Uses Of Potash Alum

The hydrated form of potassium aluminium sulphate is Potassium alum. It has the chemical formula KAl(SO4)2·12H2O. Any of the compounds procured with the formula AB(SO4)2·12H2O are considered to be alum. Alum also had its crystalline form. It is also widely sold as a powder. Salts like this are used in dyeing and various other industrial procedures. They are water-soluble, astringent, acidic, sweetish in flavour, react acid to litmus, and crystallise in regular octahedra. They liquefy when heated; if heated further, the water of crystallisation is pushed off, the salt froths and swells, and an amorphous powder is left.

Alum Powder and Its uses

Alum powder is a fine white, odourless powder that can be purchased in the spice area of most supermarkets and can be used as a preservative in pickling recipes to keep fruit and vegetables fresh. Alum powder that you can find sold with groceries or pickling ingredients. Its crystal is used as a flocculant for water purification and is also called a deodorant rock often used for underarm use. Other alum uses are leather tanning and a soothing aftershave ointment. Uses of potash alum are also to fireproof textiles.

Alunite and leucite are minerals that contain aluminium potassium sulphate (alum powder). Alum powder is also used as a filler in paper, cement, and paints. Gelatin, plaster, and cement are all hardened with it. Lake pigments have also been made using potassium alum as a substrate.

Water Treatment Applications

Alum is used by municipal water providers, such as your local water utility company, to cleanse water for human consumption. In addition, when bacteria or silt would produce an undesirable effect, process water (non-drinking water) could be treated with this chemical for purification. 

Aluminium sulphate causes small contaminants to cluster into larger particles when added to water. These clumps eventually sink to the bottom of the container, where they may be filtered away. As a result, the water is safer to drink. Alum is sometimes used in swimming pools to reduce cloudiness.

Dyeing Fabrics

Aluminium sulphate is also used in the dyeing and printing of textiles. Aluminium hydroxide is formed when the chemical is dissolved in a large amount of water with a neutral or slightly alkaline pH. By rendering the dye water-insoluble, this goo aids in the adhesion of dyes to fabric fibres. Aluminium sulphate serves as a dye “fixer,” combining with the molecular structure of the dye and the cloth to ensure that the dye does not run out when the fabric is wet.

Paper Making

It’s also used in paper sizing. The absorbency of the paper is changed by combining alum powder with rosin soap, which modifies the paper’s ink-absorbing characteristics. Aluminium sulphate creates acidic conditions, but the acid-free paper is created using synthetic sizing agents and does not break down as quickly.

Medical Purposes

It’s mostly used as a deodorant and coagulating agent for minor cuts and abrasions (due to its antibacterial properties). This chemical also adsorbs and precipitates protein antigens in solution, improving vaccination immunogenicity by allowing the gradual release of antigen from the vaccine depot created at the inoculation site. For small cuts and abrasions after shaving, aluminium sulphate is commonly acquired over the counter in a solid stick or powder. It is used as a post-shaving treatment and an astringent in styptic pencils to stop bleeding from superficial wounds.

Food Making Purposes

Alum is used in food for various applications and is generally considered safe when used by appropriate production practices. Because it is water-soluble, it is mostly employed as a thickening and emulsifier.

Alum can also be used to:

• Control the pH of beets, tomatoes, and other vegetables.
• Sugar beet juice purification
• Control the pH and colour of your wine and liquor.
• Serve as a leavening agent in cake batter (baking soda)
• Cheese curdling and thickening

Gardening

Because aluminium sulphate is quite acidic, it’s occasionally used to regulate the pH of severely alkaline soils. Alum used in gardening helps by reacting with water to produce aluminium hydroxide and a diluted sulfuric acid solution, which changes the soil’s acidity. Because hydrangeas are sensitive to soil pH, gardeners who plant them use this property to modify the colour of their flowers (blue or pink).

Conclusion

The manufacture of potassium alum from alunite has been documented archaeologically on the Greek island of Lesbos. G.E. Stahl claimed in the early 1700s that reacting sulfuric acid with limestone created alum. Alunite, the most important alum, is found as a mineral. Industrial production of the most notable alums – potassium, sodium, and ammonium – is common. Aluminium sulphate and the monovalent sulphate cation are commonly used in recipes. Sulfuric acid extracts aluminium sulphate from minerals such as alum schist, bauxite, and cryolite. The monovalent cation is used to name aluminium-based alums. Unlike the other alkali metals, lithium does not produce alums, which is due to its ion’s small size.