The Fusibility of Blended Coal Ash

Abstract

The fusibility of blended coal ash was studied by comparing the standard ash fusibility temperature test, temperatures at particular penetration levels measured by thermomechanical analysis (TMA), and predictions of liquid proportion with temperature thermodynamic equilibrium. Ash fusibility temperatures (AFT) of coal ash are found at temperatures below the predicted liquidus temperature and, for ashes from blended coals, are generally nonlinear with respect to the blend proportion. The conclusion that trends in AFTs with blend proportions are mirrored by changes in the liquidus temperature from ternary systems, as was found by previous investigators, is not supported. This study provides support for the use of TMA to characterize ash fusibility. That is, TMA temperatures change with blend proportions when AFTs do not, and also mirror temperature changes at defined liquid contents predicted at thermodynamic equilibrium.