A new model for the viscosity of singlephase liquid slags and glasses has been developed. It is distinct from other viscosity models in that it directly relates the viscosity to the structure of the melt, and the structure in turn is calculated from the thermodynamic description of the melt using the Modified Quasichemical Model.
The model requires very few parameters which were optimized to fit the experimental data for pure oxides and selected binary and ternary systems. The viscosities of multicomponent melts and glasses are then predicted by the model within experimental error limits without using any additional parameters.
The model has been checked against the experimental data available for Al2O3B2O3CaOFeOFe2O3K2OMgOMnONa2ONiOPbOSiO2TiO2Ti2O3ZnOF melts and for Al2O3B2O3CaOK2OMgONa2OPbOSiO2 glasses.
There are two viscosity databases. The database for melts is valid for liquid and supercooled slags with viscosities which are not too high, that is when log10(viscosity, Poise) is less than about 7.5 or ln(viscosity, Pa·S) < 15. In most cases, this corresponds to temperatures above about 900 oC. On the other hand, the database for glasses can be used at and below the glass transition temperatures. In principle, this database is valid over the whole temperature range from liquid melts to glasses, but sometimes it may be slightly less accurate for liquid slags than the first database. Click “Options” to select one of these databases.
The viscosity module works for all users who have access to the FToxid database. It is easy to use: select either the Melts or Glass database, select units for the composition, temperature and viscosity, enter a composition (in moles or grams) and a temperature and click the "Calculate" button. A range of compositions and temperatures can be pasted from Excel and the results can be saved in an Excel or text file.
References
1. S. A. Decterov, A. N. Grundy, I.H. Jung and A. D. Pelton, “Modeling the Viscosity of Aluminosilicate Melts”, In: Computation in Modern Science and Engineering, (Proc. Int. Conf. on Computational Methods in Sciences and Engineering), AIP (American Institute of Physics) Conference Proceedings, Vol. 963, Issue 2, Pt B, Eds. T. E. Simos and G. Maroulis, pp. 404407 (2007).
2. Grundy A.N., H.C. Liu, I.H. Jung, S.A. Decterov and A.D. Pelton, "A Model to Calculate the Viscosity of Silicate Melts. Part I.: Viscosity of Binary SiO2MeOx Systems (Me = Na, K, Ca, Mg, Al)". Int. J. Mat. Res., 2008,vol. 99(11), pp. 11851194.
3. Grundy A.N., I.H. Jung, A.D. Pelton and S.A. Decterov, "A Model to Calculate the Viscosity of Silicate Melts. Part II.: Viscosity of the Multicomponent NaO0.5MgOCaOAlO1.5SiO2 System". Int. J. Mat. Res., 2008, vol. 99(11), pp. 11951209.
4. Kim W.Y., A.D. Pelton and S.A. Decterov, "A Model to Calculate the Viscosity of Silicate Melts. Part III: Modification of the model for melts containing alkali metals". Int. J. Mat. Res., 2010, submitted.
5. Brosh E., A.D. Pelton and S.A. Decterov, "A Model to Calculate the Viscosity of Silicate Melts. Part IV: Borosilicate melts". Int. J. Mat. Res., 2010, submitted.
6. Brosh E., A.D. Pelton and S.A. Decterov, "A Model to Calculate the Viscosity of Silicate Melts. Part V: Borosilicate melts containing alkali oxides". Int. J. Mat. Res., 2010, submitted.
7. S. A. Decterov, A. N. Grundy and A. D. Pelton, “A Model and Database for the Viscosity of Molten Slags”, Proc. VIII Int’l Conf. on Molten Slags, Fluxes and Salts, Santiago, Chile, pp. 423431 (2009).
8. Kim W.Y., A.D. Pelton and S.A. Decterov, "Modeling the Viscosity of Silicate Melts Containing Lead Oxide". Metall. Mater. Trans., 2010, submitted.
Fig.
1
 Viscosity
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