Aluminium Sulphate

Water Treatment

The major area of use for Alum is in Water treatment and clarification. Its clarifying action is attributed to Aluminium Hydroxide formation by hydrolysis. This, in turn, carries down all the colloidal impurities and forms a slimy layer at the bottom

Sizing of Paper

The other major area of use is in sizing of paper. It reacts with sodium resonate to give insoluble Aluminium resonate. For sizing of paper, Alum should be free from Ferric ions or else the paper will be discoloured. Ferrous ions do not farm since they form a soluble colourless resonate which, however, would represent a loss of resonate. Alum imparts certain degree of resistance to penetration by liquids during sizing of paper.

Miscellaneous Application

Alum is also required in various other industries like Dyes, Food, Petroleum, Pharmaceuticals, Fire-proofing, tanning etc.