Sodium silicate is an inorganic compound containing sodium oxide and silica, also known as water glass or soluble glass or Sodium metasilicate. It is basic in nature, white to greenish opaque crystals, highly soluble in water with high melting point. This alkaline substance is available as a nearly colorless, glass-like powder, or as a syrup-like liquid when mixed with water and heated under pressure. The viscosity of this compound depends on the ratios of silica and sodium oxide used. Sodium silicate has a variety of industrial, agricultural and manufacturing uses.
It is stable in neutral and alkaline solutions, in acidic solutions, the anion silicate reacts with hydrogen ions to form silicic acid. Silica gel a well known desiccant is a hard and glassy substance is formed by heating and roasting of sodium silicate.
Sodium Silicate (Na2SiO3) is prepared by melting sand and Sodium Carbonate (Soda Ash). Its wide range of applications includes the manufacturing of Detergents, Silica Gel, Card-board and Paper, Textiles, Paints, Adhesives, Pottery and Sanitary ware, Refractories, Foundry and Wood Processing Industries. The liquid form of sodium silicate is used in the manufacturing of additives because of its low cost, non toxic and environmentally friendly nature. In modern day’s sodium silicate is also used to stop the leak in engine parts hence it is called as water glass. It is also used in the manufacture of laundry soap, detergent cake, sodium metasilicate, fire resisting & acid proof cement, casting, electrodes. This compound finds applications in water treatment as coagulant/flocculating agent by binding to colloidal molecules, creating larger aggregates that sink to the bottom of the water column.