What is Alum?
chemical compound (usually a hydrated double sulfate salt of aluminium) with the generic formula XAl(SO4)2·12H2O. X is a monovalent cation such as potassium or ammonium. It often refers to potassium alum, with the formula KAl(SO4)2·12H2O.
The name is also used, more generally, for salts with the same formula and structure, except that aluminium is replaced by another trivalent metal ion like chromium(III), and/or sulfur is replaced by other chalcogen like selenium. The most common of these analogs is KCr(SO4)2·12H2O.
[caption id="attachment_1460" align="alignnone" width="300"]
Al2(SO4) 24H2O or KAl(SO4), for example, aluminum sulfate and potassium sulfate are dissolved in water, and then upon evaporation it crystallizes out of the solution. A more common production method is to treat bauxite ore with sulfuric acid and then with potassium sulfate
Potassium Alum that also known as potash alum or tawas. It is aluminum potassium sulfate. This type is find in the grocery store for pickling and in baking powder. It is also used in leather tanning, as a flocculant in water purification, as an ingredient in aftershave and as a treatment to fireproof textiles. Its chemical formula is KAl(SO4)2.
Soda Alum with the formula NaAl(S O4)2·12H2O. It is used in baking powder and as an acidulent in food.
Ammonium Alum or N4Al(SO4)2·12H2O is used for many of the same purposes as potassium alum and soda alum. It finds uses in tanning, dyeing and making textiles flame retardant, porcelain cement,vegetable glues, water purification and in some deodorants.
Chrome or chromium alum has the formula KCr(SO4)2·12H2O. This deep violet compound is used in tanning and can be added to other alum to grow lavender or purple crystals.
Selenate alums occur when selenium takes the place of sulfur (SeO42-). The selenium-containing alums are strong oxidizing agents. they uses as antiseptics, among other uses.
Aluminum Sulfate: This compound is also known as papermaker’s alum. However, it is not technically an alum.It`s chemical formula is Al2(SO4)3.
It has several household and industrial uses:
in styptic pencil to stop bleeding from minor cuts
purification of drinking water as a chemical flocculant
the adjuvant in vaccines ( a chemical that enhances the immune response)
pickling agent to help keep pickles crisp
the acidic component of some types of baking powder
ingredient in some brands of toothpaste
an ingredient in some homemade and commercial modeling clay
an ingredient in some depilatory (hair removal) waxes
In the Middle East, as a deodorant, astringent and basic antiperspirant. It is also used on cuts after shaving because of its styptic properties (stops bleeding and closes pores).
It uses in deodorants for its antibacterial properties, which helps to inhibit the growth of bacteria on the skin. It is the bacteria which causes the bad smell. Some people find it also performs a basic antiperspirant function, but others don’t and so we class it purely as a deodorant.
Treats Canker Sores:
It is an excellent part for treating canker sores or mouth ulcers.
Combats Body Odor:
This may come as a surprise to most of you, but it`s also an excellent natural deodorant.
Excellent For Tonsillitis:
It`s antibacterial properties can help relieve a sore throat caused due to tonsillitis.
It uses widely for purifying water.
Sources and Production:
Several minerals are used as the source material to produce it, including alum schist, alunite, bauxite, and cryolite.
The specific process used to obtain the alum depends on the original mineral. When it obtained from alunite, the alunite is calcined. The resulting material is kept moist and exposed to air until it turns to a powder, which is lixiviated with sulfuric acid and hot water. The liquid is decanted and the alum crystallizes out of solution.