Sodium sulfate

Sodium sulfate is the sodium salt of sulfuric acid. With an annual production of 6 million tonnes, it is one of the world's major commodity chemicals. Anhydrous, it is a white crystalline solid of formula Na2SO4; the decahydrate Na2SO4ยท10H2O has been known as Glauber's salt or, historically, sal mirabilis since the 17th century.

Sodium sulfate is mainly used for the manufacture of detergents and in the Kraft process of paper pulping. About two thirds of the world's production is from mirabilite, the natural mineral form of the decahydrate, and the remainder from by-products of chemical processes such as hydrochloric acid production.