Aluminium potassium sulphate, also known as potassium alum or potash alum, is a chemical compound with the formula KAl(SO4)2·12H2O. It is a double salt that consists of the sulphate anion, aluminium cation, and potassium cation. The compound forms large, transparent, octahedral crystals that are soluble in water.

Potassium alum has a wide range of applications due to its properties as an astringent, antiseptic, and flame retardant. It is commonly used in the production of water purification systems, flame retardant textiles, and as a mordant in dyeing fabrics. Additionally, it has a long history of use as a traditional medicine for various ailments such as sore throats, canker sores, and skin irritations.

As a mordant in dyeing and printing textiles
In the preparation of lakes and pigments for painting
In the manufacturing of baking powder and self-raising flour
In the preparation of pickles and other food products as a firming agent and stabilizer
As a clarifying agent in the production of beer and wine
In the paper industry as a sizing agent
As a flame retardant in some plastics and coatings
In water treatment as a coagulant to remove impurities
In the production of specialty glass, ceramics, and alum crystals
In the pharmaceutical industry for various applications such as antiperspirants and wound healing products

Minimum Assay: >99.5%
Molecular Formula: AlK(S04)2.12H20
Molecular Weight: 474.38 g/mol
Melting Point: 92 C
Water: <4.5%
Chloride: <0.01%
Iron: <100ppm
Aluminium: 5-6%

Hazard Phrases: Not considered harmful under normal laboratory conditions

Cas No: 7784-24-9
Einecs No: 233-141-3