SiO2-MgO混合粉体の加熱過程での反応性に及ぼす振動ボールミル処理の効果
1998 年 35 巻 2 号 p. 118-124
詳細
1998 年 35 巻 2 号 p. 118-124
The effect of vibration ball-milling of a SiO2-MgO powder mixture on Mg2SiO4 formation by a solid-state reaction between SiO2 and MgO was examined. The results obtained are summarized as follows:
(1) It was confirmed that Mg2SiO4 formation during firing was accelerated by the vibro-milling of the SiO2-MgO powder mixture. The Mg2SiO4 formation reaction seemed to be a diffusion controlled process regardless of the vibro-milling and firing conditions, and the rate of this reaction obeyed the Ginstling-Brounshtein equation. The apparent activation energy of this reaction decreased from 311 to 94kJ/mol with the increase in the milling time up to 120hrs.
(2) In addition to the compositional homogenization during vibro-milling, the enhancement of the SiO2-MgO solid state reaction due to both the activation of MgO induced by amorphization during milling and the increase in the contacts between MgO and SiO2 under the mechanical stress was thought to largely contribute to the acceleration of the Mg2SiO4 formation during firing.
