Anode Baking Furnaces – Wear of Applied Refractories

Rainer Telle, Thorsten Tonnesen

RWTH Aachen University, Institut für Gesteinshüttenkunde, Aachen, Germany

Revision

Volume 1, Issue 2, Pages 84 - 89

Abstract

Refractory linings of anode baking furnaces suffer severe corrosion during operation. The service life is therefore in relation to the construction of the flue channels and walls, operation procedures of the loading and de-loading process, firing conditions, choice of the used anode raw materials, used coke for packing and recycled anode butts. The refractory lifetime is mainly influenced by corrosive attack on the flue wall refractories and occurring creep at the bottom of the walls. In principle two type furnace technologies are available for the baking process of anodes. Open top ring pit furnaces reveal a horizontal gas flow through flue walls. Pre-heated gas flows along a labyrinth of tie bricks. Closed ring pit furnaces have a vertical gas flow through the flue walls. In these post mortem studies wear and corrosion behaviour of applied refractories was observed in regard to the different furnace types. The different atmospheres and firing conditions lead to microstructural changes with different reaction zones.These are worked out by means of SEM, EDS and XRD. At the hot face a decrease in alumina and silica is significant for the examined bricks. Due to condensation and precipitation of alkaline compounds the high temperature properties have been examined in particular. Differences in the operation of the furnace are recognized for the refractories since phase formation due to volatile compounds such as ZnO, NiO and V2O5 were just found for the open top ring pit furnace.

Keywords

anode baking process, top ring pit furnace, wear, refractories

References

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