Verres Céramiques Composites
Volume 5, Numéro 2, Pages 7-12

Kinetics Parameters Of The Thermal Dehydroxylation Of Gibbsite Al(oh)3 By Differential Thermal Analysis (dta)

Authors : Redaoui Djaida . Sahnoune Foudil .


In this present study, the thermal decomposition of gibbsite Al(OH)3 was studied by the Differential Thermal Analysis (DTA) technique under non-isothermal conditions, the gibbsite powder were carried out between room temperature to 900 °C using heating rates of 5, 10, 15 and 20 °C/min.The obtained DTA curves show two different peaks: the first peak is due to partial dehydroxylation of gibbsite and formation of boehmite, the value of the activation energy (EA) corresponds to 143 KJ/mol. The second peak corresponds to transformation of gibbsite to -Al2O3 phase, the activation energy (EA) was found around to 185 KJ/mol. The values of apparent activation were determined by Ozawa–Flynn–Wall (OFW), Boswell and Kissinger–Akahira–Sunose (KAS) methods and by applying the basic solid-state kinetic equations. The phases formed and the structural changes were investigated by differential thermogravimetry (DTG) and X-ray diffraction (XRD) for gibbsite powder treated at different temperatures from room temperature to 1100 °C.


Activation energy, Decomposition kinetics, Differential Thermal Analysis (DTA), Gibbsite