Authors:
Marcel Bastian | Forschungsgemeinschaft Feuerfest e. V. | Germany
Dr. Johannes Kasper | Forschungsgemeinschaft Feuerfest e. V. | Germany
Dr. Christian Dannert | Forschungsgemeinschaft Feuerfest e. V. | Germany
Dr.- Ing. Ashish Pokhrel | Hochschule Koblenz | Germany
Prof. Dr. rer. nat. Olaf Krause | Hochschule Koblenz | Germany
The workability is the main factor responsible for the quality of a lining or a prefabricated part made from a refractory castable. It is the rheology, especially the shear rate dependant dynamic viscosity, of a refractory castable that defines this workability while flowing, levelling, compaction, casting, and pumping. Commonly, the rheology of refractory castables is determined by measuring the spread flow. While this is a quick and simple method, it is not able to determine quantified rheological data like the shear rate dependant viscosity. So far, no methods that allow to determine the shear rate dependant viscosity of refractory castables are available. The result is a lack of knowledge on the rheological description of refractory castables, which hinders the optimization of the quality of linings and prefabricated parts.
For this reason, a new method for the determination of the shear rate dependant viscosity of refractory castables was constructed, which allows the measurement of the rheological values of refractory castables. The new method is based on a lifting sphere rheometer for the determination of the viscosity and a coupled CFD-FEM-analysis for the determination of the prevailing shear rate during the measurement.