Synthesis and thermal behavior of cordierite ceramics from algerian kaolin and magnesium oxide

Kaolin DD1 (from Djebel Debbagh, Guelma, Algeria), kaolin Tamazarte KT (from Jijel, Algeria) and magnesium oxide MgO mixtures with relative weight ratios of 59/29/12 have been studied in this work in order to obtain cordierite ceramics with the stoichiometric formula (2MgO·t2Al₂O₃·t5SiO₂), by mixing raw materials abundant in Algeria. Thermogravimetric analysis and differential thermal analysis were carried out on powder from room temperature to 1300°C, at heating rates from 10 to 50°Cmin^-1. The phases and their transformations were determined by X-ray diffraction for the mixture of kaolin (59 wt.% DD1 + 29 wt.% KT) and 12 wt.% of magnesium oxide powder treated at different temperatures between 900 and 1250°C for 2 h. The activation energies of α-cordierite formation calculated from isothermal data were around 372 kJmol^-1. The average Avrami parameter is found to be around 1.95 for each heating rate.