Activated alumina is a form of aluminum oxide (Al2O3) with a myriad of industrial uses. A recent industry report by Grand View Research estimates the activated alumina market will see a CAGR of 5.4% up to 2025, largely as a result of its use in water treatment applications, which continue to grow in importance, as well as its use as a catalyst in the oil and gas industry.[u]hslabrasive[/u]
Activated alumina exhibits a number of characteristics that make it ideal in many industrial process settings. This includes a high crush strength, resistance to thermal shock, resistance to chemical attack, and more. The characteristic that has pushed activated alumina to the forefront of many applications is its capability as an adsorbent, courtesy of its high porosity and surface area.
In most cases, activated alumina starts out as an aluminum hydroxide (gibbsite, boehmite, etc.) – a material obtained through a series of chemical reactions in the Bayer process used to transform bauxite ore into alumina.
Once the aluminum hydroxide has been produced, it is thermally treated via calcination in a rotary kiln. This calcination step serves to dehydrate, or remove bound moisture from the aluminum hydroxide in order to produce alumina, or aluminum oxide (Al2O3).
Activation, a phase in which the alumina structure becomes highly porous, occurs within a specific temperature range, with process parameters such as residence time and temperature profile used to control the properties of the end product. The makeup of the original bauxite source can also influence the characteristics of the end product.
ADSORBENTS
Activated alumina is a highly effective adsorbent in both gas and liquid applications, and as such, is employed by a number of industries for targeted removal of components from other media.
As an adsorbent, activated alumina is most well known for its use in water filtration applications, where it serves as a cost-effective adsorbent for removing fluoride from water. It is also capable of removing a variety of other contaminants, including arsenic, lead, and sulfur.
DESICCANT
Similar to its role as an adsorbent, activated alumina can also adsorb water from air, allowing it to be used as a desiccant; activated alumina can capture and trap water in order to keep things dry, much like silica gel. As a desiccant, activated alumina can adsorb up to 20% of its own weight in water at a relative humidity of 50%.¹
Activated alumina is employed as a desiccant in a wide variety of applications, including the removal of water vapor from gases in industrial settings. Water adsorbed onto the activated alumina can then be desorbed via thermal treatment and the alumina reused.
CATALYSTS
Activated alumina is also widely used as a catalyst, with roles as the catalyst itself, as well as an inert carrier, or substrate for other catalysts.
As a catalyst, activated alumina is most well known for its role as a Claus catalyst; activated alumina is the most commonly used Claus catalyst in sulfur recovery endeavors at oil and gas refineries.[u]silicon carbide grit bulk wholesale[/u]
