was complicated, wasteful and dirty, so chemists soon became intent on finding a better way to make soda ash.
  
  

Solvay Process

• Ernest Solvay, working for his uncle's Belgian gasworks facility in 1859, improved the production of soda ash through the use of ammonia. The Solvay process was put into practice in the 1860s, and variations of it are still used today. It combines sodium chloride and calcium carbonate through an intricate process involving ammonia -- resulting in sodium carbonate with an excess of carbon dioxide. This product is converted to sodium bicarbonate, which is then heated and reduced to soda ash. The carbon dioxide can be recycled, and most of the ammonia is recovered. The only major byproduct is calcium chloride, which can be sold as road salt.
  
  

Solvay Versus LeBlanc

• The Solvay process replaced the LeBlanc process because it proved to be more cost-effective, especially due to its use of inexpensive materials and plentiful raw materials. By the end of the 19th century, the Solvay method was being applied worldwide to alkali production. The Solvay Process Company built a plant in Syracuse, New York, in 1884; other U.S. plants followed.
  
  

Discovery of Trona

• In 1938, the largest known deposits of trona ore were found in the Green River Basin of Wyoming. Trona can be converted to natural soda ash through a purification process that is much less expensive than production of soda ash in a Solvay plant. According to General Chemical, which established its Green River facility in 1968, trona ore is transformed into crude sodium carbonate, water is added and impurities are removed. The resulting liquid is heated and reduced to crystals, which are separated and dried. Although Solvay plants still contribute much of the world's soda ash production, American Solvay plants disappeared by 1986.
  
  

Commodity

• Soda ash has many uses and can be found in most industries. According to General Chemical, soda ash is such an important material that government and commerce agencies follow its production to determine fluctuations in the economy. You may have experienced soda ash as a softening agent found in laundry detergents. Soda ash precipitates metal from hard water -- metals that otherwise would form a scum that does not dissolve in water and will stain clothes.