You are currently viewing Alum (Fitkari)
Alum

Alum (Fitkari)

  • Post comments:0 Comments
  • Reading time:6 mins read

What is it?

Alum (also known as aluminium sulfate or illuminate) is the name of a class of chemical compounds that contain aluminium, a metal element with a symbol Al and atomic number 13. It is a type of salt that chemically combines an alkali metal (such as ammonium, potassium, or sodium) and a trivalent metal (such as aluminium or chromium). Alum exists in crystalline form, but can also be sold in powder form. 

Alum properties 

Alum is a white crystalline substance that is colorless, odorless, with a sweetish taste, and that is soluble in water. 

  • It is non-toxic 
  • It is non-combustible
  • It reacts as an acid.
  • It crystallizes when precipitated (from water) in its regular octahedral form.
  • It liquefies when heated. 

Types of Alum

Alum is a hydrated double sulphate salt of aluminium, with the general formula XAl(SO4)2·12 H2O. Potassium alum is the most common type, so much so, that the name alum is often used to refer to it. 

  • Ammonium Sulphate alum (Ammonium alum) NH4Al(SO4)2·12 H2O
  • Chromium alum (Chrome alum) KCr(SO4)2·12 H2O.
  • Potassium alum also known as potash alum KAl(SO4)2·12 H2O
  • Selenium alum (Selenate alum) SeO42Al(SO4)2·12 H2O
  • Sodium alum also known as soda alum  NaAl(SO4)2·12 H2O

Uses of Alum

Alum is used in everyday and various industrial applications. It is used as an ingredient in toothpaste, kitchen spices, cosmetics (such as skin whitener and hair removal waxes), vaccines, and antiseptics. 

Cosmetics

  • It is used as a deodorant.
  • It is used as a toner or astringent. 
  • It is used in skin whitening.
  • It is used in hair removal waxes. 
  • It is used in toothpaste. 

Food 

  • It is used in pickling to preserve food in a brine. It is also used to preserve flour. 
  • It is used as a natural meat tenderizer.
  • It is used in baking soda and baking powder as well as a leavening agent.
  • It is used in kitchen spices.

Medicine

  • It is used in antiseptics. 
  • It is used in styptic pencils, to stop bleeding.
  • It is used for skin irritation and cuts. 
  • It is used in vaccines.

Other Industrial applications

  • It is used as a flocculant to remove color and turbidity and purify drinking water. 
  • It is used in electrolytic copper plating.
  • It is used in printing. 
  • It is used in fire extinguishers and fire-proof paper and cloth.
  • It is used as a mordant to set dye on fabrics. 

Alum is added to water that is used in cleansing and divination rituals

Leave a Reply