Calcium hydroxide; Ca(OH)2; Molar mass 74.093??/mol Also known as Slaked lime, Milk of lime, Pickling lime, Hydrated lime, Portlandite, Calcium hydrate, Calcium dihydroxide, cal, E526 It is an??norganic compound and is produced when quick lime or calcium oxide is slaked with water. As E526 it is used in food preparation but it is best known for its use in the building industry to make cement and plaster. Another important use is as a flocculant to remove small particles from sewage and water. Other uses include raising the pH of water, production of ammonia gas and in paper production.