Caustic Soda

Caustic soda is one of the common names for sodium hydroxide (NaOH), which is also known as lye. Its common name derives from its chemical identity as a sodium hydrate and because it is caustic or corrosive. In pure form, caustic soda is a waxy, white solid. It readily absorbs water and forms aqueous solutions. Commercially available caustic soda or sodium hydroxide is usually sodium hydroxide monohydrate, NaOH·H₂O.

Production:

Nearly all caustic soda is generated by the electrolysis of sodium chloride solution using one of three cell types: mercury, diaphragm and membrane cells. The electrolysis process produces 2.25 tonnes of 50% caustic soda with each tonne of chlorine.

The primary raw material is common salt, usually in the form of underground deposits which are brought to the surface as a solution in a pumped high pressure water supply. The sodium chloride solution is often called brine.

Uses & Benefits

Sodium hydroxide is used to manufacture many everyday products, such as paper, aluminum, commercial drain and oven cleaners, and soap and detergents.

Sodium Hydroxide in Cleaning & Disinfectant Products

Sodium hydroxide is used to manufacture soaps and a variety of detergents used in homes and commercial applications.

Sodium Hydroxide in Energy

In the energy sector, sodium hydroxide is used in fuel cell production. Epoxy resins, manufactured with sodium hydroxide, are used in wind turbines.

Sodium Hydroxide in Water Treatment

Municipal water treatment facilities use sodium hydroxide to control water acidity and to help remove heavy metals from water. Sodium hydroxide is also used to produce sodium hypochlorite, a water disinfectant.

Sodium Hydroxide in Food Production

Sodium hydroxide is used in several food processing applications,

Sodium Hydroxide in Wood & Paper Products

In many paper making processes, wood is treated with a solution containing sodium sulfide and sodium hydroxide.  In the paper recycling process, sodium hydroxide is used to separate the ink from the paper fibers.

Sodium hydroxide is also used to refine raw materials for wood products such as cabinets and furniture and in wood bleaching and cleaning.

Sodium Hydroxide in Aluminum Ore Processing

Sodium hydroxide is used to extract alumina from naturally occurring minerals.

Sodium Hydroxide in Other Manufacturing Uses

Sodium hydroxide is used in many other industrial and manufacturing processes. It is used to manufacture rayon, spandex, explosives, epoxy resins, paints, glass and ceramics. It is also used in the textile industry to make dyes, process cotton fabric and in laundering and bleaching, as well as in metal cleaning and processing, oxide coating, electroplating and electrolytic extracting. Sodium hydroxide is used to help manufacture a variety of medicines and pharmaceutical products, from common pain relievers like aspirin, to anticoagulants