Study of the Degradation of Ordinary Refractory Bricks in an Aluminum Reduction Cell

On the lining of the aluminum reductionAluminum reduction cellsCell, layers of refractories are used to ensure proper thermal equilibrium as well as the protection of the insulating bricks underneath from high temperaturesHigh-temperature and chemical attacks. These materials, which largely affect the cellCell's life, are subject to corrosionCorrosion by the electrolyte bath. In this paper, the breakdowns and/or the degradationDegradation of the ordinary refractory bricksOrdinary refractory bricks (ORBs) located on the sidewalls and below the cathodeCathode blocks are investigated during industrial autopsiesAutopsies performed after cellCell failure or scheduled shutdowns. Subsequent chemical characterizationCharacterization on the ORBs was carried out using Scanning electron microscopy with energyEnergy dispersive X-ray spectroscopy (SEM–EDX), X-ray fluorescence (XRF)XRF, X-ray powder diffraction (XRD)XRD, and Differential scanning calorimetry (DSC) analysis. The XRD results indicate that nepheline, cryolite, and silicon are present in both sidewall and bottom ORBs with higher presence of sodium fluoride phase in bottom ORBs. Comprehensive literature review is also conducted based on the degradationDegradation of ORBs and compared to the results obtained during industrial autopsiesAutopsies. Subsequently, ORBs samples will be exposed to electrolytic bath contamination at different temperatures and durations at the laboratory scale. The aim is to examine the contamination history endured by ORBs in an aluminum reductionAluminum reduction cellCell.