Ammonium Alum Uses

Ammonium Alum is used in various industries for various purposes. Worldwide, the majority of ammonium alum is manufactured for fertilizer, water treatment, food preservatives, leather tanning and crystal deodorant.


Water Treatment

The pre-treatment of water via coagulation, flocculation, and filtration are all essential methods for purifying water. Water treatment coagulants work by creating a chemical reaction that eliminates the negative charges which cause particles to repel each other.  Ammonium alum is added to the water source to serve as a chemical coagulant and help facilitate the clumping of particles.  The mixture of ammonium alum and water is slowly stirred and flocculation occurs, thereby further promoting coagulation.  When the particles clump together, or form bonds, they are then removed more easily during the filtration process.

Food Preservatives

Ammonium alum serves as an effective food color fixative, firming Agent, and most notably a preservative.  When ammonium alum is combined in the correct ratio with citric acid, the composition retards deterioration of fruits, vegetables and meats, without substantially changing the flavor, appearance, odor or texture of the food.  When treated properly foods may be prepared well in advance of use or consumption and yet may be maintained in fresh condition.  Also, as ammonium alum acts as a coagulant in water treatment, the same basic principle applies to its function as a fruit firming agent, whereas the aqueous particles, including water, are clumped together thereby hardening the fruit.

Other Uses

  • Fertilizer
  • Leather Tanning
  • Disinfection
  • Rubber
  • Washing powder
  • Livestock feed
  • Pencils.