Sodium sulphate is the sodium salt of sulphuric acid. When anhydrous, it is a white crystalline solid of formula Na2SO4 known as the mineral thenardite; the decahydrate Na2SO4·10H2O is found naturally as the mineral mirabilite, and in processed form has been known as Glauber’s salt or, historically, sal mirabilis since the 17th century. Another solid is the heptahydrate, which transforms to mirabilite when cooled. It is a major commodity chemical product.

Used to stain blood smears to diagnose malarial parasites.
The glass industry provides a significant application for sodium sulphate, as second largest application in Europe. Sodium sulphate is used as a fining agent, to help remove small air bubbles from molten glass. It fluxes the glass, and prevents scum formation of the glass melt during refining.
Sodium sulphate is used for dyeing textiles. It is an ideal compound for this purpose, because it does not corrode the stainless steel vessels as sodium chloride (which can also be used in this manner) does. Sodium sulphate is a leveling agent, reducing negative chargers on the fibers, which allows the dyes to penetrate evenly.
Another use for sodium sulphate compound is in the Kraft process, also known as the sulphate process, of wood pulp manufacturing which is widely used to make paper products and building supplies.
Sodium sulphate is used in many laundry and detergent products.
In the labratory, anhydrous sodium sulphate is widely used as an inert drying agent for removing traces of water from organic solutions. It is more efficient, but slower-acting, than the similar agent magnesium sulphate. It is only effective below about 30 °C, but it can be used with a variety of materials since it is chemically fairly inert. Sodium sulphate is added to the solution until the crystals no longer clump together but some crystals flow freely once a sample is dry.
As an additive to cattle feed
De-frosting windows
In carpet fresheners
In starch manufacture
Sodium sulphate has been found effective in dissolving very finely electroplated micrometre gold that is found in gold electroplated hardware on electronic products such as pins, and other connectors and switches. It is safer and cheaper than other reagents used for gold recovery, with little concern for adverse reactions or health effects.
Sodium sulphate’s unique heat storage properties make it an ideal candidate for use in many future processes and products.


Minimum Assay: >98%
Molecular Formula: Na2SO4
Molecular Weight: 142.04 g/mol
Melting Point: 884°C
Alkalinity (Na2CO3):< 0.1%
Thiosulphates (S2O3): < 0.01%
Iron (Fe): < 0.0005%
Heavy metals (Pb): < 0.001%
Selenium (Se): < 0.0005%
Arsenic (As): < 0.0001%
Lead (Pb): < 0.0002%
Mercury (Hg): < 0.0001%

Hazard Phrases: Not considered harmful under normal laboratory conditions

Cas No: 7757-82-6
Einecs No: 231-820-9