January 26, 2024
Activated alumina is a porous, solid form of alumina, also known as Al₂O₃. It is also the mineral that makes up the precious rubies and sapphires, the impurities of which are the source of the stones' brilliant color. After activated alumina has been heated to expel existing water, the material's high surface area and many pores allow water and other molecules to be absorbed by adsorption.
The porous spherical form is the most obvious feature of activated alumina, and these spheres are actually "tunnel-like" on a microscopic level, which makes them easy to use for many different tasks. For example, they can be used to dry gases, as the drying of gases is often essential for the safe transport of volatile gases. Gases such as propane must be dried before use to prevent equipment from corroding and causing dangerous leaks.
Another important characteristic of activated alumina is that it is very stable. It will combine with other substances without changing its chemistry or form. And, because it is porous, its surface area is much greater than its weight, allowing it to adsorb large amounts of things.
Activated alumina is also adsorptive, as the chemical is drawn into the pores of the activated alumina spheres it binds to the solid material. Once inside, it will not come out without considerable heating.
