Alumina:- Properties, Applications, Hazards and Activation

Alumina (Aluminum Oxide) is a whitish solid which has got numerous applications in the field of health, electronics, etc. Similarly, activated alumina is also widely in use.


Chemical Formula



Solid white in color




Insoluble in all the solvents including water

Melting point



3.987 gram/cm3

Importance of Alumina

Some of the most significant applications are as follows.

  • Alumina Ceramics:- It is a good insulator of heat and electricity.  Besides that, it has also got a high resistance towards wear and corrosion. Also, high strength and hardness have made it suitable for the manufacturing of ceramics. 
  1. In the medical field, it is used in the manufacturing of dental crowns, artificial joint replacement, cochlear implants, medicine grinder, etc.
  2. In electronics, it is used in the manufacturing of resistors, capacitors, etc.
  3. In chemistry, it is used in storing and transporting chemicals.
  • Alumina Homeopathy:-  It is widely used for medical treatments. 
  1. Alumina is useful for people who catch a cold quickly. It increases the blood circulation in the body. Thus, an increase in the blood flow causes an increase in body temperature. 
  2. It is also suitable for patients who are suffering from depression and anxiety.
  3. Similarly, it helps to reduce the problem of constipation, gastritis, etc.
  • Alumina Glass:- Alumina helps to give shape to the glass. Besides that, it also reduces the thermal expansion and provides stiffness. 
  • Activated Alumina:-Scroll down the page to know about it.


It is generally not hazardous to human beings. However, a high concentration can have some side effects. 

  • It can cause skin and eye irritation.
  • If ingested, it can show some irritation to the alimentary canal, respiratory tract, etc.
  • It is generally non-toxic in nature. 

Activated Alumina

When aluminum hydroxide is dehydroxylated in a certain way, a highly porous material with a higher surface area is formed. This kind of aluminum oxide is known as the activated alumina. The activation of this element allows the material to take part in the process of adsorption. 


  • Desiccants:- By the process of adsorption, it can absorb moisture through the air. The waver vapor gets trapped within the crystal. This helps to dry out any liquid or gas. 
  • Adsorption:- The adsorption of the elements such as chloride, arsenic, fluoride, etc is useful for the treatment of drinking water and gas.   
  • Acid Removal:- The lubricating oils, transformer oils, and refrigerants form degradation acids when used. This can mainly affect the manufacture of chlorinated or fluorinated hydrocarbons. And hence, activated alumina can be used to get rid of the acid.


Adsorption is a reversible process. When the temperature of the activated alumina goes beyond 200°C, the trapped water begins to escape from the surface. This process is known as regenerating the desiccant. 

It can be reused by heating the alumina in a microwave at a temperature of 200°C or above for an hour. 

Comparison between Activated Charcoal and Activated Alumina

Now let us compare it with activated charcoal.

Activated Charcoal Activated Alumina
1 gm of activated charcoal has more than 3000 m2 surface area. 1 gm of activated alumina has more than 200 m2 surface area.
Used to filter volatile organic compounds such as acetic acid, ethanol, and also chlorine from the fluid Used to filter heavy metals such as arsenic from the fluid
Cannot be regenerated Can be regenerated

My Thoughts

From the above paragraphs, we can conclude the following things.

  • Alumina is an inert, tough, hard, and poor conductor of electricity. Thus these properties have been useful for various applications such as the production of ceramics, glass, electronic components, etc.
  • It is cheap, popular, and easily available in the market. 
  • Although it is not hazardous to human beings, one should not handle it carelessly. If you happen to consume it accidentally, you are strongly advised to visit a doctor. 
  • Activated alumina is widely used as a desiccant, purification of the drinking water, acid removal, etc. 
  • It can be regenerated and reused multiple times.  

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