Abstract
Autopsies of six spent potlinings with different carbon cathode block grades, amperage regimes and cell technologies were conducted at three separate smelters to reveal possible mechanisms causing cathode wear. Microstructure of the cathode samples from the autopsies was investigated by optical and electron microscopy and X-ray computed tomography, while the composition of solid bath at the surface and in the interior pores were investigated by X-ray diffraction and electron microscopy.