Crystal structure of single phase and low sintering temperature of α-cordierite synthesized from talc and kaolin

Comparative mineralogical study of thermally-altered coal-dump waste, natural rocks and the products of laboratory heating experiments

“…It may be synthesized from a stoichiometric oxide mixture at P = 2kB starting from 712°C (Cho and Fawcett, 1986). The alpha-form of cordierite (hexagonal, and thus likely to be indialite) may crystallize from a glass formed from a talc-kaolinite mixture at 900°C -a process requiring just 13.5 min (Banjuraizah et al, 2009). Indialite is stable above 1450°C (Putnis and Bish, 1983).…”

Effect of melting temperatures on the crystallization and densification of 2.8MgO·1.5Al2O3·5SiO2 glass–ceramic synthesized from mainly talc and kaolin

“…The impurities that was existed from the initial raw materials was expected to concentrate in the matrix of amorphous glass rather than interstitial inside the crystalline phase that remain in the glass powder samples. During heat treatment or crystallization of the amorphous glass phase, these impurities tend to concentrated in the grain boundaries thus, an increase in polarization will results in high dielectric loss [36].…”

Influence of Sintering Temperature on Crystallization Behavior of Cordierite synthesized from Non-Stoichiometric Formulation

“…Recently, Cordierite has been focuses in numerous important applications due to its excellent properties, such as low thermal expansion coefficient (3.0 x10 -6 / o C), excellent thermal shock resistance, low dielectric constant (4.0-5.0), good chemical durability, excellent refractoriness, and mechanical properties [1][2][3]. Moreover, cordierite has lower sintering temperature and lower density than the alumina, it also much cheaper and can be synthesized using mineral talc and kaolin [4]. Among the three cordierite polymorph, α-phase is more preference due to it has unique properties, which are very low coefficient of thermal expansion, dielectric constant and dielectric loss, density and stable at elevated temperature [5].…”

“…Recently, non-stoichiometric cordierite composition (2.8MgO.1.5Al 2 O 3 .5SiO2) has been discovered to give high purity of D-cordierite phase at lower temperature using control crystallization of glass method [4]. The present of high concentration of secondary phase such as forsterite, spinel and mullite (which have different coefficient of thermal expansion and different volume) in cordierite synthesis using stoichiometric composition might affect the performance and its application especially in evaluated temperature atmosphere.…”