Investigation of Refractory Degradation in Hall-Héroult Cell

Abstract

Cell lining design must ensure the presence of solidus isotherm in the upper refractory layer to maintain the pot thermal balance. The depth of melt penetration in lining depends on the endurance of refractory layer. The melt penetration causes the mineralogical transformation of refractory layer, which acts as a barrier for further penetration. However, the barrier resistance is dependent on the chemistry of transformed phases of refractory material. This study outlines an on-field investigation of cell lining materials. A detailed autopsy of a high amperage cell has been performed to identify the probable causes of reduced cell life. The autopsy results exhibit substantial deterioration of powdered dry-barrier refractory layer at an early age of cell life, leading to premature cell failure. The greater percolation of vitreous phases through the dry-barrier could be attributed to its pulverulent nature resulting in higher permeability than the refractory bricks of similar composition.