Aluminum sulfate

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Aluminum sulfate is known by a variety of names, among them cake alum and filter alum. This latter name refers to its use in water treatment. It is found in anhydrous form near volcanoes and in the waste dumps at coal mines.

The molecular formula for aluminum sulfate Al2(SO4)3 is composed of two aluminum atoms and three sulfates (SO4) groups. At room temperature, it usually looks like a white crystalline solid. The melting point for this compound is 770 degrees Celsius.

The primary usage for filter alum is in water filtration. Particles of the compound function excellently as flocculating agents. The impurities coagulate around it and become much easier to remove when the formerly suspended particles settle to the bottom of the container.

This compound also works as a mordant for the textile industry. Its proper application helps dyes to attach to fabrics.

In personal care applications, aluminum sulfate is used for its antiperspirant, astringent, and deodorant properties. A lot of products on the market include cake alum, such as skin care preparations, makeup, antiperspirants, and deodorants.