The decomposition of tricalcium silicate in the temperature range, 1,000 degrees-1,300 degrees C

Abstract

Using a high temperature X-ray diffractometer and differential thermal analysis, the thermal decomposition of tricalcium silicate has been investigated. The tricalcium silicate is prepared by heating the mixture of guaranteed reagents of calcium carbonate and silica. After heating the tricalcium silicate powder for a long time of about 24 days at high temperature such as 1 000∼1 250°C, sixteen per cent of free lime are formed by the thermal decomposition of tricalcium silicate. In order to predict and discuss the chemical equilibrium of the reaction 2CaO·SiO2+CaO→3CaO·SiO2 the entropy, enthalpy and free energy changes for the reaction have been calculated in the temperature range of 300~2400°K. © 1963, The Society of Materials Science, Japan. All rights reserved.