Very large amounts of wastes (called Kira) are produced by the purification of raw materials for sheet glass and porcelain manufacture in Japan; it is highly desirable to develop effective usage of this waste. To this end, the crystallization behavior of CaO-Al2O3-SiO2 glass prepared from mixtures of Kira and CaCO3 was investigated to obtain fundamental data about these glass-ceramic materials. The glass powders obtained by melting at 1400°C were water-quenched and ground, then re-heated at 900-1250°C for 2-240 min. Wollastonite (Wo), the low temperature phase of CaSiO3, crystallized at ∼900°C. The amount of Wo increased very steeply with higher heating temperature to a maximum content of 55 vol%. Anorthite was formed only as a minor phase under restricted conditions. The Wo transformed into the high temperature phase pseudowollastonite (PW) above 1150°C but the transformation is relatively slow, requiring heating times >60 min. The activation energies for nucleation and nucleation-growth of Wo were 223 and 259 kJ/mol, respectively, significantly smaller than other reported values. The crystallization and phase transformation of Wo showed complicated behavior related to the particle size.
|Number of pages||4|
|Journal||Key Engineering Materials|
|Publication status||Published - 2004|
- Glass Ceramics
ASJC Scopus subject areas
- Ceramics and Composites
- Chemical Engineering (miscellaneous)