Mechanochemical Activation on the Preparation of β-Eucryptite from Powder Mixture of Pyrophyllite, Gibbsite and Lithium Carbonate

Abstract

β-eucryptite (Li₂O·Al₂O₃·2SiO₂) was prepared by mechanochemical activation followed by calcination of the powder mixture containing pyrophyllite, gibbsite and lithium carbonate. XRD and FT-IR results showed that the crystallization of β-eucryptite occurred from the milled mixture by calcination. Dry milling using a planetary mill promoted the amorphization of the mixture. The crystallization of β-eucryptite increased with increment of milling time and calcination temperature. Trace amount of undesired phases such as cristobalite and quartz disappeared completely at 950°C in the mixture milled for 120 min. The thermal expansion behavior characteristics were found to be strongly influenced by the milling time of the constituent powder mixture and calcination temperature.