Predicting coal ash slag flow characteristics (viscosity model for the Al2O3–CaO–‘FeO’–SiO2 system)

✍ Scribed by Alex Kondratiev; Evgueni Jak

• Publisher: Elsevier Science
• Year: 2001
• Tongue: English
• Weight: 247 KB
• Volume: 80
• Category: Article
• ISSN: 0016-2361
• DOI: 10.1016/s0016-2361(01)00083-7

✦ Synopsis

A model has been developed which enables the viscosities of coal ash slags to be predicted as a function of composition and temperature under reducing conditions. The model describes both completely liquid and heterogeneous, i.e. partly crystallised, slags in the Al 2 O 3 ±CaO± `FeO'±SiO 2 system in equilibrium with metallic iron. The Urbain formalism has been modi®ed to describe the viscosities of the liquid slag phase over the complete range of compositions and a wide range of temperatures. The computer package F p A p C p T was used to predict the proportions of solids and the compositions of the remaining liquid phases. The Roscoe equation has been used to describe the effect of presence of solid suspension (slurry effect) on the viscosity of partly crystallised slag systems. The model provides a good description of the experimental data of fully liquid, and liquid 1 solids mixtures, over the complete range of compositions and a wide range of temperatures. This model can now be used for viscosity predictions in industrial slag systems. Examples of the application of the new model to coal ash ¯uxing and blending are given in the paper.