Laminated carbon cathode for cells for the production of aluminium by electrolytic smelting

摘要

A laminated carbon cathode includes two layers of carbon blocks, i.e. and the upper layer of graphite of graphitised carbon, and a lower layer of a cheaper anthracite carbon. The two layers are so displaced with respect to one another that there are no vertical seams leading straight from the upper surface of the carbon cathode to the its underside. Dividing the cathode into two horizontal layers is combined with the embedding of current-carrying steel conductors in precise grooves between the layers. In order to capitalize on the good electrical conductivity of aluminum, an aluminum extension is friction-welded to each steel conductor as close to a shell enclosing the cathode while at the same time a collar is formed which provides an air-tight seal at the point where the cathode bar enters the side of the shell. The proposed arrangement facilitates a very practical and simple check on dimensional deviations in the carbon blocks/cathode bars, and of fitting accuracy, by the visual inspection of seam tolerances and the displacement of axes during the lining operation.