The Kinetics of Spinel Formation of Algerian Halloysite by Differential Thermal Analysis
M. Heraiza, F. Sahnoune a, H. Belhouchet b, A. Raghdi a and A. Ouali a
aPhysics and Chemistry of Materials Lab, Department of Physics, University Mohamed Boudiaf of M'sila, 28000, M'sila, Algeria
bLaboratoire des Matériaux non Métalliques, I. O. M. P, Université Ferhat Abbas Sétif 1, 19000, Sétif, Algeria
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The kinetics of spinel (Al-Si) crystallization from Algerian halloysite (DD1) was investigated using differential thermal analysis. Experiments were carried out on samples between room temperature and 1400°C with constant heating rate from 2 to 20°C min-1. The activation energies measured from isothermal and non-isothermal treatments were 1054.85 and 1140 kJ mol-1, respectively, for the spinel (Al-Si) formation. The Avrami constant n obtained by the Ligero method and the m parameter obtained by the Matusita method were about 2 for spinel crystallization. This value indicates that the crystallization mechanism of Al-Si spinel phase proceeds by bulk nucleation of the phase formation with a constant number of nuclei and that the three-dimensional growth of crystals is controlled by diffusion.

DOI: 10.12693/APhysPolA.131.139
PACS numbers: 81.70.Pg, 81.20.Ev, 82.20.-w