Investigation of Corrosion Mechanisms between Copper and Lead Melts with Various Refractory Materials

Werner Schoenwelski, Jens Sperber, Viktor Schönhof

Steuler-KCH GmbH, 56203 Höhr-Grenzhausen/Germany

Revision

Volume 7, Issue 4, Pages 68 - 74

Abstract

In this article the different interactions between molten copper and lead and various refractory materials are investigated by crucible tests. The refractory bricks were chrome-corundum resp. chrome-zirconiacorundum bricks and silicate-bonded and nitride-bonded silicon carbide bricks. The test samples were analysed by: • macroscopic investigation • microscopic investigation • scanning electron microscope (SEM) • X-ray diffraction (XRD). Corrosion mechanisms and reaction products were studied. For economic reasons not all tests and analyses were made for all samples, but for a reasonable selection. For copper the results show that the corrosion resistance of chrome-corundum bricks can be improved if corundum is present in the form of white fused alumina instead of sintered alumina. Increasing the chromium content only helps if a considerable amount of it is prereacted with corundum to form ruby. Zirconia addition reduces Young’s modulus, but has no influence on corrosion. Both silicate-bonded and nitride-bonded SiC shows good corrosion resistance with an advantage for nitride bond. For lead the results are similar. For chrome-corundum the same graduation as for copper is observed, but lead chromates are formed having negative environmental effects. For SiC once again the nitride bond looks more promising, whereas silicate-bonded SiC under oxidizing conditions forms lead silicates. Like for aluminium [1] reaction mechanisms are strongly atmosphere dependent.

Keywords

microscopic investigation, crucible tests, corrosion mechanisms

References

[1] Schönhof, V.; et al.: Interactions between Molten Aluminium and Various Refractory Materials. refractories WORLDFORUM 6 (2014) [4] 76–82

Copyright

Göller Verlag GmbH