Sodium sulfate

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Sodium sulfate (also known as Glauber's salt, thenardite, and mirabilite) is the inorganic compound with the chemical formula Na2SO4. It is a white crystalline solid that is highly soluble in water. Sodium sulfate is primarily used in the manufacture of detergents and in the kraft process of paper pulping.

History

Sodium sulfate was discovered by the Dutch/German chemist Johann Rudolf Glauber in the 17th century. He found it in the brine from an Austrian spring and named it "sal mirabilis" (miraculous salt) due to its medicinal properties.

Production

Sodium sulfate is obtained from natural sources and as a byproduct of various industrial processes. The primary sources include:

• Mirabilite (natural mineral form of hydrated sodium sulfate)
• Thenardite (natural mineral form of anhydrous sodium sulfate)
• Byproduct of the manufacture of hydrochloric acid from sodium chloride and sulfuric acid (the Mannheim process)

Applications

Sodium sulfate has a wide range of applications, including:

• Detergents: It is used as a filler in powdered home laundry detergents.
• Paper industry: It is used in the kraft process for the manufacture of wood pulp.
• Glass industry: It is used to remove small air bubbles from molten glass.
• Textile industry: It is used in dyeing processes to level the dye.
• Medicine: Historically used as a laxative.

Chemical Properties

Sodium sulfate is chemically stable and non-reactive at room temperature. It decomposes at high temperatures to produce sodium oxide and sulfur dioxide. It is also hygroscopic, meaning it can absorb moisture from the air.

Health and Safety

Sodium sulfate is generally regarded as non-toxic. However, ingestion of large amounts can lead to gastrointestinal irritation. It has an LD50 of 5989 mg/kg in rats, indicating low acute toxicity.

See also

• Sodium carbonate
• Sodium chloride
• Sodium hydroxide
• Sodium bicarbonate
• Sulfuric acid