Optimisation of an anode furnace refractory lining using distinct magnesia-chromite refractory types

Abstract

In the present paper the results of a four-year investigation of the wear mechanisms affecting anode furnace linings are described. At the time when this study was initiated, the entire lining (apart from the tuyere blocks) consisted of a traditional direct-bonded magnesia-chromite brick. The latter suffered from acute wear due to the stringent chemical, thermal and mechanical conditions imposed. As a result of a microstructural study of samples prepared from industrially worn bricks, the major degradation mechanisms influencing the refractory lining were unravelled. On the basis of the identification of different wear zones in the lining, an optimised refractory configuration was proposed and installed in order to prolong the furnace campaigns. Distinct magnesia-chromite qualities were selected for the different wear zones. During the two following relinings worn bricks from various locations in the lining were collected and investigated. It was confirmed that refractory degradation in anode furnaces comes as a consequence of the combined action of chemical, thermal and mechanical drivers, which interact synergistically with one another. Depending on the region in the lining the relative importance of the drivers varies. Specific attention was given to the chemical wear mechanisms, namely: copper and slag components infiltration, forsterite formation and spinelisation. As a result of the installation of the new, zoned lining configuration a significant improvement of the overall lining lifetime was achieved.status: publishe