Discovered by German-Dutch chemist Johann Rudolf Glauber in 1625, Glauber's salt is the processed form of mineral mirabilite, a decahydrate sodium sulfate. The hygroscopic nature of sodium sulfate causes it to absorb water and moisture, forming Glauber's salt. It exists as a natural resource and is found in the bed of lakes such as in Saskatchewan.
Glauber's salt is also a synonym for sodium sulfate anhydrous and is commonly used in the industries. Sodium sulfate anhydrous, also known as thenardite, has a formula of Na2SO4. It has an appearance of white crystalline solid and is chemically very stable. It is unreactive toward most oxidizing or reducing agents at normal temperatures. In addition to that, it can be converted to sodium sulfide at high temperature by carbo-thermal reduction.
Mining: Since Glauber's salt is available in abundance as a natural resource, almost two-thirds of the world's production of Glauber's salt come from mining. This is done by pumping water into smaller ponds and allowing it to evaporate. Upon evaporation, sodium sulfate crystals will be precipitated out, and hence isolated and collected.
Byproduct from Manufacture of Viscose Rayon Fiber: Viscose Rayon Fiber is the oldest commercially available man-made fiber. They are highly absorbent, soft and comfortable, easy to dye and drapes well. It is manufactured using wood pulp and sodium hydroxide to regenerate cellulose. Through a series of processes such as steeping and pressing, viscose rayon fiber is manufactured, with sodium sulfate as a major by-product.
Byproduct from Manufacture of Methionine: Glauber's salt is also manufactured as a byproduct in the manufacture of methionine. Methionine, being one of the most essential amino acids, is manufactured via fermentation process. Through fermentation process, various nutrient mediums such as glucose or sugar cane juice yield different amount of methionine and by-product, sodium sulfate.
Sodium sulfate is used as a "leveling" agent where it reduces the negative charges on fibers. By doing so, it allows dyes to penetrate the textiles evenly and effectively. In addition to that, it does not corrode the stainless steel vessels used in dyeing as compared to the used by conventional salt; sodium chloride.
The major use of sodium sulphate is as a filler in powder products, for example in detergents. Nowadays, liquid detergent that doesn't include sodium sulphate has become more popular which decreasing the used of sodium sulphate.
In paper industries, sodium sulphate is use in the Kraft process of wood pulp. The wood chips loaded by sodium sulphate and being heated. This cause the sodium sulphate reduce into sodium sulfide that breaks the bond in cellulose of the wood, therefore the wood chips become soft and easily form into wood pulp.
Another common use of sodium sulphate is in glass industries to prevent the formation of air bubbles in molten glass. Sodium sulphate also act as dryer for organic compound. It removes water from organic compound, although it remove slower than another drying agent such as magnesium sulphate, it is more efficient.
Sodium sulfate is used as a drying agent in an organic solvent. During separation and extraction between an aqueous and an organic phase, sodium sulfate is often added to the organic extracts to dry the organic phase. It is also used in the de-frosting of windows, carpet fresheners, starch manufacture, and additive to cattle feed.