Sodium sulphate

Sodium sulphate (also known as sulphate of soda) is the inorganic compound with formula Na2SO4 as well as several related hydrates. All forms are white solids that are highly soluble in water. With an annual production of 6 million tonnes, the decahydrate is a major commodity chemical product. It is mainly used for the manufacture of detergents and in the kraft process of paper pulping.

Chemical properties

Sodium sulphate is a white crystalline solid. It is odourless and has a bitter, salty taste. It is soluble in water and glycerol but insoluble in ethanol. When heated, sodium sulphate decomposes to form sodium oxide and sulphur dioxide.

Production

Sodium sulphate is mainly produced by the process of evaporation of brine. In this process, the brine is evaporated under vacuum to obtain the sodium sulphate crystals. The crystals are then separated from the mother liquor by centrifugation.

Uses

Sodium sulphate is primarily used in the manufacturing of detergents. It is also used in the kraft process of paper pulping, where it helps in the removal of lignin from wood. Other uses include the manufacturing of glass, textiles, and in the production of sulphuric acid.

Health effects

Exposure to sodium sulphate can cause irritation to the eyes, skin, and respiratory tract. Ingestion can lead to gastrointestinal disturbances. Long-term exposure can lead to more serious health effects such as kidney and liver damage.

See also

• Sodium
• Sulphate
• Detergents
• Kraft process