Method for making carbon blocks highly resistant to thermal shock

摘要

The invention concerns a simplified manufacturing method for obtaining carbon blocks, and in particular anodes designed for making aluminium by electrolysis according to the Hall-Héroult process, displaying high resistance to thermal shock. Said method comprises an operation which consists in adjusting the size grain distribution of a carbon-containing aggregate which includes: (a) separating a carbon-containing an initial run-of-mine aggregate AC into a first fraction F1 consisting of grains whereof the size is less than X and into a second fraction F2 consisting of grains whereof the size is not less than X, X ranging between 0.2 and 2 mm; (b) grinding B1 the first fraction F1 and part P1 of the second fraction F2, so as to obtain a powder F comprising a controlled proportion of ultrafine grains; (c) mixing the remaining part P2 of fraction F2 and said powder in proportions for obtaining raw carbon blocks whereof the ratio called Gr/S between the proportion PGr of grains with size more than 0.3 mm and the proportion PS of grains with size ranging between 30 mu m and 0.3 mm is at least 4 and the baked high density carbon blocks.