Slag temperature-viscosity curve

The most widely used model to predict the temperature-viscosity curve was established by Urbain et al. [102] for ceramic melts and was later applied to natural mineral compositions. The semiempirical model predicts the viscosity of fiilly liquid slags. 

Slag Viscosity/Composition Correlations. Several attempts have been made in the past to define the linear portion of the viscosity/ temperature curve based on the composition of the coal ash. In the mid-1960 s, workers at the British Coal Utilization Research Association (BCURA) developed. two such correlations based on work with British (bituminous) coals, now generally referred to as the Watt-Fereday (4) and S (3) correlations (6). Unfortunately, attempts to apply this correlation to low-rank coal slags, using either ash or slag composition data, have been generally unsuccessful. 

Thus, for each slag, values for m and b can be derived from the experimental viscosity data which uniquely define the linear portion of the viscosity/temperature curve by means of Equation 5. The process then becomes one of correlating the variables m and b with some particular property of the slag. 

---