There is a need to predict viscosities for coal ash and fluxed coal ash sla
gs at the tapping temperatures of entrained flow gasifiers and this note ex
tends previous work on artificial mixtures in the quaternary SiO2-Al2O3-CaO
-FeO system at the 15 wt% FeO level. The viscosity measurements have been f
itted empirically using a modified Urbain treatment. (C) 2000 Elsevier Scie
nce Ltd. All rights reserved.