Properties of activated alumina obtained by flash calcination of gibbsite

On exposing gibbsite, with granulation below 10 μm to flash calcination of 0.5 s in the regime of pneumatic transport and at temperatures above 883 K, a microcrystalline material with a high degree of amorphization was obtained, as established from data of XRD analysis. It was shown that at 883 K the mechanism of gibbsite dehydration changes with a decrease of the activation energy from 141 to 53 kJ/mol. The obtained activated alumina is characterized by a specific surface area of over 200 m2/g and a pore structure with micro- and mesopores developed in the inside of grains of the starting material