| abstract |
There is a need for lining-materials of aluminium electrolysis cells which are resistant to the electrolytic bath of molten cryolite, liquid aluminium and other intermediate reactants of the electrolytic process. <??>It was discovered that an aluminium reduction cell refractory material comprising a bottom and side lining in the form of blocks, slaps and bricks can be used for such purpose if the bottom and side linings are made of carboceramic bonded by a tar-pitch-binder. <??>A process for the manufacture of such carboceramic-blocks, pastes or bricks consists of mixing at 150-200 DEG C fine, calcined oxides with electrode pitch and powdery additives like silicon, nitrides, graphite or coke, molding or forming into reforms like saggars, brickets or extrusion billets, baking said preforms at temperatures of 1000-1200 DEG C for a time sufficient to produce at least 50 % carbon oxides, crushing and screening said carbon oxide material into different particle fractions, mixing said carbon oxide particles at temperatures between 50 and 200 DEG C with pitches and additives like silicon, nitrides, graphite or coke to form a green mix which can be used as rumming paste, and vibroforming said green mix to green blocks, or baking said green mix to baked blocks and machining it into carboceramic blocks. |