Evaluation of Modulus of Elasticity of Refractories

Authors: W. Schulle, F. Tomsu, J. Ulbricht (2000)

Abstract

The knowledge of the modulus of elasticity (MoE) of refractories and its dependence on the temperature is necessarily for (a) the calculation of the stress-deformation state of kiln linings as a basis for optimizing the kiln construction and for calculating of the allowable speed op the heat up and cool downs. (b) the non-destructive quatlity control. To determine the MoE (ultrasound or resonance frequency) dynamic or static ( dependence of the stress on the deformation by measurement of the mechanical strength) methods are used. The different measurement methods deliver deviant results. To understand these differences, experiments with the following four different refractories were carried out : (1) two different mullite bonded corundum refractories - without/with ZrO2 addition. (2) two different magnesia refractories - with/without ZrO2 addition. For all four the MoE were measured by different dynamic and static methods. According to the measurement method different values of MoE were received. This is caused by the rheological behaviour of the refractories. At room temperature there is a nearly elastic behaviour. At elevated temperatures non-elastic irreversible time dependent deformations appear. In the application of the MoE values in practice, above all the time coarse of the loading must be taken into account.

More info can be found here: https://www.osti.gov/etdeweb/biblio/20076327