A thermochemical study of the reaction of calcium hydroxide, silica gel, and water

Abstract

The h eat of reaction of calcium hy droxid e, s ilica gel, a nd water " 'as meas ured by a h eat-of-solu t ion m et hod. The reaction was carri ed ou t at 25° C in p astes h aving a ,,'ater s olid ratio of a bou t LO. The heat of reaction, -L'.H a t 25 ° C, for t he reaction was found to be a bou t 10.3 kilocalories. The h eat of t he reaction is abo ut 1.6 kil ocalories p er m ole of added Ca(OHh About half of t he total meas ured heat of reaction r epresen ts t he heat of " 'etting of t he reaction produ cts. Differen t ia l t hermal analyses and dryin g exp erimen ts indicated t hat 3CaO·2Si0 2 ·2H20 was formed in so me of th e past es.