Cathode bottom for producing aluminum

Abstract

A cathode bottom, to a method for the production thereof, and to the use thereof in an electrolytic cell for producing aluminium. The cathode bottom has at least two cathode blocks and/or at least one cathode block and at least one sidewall block, which are arranged at a distance from each other. The gap is filled with a pre-compressed graphite plate, composed of expanded graphite and a graphite intercalation compound.

1 - 10 . (canceled) 
     
     
         11 . A cathode bottom for an electrolysis cell for producing aluminium, comprising at least two cathode blocks and/or at least one cathode block and at least one side-wall brick, which are arranged at a predetermined distance from one another, the gap being filled with a filler that can be pre-arranged on at least one cathode block or at least one side-wall brick, characterised in that the filler is a pre-compressed graphite plate consisting of expanded graphite and a graphite intercalation compound. 
     
     
         12 . The cathode bottom according to  claim 11 , characterised in that the proportion of expanded graphite in the pre-compressed graphite plate is between 70 and 99.5 wt. %. 
     
     
         13 . The cathode bottom according to  claim 11 , characterised in that the proportion of graphite intercalation compound in the pre-compressed graphite plate is between 0.5 and 30 wt. %. 
     
     
         14 . The cathode bottom according to  claim 13 , characterised in that the intercalate of the graphite intercalation compound is an electron acceptor in the form of an acid selected from the group consisting of sulfuric acid (H 2 SO 4 ), acetic acid (CH 3 COOH) or nitric acid (HNO 3 ), or mixtures of sulfuric acid/nitric acid and sulfuric acid/acetic acid. 
     
     
         15 . The cathode bottom according to  claim 11 , characterised in that the pre-compressed graphite plate has a thickness of 2 to 35 mm. 
     
     
         16 . The cathode bottom according to  claim 11 , characterised in that the pre-compressed graphite plate has a density of 0.04 to 0.5 g/cm 3 . 
     
     
         17 . The cathode bottom according to  claim 11 , characterised in that the filler is arranged on two opposing surfaces of a cathode block and/or side-wall brick that adjoin the surface of the cathode block that forms the gap, and on and in the gap, such that the filler is flush. 
     
     
         18 . A method for producing a cathode bottom according to  claim 11 , comprising the following method steps:
 a) providing at least one cathode block;   b) arranging a filler on at least one surface of the at least one cathode block, wherein the filler comprises at least one pre-compressed plate based on expanded graphite and a graphite intercalation compound;   c) arranging at least one other cathode block or at least one side-wall brick at a predetermined distance from the at least one cathode block such that the filler fills a gap that is formed by arranging the other cathode block or side-wall brick at the predetermined distance from the at least one cathode block.   
     
     
         19 . The method according to  claim 18 , characterised in that the arrangement of the filler on the at least one surface of the at least one cathode block comprises securing said filler to the surface by means of an adhesive. 
     
     
         20 . A use of a cathode bottom according to  claim 11  in an electrolysis cell for producing aluminium.