Viscosity measurements and empirical predictions for some model gasifier slags

The increased interest in the Integrated Gasification-Combined Cycle (IGCC) power generation technology has led to a need to predict viscosities for c oal ash and fluxed coal ash slags at the tapping temperatures of entrained flow,gasifiers. Slags derived by fluxing Australian bituminous coal ashes w ith limestone have properties that may be approximated by the SiO2-Al2O3-Ca O-FeO system. This note presents experimental determinations of the viscosi ty and the temperature of critical viscosity for artificial mixtures coveri ng the anorthite region at the 5 and 10 wt.% FeO levels of this quaternary system. The viscosity measurements were fitted empirically using a modified Urbain treatment. Contour plots of viscosities at 1400 degrees C, 1450 deg rees C and 1500 degrees C and of temperatures of critical viscosity at the 5 and 10 wt.% FeO levels are presented as an aid for predicting slag behavi our in entrained flow gasifiers. The viscosity results also form a self con sistent data base for future theoretical studies. (C) 1999 Elsevier Science Ltd. All rights reserved.