Wear of Monolithic Al2O3–SiC–C Refractories in the Slag Runner of a Cupola Furnace

Olaf Krause1, Peter Quirmbach2, Jörg Zimmermann3

1 Hochschule Koblenz, 56203 Höhr-Grenzhausen/Germany
2 Deutsches Institut für Feuerfest und Keramik, 56203 Höhr-Grenzhausen/Germany
3 Forschungsgemeinschaft Feuerfest e.V., 56203 Höhr-Grenzhausen/Germany

Revision 31.05.2013, 24.09.2013

Volume 6, Issue 1, Pages 85 - 90

Abstract

The cupola furnace is the most important melting device in the foundry industry. Currently, the availability of the cupola, i.e. the possible iron output as a function of time, is particularly restricted by the lifetime of the refractories used in the slag runner. In order to understand the mechanism decisive for the wear of slag runner refractories in more detail, a commercially available and frequently applied Al2O3–SiC–C ramming mix was investigated in the initial condition and post mortem. The results show that during application in the slag runner the graphite of the ramming mix is not subjected to oxidation. Therefore, the cupola slag does not infiltrate the matrix of the ramming mix. Unlike graphite, both alumina and silicon carbide are significantly corroded during application. Alumina is transformed and dissolved by silicate cupola slag, whereas silicon carbide is atmospherically degraded to secondary carbon and silicate melt. The findings are considered fundamental for the development of monolithic refractories with improved durability for application in the slag runner.

Keywords

Al2O3–SiC–C, cupola furnace, wear, post-mortem

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