Abstract: The invention relates to aluminium smelters in which the treatment of spent potlinings (carbonaceous products resulting from the demolition of the lining of the walls and bottom of the electrolytic pots) requires a prior reduction of the potlinings into pieces not bigger than a few millimetres in size. The grinding process forming the subject of the invention is characterized in that it includes a crushing operation (12) in which the spent potlinings are reduced into pieces not bigger than 50 mm, a screening operation (16) permitting to separate those drains measuring a few millimetres and constituting the finished product, and a grinding operation (14) permitting to reduce the screen oversize to the finished product dimensions.