Formation of anorthite containing cordierite materials through reaction sintering kaolin, MgO and CaO precursors

Smail Lamara, Djaida Redaoui, Foudil Sahnoune, Menad Heraiz, Nouari Saheb
2020 Science of Sintering  
The effect of CaO on cordierite formation from kaolin-MgO-CaO powder mixtures, milled for 5 h and reaction sintered for 2 h in the temperature range 900-1400 °C, was investigated. Phases formed in the developed materials were characterized by x-ray powder diffraction method (XRD) and Raman spectroscopy. Non-isothermal differential thermal analysis (DTA) and thermogravimetric (TG) experiments were performed from room temperature to 1400 °C, at heating rates from 20 to 40 °C/min. Activation
more » ... n. Activation energies were determined using Kissinger method. It was found that sintering the stoichiometric kaolinmagnesia mixture led to the nucleation and growth of monolithic cordierite; while cordierite along with anorthite were present in the other two samples where 4 or 8 wt% of CaO was added. The increase in CaO decreased cordierite formation temperature and increased the activation energy, which ranged from 445 to 619 kJ/mol for μ-cordierite and from 604 to 1335 kJ/mol for α-cordierite.
doi:10.2298/sos2002135l fatcat:vfm56sq3pvcszcim6wsgnsviqi