Variations in effects of heating on the dissolution of amorphous alkaline earth silicate fibers in a simple amino acid solution

Abstract

Dissolution experiments of amorphous alkaline earth silieate (AES) fibers heat-treated in the temperature range of 110 to 1260°C have been earried out in a glyeine, a simple amino acid, Solution. Results of the experiments suggest that variations in the dissolution rate of AES fibers in the glycine solution as a function of heat treatment temperature can be categorized into two types, one of which shows a peak around 700°C, whereas the other exhibits a sharp rise up to 800°C and then is kept constant in the temperature range over 800°C. The AES fibers which fall into the first category are in the Mg-rich systems and are crystallized dominantly into enstatite, augite or diopside by heating at a temperature of 800°C or over. Meanwhile, the AES fibers of the second category are in the Ca-rich Systems and are crystallized dominantly into wollastonite or pseudowollastonite by heating at a temperature of 800°C or over.