Sodium bicarbonate refined grade is in the form of small opaque, monoclinic crystals or as a white minutely crystalline powder, free from dirt and other foreign matter. It is liable to lumping if exposed to dampness or subjected to too high a pressure. Sodium bicarbonate is obtained as an intermediate during the production of synthetic soda ash using the ammonia-soda process, popularly known as the Solvay process. Calcium carbonate (limestone) on heating releases carbon dioxide, which is passed into an ammoniated salt solution producing a sodium bicarbonate precipitate.
Sodium bicarbonate refined grade is used as baking powder, in the manufacture of effervescent salts and beverages. It also finds use in artificial mineral waters, gold and platinum plating, tanning industry, treating wool and silk, fire extinguishers, ceramics, jaggery manufacture, insecticides (bulking agent) and as an ingredient of cattle licks, self-raising flours and savories.